கவனிக்க: இந்த மின்னூலைத் தனிப்பட்ட வாசிப்பு, உசாத்துணைத் தேவைகளுக்கு மட்டுமே பயன்படுத்தலாம். வேறு பயன்பாடுகளுக்கு ஆசிரியரின்/பதிப்புரிமையாளரின் அனுமதி பெறப்பட வேண்டும்.
இது கூகிள் எழுத்துணரியால் தானியக்கமாக உருவாக்கப்பட்ட கோப்பு. இந்த மின்னூல் மெய்ப்புப் பார்க்கப்படவில்லை.
இந்தப் படைப்பின் நூலகப் பக்கத்தினை பார்வையிட பின்வரும் இணைப்புக்குச் செல்லவும்: Tropical Agriculturist 1961.10-12

Page 1
TROPICA * AGRICUL
AGRICULTURA
VOLUME CXVI OCTOBER-DECE
 
 

TURISTI
JOURNAL OF CEYLON
CE:Y L0 Ni
NUMBER 4 MBER 1961

Page 2


Page 3
2ణ్ణి Οις جمع فيه \ سکریمصلى الله عليه وسلم
Prepare Control
wit
HEXDOE 1 O/DU
(containing .35%
Supplies & Information from -
FIS ONS (CEYLC
P. O. BO
COLOM
2-R, 7475-1510 (1163)
 

s
for a better yield the paddy fly
h
B. H. C.
JST
Gamma isomer)
DN) Li MI
Χ 69,
I BO.
FISONS ଠୁ 岑
Ο 2 LIMITED
TED

Page 4
PHYTOMIC
Official organ of the Plant N
PHYTOMORPHOLOGY is morphology including origina edited by Professor P. Mahesh of advisory editors. Articles a French from only the Members Morphologists.
The current rates of member are as follows :
Personal Life membership
Personal Ordinary member
ship (annual)
Institutional subscription
(annual)
Cost of each back volume
The membership fee and sub and may be remitted by a c in favour of the INTERNA MORPHOLOGISTS. UN] In no case should the dues be re
Address editorial matters PHOLOGY, and other corresp
DEPARTMENT OF BOTANY.,
UNIVERSITY OF DELHI,
DELHI 6, INDIA.
让

RPHOLOGY
International Society of orphologists
devoted to all branches of plant articles and critical reviews, and is wari in co-operation with a number
re accepted in English, German and
of the International Society of Plant
ship, subscriptions and back volumes
India Foreign
RS. 25000 £ 25 S 70°40
RS. 2500 £ 2-10s. $ 704
Rs. 3800 £3.10s. S. 9-85
Rs... 5000 £ 3°15s. $ 1054
scriptions become due on January 1, rossed cheque or bank draft drawn TIONAL SOCIETY OF PLANT ESCO Coupons are also acceptable. mitted by a postal money order.
to the Editor, PHYTOMORpondence to the Secretary-Treasurer.
B. M. JOHIRI, Secretary-Treasurer.
༄གྱིས་བྱེས་

Page 5
BAUR
Have a special
FERTILISER
FOR EVE
GROWN
Based om OW Experien
A. BAUR &
P. O. Box 11,
 

RY CROP
\ CEYLON
er 60 years
ᏣᎾ
CO., LTD.
COLOMBO.
iii

Page 6
A N N OU THE CEYLON CO
A Quarterly Magazine dealing wi and its Ov
JANUARY APRIL.
First issue
Special Features
O Factual and Statistical Review
O. Coconut Gazetteers contair Merchants, Millers, Shipp
O Planting Notes.
O Trade Offers and Enquiries,
advertisement.
| ADVERTISEMENT RA
PRCE PER
Annual Subscription : Local
Foreig
Write for particulars to : PRINTN
256, Bank of Ceylon Buildir
GOVIKAM S
(QUA
The only Fa in S
Annual Subscription
Price per Copy
Apply :
THE AGRICU
(Pu No. 19, SAU COL(
(P. O.
iv

|
| N C / N G CONUT JOURNAL
ith the Coconut industry in Ceylon erseas Trade
JULY OCTOBER October, 1956
is of Ceylon's Trade in Coconut Products.
hing names and addresses of Coconut ers, Auctioneers & Brokers, Dealers.
Local and Foreign : Excellent media for
TES ON APPLICATION
COPY Rs 250
Rs. 10/- (including postage) n £ (including postage)
G House ng, York Street, COLOMBO |
ANGARAWA
ARTERLY)
rm Magazine
inhala
. . . . . . . . Re. 1/OO
-/25 cÍS.
TURAL OFFCER
Iblicity) JNDERS PLACE OMBO || 2
Box 636)

Page 7
a C
Μ
| Simazine 50 W ag
creates a new field for pre-emer
weed control in maize
| A single application of Simazine 50W c keep Maize weed-free for months. Grass
as well as broad-leaved weeds are cont
Supplies and Information from
FISONS (Ceylon) LTD., P.
 
 
 

2们 persistent selective safe
SeS
rolled by Simazine 50W.
O. Box 69, Colombo.
FISONS )

Page 8
COMMONWEALTH
Recent publications
A Review of Commonwealth Raw M A Review of Commonwealth Raw M. Commonwealth Trade 1959-60 Fertilisers in the Commonwealth, 195 Raw Hides and Skins (1960)
Commonwealth Development and its
No. 1. Canada
No. 2. Federation of Rhodesia No. 3. Pakistan
COMMODITY SERIES
This series reviews the significant t trade and prices for the commodities co which are revised annually, are as unc
Meat ... 8s. 1d.
Fruit ... 10s. 9d.
Grain Crops ... 10s. 10d.
Vegetable Oils and
The prices of all the above public may be obtained from The Secretary Marlborough House, Pall Mall, Lon Stationery Office, P. O. Box 569, Lo bookseller.
PERODICAL, NTELL
BY THE
Wool Intelligence (Monthly, includi
Intelligence Bulletin (Dairy Produc Weekly Dairy Produce Supplies).
Fruit Intelligence (Monthly, with su
Tobacco Intelligence (Quarterly, intervening months).
Grain Bulletin (Monthly, including
Tropical Products Quarterly, covel and oilseeds.
Hides and Skins Quarterly.
The subscription rate for Wool Inte Intelligence £1. 10s. per annum. Fo Bulletin it is £4 10s. per annum each, per annum Without the supplements. rate is £2 per annum including the Ric separately for £1 per annum. For T Skins Quarterly the subscription rate i
These publications are available oj Economic Committee.
Wi

CONOMIC COMMITTEE
of the Committee include :
aterials, Vol. II (1958) - a 16s. 0d. aterials. Vol II (1960) ... E1.16s. 5d. a 4s. 11d. 0-53 - a 4s. 4d.
6Տ. 10d.
Financing :-
- 8s. 5d. and Nyasaland - - 7s, 5d. 8s. 5d.
rends in world production, consumption Śrned The seven volumes in the series, ᎾᎢ 2--
Dairy Produce .. 8s. 1d. Industrial Fibres ... 10s. 10d. Plantation Crops ... 10s. 9d.
Oilseeds (10s. 10d.)
:ations include postage. The publications 7, Commonwealth Economic Committee, don, S. W. 1., England, or from H. M. ndon, S. E. 1., England, or through any
GENCE SERVICES ISSUED
COMMITTEE
ng Fibres Supplement).
e and Meat) (Monthly, with supplement
pplement, Weekly Fruit Supplies). with supplement, Tobacco Bulletin, in
Rice supplement).
ing coffee, cocoa, spices, vegetable oils
ligence is £2 per annum and for Tobacco r Fruit Intelligence and the Intelligence
including the weekly supplements, or £3
For the Grain Bulletin the subscription 2 Supplement which can also be obtained ropical Products Quarterly or Hides and S £1 per annum. All rates are post free.
nly from the Secretary, Commonwealth
|
ܫܐ

Page 9
*ھ لیتیبا
PUBLICATIONS ( (CENTRAL COCON
The Coconut Palm
Compiled by Dr. K. P. V. Mer Research Station, Kayangulam, Director, Central Coconut Resea Coconut Palm-A Monograph' is problems connected with the cocon scientific information that has ac during the last two decades.
The book contains 384 pages of and 19 colour plates. It has bee $ 13.00 (including postage, pa per copy. Cheaper edition Rs. 2 and forwarding charges).
First Conference of Coconut
A publication containing the pro papers on Coconut Research re. Coconut Research Workers in Ir and the discussions on them.
A “ Must” to every Research
Printed on offset paper the b 9"x 7" and is amply illustrated.
Price Rs. 12 (including posta
For copies please write to :-
THE SEC
Indian Central Co
ERNAKU KERALA STATE,

F THE INDIAN UT COMMITTEE
I-A Monograph
lon, Director, Central Coconut
and K. M. Pandalai, Joint rch Station, Kasaragod, “ The s a comprehensive treatise on all utindustry andfills a long gap of cumulated in coconut research
size 8" x 11 "150 illustrations n priced at Rs. 43/— Sh. 90/— cking and forwarding charges) 1.00 (including postage, packing
Research Workers in India
oceedings and texts of forty-five ad at the First Conference of dia held at Trivandrun in 1959,
institute and Library.
ook contains 464 pages of size
ge and forwarding charges)
RETARY
conut Committee
LAM—1
S. INDIA

Page 10
SEEDS
of Poosa Sravani Bhenelee (Ladys finger)
| Fruits 10" long-Green Velvet-leke
Immense Cropper—Marketable
Himalaya-GroWn Vegetable and Flower Seeds
| KUMAON NURSERY | RAMNAGAR (NAINITAL) U.P.
"THE COCONUT
is a beautifully illustrate maps, charts and graphs a1 tive manner acreage and India and the world, trend trends in prices of coconut India and Some of the countries of the World.
Beautifully printed on oj the book contains 98 pa priced at Rs. 18/– (for bl and Ceylon) and at £2. buyers) inclusive of postag
i

KAMATH THOLIL WILAKKAMI
(Quarterly)
The only farm magazine in Tamil
Annual Subscription Rs. 1.00
Apply:-
The Agricultural Officer
(Publicity)
19, Saunder's Place Colombo 12 (P. O. Box 636)
Price per Copy 25 CtS.
ATLAS OF INDIA."
i publication that tells in hd tells in a simple and effecproduction of coconuts in S in import and export and I, copra and coconut oil in important coconut growing
fset paper with rexine cover ges of size 113 "X9" and is yers within India, Pakistan ).0. and $6.00 (for foreign o, etc.
R

Page 11
DIMECRC
NEWEST ODOUR
SYSTEMIC
INSECTICDE
SAP
CHE
STEN
FRU|
I LEAF
ON
TOBACCO
PINEAPPLE
ONION
CHILLI
VEGETABLES
FRUIT TREES
PADDY ETC.
Treated crops may sa 6 days from
A. BAUR &
P. O. Box 11,

CONTROLS SUCKING PESTs
WING & BITING INSECTS 4 & FRUIT BORERS
T FLIES
F MINERS
felly be harvested spraying
CO., LTD.
COLOMBO.
ix

Page 12
HURRICAN
POWERED MIST
ULTR
Coverage
SAW WALL
LIM
P.O. Box 137 COL

NE MINOR
A LOW WOLUME
PEST AND DISEASE
CONTROL
20-30 acres/day
ACE & HEDGES
ITED
OMBO 3 TEL. 7827
..

Page 13
༈ །
Wol. CXVII, No. 4
CONTE
EDITORIAL
ARTICLES
D. V. W. ABEY GUN AWARDENA and I. BALAso
Cultivation
D. W. W. ABEY GUNAWARDENA and A. A. P. S.
Potato Cultivation
V. ABEYWARDENA-A comparison of some Pop the determination of the Physical Production Fertilizer Responses
D. M. RoDRIGo-The Relationship between
Characteristics of Paddy Soils in the Dry State
METEOROLOGICAL REPORT
Summary for October-December, 1961
 

DECEMBER, 1961
NTS
Page
209
ORIYA-Disease Hazards in Potato
21.
IRIWARDENA-Disease Hazards in
22.
ular Mathematical Models used for
Function in respect of Univariate
227
Chemical and Physico-Chemical and on Continued Submergence . . 245
273

Page 14
SUBSCRIP
(Inclusi
A
Local R
India, Burma, and Pakistan R
Other countries R
All subscriptions should be ser Division, P. O. Bo.
Eacchanges should be addresse
Agriculture,
ADVERTISE
(Per
Full Page Half Page
Quarter Page
Back Cover
Inside Back
Inside Front
All correspondence and payments reg to the Agricultural Officer (Public Colom
THE TROPICAL AGRIC AS A NEWSP
xii

TION RATES
pe of Postage)
nnual Single Copy
S. 5.00 . . . . Re. 1.50
s, 6.50 . . . . Rs. 2..00
s. 8.00 . . . Rs. 2.50
it to the Publicity Officer, Publicity x 636, Colombo, Ceylon
a to the Librarian, Department of Peradeniya, Ceylon,
MENT RATES Insertion) -
Contract Casual . Rs. 30 0 ... Rs. 35 . Rs 17 o ... Rs... 19
. RS. 8 50 . . Ris. 10
. Rs.. 40 0 . . Rs... 50 . Rs. 35 0 ... Rs.. 40
. Rs... 35 0 . . Rs.. 40
Iarding advertisements should be addressed ty), Publicity Division, P. O. Box. 636, bo, Ceylon.
ULTURIST ' IS REGISTERED APER, IN CEYLON

Page 15
|
EDITC
Weed Cont
PROFUSE weed growth which sc crop is one of the major causes of Ceylon. However, as the density
field to field it is very difficult to weeds depress rice yields each se
At present weed supervision i. through preparatory tillage and in of Weed control can be achieved buried by ploughing and kept impounding water. But field prep the rice acreage in Ceylon has to short period that this method o. satisfactory results, and weeds ap lings. In row-planted and row-see effectively controlled with the crushes all Weeds in-between th cultural techniques which can be weed suppression are still prac alternative methods of weed cont) of broadcast fields.
So far the only effective met rice has been the actual removal ( hand weeding is both difficult an hand weeding is the close resem ings to rice. Many of them be practically indistinguishable from them Out in a broadcast rice fiel the growing crop, though less satisfactory alternative where la
 

) RIAL
rol in Rice
metimes completely smothers the poor rice yields in many parts of of weed growth varies even from
assess the exact extent to Which
eaSO).
n rice fields is attempted mainly npounding of water. A high degree
by this method if the weeds are submerged for a long period by aration over the greater extent of be hurriedly carried out within a f weed suppression seldom yields pear even ahead of the rice seedded crops, however, weeds can be aid of the rotary weeds which he rows of rice seedlings. These interpreted largely as measures of :tised on a restricted Scale that rol are needed for the large extents
hod of weed control in broadcast of weeds by hand. Though effective, d expensive. The main difficulty in plance of the pernicious weed seellong to the grass family and are rice till they flower. Hence, picking d is extremely difficult. Harrowing effective than hand-weeding, is a bour is scarce and expensive.
209

Page 16
TROPICAL, AGRICULTUR
The real answer to the problem the use of weed killers that will no Since World War II Selective We increasingly important role in crol could be safely applied in rice cl available till very recently. Now come it seems only a matter of t regular feature in paddy cultivatio appears to check the rapid spread the present high price of weedic weedicides will shortly be available
210

LST, VOL. CXVII, 1961
of Weeds in rice appears to lie in cause any harm to the rice plant. 'edicides have begun to play an production but a weedicide that ultivation in the tropics was not that the final break-through has ime before weedicides become a n in Ceylon. The only factor that Of this method of Weed control is des. It is, therefore, hoped that 2 at a more reasonable price.

Page 17
DISEASE IN POTATO (
I.- Late Blight caused b
(Mont)
B
D. V. W. ABEYGUNAWA
(Agricultural Researc
INTROD
LATE Blight is undoubtedly the humid and Wet areas of the hill potato plants and invades the tub amply demonstrated that spraying disease is an important factor ( Ceylon and epiphytotics may occur seasons. The Weather is rather v. With cool nights, frequent rains an under which the disease can be se inoculum does not necessarily de tomato and other Solanaceous cr round. The occurrence of epi hill country areas, is, therefore, Phytophthora infestans and to the ment. In the Nuwara Eliya area climates apparently adequate for pathogen.
The question of controlling lat for the successful potato culture in to the control achieved by fung necessary, that adjustments in C resistant varities are factors which of the disease, more specially in
SYMPTOMS A
LATE blight appears on the leas spots or large dead areas until th ditions and with susceptible varié
 

HAZARDS
ULTIVATION
y Phytophthora infestans de Bary
y
RDENA & I. BALASOORIYA
h Station, Rahangala)
|UCTION
most serious disease of potato in country. It attacks the foliage of ers causing a wet rot. It has been for blight pays in areas where the 1,2...). The disease is endemic in at any time during certain growing variable in the Nuwara Eliya area d high relative humidity, conditions erious. The source of the primary pend on infected tubers as potato, ops grow spontaneously the year phytotics of late blight in the attributed to the endemism of generally favourable local environthere are many unsuspected micro
the year round existence of the
e blight is an important requisite the hill country areas. In addition icidal spraying, it was considered ultural practices and the use of n may contribute to the prevention the hands of peasant cultivators.
AND EFFECTS
ves where it causes brown, dead e leaves are killed. In moist con2ties the entire leaf may be killed
2.

Page 18
TROPICAL AGRICULTUR
in 1-4 days. With the interven infection is retarded and blighted
under moist conditions they deca blackening and Wilting of entire to the stems as well as the foliage whitish or greyish fungus on the u of Late Blight on tubers may be
blighting of the foliage will redu. The primary infection of tubers, O. rot according to the prevailing con
It has been clearly demonstrates tons per acre of harvested tubers ) plantings where the disease was e crop due to the disease can be et and with highly susceptible variet
RESISTANCE OF POTA
THE genetics of resistance to Late understood during the last few dec two types of resistance, namely resistance and field resistance Or I type of resistance is conferred by 4 as R1, R2, R3 and R4. Each gene w dently and conferred resistance to pathogen as well as certain spe genotypes including the recessive involving the 4 major genes. On th resistance appears to be equally
pathogen. This type of resistanc Variation and its inheritance is attr.
IDENTITY OF RACE
WITH the object of exploiting majo especially, as large scale cultivation gation was undertaken to ascertair tans present in the potential potat genotypes obtained through the co nication) consisting of the individ and the recessive Were used for
P. infestans. The different ger submitted to trial at Nuwara Eliy
22

IST, VOL. CXVII, 1961
|ion of dry weather, progress of eaves soon curl and shrivel, while y rapidly. The disease results in ps followed by a wet rot involving
The lesions produce a delicate nder Surfaces Of leaves. The effect primary or secondary. The early be the size and number of tubers. h the contrary, causes a dry or wet litions.
(2) that an increase of nearly 4 has been obtained in experimental 'ffectively controlled. The loss of hormous in severe blight weather LeS.
ATO TO LATE BLIGHT
Blight in potato has been clearly ades (3, 4, 5). There are basically field immunity or major gene minor gene resistance. The former major genes labelled by Black (5) was found to be inherited indepenhe common physiologic race of the cialised races. Sixteen different
have been obtained from crosses e contrary, the minor gene or field effective against the races of the e is characterised by continuous ibuted to a polygenic system.
S OF P. INFESTANS
r gehe resistance in potato culture, 1 is new to the country, an investithe physiologic races of P. infeso growing areas. Fifteen different urtesy of Black (personal commuLal major genes or in combination the identification of the races of otypes and the recessive were a, Bopatalawa and Horton Plains.
གྲོང་

Page 19
DISEASE HAZARDS IN E
Late Blight did not appear in the of the tests at Nuwara Eliya a summarised in Table 1. In both were completely immune, those lac tion exhibited hypersensitivity. Th be most virulent in both test areas test at Bopatalawa the race 3, 4 W. form ; the same race of the patho. the tests at Nuwara Eliya. It has b of the fungus normally, progresses b towards a wider host range; the m attributed either to physiological ad
In view of the existing races of P. ance of new races, large-scale culti temporary. In Tanganyika, howe hypersensitivity has been cultivate signs of blight attack. (6).
TESTS ON VARIET
EARLY attempts to determine the
infection were made at the Agricult Different potato varieties were sub. monsoon season when epiphytotics varieties evaluated are grouped b resistance shown in the experiment
(a) Varieties with 100 per cen Craigs Defiance, Hybrid 9, Home ( Arran Pilot, Arron Banner, King Peak and British Queen. The varie 100 per cent. leaf blight in 6 we required 8-10 weeks to reach the sa
(b) Varieties with 50 per cent. f. Japanese No. 6 and Meerster showe
(c) Varieties with no active infe had hypersensitive spotting on fol
Later tests On resistance were cc the prevailing cool nights, frequent humidity were conducive to seve evaluated for the degree of suscepti

OTATO CULTIVATION
last named test area; the results nd Bopatalawa are collectively Jest areas none of the genotypes 'king, lesions with active sporulae races of P. infestans found to were 0, 1, 2, 4 and 1, 2. In the as also present in a less virulent gen was identified in subsequent een shown (4) that specialisation y steps from one order to another Lode of origin of new races being aptation or mutation.
infestans and the possible appearvation of these genotypes may be ver, a genotype known to show 2d for several years without any
AL RESISTANCE
varietal resistance to late blight ural Research Station, Rahangala. mitted to natural infection in the usually occur on a field scale. The below, according to the level of
S.
t. foliage infection. Up to Date, Guard, Craigs Royal, Kerrs Pink, Edward, Majestic, Alpha, Arran ty British Queen succumbed with eks Whereas the Other Varieties me grade of infection.
oliage infection. Japanese No. 4, d this rating in 12 weeks.
action. Ulster Torch. This variety iage.
onducted at Nuwara Eliya, where rains and constant high relative re infection. Each variety was bility to infection by the pathogen
23

Page 20
TROPICAL AGRICULT
and to the field resistance showr listed according to the degree O belloW.
(a) Highly Susceptible Vari Broekema, Poet, Profijt, King Selection S. tuberosum. Sub spec Courtland, Saco, Harford, Pla Phulwa, Darjeeling Red Round 1360 and Ambassadeur. Of th Eward, Tedria, Up to Date and active sporulating lesions in le varieties sporulation was delaye
(b) Moderately Susceptible V Seedling ON 45 sporulating lesi
(c) Resistant Varieties. Dekar 5210-5-9 and GB 5244-8 produce the leaves.
Perhaps the most important co is the rapidity with which potato natural epiphytotic conditions. been listed in Table 2 on the b: by the pathogen.
The varieties Delus, Up to D: susceptible to late blight and ex relatively good yield pote to early tuberisation of these va Profijt while being highly susce degree of field resistance enabl These varieties, in contrast, to o ability to tuberise relatively e. susceptible to initial infection a Gineke it succumbs to infectior the local Selection S. tuberosum susceptible to infection but do r thus possessing a high degree of and Ambassadeur tuberise relati exhibited a poor yield potential GB 5269-22 and Dekama produc the least affected by the diseas blight being negligible in these hands of peasant cultivators.
24

JRIST, VOL. CXVII., 1961
after infection. The potato varieties susceptibility to infection are given
»ties. Voran, Maritta, Alpha, Prof. Edward, Tedria, Up to Date, Local Les andigenum (8), Delus, Ashworth, cid, Pungo, Essex, Prisca, Gineke,
Indian Seedlings ON 2236 and ON e varieties in this category King
Indian Seedling ON 1360 produced ss than 7 weeks whereas in other d to 8-9 Weeks.
arieties. On Rival, Virgil and Indian ons appeared after 9 weeks.
na, Dutch Seedlings GB 5269-22, GB d hypersensitive type of spotting on
insideration in determining resistance varieties succumb to infection under The potato varieties evaluated have asis of resistance shown after attack
ate and King Edward though highly hibiting poor field resistance showed ntial, a condition attributable rieties. Gineke, Prof. Broekema and ptible to infection exhibited a useful ing the crop to succumb gradually. thers of the same category, have the arly. The variety Tedria is highly nd has poor field resistance. Unlike rapidly. Voran, Ambassadeur and Sub Species andigen um are highly ot break down with disease rapidly,
field resistance. The Varieties Voran “
vely early whereas the local selection
Linder blight conditions. The seedling ed hypersensitive reaction and were e. The loss of crop caused by late varieties they would be safe in the
ബ

Page 21
DISEASE HAZARDS IN PO
CLIMATIC FACTORS IN R
DEVELOP
FACTORs which define the growing s the hill country are rainfall, tempera humidity and rainfall play an import spread of late blight. Rain provides germination of sporangia on the lear within the crop. Sporangia are pro phere with more than 91 per cer temperature range of 46-59 F. Th lose their viability in 1-2 hours ex described (7) that free water or de requirement for sporangial germinat tion occurs at 48-79°F whereas inc require both free moisture and lov humidity and temperature requirem germination and rapid field spread certain seasons in the hill country a that the growing seasons should k escaping blight epiphytotics or rai infection. The climagrams (Figs. 1
seasons in respect of each climatic dominantly the South-West Monsoo partly escape blight are in the Octol While the temperatures are satisfa all the year round, blight epiphytoti the monsoon rains from May to S country influenced by the North-Eas or partly escape blight would be i sowing seasons. Accordingly the cr blight epiphytotics could be outlin Zone. In the climatic Zone influence rains. (Fig. 1), viz., Bandarawela, W the recommended seasons for disease
(a) January–April Season. With is susceptible to infection but posses 1-4 protective fungicidal sprays wou of rainfall and relative humidity to
(b) April-July Season. During grown in protected locations due to experienced. The humidity is rela
 

EATO OUT TIVATION"
ELATION TO DISEASE
MENT
easons in each climatic Zone in ture, wind and frost. Both high ant part in the development and the moisture necessary for the ves and also raises the humidity luced liberally (7) in an atmosit. relative humidity and at a e sporangia have been found to posure to dry air. It has been tw. On the leaves is an essential ion. Direct sporangial germinadirect germination by Zoospores v temperatures 58-59°F. Ideal ents both for indirect sporangial of the disease are found during reas. It is, therefore, necessary be restricted with the View to sing crops with the minimum & 2) show the different growing
Zone. In areas receiving preh rains the crops which fully or per and January sowing seasons. ctory for economic tuberisation cs would be specially serious in eptember. In parts of the hill t Monsoon the crops which fully in the January, April and July opping seasons for escaping late 2d as follows for each climatic d by the North-East Monsoonal elimada, Ragalla, Maturata, etc., ! eScape are
a variety like Gineke which sing considerable field resistance, d be necessary with the increase wards the close of the season.
this season potato crops are the strong and desiccating winds ively low and unfavourable for
2.5

Page 22
TROPICAL AGRICULT
blight development. Spraying in regions where the local cli fungicidal protection.
(c) July–October Season. W necessary particularly with the atmospheric relative humidity causing conditions favourable fo)
In the climatic Zone, influenced (Fig. 2), viz., Nuwara Eliya, Bop seasons recommended for blight
(a) October-January Season. sprays are required mostly in t When both rainfall and relative development.
(b) January–April Season. P. applications, may be necessary b close of the season. When the re. favourable for disease developme
DISC
EvIDENCE is presented on the m by any one or combination of cidal spraying, (b) the use of hy (c) restriction of cropping seas blight epiphytotics.
In view of the existence of P. infestans and of the possibilit use of major gene resistance ma potato varieties on the basis of S of resistance exhibited after infe sensitive varieties and those inc and high yield potential which local conditions.
The analysis of climatic facto the conditions prevailing in the part suitable for disease devel
26

JRIST, VOL. CXVII, 1961
is unnecessary in most areas except mate or microclimate necessitated
th. Gineke 1-4 sprays would be advance of the season. When both and the rainfall increase, thereby
development of blight.
by the South-West Monsoonal rains atalawa, Hatton, Kuda Oya, etc., the escape are the following :-
With Gineke, about 1-5 protective he first half of the growing season humidity are conducive to disease
rotective spraying, about 1-6 spray oth in the first half and towards the slative humidity and rainfall appear ent.
CUSSION
ethods of field control of late blight the following methods :-(a) fungipersensitive or resistant varieties, and ons in each climatic zone to escape
a number of physiologic races of y of the appearance of new races the y be short lived. The evaluation of asceptibility to attack and the degree !ction, revealed that there are hyper
orporating both good field resistance it
can be successfully cultivated under
rs in relation to disease showed that hill country areas are for the most pment and spread. The climagrams

Page 23
DISEASE HAZARDS IN
illustrate the cropping seasons in
object of escaping blight epiphy inherent varietal resistance and fi 書- avoidance of disease by restricting
SUMM
1. The physiologic races of
country areas have been
2. A large number of potato
both hypersensitive rea relative yield potential i
3. Climagrams have been pi Seasons with a View to e
* ACKNOWL
THE authors are thankful to Mr. some of the experimental work.
REFER
1. ABEYGUNAWARDENA, D. W. W. and the fungicidal Control of late blight Tropical Agriculturist, CXIV, 89.
2. ABEYGUNAWARDENA, D. V. W. control of late blight of potato. (1) of the field control of ephiphytotics.
3. BLACK, W. 1952. Inheritance O. infestans) in potatoes : inter-relation Soc. Edinburgh, B, 64, 312.
4. BLACK. W. 1952. A genetical b. Phytophthora infestans. Proc. Roy. S
5. BLACK, W. 1954. Late blight re J. 31, 93.

POTATO CULTIVATION
he major climatic zones with the
iotics. While incorporating both
Ingicidal control the necessity for
growing seasons is emphasised.
A R Y
... infestans prevalent in the hill identified.
varieties have been evaluated for ction and field resistance. Their in blight conditions is discussed.
resented illustrating the cropping scape blight epiphytotics.
EDGMENT
D. Gunawardena for assistance in
ENCES
PEIRIS, J. W. L. 1958–Experiments on of Potato (1) Screening of Fungicides,
1960-Experiments on the fungicidal .) Some aspects on the improvements
Tropical Agriculturist CXVI, 125.
resistance to blight (Phytophthora ship of genes and strains. Proc. Roy.
asis for the classification of strains of
oc. Edinburgh B, 65, 36.
sistance Work in Scotland. Am. Potato
217

Page 24
TROPICAL AGRICULTU
6. Cox, A. E., and LARGE, E. S. 1960 Agriculture Handbook, No. 174, 177.
7. CROSIER, W. I 1934. Studies in ith (Mont) de Bary. N. Y. (Cornell) Ag
8. PUSHKARANATH, 1960. Report on Ceylon. Tropical Agriculturist CXVI,
TABL
Races of P. Infestans iden
Type of Genotype ---
Sporulated
--
R, - -- R --
R - R R.R, RRa
R.R. -
RiRa - - - RF
RR, - - -- RRR's -
RRR- -
RRR - -
RRR -
RRR;B, - - -
-
* Only identified at Bopatalawa. -- Infection present.
- Infection absent.
28

IST, VOL. CXVII, A 1961
Potato blight Epidermics. U. S. D. A.
e biology of Phytophthora infestams ", Eасpt. Sta. Мет, 155.
the Potato Development Project in 76.
E I
ified in the hill country
Leaf Lesion 一ーーい Physiologic -ܓA -
race present
Hypersensitive
-
3,
4.
米
-

Page 25
DISEASE BAZARDS IN
*820*$20*920*SZO wị quoqď.w? quoqdiw? quoqd.sư, quoqď „od pso? Xwod, p49%.A.„od pso? Xwəd pso? X woŋƏJÄTfiņ94,0AwoŋƏJÄIfiņəĝ./0AwoɔIAIfiņ04./0A'wposÁTfiņo?.wpA øaqqq.8\u08./0d/fiss90,048?808s po0s)- 90'wp,848031 040.wapoȚAT90,048?898 I 400.-T.
suo saput :) &quoŋɔɔJuĮ Jøsse səŋɔɲɛA 01e10ā 10 00ue|sssoas pue p101A 0A11e188
·
II G[[{{W„L
|-|-|×

CULTIVATION
POTATO
99- 1, IZ-8 I9-0I Ig-† I
8—寸寸Z9:9) 6–g–0IZg "{{'{) seu rexioCI ZZ-69Zg *o[{)
ZL-Z
89-8 06寸 60-L I† • 1,
(uosqɔɔsos [bool) ownwoßspur) sə səəds qns own 80.000?!! 'S' [8AĻĶI seqdȚy UBIOA Jon posse quIV
80・3 9I-Z Z†-Z 99动 01. - † † T -9 9」・g
ミ8・9 60 • 1, †0-6 08-0I Z9-01
'8AAȚnųGI
98% NO
projā 8H
- -098 I NO - -xəssGH oơ8S
9寸NO
oẩunās
'8ļļļJBIN
qțgo,I * ' BUJQX100 JA "JOJ ĈI ə>sous)
16-I †Z-8
Z98 18-j; 9寸寸 £8-f7
L99 0寻9 [0-1. [0-6 Ig-01
qəOēI puno? I pƏs 3ưIIọ9țIBOT IsãIȚA þUTBIQ-InOO UĻIOAALISV pȚ08[ā.
8ļā pƏT, '80SȚIEI p.se/wpGI 3LIȚy! 94 BCT 04đƆ. SnĮ9GI
219

Page 26
TROPICAL AGRICULTU
2O DiyATALAWA
JAN FEB MAR APR MAy JUN
Figure 1.-Long-term average monthly rai humidity in relation to potat epiphytotics in the climatic zo
20 | NUWARA ELIYA
O
6
2
ހ
JAN FEE MAR APR MAY J UN
Figure 2-Long-term average monthly rain humidity in relation to potat epiphytotics in the climatic zo:
220
 
 
 
 
 

TRIST, voIL. CxvLI, 1961
- - - - - HUMIDTy
-- TEMPERATURE.
00
ノベ 90 /
- - - 8O
一・一ー・一 ገQ
ལོ། ། ། །
60
JUL AUG SEP OCT NOU DEC
infall, mean temperature and mean relative O cropping seasons for escaping late blight ine influenced by the North-East Monsoon.
- - - - - - HUMID Ty
- TEMPERATURE
100
- - - - - - ༤ ། ། ། ー一ー** 『 へ 190 ۔ ۔ ۔ ۔ ۔ ۔ ۔
8O
70
li, O SR
JUL AUG SEP OCT NOW DEC
fall, mean temperature and mean relative p cropping seasons for escaping late blight ne influenced by the South-West Monsoon.

Page 27
DISEASE IN POTATO C
II. - Brown Rot or Bac. Pseudomonas S
By D. V. W. ABEYGUNAWARDEN, (Agricultural Research
INTROD
BROWN rot Or bacterial Wilt Cause is the most disastrous of all dise: Ceylon. The first systematic survey (1). This survey revealed that the C factor in the extension of the crop at elevations below 5,000 feet. In combating this disease the importa varieties was recognised. Most Worl countries involved the testing of c( but none of these have shown high r has been made herein to analyse raising successfully both seed and C With a view to combat and avoid th
SYMPTOMS (
THE above ground symptoms charac stunting and yellowing of the folia seen on a warm day is the drooping
but this condition may be mistake affected leaves may recover their tu ing will extend further the followi lower leaves becomes evident when times only one branch on a single wilt. In Other cases, however, foliage (Plate I). Potato tubers from disea external symptoms. Brownish disc through the skin indicating that

HAZARDS
ULTIVATION
terial Wilt caused by
olanacearum.
7.
A & A. A. P. SIRIWARDENA,
Station, Rahangala)
UCTION
ed by Pseudomonas Solanacearum, ases affecting the potato crop in of the disease was made in 1960 disease is more or less the limiting into existing cultivators' holdings the absence of direct methods of ance of obtaining resistant potato k done in this connection in other Dmmon varieties and hybrid lines esistance or immunity. An attempt the factors which would help in Iommercial potato crops in Ceylon he disease.
DF DISEASE
2teristic of the disease are Wilting, age. The first symptom invariably of tips Of One or more lower leaves n for shortage of soil water. The urgidity towards evening but Wiltng day. A slight yellowing of the the leaflets begin to droop , somepotato hill may show symptoms of 2 of an entire hill may quickly wilt. ased plants may or may not show olorations can Sometimes be seen the disease is well advanced.
22

Page 28
TROPICAL AGRICULTU
Examination of infected tubers u localised in the vascular rings. If
sure will force the typical greyis vascular ring. (Plate II). Infected to decay especially in wet weath entry and cause the breakdown Surrounded by a thin layer of out
The Pathogen. Rapid multiplic relatively high temperatures ; it temperatures (3). The bacterium and rapidly multiplies under alka level resulting from high water ta development of bacterial wilt. Th. and flooding soil as practised in pa on its Survival. This accounts f recorded in potato crops raised in
Investigation on Resistance of relative susceptibility of potato va and conflicting. In extensive replic ties were planted in heavily infest Station, Rahangala. In these exper rated as susceptible with more thal bacterial wilt. In these tests the p the only criterion adopted in evalu and tuber infection Were also con are Sebago, Up to Date, Green Woran, Gineke, Majestic, Arran Phulwa, Hokkai 17, Pungo, Ulster' Profijt, Essex, Tedria, Indian seedl Wulong, Saco, Ambassadeur, Vir Cherokee, Noordeling, Arka, D GB 5210-5-9, Libertas, Maritta, Pi. variety S. tuberosum sub species known to show Some resistance t Prisca, 2117-117, 2407-12, 2410-78 courtesy of Prof. Neilson of Nort included in tests for resistance. Fi relatively resistant variety Prisc Dekama when tested in heavily exhibited fair resistance to bacteri as against 95 per cent. of the varie
222

IST, VOL. CXVII, 1961
sually reveals a distinct brown rot a disease tuber is cut a slight presin White bacterial slime out of the tubers left in the ground continue er. The secondary organisms gain of the tuber into a slimy mass er tissue.
ation of P. Soland cerum occurs at shows resistance to relatively low is inactivated at pH below 4.0 (2) line conditions. High soil moisture ble or heavy rainfall usually favour e bacterium is known to be aerobic uddy cultivation has harmful effects Dr the lesser incidence of disease rotation with paddy (1).
Potato Varieties. Reports on the Irieties to this disease are numerous ated field experiments potato varieed soil at the Agricultural Research timents the following varieties were in 75 per cent. of plants affected with ercentage of plants wilted was not lating resistance. The age of wilting sidered useful factors. The varieties Mountain, Katahdin, Great Scott, Banner, Huron 1, British Queen, Torch, Rival, King Edward, Dekama, ings ON 1360 and ON 2236, Kentang, gil, Courtland, Placid, Poet, Alpha, utch Seedlings GB 5269-22 and mpernal, Eigenheimer and the local andigenum. Five potato selections ) bacterial wilt in U. S. A. namely
and 56C-3 obtained through the
n Carolina State College were also gure 11 shows progressive Willting of and a highly susceptible variety
infested soil. The variety Prisca al wilt, 72 per cent, of plants wilting ty Dekama.

Page 29
DISEASE BAZARIDS IN,
CONT
SINCE the pathogen can be dissemina should be given to the use of dise such a recommendation is to preve into fields where it is not presel infection is greatly reduced when free seed in fields where infestatic disease free seed in infested soil, ho the danger of serious crop losses. paramount importance in countrie in infested soil. Rigid seed potato important means of reducing losses zation of the cutting knife with bo. a flame or dipping in mercuric c possibility of transmitting the bac tubers is recommended. The contro. susceptible crop has been attribut from infected Soil.
ACKNOWL
THE authors are thankful to Mr. D. ( investigations.
REFERE
(1) ABEYGUNAWARDENA D. W. W. and of Potato Seed Production in Ceylon. T
(2) EDDINS, A. H. (1936). Brown F Fla. Agr. Eacpt. Sta. Bul. 299, 44.
(3) SMITH, E. F. (1896). A Bacterial Potato (Bacillus solanacearum nov. sp) Path. Bull. 12, 1.

POTATO, CULTIVATION
'ROL
ated in seed potato tubers emphasis ase free seed. The main object of int the introduction of the disease nt. Furthermore, the severity of
plantings are made with disease on is mild or uneven. Planting of wever, Will not necessarily obviate The use of disease free seed is of s where seed potatoes are grown
Selection Would therefore be an ; caused by bacterial wilt. Steriliiling water or by passing through hloride Solution. When there is a terium from infected to healthy L obtained by rotation with a noned to starving out the organisms
EDGMENT
unawardena for assisting in these
NCES
WIJESOORIYA, R. A. (1960). Methods ropical Agriculturist CXVII 131.
tot of Irish Potato and its Control.
disease of Tomato, eggplant and Irish U. S. Dept. A gr. Div. Veg. Phys and
223

Page 30
100
日0
60
ヌ
ل
石
岂
5 4口
C
a
-
Z
名
拉 20
TROPICAL AGRICULTU
DEKAMA - - - - -
PRISCA
----
3O 36 44
DAYS A
Fig. 1.-Relative susceptibility of the pota
wilt caused by P. Solanacearium.
Plate I.-Potato plants affected with
224
 

RIST, VOL. CXVII, 196l
。ー「
52 59 4.
FTER PLANTTING
to varieties Dekama and Prisca to bacterial
bacterial wilt caused by P. Solanacearum.

Page 31
DISEASE BAZARDS IN P.
Plate II-Cross section of an infected of the vascular region and
 

ΟΤΑΤΟ OUITIVATION
potato tuber showing discoloration bacterial ooze of P. Solanacearum,

Page 32


Page 33
r
A comparison of some
Models used for the d Physical Production I
of Univariate Fert
By
W. ABEYWARDENA, Coconut Re
THE determination of economic fer ultimate goal in any fertilizer expe tural crops; and rightly so the increasingly conscious of the import use. However as the major portion evaluation of the economic dosages mination of the physical production to yield-falls within the domain o tural Economist, it is felt that techniques will be welcome by mos research. In fact, even if the service Such information may be useful in worker to satisfy himself indepe equation fitted by the Statistician d principles.
This paper is devoted to a compa tical models used for fitting curves (namely, responses to different le predetermined fertilizer mixture), more universally applicable model. review of Some basic consideratic patterns as it is felt that such a p appreciation of the above comparisc
1. A REVIEW OF SOME POPU FERTILIZER RESP
(a) The generalized fertilizer respc
EVER since the classical work of responses, several investigators, on

'opular Mathematical etermination of the Function in respect ilizer Responses
search Institute of Ceylon
tilizer dosages is necessarily the 'rimental programme on agriculagricultural scientist is now ance of the economics of fertilizer of the techniques involved in the of fertilizers-specially the deterfunction relating fertilizer inputs f the Statistician or the Agriculany hints of guidance in such t workers engaged in this field of is of a Statistician were available, that it will enable the Research indently that the mathematical oes not run contrary to scientific
arison of some popular mathemaon univariate fertilizer responses 7els of a single nutrient or of a
With a view to determining a
It also deals with a background ns regarding fertilizer response relude Will be useful to a better
S.
LAR NOTIONS REGARDING ONSE PATTERNS
ՈՆՏe CՆՆՈ՞Ղ) e
Mitscherlich (1909) on fertilizer the basis of experiments with the
227

Page 34
TROPICAL AGRICULT
effects on yields of varying fertili that the production function rela trinsically an “S” shaped curve. . this trend observe that “very mostly no effect at all or at best not justify the expenditure. It
fertilizer must exceed a thresh visible. The yield curve based O. has therefore an S-shaped course
Explaining this same trend, production function relating fert transformation of plant nutrient the plant itself. If all other natura and attention is concentrated onl then it is noticed that the metal plant growth, different proportion Soil in fertilizers. There is a small the Soil retains more nutrients addition of a minimum effective follows in the plant; this respc metabolism reaches the Saturat, additions Of mineral nutrientS haN plasm and can actually result in
Fig. 1 gives a typical S-shaped soil originally (i.e. at zero level of completely void of nutrients. Nea is negligible; as the dosage is response at first giving indications dosages (Once the point of inflex away on a diminishing returns ba with very high dosages, the respo
(b) Non-applicability of a standa
Due to the limited range of fert out in field trials and the Wide va complex in which such trials are practice does not exhibit anythi therefore, for all practical purp equation may be a misnomer. L. States that “the relationship betw in actual SOil Conditions Can SOm
228

TRIST, VOL. CXVIII, 196l
er inputs, have been led to conclude ting fertilizer inputs to yield is inacob & Uexkill (1960) in describing Small dressings of fertilizers have an unsatisfactory effect which does appears as though the amount of ld value for the result to become 1 increasing quantities of fertilizers
yy
Lamer (1957) observes that “the ilizers and yields depend upon the s in fertilizers into plant food by l factors are maintained as constant, y On the effect of mineral nutrition, polic process uses, in each stage of s of the plant nutrients added to the l response on first addition because than the plant absorbs; after the : dose, a quick and large response nse, however, slows down as the ion point; beyond this point the ve an irritating effect on the plant's negative response in output '.
fertilizer response curve where the fertilizer) can be considered almost r about the Zero level, the response increased, there is a very marked of increasing returns; with further ion I is passed), the response falls siis to reach a maximum at M; and nse is negative.
"d equation in practice.
lizer inputs that one normally tries riations of the plant-soil-climatic
conducted, the response curve in ng called a standard pattern and Ses, the term * standard response mer (1957) refers to this when he !en fertilizer inputs and crop yields atimes be described by a Sigmoid

Page 35
POPULAR, MATHEMATICAL MODELS TU
UNIVARIATE FERTII
Fig
S - shaped Fertilise
8
positive 7 TV-JPur;">
S 6
لكن 동 5 ○シ s کارل
> Ε και s ՄՈ 7
3 و Oy
d で 2 M ち -
> گھر レ+つ .A اس حصے O 2 莺 S
Fet til Sgr
I - Point of in
M - Point of Mox
D - Profit
curve, whereas at other times ther additional yields. It is necessary to in each specific case, because differe of crops, and types of fertilizers re
If we refer back to the generalise in Fig. 1, it is conceivable that, observations may fall on different ra ing on the original nutrient status fertilizer used, and a host of other ranges may be 0–3, or 3-8, or 4for different treatment from the curves. The pattern of response extracted from the relevant sectic and also the type of empirical mc each such pattern, are summari explanatory.
3-R. 7475 (1163)

ED FOR THE DETERMINATION OE IZIER TRESPONSES
)
r Response Curve
|e-->|negati
• JPV Tav,
e
以
O nox ***
北イエ°
سلبية S 7 8 9 O 2
Inputs (x) סptחזוuוח
do soge חסו אfte
munn. TeSponse
e is an immediate diminution of determine the productivity curve nt conditions, species and varieties sult in different responses ',
d fertilizer response curve shown in a particular experiment, the Inges of the fertilizer axis depend
of the soil, the efficiency of the
considerations. For instance, the 10, or 6–12. Each range may call point of view of fitting response Within each of these ranges as n of the general curve (Fig. 1) del that may reasonably explain sed in Chart 1, which is self
229

Page 36
230
TROPICALAGRICULTUR
Chart
Fertil ser Resp.
Rα η 9 e
of Rete want Potte f n Fert I til Ser of
y | et d response (Ref. Fig. I )
A
3
O - 3 2.
O
O 2 3. 禹 5 e
6
5
3 - 8
3
2
3 5 6 7 8 9
6
/ 4 - 10 A
3
== سه ساختهاست همسایمیستهستا۵ Z 5 6 7 8 9 1
レつー
6 - 12 ム闘
The first le vel in the T
fert L ser le y el

IST, VOL. CXVII, 1961
bnse Patter ns
T f- e n dS S u i t o b t. e
of Empirico li T e S P O ni S e m o del
1) Incre as I ng
Logístic Curve Teitu Trns
'g Cobb Douglasחן shן חו הח! D (1
O
| etu rns
2) NO in dCOtons Mitschertuch’s
öf O depression Polynomial
1) Diminishing
returns
Polynomial 2) S Light
depress on
1) DIm Ir Ishing
returns Polynom ta li
2) Symmetru c0 ! po fO bollic)
before & ofter
fՈ GXIfՈԱm
Inge gives the Org / n Ol
In the Sol (

Page 37
POPULAR MATHEMATICAL MODELSU
UNIVARIATE FERTI
From the above, it is reasonable t standard equation for fertilizer conditions-if such an equation ex basis. On the other hand, such in troduce serious divergences betwee in some portions of the curve-a si tory in problems of estimating of situation, therefore generally calls On its own trends as Well as Other S.
(c) Truncated nature of response C
of Optimum fertilizer dosages.
While so many types of curves a response patterns, the data from fie increasing returns part of the gene encountered unless the soil is ext Russel (1932) confirms this in his not always give sigmoid curves, bu tinuous fall in effect of the nutrient, largest effect and subsequent increm no additional gain and sometimes ex the sigmoid or the continuously fall the normal effect of nutrients on possible that the curve is usually S. is so near the origin that it is comm
However, even if there are siti returns portion of the curve is clear that due to limitations imposed observations, such a curve very sels Of inflexion of the curve-that is th diminishing returns phase. And in estimating optimum fertilizer dosa prepared to tolerate a very lengthy
Lamer (1957) probably sums up states that “ Fertilizer experts are curve below the point of inflexion'
Therefore our problem of fitting to estimating optimum fertilizer do practice-being restricted to the r type of curves following the law o creasing-decreasing ' curves as the

SED EOR TEIE IDETERMINATION OE LIZER RESPONSE
) suggest that the idea of fitting a responses observed under field ists at all-has no sound factual discriminate treatment may inn observed and predicted values tuation which is very unsatisfactimum fertilizer dosages. Every for independent treatment based cientific considerations.
Arves met uUith in the estimation,
re applicable in determining the :ld experiments are such that the }ralised response curve is seldom remely poor in nutrient content. observation that “experiments do t a simple shape showing a con
the first increment producing the ents less and less effect till finally Jen disadvantage ensues. Whether ing curve more nearly represents plant growth is not known. It is igmoid, but the point of inflexion honly missed”.
Jations in which the increasing ly indicated, it will be appreciated by the experimental range of lom extends far beyond the point Le point of commencement of the Such a situation, the question of ges does not arise unless one is
and doubtful extrapolation.
the above contentions. When he not interested in the part of the
response curves as a preliminary sages, becomes more simplified in 2gular concave (to the abscissa) diminishing returns or the “iny are usually termed. In fact what
23.

Page 38
TROPICAL AGRICUL
we observe in practice may be on response curve-that is with the obscured or of no interest.
(d) Variation of “Increasing-D
Even within the simplified incr ed above, response curves can ex distinct types can be reasonably range and these in fact may be ch set-up under consideration.
Fig. 2 shows the “increasing de The dotted extensions to the co distinct variations within this fan field conditions. All four curves a (a) the rate of increase tends to : A continuous positive response is may be. In (b) the rate of increa ceeds asymptotically. Here again the rate of increase falls below depression; but the rate of fall of rate. In (d) the increasing-decre the rate of fall of the gradient is a that the continuous line drawn cc purely for convenience. This early the above four types; or it may et positive response follows a certai depression follows yet another lav the scope of our present knowled of the present paper where we are fit univariate fertilizer responses.
2. RECOGNISED EMPIRICAL
DECREASING' R.
BEFORE suggesting mathematical type of response curves, it will be: in which such models are sugges when they suggested mathematic mainly interested in determini implying universality of applicatio in problems of estimating optimu
282

URIST, voL. CXVIII, 1961
y a truncated form of the S-shaped increasing returns portion absent or
creasing response curves.
asing—decreasing pattern mentionhibit Wide variations. At least four expected within the experimental tracteristic of the soil-plant-climatic
creasing ' curves referred to above. mmon continuous line show some lily of curves to be expected under re the diminishing returns type. In zero but never Seems to reach Zero.
expected, however, infinitisemal it se reaches zero and the curve prono depression is anticipated. In (c) zero and therefore gives rise to a the gradient occurs at a decreasing asing pattern is similar to (c) ; but constant. It must however, be noted, immon to all four types, is so done section too may vary according to 7en be that the portion showing the n law and the portion showing the v. But such refinements are beyond ge and certainly beyond the scope only interested in a single curve to
MODELS FOR “ INCREASINGESPONSE CURVES
models for use in fitting the above
mportant to understand the context ed. Mitscherlich and a few others 1 models for response curves were ng “ constant efficiency factors”, n to some degree or other. However m fertilizer dosages, one thinks of

Page 39
POPULAR MATHEMATICAL MODELS UNIVARIATE FEI
Tot o
s
있
 

USED FOR THE DETERMINATION OF
TILIZER RESPONSE
Yet d
233

Page 40
TROPICAL AGRICUL.
the response curve primarily as a probably with some provisional thereby that no attempt whatso applicability. In fact Crowther a an adaptation of Mitscherlich's r
On this basis, Several algebrai successfully used in fitting fertilizer responses. These incl. curves which have given excelle they perform well within the recommended because apart fro have, according to Anderson (19 and large values of the level C “although this undesirable featu as it performs satisfactorily with in estimating optimum fertiliz complex higher degree curves indicate four specific types of f fitting fertilizer response curves sometimes used-for example, model used by Spillman (1933) the main principles are those cov (1957) in fact has used these foi some special aspects of fertilizer that Cobb–Douglas' model give used very often in studies on or
The models are given below :-
Model
(1) Mitscherlich’s Model
(2) Allometric Model
(Cobb-Douglas) lO
(3) Quadratic Model
(4) Square Root Model
234

URIST, VOL. CXVIII, 1961
convenient method of interpolationo for a little extrapolation-implying Ver is made to establish its universal nd Yates (1941) when they employed lodel, did so on this same principle.
C forms are available and have been urves to “increasing-decreasing” ude Several complex higher degree int fits. However the latter, although
observed range, are generally not in the computational difficulties, they 57), undesirable properties for Small f fertilizer. He also points out that re may not be too important so long in the relevent range, it is important er application ”. If then we avoid we observe that published work unctions that are popularly used in 3. Different adaptations of these are the adapted forms of Mitscherlich's
and Crowther & Yates (1941). But 7ered by these four models. Anderson ur models in a study with respect to responses. It may be noted, in passing, in herein is the Allometric equation ganic growth.
Εημαίίοη
- A-beT적
Α. ΟΙ Χ Y = A-br (log, r = —a)
ΟΙ (Α. γ ́) = log b --X log r (linear form)
Υ = a -- β Χ α
ΟΙ (Y-a) = log3 + C log x (linear from)
Y = a, ——bx—cx*
Y = a - bx + c Vx

Page 41
POPULAR MATHEMATICAL MODELS
UNIVARIATE EERT
y is the expected yield; A is fertilizer conditions to be estimate fertilizer , a, b & c in the quadrati of the Mitscherlich's model, and are parameters to be estimated by the Allometric model is the averag estands for epsilon = 2.71828.
The quadratic and the square which do not presuppose any fixed the Mitscherlich’s and Cobb-Dougla and the second an ever-increasing tation with respect to the pattern equations in their simplified linear
(a) Mitscherlich's equation :-
The logarithm of the decrement is linearly (negatively) correlated
(b) Cobb–Douglas' equation :- The logarithm of the increment i.
of fertilizer is linearly (positively) the fertilizer level.
3. A COMPARISON OF TE
(a) Mathematical considerations.
In studies on dynamics of produ “input' (yield versus fertilizer i conventionally direct their attentic production curve-namely;
(1) Curve of total product (pr. (2) Curve of marginal product
(3) Curve of the rate of the
curve).
The curve of the total product total yield curve with respect to the The curve of the marginal producti of the yield curve, and shows the additional fertilizers. The rate of

SED FOR THE IDETERMINATION OE" TIZER RESPONSE
the maximum yield under ideal from the data; x is the level of and Square root models, b, r & a & 3 of the Allometric model, the method of least squares; a in e yield at zero level of fertilizer;
root models are polynomial types theory as such. On the other hand, s' models-first an asymptotic type type-both imply a distinct expec
of fertilizer response. The latter orms may be defined as follows :-
in yield from the maximum yield With the fertilizer level.
n yield over the yield at zero level correlated with the logarithm of
HE EMPIRICAL MODELS
:tion with respect to any effective in this instance), Econometricians in on three specific aspects of the
mary curve).
(first derived curve). marginal product (second derived
y), in the present context, is the increasing levels of fertilizer (x), the curve of the gradient (dy/dx). potential productive capacity of he marginal product is given by
235

Page 42
TROPICAL AGRICULTU
||m pu 16Jow 000(x) , -8 }3n poud 1 b 3 0 1 _x} ɔ * xq - Do &+ xɔ-xq * 0 = &>*& 환공의지7× 6- og - Voss,u01.Jo!Jo } o ou øu pnbsɔ lɔpup on to„sphốnoq qiqo os, qɔ ŋjɔųɔsął wɔɔɓəuuouo 33 slēpou lɔɔŋldųạ so spua, 1 103 sēJõēū
11
}J D'AQ
236
 

感。
x? (x) "A P
yɔnp oud įoul fij puu
Đụy 40 oạDJ
RIST, vo. CXVII, 1961
x s Á p
(×), o
yɔnpojď

Page 43
POPULAR MATHEMATICAL MODELS U. UNIVARIATE FERTI
the curve of the gradient of the gra and shows the tempo of the potentia fertilizers.
The four mathematical models : herein through these three specific be examined on the basis of mathe
Chart II, gives the general trends second derived curves (namely of y to each of the four models. These, the curves of total product, margina product respectively.
The curves (though not drawn broad patterns in respect of each of
(1) Total product curve (y).
All equations show a positive Mitscherlich's model reaches a de that level; Cobb-Douglas' model te reach a finite maximum ; and in and Square root-the response reach followed by a negative response.
(2) Marginal product curve (dy/
From the point of view of the show diminishing returns by their Mitscherlich’s and Cobb-Douglas” marginal product (the latter doe polynomial models can cater to a
(3) Rate of marginal product (d
The rate of the marginal produc this is necessarily implied in all fo of diminishing returns. The rate product itself decreases in the cas and the square root models-this forms of biological responses. F different, in that its rate of the ma
(b) Theoretical trends of mod
reSOO2S2S.
The efficiency of a mathematica behind a given set of observed da

ED FOR THE IDETERMINATION OF
IZER RESPONSE
dient (dy/dx) of the yield curve productive capacity of additional
uggested earlier will be studied Criteria and their trends will first natical considerations.
of the primary and the first and dy/dx and dy/dx) with respect as explained above, correspond to l product and the rate of marginal
to scale) indicate the following the three econometric criteria.
response at the outset. But the inite maximum and continues at nds to, although it does not really the polynomial models-quadratic les a certain maximum and is then
'dx). marginal product, all four models downward trends. However, the models set a limit of Zero to the s not reach zero), whereas the negative marginal product too.
y/dx). t is negative in all the curves and rms of responses following the law of this decrease of the marginal e of Mitscherlich’s, Cobb-Douglas” again being in keeping with most owever the quadratic model is 'ginal product is a constant.
els vis a vis trends of fertilizer
model used to determine the law a in respect of some problem, has
237

Page 44
TROPICAL AGRICULT
to be guaged by the flexibility ( 'to the whole range of variation e theoretical background of the ta four models, has to be examine established basic trends of responses, which may be summa
(1) A positive response in maximum later. Still may not be observed.
(2) Decreasing positive mar may or may not be fol
(3) Decreasing rate of fall
CaSeS.
From the above it follows are superior to the other models even depressing yields, and (2) f of the marginal product, Mits Square root models are Superior latter suffers from the restriction marginal product.
Therefore one may reasonably Square root model is the most fl tended that in a specific set of c models would fit better and may
(c) Comparisons on the basis of
The above four models have be based on four or more levels of certain experiments conducted at Ceylon. The data selected were significance in the Analysis of V:
The Mitscherlich’s and Cobb-D the basis of linear equations in re transforming one or both varia case of Mitscherlich’s model, the estimated by Stevens’ (1951) m reported by Anderson (1957). T fitted by the usual method of Mul
238

UTRIST, VOL. CXVIII, 196l
f the model-that is its adaptability pected in the problem. Therefore the ends set out above in rspect of the di in the light of certain reasonably "increasing-decreasing ' fertilizer rised as follows :-
the total product giving rise to a later a negative response may or
ginal returns tending to zero. This lowed by negative marginal returns.
away of marginal returns in most
that (1) the polynomial models in that the former can accommodate rom the point of View of the pattern cherlich's, Cobb-Douglas' and the to the quadratic model, because the of a constant rate of fall away of the
conclude that, on a broad basis, the exible type. However it is not conircumstances, any one of the other
even be more meaningful.
applications om eacperimental data.
en fitted on fertilizer response data nutrient application in respect of the Coconut Research Institute of Only those that showed statistical İriance.
buglas' models have been fitted on spect of these models given earlier, ples as the case may be. In the maximum response (A) has been ethod of successive approximation. le other two equations have been iple Regression.

Page 45
POPULAR MATHEMIATICAL MODELS
UNIWARDIATE FERT]
A comparative index of the good is calculated by
R. (or r) = |Sums ofs
V/ Table I gives (1) the source of the nutrient applied (4) number
(5) index of the goodness of fit R.
The Mitscherlich's and Cobb-DO on data which showed any depre fertilizer-being obviously unsuita
The observed and expected yie Space.
The comparative merits of the the basis of mathematical consid these applied results.
In general, polynomial models : Cobb-Douglas' models; and the than not superior to the quadrati Some specific cases, any one of th also confirmed. It may also be not where the quadratic model is supe extent of the Superiority is not st recommending the square root mot for “increasing-decreasing ' curv
DISCU
The selection of a suitable math response curves, calls for considera of View of the mathematical trend natives as Well as the trends Obse from Scientific and other ad hoc
However, in practice, the need f seem to be seriously felt. Some w the pudding is in the eating of it that gives tine least residual error model with some popular law beh and attribute any deviations there to experimental errors; quite a f quadratic model in all instances re

SED FOR THE DETERMINATION OF LLIZER RESPONSE
ness of fit in respect of each model
uares due to regression
Total sums of squares of y data (2) the variety of plant (3) of levels including zero level and
ΟΙ Υ.
Jglas' models have not been fitted ssion in yield at higher levels of ble.
lds are not given due to lack of
four models explained earlier on erations are amply confirmed by
are better than Mitscherlich's and square root model is more often C model. Further the fact that in he four models may suit better is ed that even in those few instances erior to the square root model, the p large as to discourage one from del as a generally applicable model
8.S.
SSION
ematical model for fitting fertilizer ble judgement both from the point is of the models available as alterved in the data and also expected 2Onsiderations.
or that much of attention, does not ork on the basis that “the proof of '', and therefore select the model others stolidly lay their faith on a ind it-such as the Mitcherlich's- rom, however regular they may be, aw also prefer to use the common gardless of its implications. .
239

Page 46
TROPICAL AGERICULTU
TAB
A Comparison of Mathematical M. Experime
Source of Data Variety | Nutri
βγλί
C 73 First Harvest . . P. C. K C 194 First Harvest . . P. C. K C 159 First Harvest . . IP. Ο P C 189 First Harvest ... P. C Ν C 189 Thinings IP. Ο Ν C 180 Second Harvest P. C. Ν C 194 First Harvest . . P. C. P C 73 First Harvest. . . P. C. N C 180 First Harvest .. P. C. K ESTATE A (R.R.I) . . RUBBE N ESTATE A. (R.R.I) . . RUBBER K C 74. Third. Harvest. . . M. S. S C 160 Thinings IP. Ο P C 73. Third Harvest.. P. C. Ν C 189 Second Harvest IP. Ο N C 159 Thinings - - P. C. P C 194 Second Harvest P. C. K C 160 First Harvest . . IP. Ο Ρ C 173 Thinings IP. Ο Ν
Note :- (1) Experiments on Paspalum Co)
have been conducted in a Institute of Ceylon.
(2) R. R. I. : Rubber Research In
240

IST, VOL. CXVII, 1961
E I
dels on the Basis of Application on ntal Data,
R (or ) - I S. S. Due to Regression
No. of A/ S. S. Due to ay Leels
Mitsche Cobb - Quadra- Square Flch Dουια. //7/76. Root
4. 0.9964 0.9816 0.9999 0.996. 4 0.9892 0.9630 0.97.74 0.9996 4 0.9487 0.8090 O. 9578 0.986 4. 0.9734 0.9925 0.988.7 0.9986 4. 0.9849 0.9838 0.9858 0.9996 4. 0.9989 0.9999 0.9985 0.9999 4. 0.985.0 0.9999 || 0.9917 0.9999 4 O. 9825 0.9593 0.9999 0.9928 4. 0.97.27 0.9807 0.9723 0.99.79 4 0.9845 0.9724 0.9656 0.994.7 4 0.9991 0.985.0 0.9989 0.9983 5 - - 0.8066 0.9.202 4. - - 0.8238 0.921 4 - - 0.771 09209 4. - - 0.999 0.9766 4. - - 0.99.07 0.99.72 4 - - 0.9999 0.9853 4. - - 0.9605 0.99.82 4. - - O. 9286 0.9958
immersonii (P.C.) and Madicago Sativa (M.S.) Phytosolarium at the Coconut Research
stitute of Ceylon.

Page 47
POPULAR MATHEMATICAL MODELS U. UNIVARTATE FERTI
The last approach is, obviously, inc be instances where the quadratic m. The first two approaches, on the O cumstances be quite justifiable. Ger to consider these as alternative app
In general, when one has nothing information regarding expected bro the particular set of circumstancesfertilizer tested is too few to deciphe cies in the observed data, it is recon the more flexible type of mathema present study, such a flexible mode equation.
If the data were based on several observed values close to the expect (say) 5 or more levels of fertilize better fit is to be preferred.
When the observed data show a levels of fertilizer, one has the opt and the quadratic-the other two n. unless the experimenter is confident to some other extraneous causes. better fit, provided a sufficient num however, the number of levels is t and if one hopes to extraplote a bit root form. At any rate the quadrat is pretty certain that the pattern maximum response runs symmetr before. If as mentioned earlier, ar matter any other value, is known extraneous factor independent of th should be dropped from considera made (say) using some concomitan
For the sake of completeness, it comments on the fitting of curves three fertilizer levels-usually zero desirable to have at least one ferti of constants in the equation fitted error is Zero and as a result it is r. comparative goodness of fit of all numerous situation where we have

SED FOR THE DETERMINATION OF LIZER RESPONSE
t quite sound, although there may bdel may fit better and validly so. her hand, can under certain cirerally the best attitude would be roaches in different situations.
to go by-Such as some ancilliary ad trends in the yield pattern in and when the number of levels of ir any regular or irregular tendenlmended that One should resort to tical model. On the basis of the al is provided by the square root
replications, which will bring the ed values and/or when there are r, then the model that gives the
ny depression in yield at higher ion only between the square root nodels being obviously unsuitable, that the depression in yield is due
The decision again rests on the ber of levels have being tested. If, Do few (say, not exceeding four), it is preferable to use the square c form is to be avoided unless one of depression after the point of cally to the pattern of response ly depression in yield or for that to be the obvious result of some Le fertilizer, then either this value tion or some correction may be t variable.
will be pertinent to give a few to data based on a minimum of One and two. It is undoubtedly Lizer level more than the number , because otherwise the residual ot possible to get any idea of the ternative models. But there are only three levels and we still need
24.

Page 48
TROPICAL AGRICULTU
to get some idea of the optimum In such situations there is nothing a curve to 3 points, provided on such curves and also takes some
be used.
In passing, it will be of interest can be applied Successfully to a w diminishing returns. The author quadratic form in problems of c. ance analysis) for the curvilinear plot yields in coconut and also fo ing age of coconut palms on t “ error” through this approach h;
SUMA
Some popular notions regarding pattern are reviewed. It is expla response curve, relevant to proble dosages, exhibits itself only as a general S-shaped response curveing ” or concave to the abscissae t any One of four specific forms or
Four popular mathematical moi given. These are compared on til tions through three accepted eco duction functions and also on the data. Both on the basis of math basis of results of application on (1) the polynomial models are m the polynomial models, the Squar and (3) there are situations in wh be better.
Certain hints of guidance in t fertilizer response curves are give
Taking these facts into consid the question of deciding On a ur model for fitting curves to fertiliz responses showing diminishing r suggest that the Square root mod
242

TRIST, VOL. CXVIII, 196l
fertilizer dosage or the yield curve. g biologically objectionable in fitting e is conscious of the limitations of
care with respect to the model to
to note that the square root model, ide variety of relationships showing (1962) has found it superior to the orrecting (through multiple covarieffect of the stand of palms on the r the curvilinear effect Of the bearheir yields. The reduction in the as been considerable.
MARY
g the generalised fertilizer response ined that under field conditions, the lms of estimating optimum fertilizer restricted or truncated form of the -namely the “increasing-decreasype of curve, which itself may take their intermediates.
dels used in fitting such curves are he basis of mathematical consideranometric criteria applicable to probasis of application on experimental ematical considerations and on the experimental data, it is noted that Ore generally applicable (2) among e root model is the more adaptable, ich any One of the four models may
he selection of a model for fitting
II. -
eration, if one is confronted with niversally applicable Or a standard er responses or for that matter any eturns, it would be reasonable to el is relatively the most acceptable.

Page 49
POPULAR MATHEMATICAL MODELS US
UNIVARTATE FERTILI
ACKNOWLED
I am deeply indebted to Dr. S. C. I Station for the invaluable advice rec paper; and also to Messers G. Karl (Division of Biometrics, Coconut Re the statistical work and the preparati
REFEREN
1. ABEYWARDENA, V. 1962. Statistical experiments, (with Editor, Empire J. Eacp.
2. ANDERSON, R. L. 1957. Economic and novations and Resource Use-Chapter 17. Iowa, U. S. A.
3. CROWTHER, E. M. and YATEs, F. 1941. fertilizer requirements of Arable crops. E. 4. JACOB, A. and UEXKIIL, H. Von. 1960. ing of Trophical crops. Verlagsgesellschaf 5. LAMER, M. 1957. The World Fertilize versity Press, Stanford, California.
6. MITSCHERLICH, E. 1909. Das Gesetz ( abnehmenden Bodenertrages. Landw. Jahl
7. RUSSEL, SIR. E. JoHN. 1932. Soil C. Rothampstead Monographs an Agic. Scien. Co. London.
8. SPILLMAN, W. J. 1933. Use of the e experiments, U. S. D. A. Tech. Butl. 348.
9. STEVENS, W. L. 1951. Asymptotic Reg

ED FOR THE DETERMINATION OF ZER, RESPONSE}
GEMENTS
Pearce of East Malling Research eived in the preparation of this naSena and P. G. F. Fernando search Institute of Ceylon) for on of the typescripts.
CES
control of variability in coconut t. Agric.).
Technical analysis of Fertilizer InIowa Estate College Press-Ames,
Fertilizer policy in War-Time; The mpire J. Eacpt. Agric. 9 : 77-97.
Fertilizer Use-Nutrition and manurf fiir Ackerbau mbH. Hannover.
r Economy. Chap. 5. Stanford Uni
des Minimums und das gesetz des უb.
Onditions and Plant GroWith. The Lce. Chap. II. Longmans Green and
xponential yield curve in fertilizer
gression, Biometrics, 7 : 247-268.
243

Page 50

)

Page 51
The Relationship bel
Physico-Chemical
Paddy Soils in th
on Continued
Β
D. M. F.
(Department of Ag
THE Chemical and biological proce when it is submerged are of a dyna ments carried out so far by Soil C done with the rice plant in situ Chemical and Physico-Chemical submergence in the absence of the and recorded. Three important infl are :- (a) the exudation of oxyge an oxidized rhizosphere which iní dead roots make a significant con matter, which in turn intensifies r the absorption of nutrients from th the chemical regime in the absence to be an important aspect of soil SOils.
The main object of this investig and relationships between the characteristics of paddy soils in submergence.
MATERIALS AND EXPE
Twenty soils comprising of the fo
1. Strongly acid lateritic rice 2. Strongly acid humic rice so
* A paper read at the Eighth Sessio. Water and Fertilizer Practices of the New Delhi, December, 1961.
4一H7475(1/63)

tween Chemical and Characteristics of le Dry State and Submergence
RODRIGO
griculture, Ceylon)
asses that take place in a paddy soil amic character. Most of the experiDhemists on paddy soils have been ; therefore the variations in the characteristics of paddy soils on rice plant have not been observed uences of the rice plant on the soil n by the rice roots which maintains luence the soil; (b) the decaying tribution towards the soil organic eductive processes in the soil; (c) le soil. A study of the variations in of the rice plant therefore appears nutritional relationships of paddy
gation was to study the variations chemical and physico-chemical the dry state and on continued
RIMENTAL PROCEDURE
ollowing seven groups were studied.
soils of the ultra wet zone.
ils.
ns of the Working Party on Rice Soils, International Rice Commission held in
245

Page 52
TROPICAL, AGRICULTU
3. Ground water podzolic ric 4. Acid lateritic rice soils of 5. Non-Lateritic rice soils of 6. Calcareous rice soils. 7. Non-Lateritic clayey rice s
The experiment was carried O glazed pots with a side opening to the brim and the 2’ of Standi addition of distilled Water.
The dry soil was analysed for capacity, total exchangeable catio. reducible manganese, total man phosphorous, pH and mechanical
After submergence the followin Wet Soil at intervals of 2 Weeks Weeks :- Ammonia, Iron, Mang Redox Potential.
Water percolates were also ar. Nitrate, Iron, Manganese, Oxidisa
pH was measured in situ by seated permanently in each pot ( They were placed near the centre each other. The potentials were m Model G using a Saturated calome
Oxidisable matter includes Fei constituents and Soluble Organic latively mild conditions. This dete the reducing capacity. This is a comparative significance.
The method is based. On the Oxic permanganate under standard co used varied from 1.0 ml to 10 ml) 0.01 N KMnO , and 10 ml of 1 make a total volume of 100 ml, in heated in a boiling water bath for this procedure the factors (streng and time of digestion) on whic depends, were kept nearly consta
246

RIST, VOL. CXVII, 1961
e SOils.
he Wet Zone. the dry zone.
Oilis.
ut under greenhouse conditions in at the bottom. The pots were filled ng water was maintained by daily
carbon, nitrogen, cation exchange hs, free iron oxide, total iron, easily ganese, available silica, available analysis.
g determinations were made in the initially and later at intervals of 4 anese, Oxidisable Matter, pH and
alysed at intervals for Ammonia, ble Matter and Conductivity.
placing 2 blank pltinum electrodes 5 in. below the Surface of the soil. and at a distance of 3 in. apart from easured with a Beckman pH meter el electrode.
*, No, and S among the inorganic matter that is oxidised under rermination would give a measure of 'elative determination and has only
lation of the sample with potassium nditions. The sample (the volume was added to a mixture of 10 ml. of :3 H, SO, with sufficient water to a 250 ml conical flask. The flask Was 30 minutes along with a blank. By h of KMnO, acidity of the medium the figure for oxidisable matter ht. Immediately after the digestion

Page 53
THE RELATIONSHIP BETWEEN CHEMICAL A
TICS OF PADDY SOILS IN DRY STATE A
10 ml Of 0.01 N Ammonium Oxalate cess oxalate back titrated against 0.0 ween this reading and the blank rec the percolate was taken as an index matter or the reducing capacity.
About 50 grims of the soil were ext and 2 cm diameter by inserting it i This was used for the analysis of the
pH and moisture determinations v The sample was transferred to a ta. of the moist soil quickly determine oxygen free distilled water was ac pH determined with a glass electro trodes Was Washed into the beaker Sion of the bulk of Water On a Watt in an Oven at 0 15 and the moistu
The remaining soil was transfer which had been previously weight quickly determined ; a rough allow content on the basis of preliminary e of Morgan's solution added to give mately 1 : 5. The flasks were allowe sional swirling and the solution fil This solution was used for the dete ganese and oxidisable matter. Morg iron and not ferric iron. These figu) reduction of the Soil. With the aid O. added and the moisture content of ppm of the dry soil. The values for ccs of 0.0 IN KMnO per grm of d
Standard methods were used for
RESULTS AND
Dry Soils. The analysis of the dr values obtained readily permit the classes. The average of the seven gi
pH. The average pH value for the wet zone it is 5.65 ; for the dry zon it is 7.78. The pH rises from ultra w

ND PHYSICO-CHEMICAL CHARACTEIRIS-- LIND ON CONTINUED SUBMIERGENCE
Solution Was added and the ext 1N KMnO, The difference betluced to an equivalent of 10cc of of the concentration of oxidisable
racted with a glass tube 24 in long into the pot in a circular motion. a Wet Soils.
were run on the same sub-sample. red 50 ml, beaker and the weight :d. An equal weight (volume) of ided, the beaker swirled and the de. The soil adhering to the elecwith a jet of water. After expuller bath the Soil Was dried further re percentage determined.
Tred into a 500 ml. conical flask ed. The weight of the moist soil 7ance Was made for the moisture 2xperience, and measured amounts a soil extractant ratio of approxid to stand for 24 hours with occatered through fluted filter paper. rmination of ammonia, iron, mangan's solution will extract ferrous res will characterise the extent of f the amount of Morgan's solution the soil all figures are reduced to oxidisable matter are reduced to ry soil.
the other determinations.
DISCUSSION
y soils is given in Table 1. The e soils to be grouped into seven roups are given in Table III.
Ultra wet zone soils is 4.84; for the e 7.26 and for the calcareous soils 7et zone to the dry zone.
247

Page 54
TROPICAL AGRICULTU
Carbon. The carbon values tak the ültra wet zone soil with 2.4 pe cent for the dry zone it is 1.1 per 0.8 per cent. The humic soils is hi water podzolic soils is lowest wit
Nitrogen. The Nitrogen percent carbon values. It is 0.17 per cent f cent for the wet zone soils, 0.09 0,09 for calcareОUS SOils. The Niti highest with 0.52 per cent and lo with 0.035 per cent.
Cation Exchange Capacity. Ti creases with the rise in pH; 7.7 f. the wet zOne soils, 15.8 for the dr 20.8 for humic soils and a very lov podzolls.
Total Exchangeable Bases. Th increase with the rise in pH. It is the wet zone soils, 8.9 for the dry z soils. It is lowest for the ground w
Available Silica. Available Silica ppm for the ultra wet zone soils, the dry zone soils. It is lowest for ppm while the humic soils contain clayey soils have high values of 14
Free Fe/Total Fe percentage. T iron decrease with rise in pH. It tultra wet zone, with values of 64 a dry zone respectively. The humic per cent while ground water podz
This could be expected as the : is high in the ultra wet zone, less zone. The humic soils too contair total iron due to the high carbon acids. This Value is least for th weathered leached sandy soils.
General. The soils of the ultra low in cation exchange capacity
248

IST, VOL. CXVII, 1961
an opposite trend. It is high for cent, for the wet zone it is 1.3 per 2ent calcareous soils has a value of hest with. 10.4 per cent and ground
an average of 0.45.
ages follow the same trend as the or the ultra Wet zone soils, 0.11 per er cent for the dry zone soils and ogen content of the humic Soils is west for the ground water podzols
le cation exchange capacities inor the ultra wet zone soils, 11.9 for y Zone soils. It has a high value of V value of 1.3 for the ground water
le total exchangeable bases also 1.5 for the ultra wet zone, 6.1 for One soils and 10.5 for the calcareous rater podzols with 0.75.
also increases with pH. It is 23.5 76.4 for the wet zone soils, 145.2 for the ground water podzols with 6.75 33.5 ppm. The calcareous soils and 3.2 and 142.3 ppm respectively.
he percentage of free iron to total is highest with 82 per cent for the nd 49 per cent for the wet zone and soils too contain a high value of 70 ols are lowest with 38 per cent.
mount of weathering and leaching in the wet zone and least in the dry a high percentage of free iron to 2Ontent which gives rise to organic podzols as they are very highly
wet zone which are strongly acid, ndicate a kaolinite clay.

Page 55
THE RELATIONSHIP BETWEEN CHEMICAL
TICS OF PADDY SOLS IN THE DRY STAT
The non-lateritic rice Soils of th 7.26, high cation exchange capaci
high total exchangeable bases of :
silica content of 145.2 ppm indicat lonitic clay.
Water Percolates and Wet Soils. lates are given in table III. The a table IV. The analysis of the wet averages are given in table VI. figures 1 to 12.
General. There was a fall in re With time and an almost total di days of submergence. Ammonia, ) oxidisable matter and conductiv decreased.
Ammonia-Water Percolates. Th day's submergence run parallel to dry soils. It is highest With 33 pp ppm for the wet zone and 6 ppm f ground water podzols, calcareous 23, 9.5 and 14 ppm respectively.
The peak values too follow the s ppm for the ultra wet zone, with 49 for the dry zone, while the humic careous soils and clayey soils reac
The final Values for ammonia to
The difference betWeen the init cate the degree of ammonification. trend. It is highest with 99 ppm fo for the wet zone and 23 ppm for ground water podzols, calcareous of 62, 36, 27.5 and 22 ppm for the di
The differences between the ma indicate the degree of denitrificat same trend. It is highest with 78 22 ppm for the wet zone and 18 p. soils, ground water podzols, calca values of 42, 43, 23.5 and 25 ppm fo

AND PHYSICO-CHEMICAL CHARACTERISAND ON CONTINUED SUBMERGENCE
dry zone with an average pH of y of 65.2 m.e. per 100 gms clay, 7.5 m.e. per 100 gms clay, a high e a fair proportion of montmoril
The analyses of the water percoverages of the groups are given in oils are given in table V and their These are graphically shown in
dox potential, an increase of pH sappearance of nitrate within 14 reduced iron, reduced manganese, rity reached a peak and then
e initial Values obtained after a the initial nitrogen content of the m for the ultra wet zone, with 17 or the dry zone, while humic soils, soils and clayey soils contain 30,
same trend. It is highest with 132 ppm for the wet zone and 29 ppm : Soils, ground Water podzols, calin 92, 59, 37 and 36 ppm.
O take the same trend.
al and maximum Value Will indiThese values too follow the same r the ultra wet zone, with 32 ppm the dry Zone; while humic soils, soils, and clayey soils have values egree of ammonification.
ximum Value and final Value Will on. These values too follow the ppm for the ultra wet zone, with m for the dry zone ; while humic reous soils and clayey soils have r the degree of denitrification.
24

Page 56
TROPICAL AGRICULTU
When a soil is submerged the cut off and anaerobic decompo Ammonia is the most important
It is postulated that ammonia fo upwards on a concentration grad surface layer it is converted to nit on a concentration gradient diffus the reducing layers of the soil d denitrification nitrate acts as an tulents Of the Soil Viz. reduced ir matter, etc., and nitrogen escapes that there Was no detectable and Supernatent liquid and there was the percolates. This indicates that layer readily diffuses downwards fication, nitrification and denitri During initial stages of Submergenc denitrification, thus ammonia valu fication than ammonification and
At the end of the experiment th for carbon and nitrogen. Eight soils obtained before submergence are
Before Subme. -- ح^م--بہ
C. N. 1. Panagoda - - 3-4 .. 21 2. Bombuwela, Peaty ... 104 . . -52 3. Bibile 0.6 . . 07 4. Peradeniya 2-4 ... -15 5. Kundasale - - 0.8 . . 09 6. Matale 1-3 . . s 7. Ambalantiota, li 2·4 。。 19 8. Ambalantota, 2 2.2 17
1. Panagoda—net denitrification
in the wet soil; . Bombuwela Peaty—has a hig ... Bibile-C/N ratio before Subn
to 10 ; 4. Peradeniya—has a net denitrif 5. Kundasale-C/N ratio before
raised to 10 ; 6. Matale—has a net denitrificati . Ambalantota 1-has a high it 8. Ambalantota 2-has a high ir
7
250

RIST, VOL. CXVII, 1961
xygen supply is almost completely sition of organic matter sets in. product of anaerobic decomposition.
rmed in the bulk of the soil diffuses ient. When it reaches the Oxidised rate. The nitrate thus formed again es downwards and When it reaches enitrification takes place. During oxygen donor to oxidise the constion, reduced manganese, oxidisable as a gas. It may be mentioned here unts of animonia or nitrate in the no detectable amounts of nitrate in the nitrate formed in the oxidising and is quickly denitrified. Ammonilication take place simultaneously. ze there is more ammonification than es rise ; later there is more denitrithe Values for ammonia fall.
le soils were air dried and analysed which gave values lower than those given below:-
r'ge:P2Ce After Submergence
Y رN ר CJN O. N. CIN
I6 - - 3- II. . . 19 . . 16 20 . . 9.8 . . -50 . . 20 8.5 . . 0.6 . . • 06 . . III 0 16 . . 2-3 . . 14. . . I6 . . 9 . . 0.8 . . - 08 ... 10 IO .. 1.2 . . 12 ... O 13 . . 2-3 . . 18 ... 3 13 . . 2. I6 13
of 181 ppm in percolate and 163 ppm
n initial nitrogen content of .52; hergence is low-8.5 and it is raised
ication of 231 ppm in the wet soil;
submergence is low-9.0 and it is
on of 243 ppm in the wet soil; hitial nitrogen content of .19; itial nitrogen content of .17.

Page 57
THE RELATIONSHIP BETWEEN CELEMICAL A TICS OF PADDY SOILS IN THE DIRY STATE
A high initial nitrogen content or a either in the wet soil or in the perco detectable losses of nitrogen on sub. SOils.
These findings are of very importa it was believed that deep-placement vent loss of nitrogen due to denitrif this experiment that even with deep zer's denitrification still takes place ; cation of ammonium fertilizers are denitrification is beneficial as it Oxid ferrous iron which may reach toxic p concentrations. The peak values of th 28 days; during this period the young flux of increasing reduced products. is that the toxicity due to reduced certain parts of the ultra wet zone, soils submerged for some length of t before transplanting.
Reduced Iron-Water Percolates. T little ferrous iron could be expecte maximum values are highest for the as expected it is lower for the wet dry zone 38 ppm and least for the c. humic soils, ground water podzols, values of 158, 75 and 91.
The final values too follow the sar
The difference betWeen the initia amount of iron reduced and broug between the maximum and final va iron oxidised. These values too follo
The Oxidation of the Once reduced
CaLSeS :
(1) Denitrification. (2) Oxidation and precipitation in
conditions prevail. (3) By the slow diffusion of atmos Of these oxidation due to denitrifi
Reduced Manganese-Water Perco like ammonia and reduced iron. It

NID PHIYSICO-CREATEMICAL CBLARACTIEIRIS: AND ON CONTINUED SUBMERGENCE
high value for net denitrification late or a low C/N ratio will show mergence by the analyses of dry
nt practical significance. Hitherto of ammonia fertilizers will preication. It could be inferred from -placement of ammonium fertilihence the rate and time of appliimportant. In certain instances ises the reduced products such as roportions, and keeps them at low he percolates are reached in about g rice roots are subjected to an inThe practical significance of this products, which are observed in may be averted by keeping the ime till the peak value is reached
he initial values are low as very id on a day's submergence. The ultra Wet Zone With 252 ppm and zone 159 ppm, still lower for the alcareous soils with 7 ppm. The and clayey soils have maximum
me trend.
and maximum values gives the ht into Solution. The differences alues give the amount of ferrous W the same trend.
iron could be attributed to three
the surface layer where oxidising
pheric oxygen. cation appears to be considerable.
late. Manganese does not behave appears to be closely connected
25

Page 58
TROPICAL AGRICULT
with the initial pH, total mangane content. When considering the 1 percolates it is evident that for m must be sufficient total manganes amount of carbon. The highest v wet zone where all these conditic 26.7 ppm with a high initial pH o 12.3 ppm as the total manganese
From the analyses of the dry it appears that the following soi Panagoda, Bombuwela Peaty and
* Oxidisable Matter-Water Perco a measure of the reducing capaci pattern of ammonia and reduced
Conductivity-Water Percolate. from the rest as it measures the i clayey soils which may contain soils, dry zone soils, ultra wet zo and ground water podzols.
Wet Soils. The analyses of the the average of the groups are give shown in figures VI to XII. The v iron contents behave differently
Ammonia-Wet Soils. The initia nitrogen content of the dry soils for the clayey soils, dry zone soils trend for the final values. The d and the maximum values which fication that has taken place and t Values and final Values Which Wj converted back to the original fo
Reduced Iron, Reduced Mang: in pH demands special merit. The the initial pH and the increase i greater is the increase.
Initial Values of irOn Seems to di The maximum Values and the fi. content. It is of great ecological amount of iron reduced in the S
252

RIST, VOL. CXVII, 1961
se content of the Soil and the carbon naximum manganese values of the anganese to come into solution there e in the soil, a low pH and a certain alue of 41.8 ppm is obtained for the ins are satisfied. Dry Zone soils have f 7.28. The ultra wet zone soils have 2Ontent is low.
soils, water percolates and Wet Soils ls may be deficient in manganese :
Bombuwela Sandy.
late. Oxidisable matter which gives ty of the percolate follows the same
irΟη.
Conductivity behaves differently Onisable salts. It is highest for these chlorides, then come the calcareous ne soils, wet zone soils, humic soils
wet soils are given in table V, and an in table VI; these are graphically vet soils and more particularly their from the percolates.
all values appear to depend on the . The maximum values are highest 3 and humic Soils. There is a Similar ifference between the initial values will indicate the degree of ammonihe difference between the maximum ll indicate the amount of ammonia rm too follow the same trend.
anese and pH-Wet Soils. Variation re is a negative correlation between in pH. The lower the initial pH the
spend on the free iron oxide content. hal values depend on the total iron importance to note that though the pil depends on its iron content, the

Page 59
THE RELATIONSHIPBETWEEN CHEMICAL
TICS OF PADDY SOILS IN THE DRY STAT
iron brought into solution depends iron is brought into solution. This is
Group I
Group 2
Group 3
Group 4
Group 5
Group 6.
Group 7
The clayey soils with a reduced i
91 ppm in the percolate with a high Zone soils with a reduced iron conte of clayey soils) has as much as 252 pH of 4.84.
The peak values of reduced iron pH, the largest values are reached w in other Words the amount of iron b1 to the increase in pH.
From the fore-going results it is gence as well as the inter-relationsh chemical properties play a significa which result at different stages of su Soils under fields conditions-Wet S not possible to freeze the chemical State have been Studied under cond From this experiment it is evident for a specific soil group depends m gence. Once these curves are constrl for specific soil groups the chemical which the rice roots will be subjec growth are known. The analysis necessary to characterize the soil predicting the chemical and physic
ACKNOWLE
THE author is greatly indebted to
valuable suggestions, encourageme) Panabokke for the very valuable c due to Mr. I. B. Navaratne, Labo willingly assisting him in the chem

ܨ2.
AND PHYSICO-CHEMICAL CHARACTERS
TE AND ON CONTINUED SUBMERGENCE
on its pH. The lower the pH more clearly shown in the table below :
Maac imnauna, Maacmaauma, pH of Fe ppm in Fe ppm in dry Soils
percolate avet Soils
252 . . 2,157 . . 4.84 158 . . 3,042 . . 4.65 75 . . 21.0 . . 5.47 159 . . 4,885 . . 5.65 38 . . l,825 . . 7.26 7 . . 930 . . 7.78 91 . 5,162 6-22
ron content of 5,162 ppm has only pH of 6.22, whereas the ultra wet nt of 2,157 ppm (less than half that ppm in the percolate with a low
in the percolates are correlated to ith the lowest pH and vice versa or Ought into Solution is proportional
evident that duration. Of Submerips between chemical and physicoint role in the chemical equilibria ubmergence. The analysis of paddy tate-is rather impractical as it is equilibria. Paddy soils in the wet itions which permit such analysis. that the status of any constituent tainly on the duration of submerLucted under greenhouse conditions and physico-chemical environment ited to at different stages of their of paddy soils in the dry state is
group and is alone sufficient in p-chemical status on submergence.
DGMENTS
Dr. F. N. Ponnamperuma for the nt and guidance, and to Dr. C. R. liscussions. His sincere thanks are ratory Assistant, for so ably and ical analyses.
253

Page 60
254
5o
125
| OO
75 -
25 -
TROPICAL AGERICULTU
NH - WATER PE RcoLATES
Pp vin - N
P. p.m. N
28 53 84
Days from subme
FIG
1. Strongly acid lateritic rice 2. Strongly acid humic rice st 3. Ground water podzolic rice 4. Acid lateritic rice soils oft 5. Non-lateritic rice soils of t 6. Calcareous rice soils 7. Non-lateritic clayey rice so
 

RIST, VOL. CXVII, 1961
2. 4o #GG 96.
rge race
URE I
soils of the ultra, Wet Zone pils
» soils
he wet zone
he dry zone
ils

Page 61
THE RELATIONSHIP BETWEEN CHEMICAL TICS OF PADDY SOILS IN THE DRY STA
fe * * - WATER PE R colAres
566 4
Ppm - Fett
*P* F。**
28 56 84
days of A om subreger
FIGU
Strongly acid lateritic rices
Strongly acid humic rice soi Ground water podzolic rice Acid lateritic rice soils of th
Non-lateritic rice soils of th
Calcareous rice soils
Non-lateritic clayey rice soi
 

AND PHYSICO- CHIEDMICAIL CHARACTERISTE AND ON CONTINUTEID SUBMERGENCE
3ence
RE 2
oils of the ultra wet zone
ls
soils
Le Wet Zone
e dry zone
ls

Page 62
TROPICAL AGRICULTU
MM rn - WATĚ R. PE R co LATES PPm NAゆ
5ර -
Pрит Ми
I I 28 56 94.
Deys from Subrine
FIGU
1. Strongly acid lateritic rice
2. Strongly acid humic rice so
3. Ground water podzolic rice
4. Acid lateritic rice soils of til
5. Non-lateritic rice soils of th 6. Calcareous rice, soils
7. Non-lateritic clayey rice soi
 

RIST, VOL. CXVII, 1961
R>-------
s o | dع
erge Me e
RE 3
soils of the ultra wet Zone
ils -
soils
he wet zone Le dry zone
ls

Page 63
THE RELATIONSHIP BETWEEN CHEMICAL A
TICS OF PADDY SOILS IN THE DRY STAT
Oxidisable Matter Water Percolates CCS. KMnO 0 0 N Per I0 CCS.
of Percolate
CCS. KMnO, O-ON
o 28 5é 84
bays from subney gene
FIGUE
1. Strongly acid lateritic rice soil 2. Strongly acid humic rice soils 3. Ground water podzolic rice so 4. Acid lateritic rice soils of the 5. Non-lateritic rice soils of the 6. Calcareous rice soils 7. Non-lateritic clayey rice soils
 

NID PHIYSICO-CHIFEMI('AU, CHARA.CTERIS--
AND ON CONTINUED SUBMERGENCE
2 lao l68 19து
E 4.
is of the ultra wet zone
ils
wet zone
lry zone
257

Page 64
258.
TROPICAL AGRICUL.
Conductivity of peycolates
řwn mierom hos
micvom hos
35ool
5.රථ -
חן ר O 28 36 84
days from
FIG
Strongly acid lateritic rici Strongly acid humic rice Ground water podzolic ric Acid lateritic rice soils of Non-lateritic rice soils of Calcareous rice soils
Non-lateritic clayey rice is
 

URIST, VOL. CXVIII, 1961
I 2 事4C 68 96.
Svakomer 90 mee
|URE 5.
a soils of the ultra, wet zone
soils II i 1
pe soils
the Wet zone ' ' ' ' ' ' ' the dry zone
oils.

Page 65
THE RELATIONSHIP BETWEEN CHEMICAL TICS OF PADDY SOILS IN THE DRY STA)
3oo
266_
so
too -
So
N - W2 - Sol pop FYN A
Pp闷岗
I T 28 56 84.
Days_ FYomn 36z
FIGUE
Strongly acid lateritic rice sc Strongly acid humic rice soil Ground water podzolic rices Acid lateritic rice soils of the Non-lateritic rice soils of the Calcareous rice soils
Non-lateritic clayey rice soils
o
 
 

AND PHYSICO-CHEMICAL CHARACTERS
E AND ON CONTINUED SUBMERGENCE
~—
T | سمه
12 4-o 168 い9és
komer 9 ence
E 6
ils of theultravet zone
S
oils
Wet zone
dry zone
259

Page 66
TROPICAL AGRICULTU
- fe - Wek soil Sopin fe t' + FP ከ re
5000 -
4000 -
3ooo
2Ooo
a COO -
Days from sz
FIG
Strongly acid lateritic rice Strongly acid humic rice so Ground water podzolic rice Acid lateritice rice soils Of til Non-lateritic rice soils of th Calcareous rice soils
Non-lateritic clayey rice so.
260
 

IST, VOL. CXVII, 1961
t4O 69 196
bmergence
URE 7
ܐ
soils of the ultra wet zone ils
soils
le wet ZONE)
e dry zone
ls

Page 67
THE RELATIONSHIP BETWEEN CHEMICALA
TICS OF PADDY SOILS IN THE DRY STATE
M. we Soil
ppm Mn
5 රදා -
4oo -
3co
2Oo
PPr M.
ce-しっ下
I
2s 56 84
Days from 3ukner gene e
FIGUF
1. Strongly acid lateritic rice so
2. Strongly acid humic rice soil.
3. Ground water podzolic rice s
4. Acid lateritic rice soils of the
5. Non-lateritic rice soils of the
| Calcareous rice soils
Non-lateritic clayey rice soils
 
 

NID PHIYSICO-CHIEMICAL CHARACTIERISAND ON CONTINUED SUBMERGENCE
/2
I 2 140 168 (96.
த
RE 8
ils of the ultra Wet ZOne
s
oils
Wet zone
dry zone
26.

Page 68
2
2
-14
TROPICAL AGRICULTU
Oxidisable Ma KnO, o.o.
2% S6 8.
days f
EIG
Strongly acid lateritic rice Strongly acid humic rice is Ground water podzolic ric Acid lateritic rice soils of t Non-lateritic rice soils of t Calcareous rice soils
Non-lateritic clayey rice sc
 

JÜRIST, VOL. CXVIII, 196l
tter - Wet soil CCS
N per gram of soil
na o če ž rom submergenee
URE 9
soils of the ultra wet zone
oils
» soils
he wet zone he dry zone
ils

Page 69
THE RELATIONSHIP BETWEEN CHEMICAL
TICS OFIPADO SOILS IN THE DRY STATI
p* - et Seil
T -- 28 56 84
bays from submergen
FIG
Strongly acid lateritic rice is Strongly acid humic rice so Ground water podzolic rice Acid lateritic rice soils of th
Non-lateritic rice soils of th
Calcareous rice soils
Non-lateritic clayey rice soi
 

AND PHYSICO- CHEMICAL CHARACTERIS E AND ON CONTINUED SUBMERGENCE
ノ一つ
UERE II 0
soils of the ultra, wet zone
ils
soils
le Wet zone
e dry zone
ls
263

Page 70
TROPICAL AGRICULT
重姆 - - a pa
*200 一
* OO -
O -
- too
- 2 OO -
- 3oo
- - - - -
O 2 4 6 8
FIGl
Strongly acid lateritic rice Strongly acid humic rice is Ground water podzolic ric Acid lateritic rice soils oft Non-lateritic rice soils oft Calcareous rice soils
C
7. Non-lateritic clayey rice se
264

URIST, VOL. CXVIII, 1961
7.0
4. 28
ubrnevgance
سر \{1 - ܐ URE I
soils of the ultra wet zone pils
» soils
he wet zone
he dry zone
ils

Page 71
TEE RELATIONSHIP BETWEEN CEMICAL A TICS OF PADDY SOLS IN THE DRY STAT
Eh Eh d
- I 45O صے
- 75
- 200
- 225
days f
FIGUR
1. Strongly acid lateritic rice so: 2. Strongly acid humic rice soils 3. Ground water podzolic rice sc 4. Acid lateritic rice soils of the 5. Non-lateritic rice soils of the 6, Calcareous rice soils 7. Non-lateritic clayey rice soils
 

ND PRHYSICO-CHEMICAL, CH ARACTIERISAND ON CONTINUED SUBMERGENCE
t pH 7-0
| 2 tao na 94,
orn submergence
E 2
ils of the ultra wet zone
pils
wet zone
dry zone
265

Page 72
TROPICAL AGRICUL
—smos oog omožnoɑ ɑnɑɑ sumō) (8) 9·886-9 I 19. gĪ IZ-ĦI |g-88 |g-ZI | 8.802.00900- | ††000. || 00-Z | Of...I9-3 || 8-03 |0ZZg-†-0 I |g9.Ť----Āŋɛɔā esowanquos *I —8140S 90??I 04 wwm. H. pyɔF fiņowo,S' (z) 0-2. I |g-9 ||9-18 |f-8Ť |0.0Z | g-s |g. I |z|).00810. |0.3000 || g2-3 |86. I || Z. I |z-9 |gIZI- || 8-I |#I.g----eųouȚđẹIeys of g...8% |998-f8 |0.g8 |g-03 ||9.gI |8-8I |#802700- |g9000. || 69-II |zs. I9. I/*/,gIZI-3·z01•Ꭽseu esede W og 0-18G・88.9% || Z.9% || 0-681.#g. II6009ỹ0- |02.000 | 08-ff |gg.js6. II.6II/. Io6. Ig9.jsoutros IĮIN oz. 0-8 I || 8.98.6% |8-off |g.isI || 3-1,8 |† -80907900- |ZZ000. || 98.0 || Zg:0/-06:1,9IIZ.动的98, †sepoobutjà “I —øư0Z 12 AA aeqn øų po 8140S 90\%\ 0\qquoqm pļos fissuo45' (L) 斑 cae将艾章短趾斑工山江工山-强© ©-江工山玲旺亚-旺∞© |sg疆隱隱隱飄》臘躍躍 圈 z 圈。 ***珊娜娜娜*******而澀下副 劉。弘****臨「躍*啤無疆腳而一± Þo创oto这( so|-
SIỊ0S ÁIQI-I GITAVI,
266

URIST, VOL. CXVIII, 196l
震%" g. 89 || 8-s. 18.0% |foo.s.Z-8ZI !9.g. I 19-0 || Z900180. |�. || 00.9 |z| -8 |6.gI || 2.93 |ęIZI-z-Z IZ0-9 || ° °* * *z gļoque sequus oz. 0-09 |g-II |ĩ.8% |8.6g-99 I || 0-03 || 99-0 |9900380- | † 8.000 | 88-9 |g3-8 | 1,- gI || Z. 94 || 8I6I.球创,8寸9 :* * * I 840ļusesequus 'I —81\oŞ əəŋŋ fƏfioso oņuəŋŋ1-ưON (Z) 3.#L || Z.8 || Z-88 || I-g8 || 3-871 ||9-33 || 0-†8g00ỹ30. || 96000 || 66. I 190. I || 9-0 I || 0-ŻI |660.8-08/,''], |, o----suļļos” “I -|-—8140S, 904, 8 noɔɖɔɔŋŋƆ (9) I-93 | f-g, 18.6† |f.f1 | 0 || I || 8-9T-ZI800490 |ZZI00 - || 8Z-8 |00, I || -66-1, I |0I60-6-068./.. | ''Áørs) eures[ođđnȚII BUĻBIN ‘s 的9Z,28,908 f0888 I || 8.8 || Z.I6900690- | †8000. || T8-8 ||08-Z |8.gI-ŤI - || II10.3.0 || 88.9 - | * *pə’s eureIIeđổin III BUĻBIN ‘g 0.9% || 0-8 || 0-†† |0.gz |6.6ZI | 0-9 || Z.I!%008307 | 88000 | 2,8-3 |g9-0 || I-01 || -9 I || 8I0I.8-IZŤ. Z | " "* - epo5x{ernouỊH ‘Z 0-03 ||9-1Z.9† 18.ţZ || 0-86 || 6-ZI |g-Ig8008/0- |0II00- || 89-Z |Z6-0 ||9-0T |g.isI IZIII-8. I ||08-1. I o ‘* * '8AAn IỀUIUIO!0ā “I —ow02, fi, aqq fo sųoŞ øoss 04440401-ư0 N (g) 0.8% |0.g. 18.0† 19.08 |g-Ig ||9-ZI | 6-T |8900390, |00|00.. | 09.fj | g8-Z |g.g0-60I0I40. IIs-g | * *----sepuose N ‘9 0.1% || 0-2g. 93 ||8. f8 || 0-81, 1978 || !...I |3901.150. |99000. || g7-f7 |Z9. Z 10-8I-ŤI |0I£I-, , 18-I889 |“”----ə[848]W og g. 83 ||9-9g·s3 |g-g8 |Z-8ZI | I-8 I || 3:0 || 7800I90. |8I000- | †† . f. || 0g. I || 8–6 || 0-8 I |660 •8-0 |09.9 || ~ ~- -əlɛsɛpun XI off 0-08 || 0-93 || Z.g3 |g-8 I || 0-06 ||9-9 |f-I6900980. IZZI00 - || 89-1, |SZ-g | g-g ||9-8 I 19IgI.†-Z |gg-g | " "- -seĀŋuɔpɛ sɔā ‘8 0. LI | 9.9Z. Is |g.gg | g-Z8 |6.9 |6-8!900ỹ80. |Z8T00. | ĝ0-Z |88. I || 8-4 ||0.gg·32,0•9-0999):- -Ə||0||8. "Z g.g., |f(-ŻI || 2-08 |Z-63 || 0-88 ||9-23. I9800I90. 189000 || 8T-9 |g8-† 16.5 |g-II |g-ZI IZI-g. I08. g | * *- -£p£Uusso AA ‘I -—øwoZ. sɔAM aqq ļo sīļos aos oņuosus pļos (†) 8-889!,-68 |iso6s ||9-9I.9 || 1-0 |0ý00680. || 99000. || 89.0 || 9,3-0 || 8-0建T0I80-8.0Z8.9。一:- -seoseo!!??!!! oz. 0. I0.8 - |g-g8 |g-8g || 0-1.I-1, |8.5#800ỹ00" |6Ț000. || 89-0 ||03-0 || 1-0 |Z-I |g|I†0.9•በzọ.G | * *A pusaq arawanɑnsɑɑ o'r

Page 73
THE RELATIONSHIP BETWEEN CHEMICALA)
TICS OF PADDY SOILS IN THE DRY STATE
g1990: ‘ ’ 6” . ZIg@0.- * * #9 09970, ' ' 88 00ĝ00 • ” ’ 0s, Zgs,[0,2 ° ° 38 %
%�H I'{3}OJ,
ou W 1840J, o H 99), H.
• ULICÍCHĮoş olu)? IIOS ‘UULI? oos[IS OOI Ięd 00Ī Jod%% əIqes së Av rettroposso), ’o’tu’O'GH'O Á BIO% NGUIOQ IB
sə3es@asy-SIỊ0S ÁIQ-II CIVIZIVJ.
S KSYYL S 0S0 S 0SLL S LSLL S 00S S LSL S 00S0 S-- --ƏUIOZ KICI eqQ Jo sīļos aos osąsieges ūON YS00 S LS0 S 0SSL S 0SL S LLS S SL S 00S0 S• •oUIOZ QoMA ots! Jo SIJOS 90IH ɔsɑsɔqes proy ----ĝ1,29Ģs,-0----8. I----寸Z°。逾80• •970- ----Af况SIJOS90s!!!0||OZpoễIJ948AApunois) S LS00 S LSL S 0S00 S 0S00 S 00S S LS0L S 00SS S----(Isos əuo) SIJOS 90ț¢I osuun H psov KĻĢūorqŞ · S LSL S LSL S 0S0 S 0S00 S 0LS S LS S L0S SoUIOZ 40 M €IQIQ. ©UĻ
JO SIJOS 90s oņs:1948.I pỊoy Ásou o IQS
{)Hod
og
*ţ
og
 

NID IPIHIYSI[CO-CHIEMIIICAL, CHARACTERIS—
AND ON CONTINUED SUBMERGENCE
0ĝI80
005740
6.g
89
8-ZË I o ‘
3・g 、
8-ġI
ĝ-0T
· 1,9%
0.2% I
8寸9
8-ĦŻI
8I>
60 •
的Z
8-0
ZZ • 9
8s,os,
• •
SIĘoŞ ɔɔŋI ÁÐÁ,810onționatuon’l,
(Isos euo). SIJOS 90s I snoə rəə[80 · 9
267

Page 74
TROPICAL AGRICULT
CN. N. SOUIUIOJo!UI Loug 密器 . Αν Χετα μιp pτιορ GN -
བH གང4 SOվաOIOյա "XՅա 宝滨 ?S? IBIQUII JĮp "pUIOJO r r
窃$ SOUULIOOTUI TUIJ "pU00 Src)
A C SOUUUII 运é -UIOIOUI X3UI pUIOO Cది GN
H. So OUUI -UuOIOUI o?UI 'puOO
W · <° ʻXO Iʻ8UIJ 2S? ʻX8UII "JJICI ත වූ
"IJNI ʻXO "X8UI 2y I8||9|UII. JICI
GP GP *WL "AIXO IBUIII ඝ ඡ;
r
A. 1ధి అp IWI "AIXO "XEJN 斜否
শুe Qম "JN : AXO [81)IUII αο Es
UUIdd. স্ত্রণ সেন্ম = - ܒܚܛܗ 으 UIWI IBUIŲJ yo "X"BULL "JUJICI ས་ཁ4 융 UUIdd. ° 3 密 UIWI "XIBUUNI 2Ņ? IBỊ4ĻUI Į JĮJĮGI A. - 3C CO 窓 UUIddi UI JWI LEUIIH -- ܒܛܐ
ಡಾ. sh GN s UUdd UIN 'X'8W 8 .
UUIddi UIINI IEĻ4ỊUII C. N. 1
UUIdd 奈ま Q 9 || Lou!} ? "X8JA JICI r-H GNI ( s
Udd 0 爱 溪 "X8UI 2y Teg9|UI! ’JICI 二蕊
udd eH IBUIII 器运赛
- ~NH C> A. udde "Xel'N 器器猫
A) AG) C UUIdd ƏHI IBIQUII as r
N. UIdd'HN 安演3 Ieug 2 'X8UI JIOI
N. UIdd’HN ཕྱི་ "xeULI 2Ņ? Ite!) IUI Į 'JJIOI LA SS § දි ';
N UIdd'HN euII
葡 di O C. N u dd'HIN * XeJW ལོ་ཡི། །
预 2 - L IN UUIdid “HINI [BỊ4ĻUII OO
S - "SR S 闰
S ཚེབྱེ་ཙོའི་ 業達ーミ譜器 s & S N 蚤 菲
TH GNI C حصبر
268

JRIST, VOL. CXVII, 1961
698Z.10 I 1819Līgs sg.liff0S 0S0 0S0 0S0 0S0 0S0L S00 S00 KSLL 0S 0LL 0S0LL S00 S00L S0S0 00 00 00 0L KL S LLLLLLLL S 836 I || 691,000L 000L 00L S0S0L S0S0L S0S S0S0L S0S S0S S0S0S0S0S S0S000S0L S0LL SLL 00 K0 0S0 00 00 0Y 00 00 SƏ[[q}{[ 'Z 898000 000 00LL 0LL 00L S0S00L S0S S000S00 KK S0S00 K SKSK YL S0L S0LL LL S00 SII | 88 | 08 ||IŤ |8* * eposūȚIoAW 'L –9ư02 40AA øų4 fo $1?0S, ɔɔŋI 0!!!.do??? pyɔ so (†) ĝ8g00L L0L 000 L00 0S0 0S0 0S0 0S0L S0S0L S 0SL 0S0 0S0 0SL 00 LL0gz |Z8 |0. I ||sz İzz || I ||IŤ || 6 || || ' ' ’80180!!488 og 990 I |#08 | 6f8ĝIf I || IIII || 8.9 || 9.9 - ||0.5 || 8-0 I |8.57 | 9. || Z. ... |09:0 |†.0 || 6? |g9 = | ŞI || 9 ||z ||I9 || 6 ||g|| |9| |12 || • •Ápūtęs -BioAnqULIO!H ‘L —81ț0S, -· - ··øoys oụozpo, I ! woŋAM , punoaes) (8)
[88gIZ8/.../.†09I |688 I || 1.9 || 8. || || 0-8 || Z.f. I || 6-9 || f. || 0 || 10†-0 |†.0 |ɛII |g-6ĝI |gf log I |g.ŞI |z|, |z|9 ||Og |Z6 108 || • •Áļ80&I
'819MnqUCIOȘI (I . —81ț0S,
|-90% I 0!!?!!?! H.
pț0},fisốwo)/S (Z)
808 I ||I68 I 1836[8ZZ |0f8Z-IT | Ț -II || 0-9 || 1.9I |8-g || 6-3 || 6-Z | S-0 || 2-8 || 8:0 |zo I || Z.Iz9g | SIz 10. I || 0:2 | $3 | 9† 19II || 32 || ~ ~ 'eqɔusseïeys of 99TI 1909 I ||008996 I | 09f7goj; L | † • V, I || 0-0T | g-soo | T. 2. || 0-8 |#. I0.8 || 9. Ț || @TZ | GoziKJ LLK L SLL LLLL LL LLL LLL L S LLLLLLLLLL LL
O

Page 75
THE RELATIONSHIP BETWEEN CHEMICAL A
斑
<结
甲上
Ú/2
文 此,0383 ©
甲士 * 888 工
(No. 8
五2,9 3 ** 斑
©
<
sną
卫
○ 관gzI Ứ} † [8I C) No 948 I 甲
I88 I 989 I /, /, I
ZŤg I
09II 1,96
II9L 90ŢI
ŹT/, 80), /96
2,988
Ɛg0Z
9球9T
ĝ89% 0I/%
2,48||
f62
Af
60I% £I6
989 [88 990's
6.8
8.), 2-6 89
60 •
0.8 /;-&I 6建
0-9
07 09
02 09 0-8
8.II
0-0 I 8.0I
8-6 !, ¡I 8.8
0-0T 88
8. I 03 6-8
8[建 /-98 †-8I
建武
627
6. ÞI 8-9%
0.gI 8. Ig T-TZ
遍2T
02
3·9 88
Z8 90 9.ţ
8km
0追寻 闵28 0.8%
T-Z 寻3
0-08 69 6. I
球3 9%
IĝI †), I 99
Å9 230% IZ |g|I 969 |93 寸9,08 /6I9惑 ĝojo. Z | Ig 8623
23 IZ
09 逸9
1,6I ĝZZ 86
9:0 0-I
ĝ.8%
†%
9·38
ĝI 9·6 83
9-13
9Z
追寻8 I3
993
g. Z8
g.gI
g-ZI 6L
9% g-ZZ
!8
08
ZI
遍寻 83
Iý Z8
9:6
9.gI
追建
—8140Sm 20??I fiosono 9???-1940?-?) 0 N (2)
-'.ouįgoÍo-I --8140Ş 20??? 8??03:09100 (9)
KəIs) būIBIŢeđ -Ĵn III BUĻBIN († pə’I GULI?II?) -đņIII€ĽĮŁ W og sep05}{3InãUȚIEI · * * BAA mī£ūUOIOI • –9ư02 f,T os? so 87ạos, 90??? ???, ?????-wow (g)
r=ill (N
- -ህዜ)UIህIህMI '9 ----o[848 W og o o osoɛɛptIn|XI. (†
 
 

INID PHIYSICO-CHEMIIICAIL CHARACTERIS
AND ON CONTINUED SUBMERGENCE
096I 8393
098 8303
600 I !fgr
696Z 01.0†
60 IZ !, ¡OZ
89 T-9T
6. I 0
0.8 0-†
88 I-03
6-9 I-0Z
球63 に83
93 9-0
9-Z 8. I
O·33 g:08
0:4 0-08
8! !9
00I Z!
g, IZ
80I 82.
0-8 0-9
83 83
9-og ZI
0I II
88 #8
9.g Źź
Z 840ļue sequusy oz I (8404ūtī£qūIV "I
269

Page 76
TROPICAL AGRICUL.
*SOUIUIOJOJUI [eug $ 2? : XoUI : Jp : pO) (
SS - 1 a
*SOUUUIOJIGOIULUI : XeUUI 2 e2!UII : Up : puOO
SO i -UIOOTUI IguJ : puOO
중 ܕܗܝ "SOU འཁ44 s -UUIOJIOIUUI : Xt3UUI : puIOO (N yr R N g
SOU 。 -UIOIOIUI. I.e.9 U : puoo r
Ieqq “3U I : Axo ଜ୍ବଳ R [reu-4J ?y? : XBULI : JUICI 二
IƏ??) BUUI : AIXO ధి Q : x8UI 2)? ТврдU I JICI S
O J999 bUCI: Axo Ibu αο
Ie99 euII : Axo : xeWI t F
g C 岛 Le4qou : Áxo [e!quI Rদেউ
s UICd అp 3. ULWI L'EUILJ yo : XeULI : JIOI 二 Uudd UJA C) 3 Xeu y Tou! :4ICI Cמכ SS ܧܡܒܛ용 Uudd uW Leud
を (:༠ དང་ A. UUIdd UWI : XEWN に
གྱུ་ 滨 UUIddi UIVALI IEITĮUII GN こ > UUIdd 容 空
ƏHI IBUIJI 2Ņ? :: XBWI : JIOI t
= AG UUIdd Ə 烹调 さ S : XbUI AP I914 IUI : JICI AA
ULIddi ə IeuII 器
UuIddI eH : XeWI 影 赛
C Ω ULIdd əHIe4ĮuI xබ් α.
NI UUIdd OO (N I8UIJI 239 : X'8'ULI : JJ!OJI N- ག། UUIdd 용 邻 : xeUI ? Ie!)ȚUI : JICI
ཁ4 に NI ULICdd “HINI IEUE ΣΩ
GN NI ULIđđI "HINI : xew လျှော့ 3
N uIdd "HN reInput 器 윤
憩強総 : A 強 選弱陡 因發 F-1 選選華 選8毛 圣阁日 < 爵爵 塗s選自ら電器 醤涯 リ 8 km 圭装 N SS
± CA び2
r- ৩d
270
 
 

go | ZZ || II |98 |#| |" oSIĘ0$ 90ļos
KaÁt:IO ɔŋsƏŋɛI-UION */ g.gz |g. sz. Íg.gI || 3 |g-6 |(Īsos əUIO) SIJOS
Ə0ļosSn09.180Į80 °9 - -əuoZ KICI QUI? JO SIĘ0S
əəĮs oņȚIəņēI-LION og KLLLL00L 000 000 000 0SLS0 KS LLL 0S0 0S00 0S0L S0SK 0SLL 0SLLS0LL 00LL 0L 00L K KL 00 00 0L S0L SQUIOZ ļəAW 9ų į JO SIJOS
wəoss ogļļū34 es pļos o gŹ8 |gg|Ø/ZZ8!ȚII |Z688-9 || 9.8 |g-† 18.0I || Z. 1. ||6. I ||0. I || 8. || Z.Z. İZ-I || 89 |8|.zz g2 Z,8寸 989T,698Z:SIĘ0$
·əɔs ɔĮOZpočŁ
JƏ48 MW.punois) o
arrano arra",
000LS00LL S00LL L000 0000 0S0 0SL 0S0 0S0 0S0 0S0L S0S0L S S0S00 S0SLL 00 S0083 ||I6
000KS000L LLLL 0000 0S0 0S0 0S0 0S0 0S0 0S0 0S0 YS S0S 0S LS0 SL!9!
000 S00LL 00LL 00LL 000L 0S0 YS 0S0 0S0 0S0 KS0L S0S0L 0S0 S0L S0S0L 0S00 00 00 S 0L 0L SLL S00
H
NURIST, WOL. CXVIII, li96I.
සදා
--~~~, 1 ------· · ·.............--~~~--~S S S S S S S......S S S S S S......- ... ~-------~~------------

Page 77
THE RELATIONSHIP BETWEEN CHEMICAL A
女星
... → o
... u s
v_f ,
~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~--~
玉Ōot 1. I U U~ ,; I covo (+ 1 >: " Ởu” ở¿3 * 1.or yƆ * 1.urouL’o:-)±トg∞ 1.Ujae ). 홍8130S 个ø04), 0\qozpocs toņoA punois) (8) 0 LSLLLS0SLLLSKK 0S0JS0S0LL K S 0S S 0 SL00 LL S000K KL00 SL00 S00 000 00L 000 S00 SĀŋɛɔā eso AnquIOĶI "I 文-sąos aos oyun H pņos, fisốwo, S (Z) 斑送*******************ogųousseïeys of 00SLLL LS0S K SLS S00SY00S0S0 S S0SK S0L 0L 000 S0000 S0000SSL0S00S00L S0L SLL 0L 000 S00o o seu eIodess og 丑03. I |gf .9 |g9, † |z| + |g-2. ||9-g |8.6 |g-6 loĝ |0, 183T |39Ī |ZřI 19996632 | Offz | 9008 | 10 I 16 IL 180Z |0II ||633 |93eureāļJĮJN ‘Z Y LSLL SL SLL L S L S 0KY S Y SY0 SLK L00 YL YL0 SK KSYSYKS* - epoầeuea “I Z 0,02 40AM 0.41 (? off so 8140S s=s.øɔŋI ɔɲɔŋm pļos fissuolųS (I) Œœ 五 班()亦一町一班一班一圈一圈一圈一圈一圈一圈一圈一圈一_照,而一圈一圈一圈 ?|瓜謂圈欄***魏一册 -----《一了一,一限耳针一_一限。一部(-) || -祁一部! !一一砲 工,册一郎一期一一心旺一e g田溫田圍氏一斑皿、一正一江* 班| z一飞 후 활|후|國| 활활 환| || 「 「國|환|議| 활|『羅|韓 || } || } |확|환환 활|활|| } © E.- 1 No. 1 - ( i -* 1 : 1 !|-|5} || :|-! !! !! 一圈Ħ| = | = | s | & | & | Ă | E | ±후 || 록 || } || 팔 || : || : :一활 P|-一?母一班E■·BËsae|-· 澤 高_j || E斑一圈一部È | -!》, || - || |= Oo - 1 ,----|× や %概舒Ř疆溪PË辽 } +
SII0S , So WA – 个 SIỊos įsəM-A ATHVJ.露了 -|--, ~--~----sae

NID PHIYSICO- CHIIEMIICAL CHLAR,ACTERIS
AND ON CONTINUED SUBMERGENCE
89-0 !!!!-0
gs-0
Zɛ-0 60.– ĢI
69. I Ź9-I 追寻0 08. I gg. I 09-I
89-I
00-2. 03-4,
g9./.
0,3-2, 08./. 38:2 08-).
00:4 00.), 90.), 98,9
06-9
00-2.
Z惑9 8寻9
06.9
889 68-2. /f/, /, 08.).
0-8 9.8
动0
8-6 I-8
8:3
球8 I.8
8・3
g.g. 9-0I 89 0-6 に8 8-6
Z- I
†-II 1-II
Z-8
89 6-0 I 88 8. s I 9.). 3·3T
动创
I-Z 9.8
6-0
8-Z Q3 8. I A・g 8. I 8. I
0-3
gg 89
9T
13 I 68 $f; 8ZI
Z寸 ĝ6 60I fƐI 29 III
I.9
... --
6II 0II
08
89% gŢI 0I 6.1.
! 9 /j/ 89 IZ !fsl 66
球83 20寸
86
g68 ĝ0% 86
6Z动
08Tl IgI 28I g63 01 I 983
6-8
-r- ----
68Ť 0/ff
† II
339 †6% 9寸T 199
ZZZ 9j3 96% 6.Ziff 18Z 9f8
038 098
f8
693 6ŢI 98.I 82 s
g9I 66|| 88Z 80Ť 06I Alfoz
,ZI ZZ9I
SZI
†gI T93 Ź/
없었9
6IŤ
ĝ994 996 I 8938
6f83
球坛
...
896; 寻9[9
IZ6
Iso, 8I6T Ź8II 806||
0963 8II/, ZOZŤ 1989 1803 861.g
9ŢI
-------
09.18 II68
Z08
1,60% 699 I ZIZI Z9/, I
9692 80s.js 0.89% 8f88 08). I †gg8
03 I
... -r-
130g 8899
086
IgZZ 086. I 寻8ZT †8ZZ
† I08 SQ8に 追寻遍寻 9699 † 9IZ 8889
†6I
m. arz
† 2. 6/8
0I ZI Z0I I88
寸9 0Ť Z  683 !.!.! GS
8f
00I 86
08
8II 89 I IZZ 8ŢI
18 I 8Ť Z 6% IgZ †! Z0I
of I
--~~~~
09% 90%
ɛɛI
ZIZ 闵93 9/13 2,3%
IIZ gȚ8 g8
球83
† ĻI
08L
------
†8I 091
86
6II 96 #8 gII
0ZI 66 92, †ZI g8 90 I
89
球83 893
82.T
18Z 寻93 ĝ08 89Z
!,9% Z#8 90 I ggg 69 I 80%
96I
...!!!
†8 sis
0ý
93 ZI 6% 98
97 !% 0% IZI !fss
z osoque sequus oź I gļoque sequus "I
sųoŞ øøy, stoffm0 0!!!!!!0!!0!-ưON (!)
- -£UųJos os sņ0S 90ņI 8m02./00100 (9) pəys eure IIeđổin III BUĻBIN • Køī£) ĐƯỢI ĐỔ đm III BUĻBIN ‘ sepooyseľnosu ¡H * ĶÅTlJĠUIUIO[0&I o
ow0Z fi:CT
- Q Cది 

Page 78
272
TROPICA, AGRICUL
IBUIJ 2So Loo!UII eou9JoJUp Hd
Ieug. Ed
TepqIuII HIdI
Ι9η μετα : ΑΧΟ ΙετIg 2У UшllUupx8uІ әouәләфуCT
: AXO 2? 3ļļu
առաIXՅա
ƏOUIƏJIƏJțOT
IƏŋ e UUI : AXO IBUIII
IƏqqeUI : AIXO UCIn UUIXEIWL
IƏ44'EUUI : AXO [BIĻUIT
UUIdd UIAL [2UILJ 2S? UUIImUULI JX8IWI :: JUJICI
Udd UIA UInu -IXTEULI 2ẶP LEI IUI : IO
Uшđđ u W Teul
GN
器
UIdd LINunuxeIN
UUIddi UIIWL equII
UUIdd 9H [b2UIJ ?S? : X'8UUII :: JJ IOI
蚕
器
UUIdd ƏHI : XERUUI ?? LEIQUII : JIOI
UUIddi ƏHI IBUI
ལྷོ་
蜀
影
UUIdIôi e,HI : XteJN.
影
UIdd elegru
Ν UUIdd Iʻe3UILJI ?Ä? : XeUUI : JJICTI
UUIdd : XeULI Coyo Iep!!UII : JUCI
N UIdd"HN Iguig
N udd "HN unupxeIA
N. UIdd'HN leguf
 

TURIST, VOL. CXVIII, l96l
|-
) 0S0 LS0 SLS0 0S S0S000 LL S0S00 0LL S000 S00L S0L0 SLL00L 00000 L00 L0L 000 00 00K KLL 00K SL LLLL L0LL LLLL LLLLL LLLSS 8-0 || 2-2 || 6-9 || 7:0 || 8,3 |8,3 || Z.8 || 6:0 |9| | 08 || 86 |#II || #8 |SZIIZ 6Ź08086608 | 88I86g/. I |Off | ([[Os ou O) SIỊ0$ 904’T §noạ sự0Ț80 (9 0S0 0S0 0S0 S00SLS 0S 0S0 S L0 00L 000 000 00L 0YL669 I |989 I || 938 I || 93T |ggĪ | 88Z | 50I || 693 || 9Z | * *ƏūOZ ÁIQI ƏUĮĮ JO SIỊ0$ 90s's 0ļļļJ94BI UION “† 0L S0S0 0S0 0S0 0S0 0S0 LL S00 00 000 00L S0LL SL00L S0LL LL000 0L0L 0L YL S0LL K0L 00K S00 SƏUIOZ ļ9AA ot!? JO ȘIȚ0$ 90s'? I ØļļļĪ948.I pỊ0W “† 8. I || 0-4 || -9 || 3:3 ||9. I || 8. I || 9,8 ||6. I |#0£2.},ĝ98ȚI遍寻T0IZ39 || 0ȚI || 6 || I || 19 | 2,6 I 18I || ' ’ȘIȚ0$

Page 79
METEOROLOG
Summary for Octobe
SOUTH-WEST monsoon weather C too, giving light to moderate rail occasional, scattered evening thul Eastern Provinces. With the Weake the 10th, intermonsoonal conditions and 16th however, unsettled condit resulted in intermittent rain in th showers over the Central, North-Ce monsoon conditions were well est afternoon and evening thundershC the Island. An unusual phenomeno towards the end of the month was several parts of Ceylon for a few during the mornings and the aftern ated from Some local cause, Such a fire and persisted owing to lack of was reported from Gurutalawa ab greater monthly totals of rainfall ( in the Kalutara, Ratnapura and coastal areas received monthly ag. while outside the south-west quart 10 inches. Least rain (totals belo places along the eastern coast. F western and South-Western lowIsland it did not deviate apprec about 18 daily falls over 5 inches, being the greatest.
Intermonsoon conditions were November, with generally wides afternoon and evening. Thunder responsible for a few deaths. O weather conditions became unsett spread rain was experienced in the at a number of stations in Gal Oy of the central hills exceeding 5 i much damage to paddy crops in

ICAL REPORT
r to December, 1961
Ontinued for some time in October h in the south-west quarter with ldershowers in the Northern and ning of the westerly current about ; began to set in. Between the 14th ons, caused by a low pressure area, e South-west quarter and thunderintral and Eastern Provinces. Interablished by the 18th, after which wers were fairly widespread over in which attracted public attention s the occurrence of thin haze over 7 days from the 25th, particularly Oons. It is probable that this originas Smoke from chimneys or jungle Wind and convection. A Hailstorm Out twelve noon. On the 18th. The of the Order of 25 inches) occurred
Kegalla Districts. Southwestern gregates of the order of 15 inches, er the totals were generally below w 2 inches) occurred scattered in Sainfall was above normal in the country, while elsewhere in the iably from average. There were .55 inches at Ronorawa on the 31st
: well in evidence throughout pread thundershowers during the was severe at times and has been Ving to a low pressure area the led on the 19th, and heavy, wideeastern parts of the Island, rainfall a Valley and on the eastern slopes nches. The resulting floods caused Gall Oya Valley and Akkaraipattu
273

Page 80
TROPICAL AGRICULTU
areas. A Hailstorm Was reporte the afternoon of the 18th. The g. the order of 30 inches) occurred central hills, in the Bibile-Amp eastern coast. In the Western low northern and eastern parts the m the order of 15 inches, while between 5 and 10 inches. The rair the eastern half of the Island and There were about 60 daily falls o inches at Irakkamam. On the 19th
During the first few days of De became unsettled due to a low pre fairly widespread rainfall was e ably heavy on the 2nd, particular Pro Vinces and On the north-easte. many stations recorded falls exce in floods in the low-lying areas o. east monsoon was established by in the east and north-east and Over evening thundershowers in the st continued till the 16th, after whi over most of the Island up to the Fairly Widespread rain was again The greater monthly totals of rai and occurred on the north-eastel where over the Island the rainfall inches. Least rainfall (below 5 in north-western province and to th Vince. The rainfall Was above 1 eastern half of the Island, in the in the southern portions of the where the rainfall was below nor exceeding 5 inches, the highest the 2nd.
Department of Meteorology, Bullers Road, Colombo, 22.1.62.
274.

RIST, vol. CXVII, 1961
from Dekatana (Dompe) during reater monthly total of rainfall (of
on the north-eastern slopes of the arai area and at places along the country, South-east quarter and in Onthly aggregates were generally of elsewhere the totals were mainly fall Was above normal Over most of generally below normal elsewhere. ver 5 inches, the highest being 11.60
cember the Weather over the Island SSure area to the East of Ceylon, and xperienced. This rain was considerlly in the North-central and Eastern rn slopes of the central hills, where eding 5 inches. These rains resulted f the Eastern Province. The norththe 6th and there Was monSOOn rain the Central Province With Scattered outh-west quarter. These conditions ch generally fair weather prevailed 27th due to dry upper air streams. experienced from the 29th onwards. infall Were of the Order of 35 inches. in slopes of the central hills. Else| ranged generally between 5 and 25 hches) was confined to parts of the le coastal belt of the southern pronormal over practically the entire Colombo and Kalutara Districts and Kegalle and Kandy Districts. Elsemal. There were over 50 daily falls being 10.17 inches at Batticaloa on
D. J. JAYASINGHE,
Director.
ܢܠ

Page 81
METEOROLOGIC
METEOROLOGICAL REPORT FOR
TEMPERATURE E
STATION Mean Offset Mean Offset, ID:
Max Min
o C O
Anuradhapura 92.6 十3·7 73-9 --0-4 6 Badulla ... 83-7 十09 65-1 -0-4. 7 Battical Oa. 87-8 -- 0:8 75-卫。一0...2 7 Colombo 85-3 十05 74-2 -0.6 8 Diyatlalawa 75-8 -0.5 60-2 -0-3 7 e 82-6 -0.3 742 -1 * 2; 8 Hambantota, 83-3 -29 74.7 -0.6 8 工。 ,.| 86·7 | 十1·0 78-2 -- 0:6 8 Kandy ... 834 -1-8 68-0 +-0·1 7 Kankesanturai 87.9 -- 1:0 77.0 -0.1 7 Kurunegala 88.3 --1-2 73-5 -- 0-3 7 MITIDLuppallama || 91-9 || -4-3-8 73-6 -- 0-3 6 Mannar ... 88-9 --21 77.7 --0-3 7 Nuvara Eliya. .. | 67-9 || +-0-3 52-9 --0-7 8 Puttaam ... 88-3 --2-0 76-0 || -- 0:4 6 Ratnalana 85.7 -- 0:6 75-0 + 0.1 7 Ratnapura 88.0 + 0.9 723 7 5 ، (0--۔ Talama kele - - - Trincionalee 90.0 --2-0 75-9 + 0.3 7 Mullsitivu 90.7 - 73-6 - 6 Katunayake 85-7 - 74·卫 - 7 Vavuniya 92.9 - 73-3 - 6
Ν
TEMPERATURE H
STATION Mean Offset Mean Offset, D:
Max Min.
o c 9.
Аmштаdhарша 85-6 | -0)+2 72.7 --13 8 Badisula ... 77.9 -14 66-1 --0-7 8 Batticalioa S3-7 -0-5 74-8 +-0-6 8 Colombo 85-9 十0-7 72-9 -0-4 8 Diyatalanta 73-2 -1-1 60-6 十-0・8 8 Galle 84.9 --1-3 73-8 -0-4. 7 Hambantolta 84-2 || -12 74-3 十0-3 8 affna | 89 || + '8 75'2 -- 0:4 7 Kandy ... 82-6 -0-3 68.3 -- 0-9 7 Kankesanturai S4-6 H-04 75-6 十0・2 8 f Kurunegala . . S6-8 --0-1 72-3 十0-5 7 M“Illuppallama || 85-4 || -0-2 72.0 || +-1.5 7 | Mannar , , S-7 || -0-II 75-8 --0-1 S --Nuwara Eliya . . || 67-0 || —0-8 53-5 十2・4 8 PUttalam - S6+7 +-1·0 73-4 -+-0·3 7 Ratmalana S6-7 -- 0-3 73-6 -- 0-7 7 Ratnapura, S9-2 十1·4 72-2 O 7 Talawalkele - - - Trincomalee S4-0 十0-4 76-4 + 1·6 8 Mullaitivul 85-0 || - 76-0 - 7 Katunayake 87-3 || - 72-8 - 7 Vavuniya S5-O - 71-9 - 7

AL REPORT
OCTOBER TO DECEMBER, 1961.
OCTOBER
UMIDITY RAINIFAILL
AmΟ
Night | Tunti | Amoay I (from of Ulint Offset Rain Offset
Min) Cloud Days
6 % Inches
4 90 5-1 10-22 十-0・50 15 -1. 95 5-6 7-89 一卫·00 17 -2 3. 91. 4-6 I-69 -5-50 -6 1. 90 6-2 19-07 十-5・36 25 十2 7 91. 6-3 10-01. 十-0・83 23 十3 O 88 58 |1798| 十5-93 28 十8 2 88 6.6 |14·27 十9·51 18 十-5 2 89 5-6 2·90 || -6·30 9 -3 O 90 6-1 10.94 -0-67 18 O 6 9. წ5“0 5-05 ー4・57 8 -3 3. 93 5'8 1304 -1-82 19 -1. 1. 86 5、6 |12·12 | 十2·66 15 O 6 89 56 1・94 | ー4・64 9 -2 4 91. 6-2 6-41 ー3・35 19. -3 6 82 5*4 8-68 十l·25 12 -2 3 88 6-2 17-40 十4・20 24 O 85 6-5 16-00 ー2・01 24 十1
O 86 5・1 4·9卫 ー4・64 12 一4 9. 90 4-6 3-45 -8-11 12 - 9 93. 6-0 9-20 - 24 - 3. 90 5-4 6-04 -2-76 16 -
NOWEMBER,
UMIDITY RAINFALI,
Amo
Night | runt ay (from of Amo- Offset | Rain | Offset;
Min) Cloud unt Days
6 % Inches
O 95 2.7 8'38 -2:29 2. H-2 4 95 6-4 13·14 +-2-89 25 --3 2. 93 5-8 23-28 十9-42 24 --6 O 90 6-3 19-88 十6・74 23 十3 6 97 6-8 7.58 ー2・84 23 十1 8 90 5·4 7.23 一4·78 2. +-2 O 90 5-6 8·15 十0-58 20 十4 9 91. 6-1 15-12 -2-15 21. --3 3. S7 6-4 10-62 -0-08 22 十4 1. 88 6-2 16-66 -0-48 21. 十6 4 93 6-4. 995 一2·44 5 -4 4 88 6'4 10-28 || -- 0-32 23 --7 3. 93 6-4 9-33 -0.86 19 +-2 8 94. 6-7 10:15 --0-96 26 十4 2 86 6-2 740 -2.73 22 十4 1. 88 6·2 || 10·77 || -1·35 21 - O 83 6-8 5-00 +-021 24 --2
O 86 6-4 22-19 +8.25 23 十4 9 84 5-3 卫4·05 一2-00 22 - 5 93 5.7 15-01 - 19 - 8 78 6・2 |13・54 | 十0・49 20 -
275

Page 82
TROPICAL AGRICULT
TEMPERATURE;
STATION Mean Offset Mean Offset
Max Min.
Anuradhapura 82.6 -0.7 70-8 +-08 Bad Ulla, ... 763 -03 650 -- 0:5
0-7 -- 74-3 .0:1 -- || 82-0 ... ,Batticalloa ܒ Colombo ... 86.3 --08 72-1. -0.2
Diyatlalawa, . . || 71-6 || —0*4 58·9 | 十0-3
Galle . . 85.0 || +-15 73-3 O Hambantota, .. | 85-2 | + 0-5 73·4 十0.3 Jafna ... 82-5 O 73·3 +-0·3 Kandy . . || 8I-9 十0-1 66-6 + 0.8 Kankesanturai 82.4 -0.3 74·8 一0-卫 Kurunegala . . || 85-5 || —0-2 70-6 -0-1.
MI“Illuppallama || 83-0 十0·4 69•8 十02 Mannar ... 82-3 -0-5 74-8 -0-1 Nuwara Eliya 67-6 -0-1. 50-4 +-II"4 Puttalam ... 85.2 --0-4 710 -0-2 Ratmalana, . . || 87° 4 十10 72-5 --08 Ratnapura, ... 89.9 --18 71-4 -0-2 Tala Walkele. . . – - Trincomalee .. 818 -- 0.7 75·7 十0.8 Mullaitivul ... 82.5 - 75-5 - Katunayake . . 88-1 - 71-8 - Vauniya ... 824 || - 70-1 -
 
 

JIRIST, VOL. CXVIII, 196l
DECEMBER,
EUMIDITY RAINETAILL
AmO
Night unut
Day (from Of AmO- Offset Rain. Offset Min) Cloud unt Days
% % Inches
8. 95 5-5 882 -- 1:30 16 O
83 94. 6.7 12:00 --0-77 22 --
81. 90 6.5 27.67 || +-10·68 26 十6
78 90 5-6 10-25 十4·64 直4 十2
85 97 7.1 7:52 -O-55 19 -1.
75 88 6-0 4·09 一3-73 12 -2
74. 88 5-6 5.25 -0.36 9. -4
79 93 5-5 653 || -3-86 4. O
70 87 5-8 892 十0-05 13 O
80 86 5-2 10-60 +-0.86 16 十4
72 93 5.5 4-10 -2.68 LO -3
76 87 6-0 10:42 -- 2:36 15 --2
85 93 5.8 5-50 -2:29 16 +-2
85 93 5-8 720 -0-6. 16 -
70 88 58 4·50 一星•05 14. - 1
67 85 5.7 9.97 || +-3.32 14 -
65 83 64 6.35 -2.77 16 O
81. 84 6·4 21·64 十8·64 21. -+-3
79 82 5-5 1863 --0-11 卫4 -
69 74 5-1 3.99 - 13 ۔ چ
78 93 5·6 || 16·10 || - 4·52 19 -

Page 83


Page 84