Coconut Research Institute Repository

Shantha, E.S.

I N - V I T R O S C R E N N I N G F O R 
D R O U G H T - T O L E R E N C E I N C O C O N U T 
In Sri Lanka, large numbers of coco­
nut palms are annually lost due to drought and 
this has severe economic consequences. There­
fore breeding for drought-tolerant coconut 
germplasm is of prime importance. Selection 
of suitable parental material for breeding for 
drought tolerance using conventional methods 
is difficult due to the very long generation 
period and large size of the coconut palm. 
Therefore it is necessary to develop alterna­
tive methods to select drought tolerant 
germplasm. 
An in- vitro screening procedure for 
drought tolerance has been developed in our 
laboratory and this method is based on em­
bryo culture technology. In this method, em­
bryos are excised from mature seednuts. Af­
ter surface sterilization, the embryos are cul­
tured in a pre-sterilized liquid growth medium 
in test tubes. This medium contains the neces­
sary nutrients required for the germination and 
subsequent growth of embryos. The embryos 
are transferred to fresh media at four-weekly 
intervals. Once the embryos germinate and 
produce the first photosynthetic leaf, water 
stress or drought conditions are imposed by 
incorporating a drought simulating substance 
called polyethylene glycol (PEG) into the cul­
ture medium. 
Polyethylene glycol is an inert sub­
stance that is highly soluble in water. It in­
duces water stress in in- vitro grown plants 
by decreasing the available water of the nu­
trient medium without being taken up by the 
plant. These features make PEG an ideal sub-
E.S. Shantha 
Coconut Research Institute of Sri Lanka 
stance to simulate water stress under in- vitro 
conditions. 
At the beginning of screening, only a 
very low concentration of PEG (usually 1%) 
is incoiporated into the culture medium. Then 
the concentration of PEG is progressively in­
creased (at the rate of 1 % increase at four 
weekly-intervals) until the plants show severe 
symptoms of water stress, as judged by the 
A B 
A.Control B. Induced drought symptoms 
16 
cessation of growth, yellowing of leaves etc.. 
Seedlings showing severe stress symptoms 
under high water stress conditions are rescued 
by passage through gradually decreasing lev­
els of PEG. Finally, they are maintained in the 
normal growth medium until they recover 
completely from water stress. These seedlings 
are then transferred to the soil for field plant­
ing in drought-prone areas. Once planted in 
the field, their performance is monitored regu­
larly as it is very important to correlate results 
obtained under in- vitro conditions with those 
under field conditions. 
I N D I G E N O U S T E C H N O L O G Y F O R 
T E R M I T E C O N T R O L 
Termite is a pest of coconut found in 
many coconut growing areas. They damage 
not only coconut seedlings but also roots of 
mature palms. An easy way to control the 
population of termites in coconut estates is the 
destruction of termite colonies. A termite hill 
is the aerial part of the colony and the under 
ground part is the breeding ground with a 
queen living in it. A termite colony could not 
be distroyed just by removing the aerial parts 
without killing the queen found in under 
ground parts. 
A traditional method adopted by farm­
ers to destroy termite colonies is highlighted 
in this note. At the on set of rainy season, th 
aerial part of the termite colony is removed 
leveling it to the ground. 
Then make a basin like depression covering 
the entire area of the colony facilitating water 
to be collected during the rainy season. Due 
to the collection of water, an unfavourable 
environment will be created in the breeding 
part of the colony. As a result the queen 
and the entire breeding ground will be de­
stroyed naturally. You may try this in your co­
conut lands. 
By P A Henry Nimal Appuhamy 
17 


In vitro screening for drought tolerance in coconut

Perera, L.

Peries, R.R.A.

Jayatileke, R.

COCOS (1996), 11, 69 - 78 
Printed in Sri Lanka 
I M P R O V E M E N T O F S E E D L I N G Q U A L I T Y I N 
P O L Y B A G S T H R O U G H M A N I P U L A T I O N O F P O T T I N G M E D I A 
L Ferera, R R A Peries and R Jayatileke 
Coconut Research Institute, Lunuwila, Sri Lanka 
ABSTRACT 
Potting mixtures containing different proportions of river sand were used for 
raising coconut seedlings' in polybags with and without fertilizer, to evaluate their 
growth and vigour after seed nuts were allowed to germinate on a pre • nursery bed 
and then transplanted. The substitution of topsoil in the pplybag mixtures with river 
sand had no significant effect on the development of coconut seedlings. It was found 
that pure river sand alone could be successfully used, provided seedlings were kept 
free from water deficit and in this respect the first seven months from seed nut 
laying was found to be critical. 
Application of fertilizer improved the seedling height and girth but this effect was 
significant only five months after seed nut laying. However, in this study the 
improvement in seedling vigour was inadequate to justify the extra input on 
fertilizer. 
INTRODUCTION 
Raising coconut seedlings in polybags (Wuidart, 1981) is now very popular in 
most coconut growing countries and their advantages and disadvantages in replanting 
programmes have been well documented (Harries, 1983; Maravilla, 1986; Peries and 
Everard, 1994). 
In a recent study carried out in Sri Lanka (Peries and Everard, 1991), it was 
shown that river sand could be a successful alternative to the more expensive'potting 
media currently used in polybags (Ho et al., 1978; Cano et al., 1989). However, 
the poor growth of seedling in their experiment was mainly due to the slow 
germination rate in river sand. The authors have suggested a practical alternative; 
to lay the seed nuts in a pre-nursery bed to overcome the germination problem, and 
the application of nutrients to rectify the poor growth rate in river sand. Despite the 
fact that seed nuts contain adequate nutrients for germination and growth (Child, 
1974), under- certain circumstances it has been shown that growth and vigour of 
seedlings can be improved through the addition of fertilizer (Mathew and 
Ramadasan, 1964; Maravilla, 1986). 
69 
The current study was designed to test the hypothesis that seed nuts raised in a 
pre-nursery and subsequently grown in a^V^'sand~pbtting media would respond 
better to fertilizer application. A secondary objective was also to develop and 
recommend a suitable package to improve the nutritionally poor media. 
MATERIALS AND METHODS 
The study was conducted at the .Bandirippuwa estate research nursery, beginning 
in May 1991. The seed nuts T x T (CRIC 60} from the Isolated Seed Garden (ISG) 
at Ambakelle were used and were obtained from the 3rd pick during May 1991. One 
thousand seed nuts (three times the requirement) were laid in a conventional pre-
nursery bed (Peries, 1984) for subsequent transplanting in polybags. 
The seed bed took the dimensions of a conventional pre-nursery i.e., ISO cm 
wide, with unspecified length, with the earth raised to about IS cm. The nuts were 
laid verticaly at close spacing, leaving about S cm from one another on each side 
(16 Nut/m 2). 
The beds were irrigated once in three days, beginning from the seventh day after 
there was no rain for a continuous spell of seven days or more. No fertilizer was 
applied on the beds. Dry coconut fronds were used as a mulch to conserve the soil 
water. 
All sprouted seed nuts with sprout heights ranging from 9 to 19 cm were picked 
out and transplanted vertically in polybags at 18 weeks after laying in the pre-
nursery. The bags of 40 cm x 28 cm with gussets (IS cm) made up of 800 gauge 
polyethylene were filled up to 2/3rd with the different potting mixtures. The lower 
half of each bag was pierced to have 12 holes in a row to allow excess water to drain 
off. The different potting mixtures and fertilizer treatments are summarized in 
Table 1. 
The current fertilizer recommendation is to apply 70 g of a mixture containing 
3 parts of Ammonium Sulphate, 1 part of Concentrated Super Phosphate, 2 parts of 
Muriate of Potash and 1 part of Keserite per seedling at 24 weeks after seed nut 
laying (Peries, 1984). Half the quantity of polybags (25 bags) prepared with each 
potting mixture were supplied /with the above mixture in four equal split 
applications, the first at transplanting and then at 24, 28, and 30 weeks after seed 
nut laying. The other 25 polybags did not receive any fertilizer. 
The seedlings were spaced at 60 x 60 x 60 cm triangular in a completely 
randomized design (CRD). The seedlings were kept free from water deficit 
throughout the experiment by irrigating whenever there was no rain. 
Seedling height, girth at collar and number of fully opened leaves were recorded 
70 
Table 1. The proportion oftopsoil, cow dung, coir dust and river sand in the six treatment with their level of fertilizer 
Treatments Proportion of the constituents 
Topsoil River sand Cow dung Coir dust Frt. 
t l 6 0 0 0 + / -
t2 3 0 2 1 + / -
t3 1 0 2 3 + / -
t4 0 6 0 0 + / -
t5 0 3 2 1 + / -
t6 0 1 2 3 + / -
71 
at transplanting (4 months after seed nut laying) and then at 5, 6, 7, 8, 9 and 10 
months after laying in the pre-nursery. 
The data were analyzed using the analysis of variance procedure to compare the 
treatment differences in the parameters recorded with adjustment through covariance 
analysis. Initial seedling height, girth at collar and number of leaves were used as 
the covariate for each analysis, respectively. 
RESULTS AND DISCUSSION 
There was no interaction between potting media and fertilizer level indicating that 
potting media and fertilizer levels were independent. The temporal change in 
seedling height from 5 to 10 months after seed nut laying in the pre-nursery is 
shown in Figure 1. The treatment with one part o f topsoil, two parts of cow dung 
and three parts of coir dust (T3) led to a significant increase in seedling height (79.9 
cm) compared to T l , T2 , T4 and T6 at 10 months (74.4 cm, 73.S cm, 71 cm, 
72.S cm respectively). The treatments T3 and TS (Three parts of river sand, two 
parts of cow dung and one part of coir dust) were not significantly different from 
each other (75.6 cm). Eventhough a similar trend was visible from 5 months 
onwards, the difference was not significant until 10 months. 
Figure 2 shows the temporal increase in girth at collar of seedlings during the 
same period. The girth was highest in T3 (8.8 cm), though it was not significandy 
different from T5 (8.7 cm) and T 6 (8.6 cm) at 8 months and this difference was 
maintained up to 10 months. 
The mean number of fully opened leaves at 5, 6, 7, 8, 9 and 10 months is shown 
in Figure 3. The treatment difference began to show up only after 8 months. The 
treatment T3 again produced the highest leaf number (5.1) followed by T5 and T6 
(both 4.8) at 9 months. The difference between T3 and T5 continued up to 10 
months (6.1 vs 5.8). These differences were, however, not significant. 
The results indicated that the substitution of topsoil in the polybag potting mixture 
with river sand had little effect on the growth and development of coconut seedlings, 
when seed nuts were transplanted from a pre-nursery bed. Moveover, even with 
river sand alone, differences were observed only after 7 months from seed nut laying 
at which age the seedlings could be transplanted in the field. Peries and Everard 
(1991) reported that the seedling vigour in terms of height, girth and number of fully 
opened leaves, was reduced in sand-substituted media at 30 weeks (i.e., after 7 
months) with direct sowing in polybags. This reduction in seedling vigour was 
associated with a slower rate of germination in the sand containing media but in their 
case seedlings of different physiological ages were compared. However the situation 
was different when seed nuts were selected from a pre-nursery bed immediately 
after sprouting and transplanted in the polybag. 
72 
Months after seed nut laying 
Figure 1 The temporal increase in seedling height in the different treatments. 
Vertical bar indicate the LSD (p < 0.0S) 
73 
Figure 2 The temporal increase in seedling girth at collar in the different 
treatments. Vertical bars indicate the LSD (p , 0.0S) 
74 
7 - p 
Months after seed nut laying 
Figure 3 The temporal increase in number of leaves in the different 
treatments. Vertical bars indicate the LSD (p < 0.0S) 
75 
Table 2. The temporal change in seedling height, girth at collar and total number of leaves at monthly intervals after seed nut 
laying in response to fertilizer application 
Months 5 6 7 8 9 
Seedling height (cm) 
With fertilizer 25.9 40.9 51.8 66.7 71.7 
Without fertilizer 25.8 37.7 48.7 62.6 68.0 
ns * * * * 
Girth at collar (cm) 
With fertilizer 5.6 6.8 7.6 8.7 10.2 
without fertilizer 5.6 6.6 7.3 8.3 9.6 
ns * * * + 
Total number of leaves 
With fertilizer 0.2 2.6 3.4 4.2 4.8 
without fertilizer 0.2 2.5 3.4 4.1 4.8 
ns ns ns ns ns 
ns - non significance (P < 0.05) 
* - significance (P < 0.05) 
76 
Application of fertilizer on the other hand, had a significant effect on seedling 
vigour (Table 2) by improving the height and girth only after 5 months from seed 
laying. Although it had no effect on the number of fully opened leaves, it is likely 
to have an impact on leaf area (data were not recorded). Almaden and Santiago 
(1980) have also reported similar results with different levels of Nitrogen and 
Potassium. However, in the current study the improvement in seedling vigour was 
inadequate to justify the extra input of fertilizer. 
CONCLUSIONS 
The results of this study indicated that when seed nuts were transplanted from a 
pre-nursery and raised in polybags, fertilizer application would only be necessary 
under conditions of extended nursery period. River sand could be successfully used 
as an alternative to topsoil in polybag potting mixtures. The mixture containing 3 
parts of river sand, 2 parts of cow dung and 1 part of coir dust (T5) (i.e. 3:2:1) was 
shown to be the best while the 1:2:3 mixture also gave a similar result. Therefore 
if topsoil was available in limited quantity, 1 part topsoil, 2 parts cow dung and 3 
parts coir dust (T3) may also be used as an alternative. 
ACKNOWLEDGEMENTS 
We wish to thank Mr . J .M.D.T. Everard and Dr. (Mrs.) W . M . U . Fernando, 
our colleagues in the Genetics and Plant Breeding Division and Mr . D.T. Mathes, 
Head, Biometry division for their valuable suggestions on the manuscript. 
REFERENCES 
Almaden, E.A. and Santiago, R .M. (1980). Response of coconut seedlings to 
spacing and application of Nitrogen and Potassium. Ann. Trop. Res. 2 89 - 95. 
Cano, S. B., Santos, G. A, and Bahala, R. T. (1989). Germination, growth and 
development of coconut seedlings in relation to seed nut preparation, position and 
polybagging. Cited in Training manual of short course on collection, conservation 
and characterization of coconut genetic resources, Philippine, 1990. 
Child, R. (1974). Nutritional requirements and fertilizer practice in coconuts. 
Coconut. 130 - 156 pp, 2nd ed, Longman, London. 
Harries, H.C. (1983). A ten point coconut nursery programme to avoid germination 
problems. Planter, Kuala Lumpur, 59, 207- 214. 
Ho, D.T. , Loh, H.P. and Chan, E. (1978). Germination, nursery practices and field 
planting techniques for the M A W A hybrid coconut. Proceedings of the 
International Conference on Cocoa and Coconut, 1978. 
77 
Maravilla, J.N. (1986). Nutrition and fertilizer of coconut seedlings in polybags. 
Philippine J. Coconut Stud. Vol ii (i) 44 - 56. 
Matfaew, C. and Ramadasen, A (1964).Effect of N , P, K and nutrients on the growth 
of the coconut seedlings. Indian Coconut Journal. 17(4) 114 - 117 . 
Peries, R.R.A. (1984). Some observations on the pre - nursery system for raising 
coconut seedlings. Cocos 2:10 - 1 7 . 
Peries, R.R.A. and Everard J.M.D.T. (1991-1993).River sand as an alternative to 
topsoil for raising coconut seedling in polybags. Cocos 9: 40 - 46. 
Wuidart, W (1981).Production of coconut planting material - The polybag nursery 
Oleagineux, 36: 367 - 373. 
78 


Improvement of seedling quality in polybags through manipulation of potting media

Fernando, T.W.

A 
G R A D E S O F I N O R G A N I C F E R T I L I Z E R S 
F O R C O C O N U T 
The majority of coconut growers use 
inorganic fertilizers to maintain a healthy plan­
tation with sustainable production. Today, fer­
tilizers are very expensive and it has become 
the major component of the cost of produc­
tion of coconut in Sri Lanka. Although farm­
ers are familiar with the effective use of chemi­
cal fertilizers, they are hesitant in the selec­
tion of required fertilizer at the time of pur­
chase, due to inadequate knowledge regard­
ing fertilizers. To overcome this situation one 
must be acquainted with the types and proper­
ties of fertilizer. This article is aimed at edu­
cating the farmer/purchaser on coconut fertil­
izer under the following headings. 
1. Steps to be followed at the time of 
purchase. 
2. Common fertilizer terminology used in 
agriculture. 
3. Types of fertilizer. 
4. Inorganic fertilizers used in coconut 
plantations. 
T W Fernando 
Coconut Research Institute of Sri Lanka 
1. Steps to be followed at the time of 
purchase. 
According to the existing rules in the 
fertilizer trade, it is compulsory for the 
fertilizer trader or supplier to mark or 
label the following items legibly on 
the packages or containers of fertilizer. 
a. Name of the mixture in capital letters. 
b. "Fertilizer Grade" (percentage nutrient by 
weight) 
c. Name and address of the manufacturer. 
d. Registered trade mark. 
e. Net weight in kilograms 
f. Date or month and year of manufacture. 
At the time of purchase one must carefully 
check the above markings. The most im­
portant of these is the "Fertilizer Grade" and 
a detailed account of this is given at the end of 
this article. 
The following diagram shows the appropri­
ate markings on a fertilizer bag. 
Name of the mixture 
Fertilizer grade 
Trade mark 
Net weight in kg. 
—Name of the company 
Date 
8 
Table 1. Major Plant Nutrients used in coconut 
Name Of plant 
nutrient 
Symbol used Standard method of 
expressing the active 
ingredient in fertilizer 
Form in which the 
plant absorbs the 
nutrient 
Nitrogen N N NH 4 + , No3~ 
Potassium K K,0 K+ 
Phosphorous P P 2 O 5 H 2 P0 4 - ,HP0 4 ~-
Magnesium Mg MgO Mg + + 
2 Common fertilizer terminology used in 
agriculture. 
The plant foods are called plant nutrients 
and the major plant nutrients used in coconut 
and their basic terms are given in Table 1. 
The terms K 2 0, P 2 0 5 and MgO are not 
physically found in chemical fertilizer, but it 
is the standard or accepted international norm 
of expressing the nutrient concentration in fer­
tilizers. 
The last column shows the actual form 
in which plant absorb each nutrient when in­
organic or even organic fertilizer is added to 
the soil. 
rus 
or Potassium is commonly known as a staig-
ht or simple fertilizer, 
eg. Urea, Rock phosphate, Muriate of 
potash. 
b. Fertilizer mixtures or multinutritional 
fertilizers. 
Fertilizer which contains two or more 
nutrients are called fertilizer mixtures. These 
are produced by throughly mixing all the ing-
redients(straight fertilizer) in dry state either 
mechanically or manually, 
e.g. APM, ACM, YPM 
c. Complex fertilizers. 
3. Types of fertilizer. 
There are three types of fertilizers. 
a. Straight fertilizer. 
b. Fertilizer mixtures or multinutritional 
fertilizer. 
c. Complex fertilizer. 
a. Straight fertilizers: 
A fertilizer which contains only one 
nutrient source such as Nitrogen, Phospho-
Fertilizer which contains two or more nu­
trients in one granule and are free flowing (not 
presently available for coconut in Sri Lanka) 
4. Inorganic fertilizers used in coconut 
plantations. 
. There are four kinds, 
a. Nitrogenous fertilizers 
b. Phosphatic fertilizers 
c. Potassic fertilizers 
d. Magnesium fertilizers 
9 
Table 2. The properties of fertilizers. 
Type of 
fertilizer 
C o m m o n 
name 
Chemical 
formula 
Nutr ient 
concentrat ion 
Colour and 
texture 
Equivalent * 
Ac id i ty 
Cost per 
K g ** 
fert i l izer 
/ R s . 
C o s t / 
K g 
nutrient 
/ R s . 
Nitrogenous lUrea 
2 Ammonium 
Sulphate 
C o ( N H 2 ) 2 
(NH4)2S04 
46% N 
21% N 
23.7 % S 
White 
crystalline 
White or 
Brownish 
crystalline 
80* 
110* 
6.10 
10.20 
13.26 
49.00 
Phosphatic 1 Saphos Phosphate 
or Rock Phosphate 
2Eppawela Apatite 
27.5% P 2 0 5 
30-32% P 2 0 5 
Light grey 
or 
Brown 
Neutral 
Neutral 
7.00 
4.10 
25.00 
13.60 
Potassic 1 Potassium 
chloride 
or 
Muriate of 
potash (MOP) 
KC1 60% K 2 0 
48% CI 
White to 
red 
Crystalline 
Neutral 12.25 20.42 
Magnesium 1 Epsom salt M g S 0 4 7 H 2 0 16% MgO 
13% S 
White 
Crystalline 
- 14.50 90.60 
2 Kiesarite M g S 0 4 H 2 0 24% MgO 
23% S 
Off white 
Crystalline 
- 11.95 49.79 
3 Dolomite MgCQ 3 CaCQ 3 20% MgO 
30% CaO 
White 
powder 
- 2.00 10.00 
* The equivalent acidity is the number of Kg of Calcium Carbonate required to neutralize 100 Kg of fertilizer. 
** The prices as on 01 January 1998 
Some specific properties of fertilizers are 
given in the Table 2. 
Urea : 
Absorbs moisture quickly and requires 
packing in moisture proof bags. Con­
tains highest amount of nitrogen 
(46%). This is an advantage in stor-
• age, transport and handling cost, per 
unit weight of nitrogen. The mixtures 
containing urea should be prepared 
only just prior to use. 
Ammonium Sulphate : 
Will not absorb moisture and has ex­
cellent physical properties and keeps 
well during storage and transport. It 
also contains about 23.7% sulphur, 
preferably for use in alkaline and sul­
phur deficient soils. 
Muriate of Potash : 
In mixtures containing urea it tends to 
get moist and may form lumps, if 
stored for long time. On very light tex­
tured (sandy) soils or high rainfall ar-
. eas the chance of leaching is high. 
Therefore it would be better to apply 
in split doses. 
Saphos Phosphate and Eppawela Appatite: 
Both are rock phosphates and have 
very low solubility. Saphos phos 
phate is imported and has a slightly 
higher solubility. 
Magnesium Fertilizer : 
Epsom salt and kieserite are readily 
soluble and subject to leaching. It is 
• very expensive and should be used 
only to correct acute magnesium defi­
ciency. . 
Dolomite is insoluble and will not 
leach in the soil. Dolomite should be 
used regularly to prevent magnesium 
deficiency. 
"FERTILIZER GRADES" 
Fertilizer mixtures provide more than one nu­
trient, are readily available and they have made 
an impact on the fertilizer use of farmers. 
Normally fertilizer mixtures containing three 
nutrients are prepared and its composition is 
marked on the container and the composition 
read from left to right always denotes the per­
centage of N, P2O5 and K2O in the fertilizer. 
This composition is termed as the "Fertilizer 
Grade". 
Thus "Fertilizer Grade" refers to the guaran­
teed minimum percentages of total nitrogen 
(as N), phosphorus (as P2O5) and soluble po­
tassium (as K2O) contained in the fertilizer 
Grade". 
eg. 100 kg of APM (grade 12-6-32) fertilizer 
contains 12 kg of N, 6 kg of P 2 O 5 and 32 kg 
of K 2 0 (a total of 50 kg of plant food). It is 
worth mentioning here that the total contents 
of plant food in any mixture is less than 100 
and the rest constitute other chemical com­
pounds. 
Another term used in the fertilizer trade is 
the "Fertilizer ratio" which refers to the 
ratios of the three nutrients. 
eg. APM Fertilizer Grade 12-6-32 
Fertilizer ratio 2-1-5.3 
U 
Table 3 "Fertilizer Grade" of the mixtures when different proportions of straight fertilizers are 
mixed. 
Type of 
mixture 
Amount 
100 K 
used to make 
I mixture 
"Fertilizer 
Grade" 
Urea 46% N Rock 
Phospate 
27.5% P 2 O 5 
Muriate 
of Potash 
60% K 2 0 
Two component 
mixtures 
50 
50 
0 
50 
50 
50 
50 
32-14-00 
23-00^30 
00-14-30 
Three 
component 
mixtures 
APM 
YPM 
33 1/3 
50 
26.6 
28.6 
33 1/3 
25 
20 
42.8 . 
33 1/3 
25 
53.3 
28.5 
15-09-20 
23-07-15 
12-06-32 
13-12-17 
In a fertilizer mixture if a forth nutrient is included it is usually magnesium. 
e.g. A C M - N - P 2 0 5 - K 2 0 - MgO 
O - 6 - 3 2 - 5 
Table 4.The "Fertilizer Grade" of the mixtures presently recommended by the Coconut 
Research Institute. 
Age of the palm Name of the mixture Fertilizer Grade 
Adult or bearing 
palms 
Adult palm mixture 
(APM) 
"Adult Coconut" mixture (ACM) 
12-06-32 
00-06-32-05 
Young palms Young Palm mixture 
(YPM) 
13-12-17 
12 


Grades of inorganic fertilizers for coconut

Everard, J.M.D.T.

Use of RAPDs for efficient conservation of coconut germplasm

Jayasekara, C.

Nainanayake, N.P.A.D.

Jayasekara, K.S.

Photosynthetic characristics and productivity of the coconut palm

The brown dwarf:a recent addition to the varieties and forms of the coconut palm in Sri Lanka

Rajapakse, C.N.K.

Gunawardene, N.E.

Control of the red palm weevil, (Rhynchophorus ferrugineous)populations using pheromone baited trap

Meola Roger

Evaluation of insect growth regulators; juvenoids for outdoorcontrol of cat fleas in soil

Somasiri, L.L.W.

Use of Eppawala Appatite in coconut

National Science Foundation of Sri Lanka

Not a member yet

In vitro screening for drought tolerance in coconut

Improvement of seedling quality in polybags through manipulation of potting media

Grades of inorganic fertilizers for coconut

Use of RAPDs for efficient conservation of coconut germplasm

Photosynthetic characristics and productivity of the coconut palm

Improvement of seedling quality in polybags through manipulation of potting media

The brown dwarf:a recent addition to the varieties and forms of the coconut palm in Sri Lanka

Control of the red palm weevil, (Rhynchophorus ferrugineous)populations using pheromone baited trap

Evaluation of insect growth regulators; juvenoids for outdoorcontrol of cat fleas in soil

Use of Eppawala Appatite in coconut

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