Coconut Research Institute Repository

Peiris, T.S.G.

Appuhamy, P.A.H.N.

Nainanayake, N.P.A.D.

Bandaranayake, C.K.

Fernando, M.T.N.

Coconut research, development and dissemination of technologies - growers perception

Jayalath, K.Y.N.N.

Coir fibre pith as a ground cover in coconut plantations of Andigama shallow soils in Sri Lanka . an ex-post financial analysis

Ranasinghe, C.S.

Wijeratne, A.

VEGETATIVE, REPRODUCTIVE AND PHYSIOLOGICAL CHANGES IN 
COCONUT PALMS AFFECTED BY COCONUT RAPID DECLINE 
C. S. Ranasinghe and A Wijeratne 
Coconut Research Institute, Lunuwila, Sri Lanka. 
ABSTRACT 
Coconut Rapid Decline (CRD) is a disorder of unknown etiology affecting 
coconut palms (Cocos nucifera L.) in Sri Lanka. The objective of this study 
was to quantify vegetative, reproductive and physiological characters, and to 
determine the pattern of water transport in CRD-affected palms and 
compare with those of apparently healthy palms. 
The study was conducted on fifteen-year-old apparently healthy (SO) and 
CRD-affected coconut palms (var. Typica), in the incipient (S1), moderate 
(S2) and severe (S3)) stages of decline, in Makandura Seed Garden (MSG) 
of the Coconut Research Institute, Sri Lanka. The leaf canopy, trunk, 
unopened spadix and nut characters, total chlorophyll content, and the rate 
of transpiration, stomatal diffusive resistance, and xylem transport pattern 
were the parameters determined and compared. 
CRD reduced the number of fronds in the canopy by 32%, trunk girth by 
24%, and leaf chlorophyll content by 12%, and increased stomatal diffusive 
resistance three-fold. There was a concomitant reduction in the size of the 
inflorescence (by 35%), number of female flowers produced (by 71%), nut 
yield (by 54%) and copra weight of nuts (by 44%) indicating the destructive 
nature of the disorder on the productivity of affected palms. In the CRD-
affected palms there was an obstruction to the transport of water from roots 
to the canopy, and water was retained in the roots. 
Key words: Cocos nucifera, Coconut Rapid Decline, diseases of unknown 
etiology, frond drooping, trunk tapering 
INTRODUCTION 
Coconut Rapid Decline (CRD) is a disorder of unknown etiology recently 
recognized in Sri Lanka. The disorder generally affects coconut palms 
between 15 and 35 years of age. Generally, a reduction in yield is evident 6-
8 months after the appearance of leaf symptoms and the palm dies within 2-
3 years (Ranasinghe era/., 2002). 
Drooping of the middle and lower whorl of green fronds is the most 
characteristic visual symptom in the early stages of the disorder. These 
drooping fronds dry up rapidly leaving only a few erect fronds, of the upper 
1 
whorl, on the crown. As the disorder, progresses the number of healthy 
fronds in the canopy keeps decreasing, the leaves turn pale green and 
emerging fronds become shorter, causing a drastic reduction in the size of 
the crown. In the severe stage, scorching of the tips of leaflets of the few 
remaining erect fronds can be observed. Finally, the dried fronds drop off 
leaving a crownless coconut trunk. With the initial drooping of fronds, the 
trunk begins to taper and the internode length progressively decreases. As a 
result, the emerging inflorescences are bunched together, giving a 'rosette' 
like appearance to the crown. Inflorescences without any nuts (empty 
bunches) are also a common symptom of moderate to severely affected 
palms (Fig 1). 
The effect of CRD on plant characters has not been quantitatively 
expressed. Nor have studies been carried out on water transport to the 
canopy and other reproductive parts of the palm which, are of primary 
importance in investigations of a disorder such as CRD. Martin et al. (1982) 
showed that the absorption and transport of water and the root activity of 
crops could be studied using the non-radio active tracer, Lithium. Pinto 
(1998) has tested this technique at the Coconut Research Institute and 
developed an effective method to use lithium as a tracer in root studies of 
coconut. The objectives of this study are therefore to (a) quantify the 
vegetative, reproductive and physiological characters of, and (b) determine 
the pattern of water transport in, CRD affected palms and to compare with 
those of healthy palms. 
MATERIALS AND METHODS 
Plant Material 
Fifteen-year-old, CRD-affected coconut palms (Cocos nucifera L. var. 
Typica) in Makandura Seed Garden (MSG) of the Coconut Research 
Institute were used for the study. The 'affected' palms were grouped into 
three stages of decline: incipient (S1), moderate (S2) and severe (S3), 
Twelve apparently healthy palms (SO) and 24 affected palms of each stage 
S1, S2 and S3 were used in the study. 
Measurement of vegetative and reproductive characters 
The numbers of fronds in the canopy, nuts per bunch and female flowers 
produced per inflorescence were counted. The trunk girth at the base of the 
canopy, and at 30 cm below the base, length and circumference of the most 
mature unopened spadix, and length and circumference of mature coconuts 
were measured using a measuring tape. The weight of the nut and fruit 
components: husk, shell, kernel, and volume of nut water were recorded. 
2 
Determination of transpiration and stomatal diffusive resistance 
The rate of transpiration and diffusive resistance were measured on the 
central leaflets on both sides of the ninth frond (counting the youngest fully 
open leaf as one), between 9.00 and 13.00 hours, with full,sun, using the Ll-
1600 Steady Porometer (LI-COR Inc, Lincoln, USA);, . < 
Estimation of total chlorophyll content 
The central leaflets on both sides of ninth frond were sampled/on ice, cut 
into small pieces, and homogenized in Acetone using an electric crusher 
(Ultra turraxT-25, GMBH, West Germany). While homogenizing the sample 
tubes, were kept on ice to prevent the temperature within the test tube 
increasing and evaporating the Acetone.., The crushed samples were 
centrifuged at 3000 rpm for five minutes and the absorbance was measured 
at 645 nm'and 663 nm using UV7VIS spectrophotometer (Shimadzu UV 160 
- A, Japan.). Total chlorophyll content was calculated according to Arnon 
(1949). 
Determination of the pattern of water transport from the root system to 
the canopy 
Lithium was used as a non-radio active tracer to determine the pattern of 
water transport as described by Martin et al. (1982) and adopted for coconut 
by Pinto (1998). Six each of apparently healthy and CRD-affected (incipient 
stage) palms were root fed with 100 ml of 1% Lithium Chloride solution. 
Three days after treatment application, leaflets of the ninth frond, five 
month-old developing nuts, and,healthy roots nearest to the lithium treated 
root were sampled. Nut water of harvested nuts was immediately frozen at 
-20 °C. The leaflets (without mid ribs), pieces of husks and roots were oven 
dried at 80 °C for three days and powdered (1 mm sieve size) using a 
grinder. One gram each of the powdered samples was shaken for two 
hours in 20.0 ml of .de-ionized water, and filtered using Whatman No. 42 
paper. The lithium content in the filtrate and in defrosted nut water was 
determined using an Atomic Absorption Spectrophotometer (GBC, 
Australia). 
Analysis of data 
Data was analyzed by ANOVA, ufeing the GLM procedure of SAS software. 
Least Square Means (LSMs) were calculated and pair-wise t tests were 
performed to compare the LSMs. 
(a) (b) 
Figure 1: Different stages in the progression of Coconut Rapid Decline - (a) 
healthy palm (no visible symptoms of decline) (b) incipient stage, (c) 
moderate stage, and (d) severe stage: 
4 
RESULTS 
Leaf canopy and trunk characters 
The number of fronds in CRD-affected patms, in all stages of decline, was 
significantly less than in healthy palms (Table 1). Trunk girth at the base of 
the crown and 30 cm below the base was also significantly less in CRD-
affected palms. The girth at the base of the crown of moderately and 
severely affected palms was significantly less than that of CRD affected 
palms at the incipient stage (Table 1). 
Table 1 : Number of f ronds/palm, gir th of t runk (at the base of the crown and 
30 c m below) of healthy palms (SO) and CRD-affected palms: 
Incipient (S1), Moderate (S2) and Severe (S3). 
Stage of CRD Number of f ronds 
/palm 
Trunk g i r th (cm) 
At base o f the 
c rown 
At 30 c m be low the 
c r o w n 
SO 31 a 84.94 a 82.90 a 
S1 20 b 67.14 b 66.95 b 
S2 20 b . 65.01 c 67.41 b 
S3 20 b 61.83 c 62.77 c 
Values with the same letters, within a column, are not significantly different (*** p< 0.001) 
Nut and inflorescence characters 
Numbers of nuts per bunch, and female flowers produced per inflorescence, 
and length and circumference of unopened spadix in CRD-affected palms 
were significantly less than in healthy paims. However, there was no 
significant difference in these characters between the stages of decline, 
except with the number of nuts per bunch where S3 palms yielded 
significantly less than S1 and S2 palms (Table 2). 
The nut weight in CRD-affected palms, in all stages of decline, was 
significantly less than in healthy palms. However, in the length and 
circumference of the nuts a significant reduction was noted only in S3 
palms; there was no difference between SO, S1 and S2 palms (Table 3). 
Table 2: Number of nuts per bunch, female f lowers produced per 
inflorescence, and length and circumference of unopened spadix of 
healthy palms (SO) and CRD-affected palms: Incipient (S1), 
Moderate (S2) and Severe (S3). 
Stage of No. of nuts No. of female flowers Unopened spadix characters 
CRD per bunch produced per (cm) 
Inflorescence 
Length Circumference 
SO 8a 35 a 94.44 a 25.17 a 
S1 5 b 13 b 62.70 b 16.22 b 
S2 4 b 10 b 63.58 b 16.89 b 
S3 2c 7b 58.73 b 16.31 b 
Values with the same letters, within a column, are not significantly different ("* p < 0.001). 
Table 3: Weight per nut, and length and circumference of the nuts of 
healthy palms (SO) and CRD-affected palms: Incipient (S1), 
Moderate (S2) and Severe (S3). 
Stage of CRD Weight per nut 
(Kg) 
Nut dimensions (cm) 
Length Circumference 
SO 
S1 
S2 
S3 
1.736 a 
1.130 b 
1.059 b. 
1.027 b 
31.34 a 
29.42 a 
25.43 a 
20.52 b 
53.58 a 
50.86 a 
44.45 a 
35.91 b 
Values with the same letters, within a column, are not significantly different (** p <0.01). 
Table 4: Weight of f ru i t components: Husked nut, f resh and dry husk and 
shell of healthy palms (SO) and CRD-affected palms: Incipient (S1), 
Moderate (S2) and Severe (S3). 
Stage of CRD Husked nut Husk weight (g) Shell weight 
weight (g) (g) 
Fresh Dry 
SO 750 a 908 a 359 a 218 a 
S1 439 b 735 b 269 b 142 b 
S2 465 b 590 c 261 b 151 b 
S3 424 b 600 c 243 b 163 b 
Values with the same letters, within a column, are not significantly different (** p <0.01) 
The weight of a husked nut, its husk (dry), shell, and kernel (fresh and dry), 
and the volume of nut water in CRD-affected palms were significantly less 
than in healthy palms. However, there was no significant difference in these 
characters between the stages of decline (Table 4 and 5). 
1 
Table 5: Weight of solid endosperm (kernel) and volume of liquid 
endosperm (nut water) of healthy palms (SO) and CRD-affected 
palms: Incipient (S1), Moderate (S2) and Severe (S3). 
Stage of CRD Kernel weight (g) Volume of nut water (ml) 
Fresh Dry. 
SO 373 a 206 a 225.42 a 
S1 223 b 109 b 73.67 b 
S2 236 b 122 b 78.09 b 
S3 206 b 117b 57.10 b 
Values with the same letters, within a column, are not significantly different ( " p <0.01). 
Physiological parameters 
The rate of transpiration of healthy palms (SO) was significantly higher than 
in CRD-affected palms, in all stages of decline, S1, S2 and S3; and the 
transpiration rate in S1 and S2 palms was significantly higher than in. S3 
palms (Table 6). This pattern was reversed in ^ respect of stomatal diffusive 
resistance, and the: differences were statistically significant. The stomatal 
resistance of the palms at the incipient stage (S1) and of healthy palms was 
not significantly different, but,with the decline advancing S2 and S3 palms 
recorded a significantly higher stomatal resistance than in healthy and S1 
palms (Table 6). Leaf chlorophyll content of healthy palms was also 
significantly higher than in CRD-affected palms in all stages of decline; there 
was, however, no significant difference between S1, S2 and S3 palms 
(Table. 6). 
Table 6: Rate of transpiration fr/g cm "2 s'1), stomatal diffusive resistance (s 
cm'1) and total chlorophyll content (mg/g fresh weight) of healthy 
palms (SO) and of CRD-affected palms: Incipient (S1), Moderate (S2) 
and Severe (S3). 
Stago of CRD Transpiration Stomatal diffusive Chlorophyll 
resistance content 
SO 2.73 a 5.30 a 3.13 a 
S1 2.11b 11.43 ab 2.73 b 
S2 • 1:54b 15.71 be 2.81 b 
S3 1.48 c . • 21.47 c 2.68 b 
Values with the same letters, within a column, are not significantly different (" p <0.01). 
7 
\ 
Distribution of lithium in different parts of the palm 
The Li concentration in the leaves, husks and nut water of CRD-affected 
palms (incipient stage) was lower than in healthy palms, whilst the reverse 
was true of the concentration in the roots. The decrease in Li concentration 
was highest in leaves and lowest in nut water (Fig. 2). 
C o n c e n t r a t i o n o f L i t h i u m in 
d i f f e r e n t p a r t s o f h e a l t h y a n d CRD 
a f f e c t e d p a l m s 
Leaf Husk Nut Root 
Wate r 
• Healthy • C R D 
Figure 2: Concentration of Li thium in different parts of healthy and CRD-
affected palms 
DISCUSSION 
The vegetative growth, yield, nut size and fruit components, gas exchange 
capacity and water transport in palms subject to CRD, irrespective of its 
severity, are appreciably different from that of apparently healthy coconut 
palms. The marked reduction in the leaf canopy and the consequent 
reduction of its capacity to intercept light, appears in turn to reduce the 
quantum of assimilates partitioned to developing reproductive organs and 
other vegetative structures, and ultimately lower the total plant productivity, 
as described by Taiz and Zeiger, (1991). In this context it is relevant to note 
that although there was a progressive tapering of the trunk in CRD-affected 
palms, dissections did not reveal any abnormalities in the internal tissues of 
the trunk, at any stage of the decline (Ranasinghe era/., 2002). 
Abnormal stomatal closure in CRD-affected palms may be one of the factors 
that kill these palms, because significantly increased stomatal resistance 
affects other processes such as photosynthesis and water and nutrient 
8 
transport! The decrease in xylem transport to the canopy in CRD-affected 
palms, as shown by lithium tracer studies, could be mainly attributed to the 
abnormal stomatal closure. This is supported by the evidence of increasing 
stomatal resistance with the progression of the disorder. A similar decrease 
in stomatal conductance (increase in stomatal resistance) coinciding with 
the appearance of foliar symptoms was a consistent symptom of ash 
yellows in Fraxinus americana, of com stunt in maize and of lethal yellowing 
in Cocos nucifera, all of which, are diseases caused by phytoplasma 
(Matteoni and Sinclair, 1983; Leon et a/., 1996; Martinez et at., 2000). The 
pattern of lithium distribution in CRD-affected coconut palms (Figure 2), also 
suggests some obstruction to water transport from roots to canopy, and 
retention of water in the roots of affected palms. The study also revealed 
that the water transport least affected was to the developing nuts when/ 
there is a high demand for water due to high metabolic activities (Bai and 
Shivasankar, 1999). Therefore, it is of utmost importance to determine the 
factors which obstruct xylem transport and cause abnormal stomatal closure 
in CRD-affected palms as this phenomenon may be responsible for the 
disorder symptoms. 
Finally, it can be concluded that there are significant differences in 
vegetative, reproductive and physiological aspects between CRD-affected 
and healthy palms. The quantification of CRD symptoms in the present 
study would be useful in formulating an index for grading the severity of the 
disorder. It also raises the possibility of using gas exchange parameters viz., 
transpiration and stomatal diffusive resistance for the early diagnosis of the 
disorder. 
ACKNOWLEDGEMENT 
The co-operation and assistance extended by the staff of the Plant 
Physiology Division in conducting experiments, sample analysis and data 
collection is gratefully acknowledged. Sincere thanks are due to the Head 
and staff of Biometry Division for assistance in the analysis of data. 
REFERENCES 
Amon, D.I. (1949). Copper enzymes. Plant Physiology 24, 3-5. 
Bai, K.V.K. and Shivasankar, S. 1999. Flowering and fruit development. In: 
Advances in Plant Physiology and Biochemistry of coconut palm. V 
Rajagopal and A Ramadasan (eds.) Asian and Pacific Coconut Community. 
15-28. 
Leon, R., Santamaria, J.M., Alpizar, L., Escamilla, J.A. and Oropeza C. (1996). 
Physiological and biochemical changes in shoots of coconut palms affected 
by lethal yellowing. New Phytologist 134,227-234. 
9 
Martin, M.P.L.D., Snaydon, R.W. and Drennan, D.S.H. (1982). Lithiumfes a non-
radio active tracer for roots of intercropped species. Plant and Soil 64, 203-
208. 
Martinez, S., Cordova, l „ Maust, B.E., Oropeza, C. and Santamaria, J.M. (2000). Is 
abscisic acid responsible for abnormal stomatal closure in coconut palms 
showing lethal yellowing? Journal of Plant Physiology 156, 319-322. 
Matteoni, J. A. and Sinclair W.A. (1983). Stomatal closure in plants infected with 
mycoplasma-like organisms. Phytopathology 73, 398-402. 
Pinto, M. L. W. (1998). A preliminary analysis of the use of lithium chloride as a 
non-radioactive tracer in studies on root activity of coconut. - Final year 
project report, Faculty of Agriculture, University of Peradeniya. 
Taiz, L and Zeiger, E. (1991). Plant Physiology. The Benjamin / Cumming 
Company, Inc. USA. 
10 


Vegetative reproductive ad physiological changes in coconut palms affected by coconut rapid decline

Marambe, P.W.M.L.K.K.

Sivakanesan, R.

Silva, K.D.R.R.

A study in Kuliyapitiya to ascertain public awareness of the lipid composition of edible coconut kernel products and their effect on health

Gunathilake, K.D.P.P.

Bandara, A.G.A.

COCOS (2005), 17 21 - 29 
Printed in Sri Lanka 
PREPARATION OF A READY-TO-USE COCONUT CUM SPICES PASTE 
FOR CHICKEN CURRY AND EVALUATION OF ITS PHYSICO-
CHEMICAL AND STORAGE PROPERTIES 
K.D.P.P.Gunathllake1 and A.G.A.Bandara2 
'Coconut Research Institute, Lunuwila, Sri Lanka 
2
 Dept. of Food Science & Technology, Faculty of Agriculture, 
University of Peradeniya, Sri Lanka 
ABSTRACT 
A Ready-to-use Coconut cum Spices Paste (RCSP) suited for making 
chicken curry is likely to have a good demand among both local urban 
consumers and Sri Lankan communities overseas. The main objective of 
this study was to develop such a product to exploit this perceived demand, 
and evaluate its physico-chemical and sensory properties. 
A RCSP for chicken curry was prepared from roasted spices, onions, garlic, 
ginger, coconut paste and coconut oil. Its proximate composition and water 
activity were determined, and the product was packed in LLDPE/Nylon and 
LLDPE/Polyester laminated pouches, hermetically sealed, and stored at 
room temperature (28 +/-20 C). Alpha tocopherol at three levels (0, 50 ppm 
and 100 ppm) was tested as an antioxidant. Peroxide value, free fatty acids 
(FFA) value, sensory properties and microbial levels were determined at 
two-monthly intervals during the storage period of six months. 
This product contained 5.9% moisture, 7.4% minerals, 56.5% fat, 6.7% 
protein and 4.2% fiber and its water activity was 0.76. The Peroxide value of 
all samples tested over the entire storage period remained unchanged at 
zero. FFA value of the RCSP, with 0 and 50 ppm tocopherol, increased from 
0.046 to 0.072% during storage, irrespective of the type of packing material 
used..At 100 ppm tocopherol, FFA level increased from 0.046 to 0.150% 
suggesting that, tocopherol may act as a pro-oxidant at the higher 
concentrations. However, at these levels of increase in FFA there was no 
effect on rancidity development or the overall sensory properties. The 
product was found to be microbiologically safe up to six months of storage. 
INTRODUCTION 
A large number of ingredients are used in cooking food, especially in the 
preparation of curries. These ingredients include coconut, spices, table salt, 
vinegar etc., which are used to impart flavor, taste, texture and also 
enhance the nutritional value of food. 
21 
Coconut is traditionally used in preparing food in the coconut-growing 
countries. It provides the cooking medium and enhances the texture and 
flavor of curries. Coconut is a good source of nutrients. Fat is the major 
nutrient in coconut and therefore it is a good source of energy. Coconut is 
also a good source of protein. Coconut meat (kernel) contain considerable 
amounts of essential amino acids. Of particular importance is lysine which is 
deficient in cereal based foods (Woodroof, 1979). Considerable amounts of 
vitamins, especially vitamin B complex, and minerals are present in coconut 
meat (Fernando, 1995). The use of coconut paste in the preparation of 
curries enhances its nutritional value (Anon, 2002). Coconut paste is the 
product obtained by grinding of dried scraped coconut and has a longer 
shelf-life compare with aqueous form of coconut 
In addition to extracts of coconut meat, a number of spices are incorporated 
in curries. Chillies, garlic, onion, ginger, coriander, cumin, cloves, pepper 
and cardamom are some of the important spices used in cooking curries. 
Spices possess a number of beneficial properties such as antioxigenic, 
antibacterial, physiological and flavoring, as well as health and medicinal 
properties (Pruthi, 1998). This makes spices a very important component of 
cooked food. 
The preparation of delicious and wholesome curries is both time consuming 
and labour-intensive due to the need to roast, grind and blend spices, 
scrape coconuts extract its 'milk' with water, dispose residues etc. Today, 
especially in urban areas, there is a demand for convenience products. In 
response to this demand a variety of instant spice mixtures are already 
available in the market. However, a product combining spices and coconut 
is not available. As a quality product of this nature would no doubt be a boon 
to busy housewives, this study aims to develop 
MATERIALS AND METHOD 
The raw materials, whole spices, corn flour, vitamin E, table salt and 
packaging materials were procured from the local market. Fresh coconuts 
were supplied by Bandirippuwa Estate, Lunuwila. 
Preparation of the curry powder with selected spices 
Preliminary studies were conducted to determine the most suitable blend of 
spices for preparing chicken curry. These findings showed that the spice 
ingredients and quantities required for the optimum blend were: roasted red 
chillies {Capsicum annum) (1000 g), roasted coriander (Cohandrum 
sativum) (400 g), cumin seed {Cuminum cynimu) (150 g), fennel seed 
(Foeniculum vulgare) (250 g), fenugreek (Anethum graveolens) (20 g), black 
pepper {Piper nigrum) (50 g), cardamom (Elettaria cardamomum) (20 g), 
cloves {Eugenia caryophyllus) (20 g), turmeric {Curcuma longa) (20 g) and 
22 
cinnamon (Cinnamomum zeylanicum) (20 g). Each of the spices was 
powdered separately in a grinder (Super Grinder, HL 1641/D). The 
powdered spices were then mixed in a blender (Super Grinder, HL 1641/D) 
to get a homogenous product. 
Preparation of coconut paste 
Coconut paste was prepared according to the method described by Anon 
(2002) 
Preparation of the ready-to-use coconut cum spices paste (RCSP) 
One litre of Coconut oil was heated in a stainless steel vessel to 120 °C, and 
chopped garlic (200 g), ginger (100 g), red onions. (1500 g), green chillies 
(200 g) and curry-leaves (80 g) and vitamin E were added and heated for 5 
min. Two kilograms of the mixture of powdered spices was added to the hot 
coconut oil and stirred continuously. Table salt (80 g), corn flour (200 g) and 
vinegar (4% acetic acid) (200 ml) were also added while mixing. Finally, 
coconut paste (4000 g) was added and the mixture was heated for a further 
10 min at 80 °C. Vitamin E (Alpha tocopherol) was tested at three levels, 0, 
50 ppm and 100 ppm, as an antioxidant for extending shelf-life and delaying 
the development of rancidity. 
Storage of RCSP 
RCSP was packed in Nylon/LLDPE and Polyester/LLDPE laminated 
pouches and hermetically sealed. Each pouch contained 100 g of the paste. 
Twelve pouches of each type were stored at room temperature (28 +/-20 C). 
Initially, and at 2-monthly intervals, two samples of each pouch type were 
removed for peroxide value and free fatty acids (FFA) value analysis, and 
for a sensory evaluation. 
Sensory evaluation 
The sensory evaluation was performed on a chicken curry prepared with the 
ready-to-use RCSP. Fifty grams of RCSP was mixed with 450 g chicken and 
300 ml water in a stainless steel vessel. The mixture was brought to the boil 
and allowed to simmer for 10 minutes. The chicken curry thus prepared was 
presented to a panel of 20 untrained judges for grading its colour, taste, 
flavour and overall acceptability on a 5-point Hedonic scale, with 5 for 
excellent in all respects and 1 for highly disliked samples. 
Analysis 
Proximate composition of RCSP was determined by standard methods. 
Moisture, total ash and crude fat were analyzed using AOAC (2001) and 
23 
crude protein and crude fiber were estimated using the method described in 
Pearson (1978) arid carbohydrate content by difference. 
For studies on rancidity development (determination of Peroxide and FFA 
values), a 30 g sample of the paste was shaken with 250ml chloroform and 
. blended. 
To determine FFA values a 25 ml aliquot of the chloroform extract was 
treated with 25 ml of neutralized 95% ethanol solution and titrated with I 
standard 0.1N NaOH using 1% phenolphthalein solution as indicator. 
To determine peroxide value, a 25 ml aliquot of the chloroform extract was 
mixed with 37 ml of glacial acetic acid and 1 ml saturated Kl solution and 
allowed to stand for about 1 minute. Then, 30 ml of distilled water was 
added and titrated with 0.01 N Na 2S 20 3 using starch as indicator. 
The microbial status of the product was evaluated by measuring total plate 
count, as described by Ranganna (1996). 
Water activity of the product was determined by measuring the equilibrium 
relative humidity (ERH) by a modification of the graphical interpolation 
method of Landrock and Proctor. Five gram samples of RCSP were 
exposed for 24 hours to different relative humidity levels viz. 10, 30, 50, 70 
and 95% at room temperature in desiccators containing known 
concentrations of H2S04. and the gain or loss in weight of each sample 
determined. The values were plotted with reference to the RH; the gain in 
weight being shown above, and the loss in weight shown below, a 
horizontally drawn zero base line representing no change in weight. A 
smooth curve was drawn through the plotted points and the ERH 
interpolated at the point where the curve intersected the zero base line. The 
water activity was calculated as ERH%. 
i 
Statistical Analysis 
' K non-parametric ranking procedure was used with Friedman rank sum test 
for the evaluation of appearance, taste, odour and overall acceptability. SAS 
statistical program was used for analyzing the storage data. 
RESULTS AND DISCUSSION 
Traditionally, Sri Lankans use roasted spices for the preparation of meat 
curries. According to Pruthi (1998) the inclusion of roasted spices in the 
spice mixture enhances the sensory properties as many chemical reactions 
occur during roasting such as maillard browning, caramalization, streaker 
degradation, pyrolysis of protein and thermal degradation of lipids, that 
result in flavor and aroma development. Furfural, hydroxy methyl furfural, 
24 
pyridines, pyrazines, aldehydes and ketones are a few examples of flavor 
compounds generated during roasting. 
Proximate analysis 
The proximate composition of RCSP is presented in Table 1. 
Table 1: Proximate composition of the RCSP 
Constituent Composition (%) 
Moisture 5.9+0.5 
Ash 7.4+0.3 
Crude fat 56.5+1 
Crude protein 6.71+0.8 
Crude fiber 4.21+0.5 
Carbohydrate 19.3 
Water activity 0.76 
The moisture content and water activity (aw) of RCSP was 5.9±0.5% and 
0.76, respectively. Water activity was calculated as ERH/100. Water activity 
influences the growth of microorganisms. Water activity per se, prevents 
the growth of bacteria below 0.86, yeasts at 0.78 and moulds below 0.95-
0.96 (Kaplow, 1970). Fat content of RCSP was about 56% and comes 
mainly from the coconut oil and coconut paste used in its preparation. Since 
coconut fat is saturated, product containing low amount of moisture. Protein 
and crude fibre contents of RCSP was about 6.7% and 4.2%, respectively. 
The relatively high levels of these two constituents in RCSP could be traced 
to the use of coconut paste in its preparation. Consequently, using RCSP 
rather than a spice mix plus coconut milk extracted from scraped coconut, 
would increase the quality and quantity of protein and crude fibre in the 
curry. 
50 
-200 J 1 
Relative Humidity 
Figure 1 ERH curve for Instant Curry Paste at RT 
25 
Storage study 
Results of the sensory evaluation (Table 2) showed that over the six-month 
storage period, the score for overall acceptability remained at four on the 
five point hedonic scale, irrespective of the type of packing material and 
level of alpha tocopherol.except the sample with 100ppm alpha tocopherol, 
packed in polyester/LLDPE 
Table 2: Effect of packing material, alpha tocopherol level and period of 
storage on FFA value and sensory score of RCSP 
Sample Storage Period FFA Value Sensory score 
(months) (overall 
acceptabil i ty) 
A1 0 0.046 4.00 
2 0.073 4.00 
4 0.063 4.10 
6 0.073 3.90 
A2 0 0.046 3.80 
2 0.074 3.98 
4 0.062 3.98 
6 0.073 3.78 
A3 0 0.046 3.95 
2 0.072 3.68 
4 0.065 3.75 
6 0.072 3.70 
A4 0 0.046 3.86 
2 0.069 4.01 
4 0.060 3.98 
6 0.069 4.00 
A5 0 0.046 3.79 
2 0.140 3.83 
4 0.124 3.78 
6 0.142 3.80 
A6 0 0.046 3.08 
2 0.160 3.00 
4 0.135 3.15 
6 0.165 3.00 
(A1=No tocopherol + Nylon/LLDPE packs; A2=No tocopherol + Polyester/LLDPE packs; 
A3=50 ppm tocopherol + Nylon/LLDPE packs; A4=50 ppm tocopherol + Polyester/LLDPE 
packs; A5=100 ppm tocopherol + Nylon/LLDPE packs; A6=100 ppm tocopherol + 
Polyester/LLDPE packs) 
FFA value and the peroxide value were used to estimate rancidity 
development in RCSP. The FFA value and the peroxide value are measures 
of hydrolytic rancidity and oxidative rancidity, respectively (Lawson etai 
1984). Tocopherols compete with oxidation reactions and suppress the 
oxidation process in a food system (Fennima et al, 1995). 
26 
All treatments (packing materials, tocopherol and storage levels) recorded a 
peroxide value of zero. This indicates that oxidative rancidity did not occur in 
RCSP over the storage period of six months. On the other hand, the FFA 
level increased in all treatments after two months of storage. Generally the 
increases were marginal; the steepest increases were recorded in the 
RCSP samples with 100ppm tocopherol. 
— 0 tocopherol 
- • — 50ppm tocopherol 
— 6 — 10Oppm tocopherol 
Q 2 4 6 Time (month) 
Figure 2: Effect of a tocopherol level oh FFA 
RCSP samples with zero and. 50 ppm tocopherol had the lowest mean FFA 
values. These results support the report that tocopherols are most effective 
at relatively low levels, and could act as a pro oxidant at high concentrations 
Furia(1983). 
The two packaging materials behaved in similar fashion and there was no 
significant differences in the FFA levels. This indicates that both 
Nylon/LLDPE and Polyester/LLDPE laminated pouches have similar water 
vapor and oxygen barrier properties. 
Changes in FFA level did not affect the sensory properties of RCSP. The 
increases in FFA values were low in comparison to other fatty foods. This 
may due to the use of good quality oil, low moisture and water activity and 
the antioxidant properties of spices. There are several reports on the 
antioxidant effect of spices on fat in certain foods Pruthi (1998). The results 
showed (Figure 2) that the addition of alpha tocopherol is not essential to 
delay rancidity development in RCSP, and that high doses may promote 
oxidation. 
27 
Microbial changes in during storage 
The microbial load in samples of RCSP are presented in Table 3. 
Table 3: Effect of packing material, alpha tocopherol level and period of 
storage on microbial load of RCSP 
Sample 
Fresh product 
Total plate count 
After 2 months 
storage 
After 4 months 
storage 
After 6 months 
storage 
A1 
A2 
A3 
A4 
A5 
A6 
2.1x1 cr 
2.1 x102 
2.1x102 
2.1X10 2 
2.1x102 
2.1x102 
9.0x10' 
8.9x102 
9.9x102 
1.0x10* 
8.9x102 
9.6x102 
6.5x10* 
7.0X10 2 
7.5x102 
8.0x102 
7.0x102 
7.2x102 
9.0x10' 
8.5x102 
9.0x102 
7.0x102 
8.0x102 
9.6x102 
(A1=No tocopherol + Nylon/LLDPE packs; A2=No tocopherol + Polyester/LLDPE packs; 
A3=50 ppm tocopherol + Nylon/LLDPE packs; A4=50 ppm tocopherol + Polyester/LLDPE 
packs; A5-100 ppm tocopherol + Nylon/LLDPE packs; A6=100 ppm tocopherol + 
Polyester/LLDPE packs) 
Although the microbial load in the RCSP increased during the six-month 
period of storage it remained well within safety limits. This may be due to the 
tow moisture level, low water activity and the effect of spices in RCSP. 
According to Pruthi (1998), spices have antimicrobial properties and contain 
natural bactericides, and bacteriostatic and fungi static compounds. Most of 
these properties depend on chemical compounds present in spices e.g. 
allicin in garlic, eugenole in cloves, gereniole in ginger and cumin aldehyde 
in cumin. Also, coconut paste has a low water activity, and as a major 
component of RCSP it would have a positive effect on the keeping quality. 
Total colony counts were within the range of safety levels and RCSP stored 
at a room temperature of 28° C is microbiologically safe, at least for a period 
of six months. 
CONCLUSION 
The production of an acceptable ready-to-use coconut cum spices paste to 
be used as a convenience product in preparing curried chicken is feasible. 
The product has an extended shelf-life at room temperature, without added 
preservatives or antioxidants. 
ACKNOLOWLEDGEMENT 
We are grateful to Mr. A. N. Kumara, Technical Assistant, Coconut 
Processing Research Division,, Coconut Research Institute for the 
cooperation. 
28 
REFERENCES 
Anon, (2002). Annual Report of the Coconut Research Institute - 2002, Lunuwila, 
Sri Lanka 
AOAC (1999). Official Methods of Analysis. Association of Official Analytical 
Chemists, 16 t h ED AOAC INC, Arlington, USA 
Fennima, O.R. (1995). Food Chemistry. 3 r t Ed., Marcel Decker INC., USA 
Femando.H. (1995). Coconut Industry in Sri Lanka, Towards Optimum 
Development. Quest 134. Centre for Society and Religion, Colombo, Sri 
Lanka, 7-10. 
Furia, T.E. (1993). CRC Hand book of Food Additives, Second Edition, CRC press 
INC., Ohio 
Jay.J.M.J. (1996). Modem Food Microbiology, 5 t h Ed. Chapman and Hall, New York 
Lawson, W.W. (1991). Standards for Fats & Oil, Westport, Connecticut: AVI 
publishing company, INC. 
Landrock, A.H. and Proter, B.E. (1951). A new graphical interpolation method for 
obtaining humidity equilibrium data with special reference to its role in food 
packaging studies, Food Technology, Chicago, 5,332. 
Kaplow, M. (1970), Commercial development of intermediate moisture foods, Food 
technology, 24,889. 
Pearson, D. (1973). Laboratory techniques in food analysis, Butterworth and Co 
(Publishers) Ltd., England, Australia, Canada 125-130,172 
Pruthi, J.S. (1998).Spice and condiments, National Book Trust, New Delhi 
Ranganna S. (1986). Hand book of analysis and quality control of fruits and 
vegetables products.Second Edition, TATA-Mc Graw Hill Publishing Co. 
Ltd., New Delhi 
Woodroof, J . G. (1979). Coconuts: Production, Processing, Products. Second 
Edition. The AVI Publishing Company Inc., Westport, Connecticut, 
University of Georgia, 189-236. 
29 


Preparation of a ready to use coconut Cum spices paste for chicken curry and evaluation of its physico -chemical and storage properties

Keerthi, S.M.G.S.

Wanigasundara, W.A.D.P.

Gunawardane, A.M.A.P.G.

COCOS (2005), 17 46 - 52 
Printed in Sri Lanka 
PERSUASIVE EXTENSION PROGRAM FOR COCONUT GROWERS - A 
PERFORMANCE EVALUATION IN KURUNEGALA DISTRICT 
S.M.G.S.Keerthl1 .W.A.D.P Wanigasundara1, P.A.H.N Appuhamy2, 
A.M.A.P.G Gunawardane2 
'Department of Agricultural Extension, Faculty of Agriculture, University of 
Peradeniya, Peradeniya, Sri Lanka, 
2Coconut Research Institute, Lunuwila, Sri Lanka 
ABSTRACT 
There is a lack of awareness among coconut growers in Sri Lanka of the 
potential of their land holdings. This is a serious impediment to the 
development of the coconut sector. The Persuasive Extension Program 
(PEP) was launched by Coconut Research Institute of Sri Lanka (CRISL), to 
convince coconut growers, in the Kurunegala, Puttalam and Gampaha 
districts, of the potential of their holdings and to persuade them to undertake 
a systematic program of development. PEP is a participatory program, 
where a CRISL team provides a development proposal after a detailed 
study jointly undertaken with the landowners. This proposal, for a six year 
development project, consists of various recommendations related to the 
cultural practices and their benefit/cost ratios. 
The objective of the study was to evaluate the success of the PEP pilot 
project started in 1995. The evaluation focused on the adoption level of the 
PEP recommendations, the growers' attitude towards PEP, and constraints 
that limit adoption. Field investigations were carried out with 40 randomly 
selected coconut growers involved in the PEP in Kurunegala District. 
Primary data was collected from October^ 2001 to January 2002 using an 
interview schedule. Field observations and informal discussions with 
extension and research officers of CRISL were also done. An adoption 
index was developed to measure the adoption level of cultural practices. 
Farmer's attitudes were measured using an attitude score. 
The level of adoption of the six recommendations under study increased 
after the PEP commenced. However, most growers had achieved only a low 
level of adoption. Soil and moisture conservation practices recorded the 
highest increase in adoption while animal husbandry recorded the lowest. 
Ten per cent of the respondents had not adopted the cultural practices 
recommended by the PEP. The percentage of low, moderate and high level 
adopters were 67.5%, 22.5% and 0% respectively. Clearly, the vast majority 
46 
were poor adopters. However, the majority (67.5%) had a highly favorable 
attitude towards the PEP. Lack of finance, shortage of workers, unstable 
coconut prices, and lack of efficient managers were identified as the major 
constraints to implementing the recommended cultural practices. 
Although the growers' have a positive impression of the PEP the success 
achieved in the Kurunegala district is inadequate. Increasing the number of 
monitoring visits, training programs, field days and demonstrations, backed 
up with a loan or subsidy scheme could improve the effectiveness of the 
PEP. 
INTRODUCTION 
The coconut sector in Sri Lanka plays an important role contributing 1.8 and 
4.00 per cent of the GDP and export earnings respectively. Although 
coconut is grown in all administrative districts, the most important coconut 
growing area is called the Coconut Triangle, which comprises coconut lands 
in Kurunegala, Puttalam, Colombo, and Gampaha districts. (C.D.A ,2002) 
Most coconut growers do not exploit the full potential of their lands due to 
poor adoption of production technologies, very high cost of labour and 
material inputs, depleted soils, adverse weather conditions and poor estate 
management (Gunathilake, 1996). Although technology to improve coconut 
plantations is not lacking the productivity achieved by most growers is well 
below the potential of their lands. 
With the growth in population the demand for coconut is increasing. 
However, the land available to expand cultivation is limited. Therefore, the 
increasing demand should be met by raising the productivity of existing 
holdings, which will also be economically advantageous to the growers 
(Liyanage.1998). Although a wide range of technologies such as use of high 
yielding varieties, fertilizer mixtures and pest and disease management 
have been introduced by the Coconut Research Institute of Sri Lanka 
(CRISL), a significant proportion of growers do not adopt them. One of the 
reasons for low adoption seems to be the inability of the extension services 
to convince the farmers about the benefits of these technologies 
(Mahindapala,1997). 
The CRISL, as a matter of policy, accepts that participatory approaches 
such as on-farm adaptive trials, demonstration trials and packaging of 
technologies are more suited for tehnology transfer, with the direct 
involvement of scientists (Appuhamy, 1995). The Persuasive Extension 
Program (PEP) is one such participatory approach introduced by the CRISL, 
in 1995, to facilitate technology transfer. In this approach, a team of 
researchers, extensionists and economists, about five in all, visit the holding 
by prior appointment for a detailed discussion with the landowner on the 
47 
ways and means of developing his land. The team after a thorough 
investigation of the holding prepares a development plan including the 
benefit/cost ratios and various options for development of the land. If the 
grower accepts the proposal, CRISL will assist in its implementation and 
review the progress periodically. 
METHODOLOGY 
Nearly 300 innovative coconut growers in the Kurunegala, Puttalam, and 
Gampaha districts participate in the PEP. About 100 are from the 
Kurunegala district, and 40 of these fanners were selected, at random, for 
the field survey. A pre-tested and revised interview schedule was used in 
the survey. The survey data was supplemented with field observations, 
information from informal discussions with the extension officers and 
research officers of the CRISL and published secondary data. 
The pre- and post-PEP status was compared to measure the level of 
adoption of the recommended cultural practices. Six recommended cultural 
practices, pertaining to fertilizer usage, soil and moisture conservation, pest 
and disease control, weed management, intercropping and animal 
husbandry, were considered for the adoption index. The pre- and post-PEP 
status, in respect of each cultural practice, was scored; and the difference 
taken as the level of adoption. The six cultural practices were considered to 
be of equal importance and given equal weightage. The summation of the 
adoption levels of all six recommendations represented the overall adoption 
index of the farmer. The paired t test was applied to determine the 
significance of the difference between the pre- and post-PEP total scores. 
Farmers' attitudes were measured by using the responses obtained on a 
three point continuum: agree, neutral and disagree with a weightage of 3, 2, 
and 1, respectively. According to the total score for attitude towards PEP the 
respondents were divided into two categories: favorable attitude and highly 
favorable attitude. 
RESULTS AND DISCUSSION 
Status of the holdings and the respondents 
Respondents' land holdings ranged from 2.2 ha to 42.5 ha and the mean 
was 41.3 ha. Owner-operators managed 77.5 per cent of the holdings, and 
the balance by caretakers or superintendents. Most of the owner-operators 
(77.78%) were from distant cities and villages and did not live on the 
property. 
48 
Status of the cultural practices 
As a result of implementing the PEP there was some improvement in the 
adoption level of all six cultural practices recommended (Table 1). The 
largest increase in the level of adoption was recorded in soil moisture 
conservation and fertilizer usage, and the least in weed management and 
animal husbandry. 
Tablet: Level of adoption of the recommended cultural practices, before 
and after PEP (N=40) 
Cultural Practice Adoption level % 
Before PEP After PEP 
1.Fertilizer usage 52.5 85. 
2.Soil and moisture conservation 60 95 
3.Pest and disease control 40 67.5 
4.Weed management 77.5 92.5 
5. Intercropping 35 57.5 
6.Anima1 husbandry 27.5 32.5 
The application of fertilizer according to the recommended method, dosages 
and frequencies has increased as a consequence of the PEP. The lack of 
funds however was, quite often, a constraint to fertilizing at the correct 
dosages and frequencies. 
The majority of the respondents were mulching on a regular basis, prior to 
PEP, as it is a low cost operation. Therefore, the increase in the adoption of 
this practice after PEP was not significant. Many respondents who used to 
dump husks around trees (as a soil moisture conservation measure) before 
PEP, have now realized the importance of burying the husks for soil 
moisture conservation. The establishment of cover crops was minimal, both 
before and after PEP, due to unavailability of cover crop seeds and the 
difficulties encountered in maintaining a cover crop. 
Generally, the growers' perception was that it was difficult to control pests 
and diseases. PEP was successful in convincing some of them that it was 
not so. Only 12.5% of the respondents were aware of the pheromone trap 
as a pest control method. Five per cent believed that pheromone traps 
would attract the pest to their holding from elsewhere and worsen the 
situation. Therefore, they felt that CRISL should extend this methodology to 
their neighbors as well, and ensure simultaneous trapping in all holdings. 
This issue needs careful investigation by the CRISL. 
There was no marked increase in the adoption of weed control measures as 
most growers were weeding regularly even before PEP. 
49 
Only a very small proportion of coconut growers engaged in animal 
husbandry; they were reluctant to rare animals. The low level of emphasis 
on animal husbandry was also reflected in the composition of the PEP 
teams; they lacked specialists in animal husbandry. 
The overall level of adoption of recommendations 
Using the adoption index, which reflected the farmer's overall level of 
adoption, the respondents were divided into four adoption categories. 
Table 2: Distribution of respondents according to the overall adoption level 
(N=40) 
Adoption category Adoption Index Percentage 
No adoption 0 10 
Low adoption 1-8 67.5 
Moderate adoption 9-16 , 22.5 
Hiqh adoption 17-24 0 
It is evident from Table 2, that the level of adoption displayed by the majority 
of the respondents (77.5%) was poor. Only 22.5 % had a moderate level of 
adoption; and there was none in the high adoption category. 
Reasons for poor adoption 
The constraints faced by respondents in implementing the 
recommendations were studied, using a questionnaire, to understand the 
reasons for poor adoption. The results are presented in Table 3. 
Table 3: Percent respondents affected by major constraints In 
implementing PEP recommendations (N=40) 
Constraints Percentage 
1. Financial problems 82.5 
2. Busy with other engagements 47.5 
3. Problems with caretakers 37.5 
4. Labour scarcity 70.0 
5. Inadequate knowledge & skills 35.0 
6. Unstable price for coconuts 42.5 
Lack of funds was the most important constraint and affected the high cost 
operations. The use of fertilizers at the correct dosage and frequency and 
husk burial were the most capital intensive operations. Labour requirement 
for coconut cultivation is relatively low in comparison to other plantation 
crops. Nevertheless, labour scarcity was a burning problem to many 
growers because workers were now seeking better jobs with a higher status. 
50 
As most owners lived outside their estates, and had other interests, 
caretakers or superintendents were employed to manage their lands. Often 
the management was very poor due to the inefficiency of the managers. , 
The price of coconuts was high during the study period. But farmers were 
worried about the stability of the prices, as they have experienced wide price 
fluctuations in previous years. The instability of intercrop prices also was 
seen as a problem for those who practiced intercropping. It also transpired 
that training and other extension facilities were inadequate for animal 
husbandry. 
Growers' attitude to the PEP 
Growers' response to 10 elements, including the usefulness of PEP 
recommendations, training needs and interactions with the CRISL, were 
measured to ascertain their attitude to PEP, and also to identify ways of 
further improving the PEP approach. Although all respondents mentioned 
- that PEP is beneficial none of them had a high level of adoption of the 
recommended cultural practices. Only 20 per cent accepted that their 
income and production increased after the PEP. 
Growers' knowledge on scientific aspects of cultivation had improved 
significantly, as all activities to be performed were explained in the PEP 
development proposal. But 60% felt that the training given under the PEP is 
not adequate, and the follow up visits and interactions with the officers were 
not sufficient. Extension staff ascribed these deficiencies to inadequate 
resources. 
Most respondents (92.5%) were of the view that PEP should be 
complemented with a loan or subsidy scheme. A majority stated that if the 
coconut prices are high and stable, they would invest more on cultural 
practices. 
The total 'attitude score* for each respondent was calculated, and on this 
basis the respondents were divided into two categories.(Table 4) 
Table 4: Distribution of the respondents according to attitude score 
Att i tude category Att i tude score Percentage of 
respondents 
Less favorable 10-20 32.5 
More favorable 21-30 67.5 
Clearly, the majority of the respondents have a positive attitude towards the 
PEP. 
51 
The relationship between attitudes and the adoption level was tested using 
the Chi-square test. The attitude level did not show a significant relationship 
with the level of adoption (Table 5) 
Table 5: Distribution of respondents by attitude level and level ofjadoption 
Att i tude level 
Adopt ion level 
Total No adopt ion Low adopt ion Moderate 
adopt ion 
Low attitude 5 30 15.0 50 
High attitude 5 37.5 7.5 50 
Total 10 67.5 22.5 100 
xa-1.333,p0.513 
CONCLUSION AND RECOMMENDATIONS 
1. All the six recommended cultural practices showed an increased 
level of adoption after the PEP. High priority should be given further 
to the practices, like animal husbandry which had low adoption. 
2. Overall adoption index showed that none of the respondents were 
highly adopted to the recommended practices while majority was low 
adopted due to various reasons. The greater attention should be 
paid for minimizing those constraints of the growers. 
3. Increasing the number of monitoring visits, training programs, field 
days and demonstrations and the introduction of a subsidy scheme 
along with the PEP could improve the effectiveness of the PEP. 
REFERENCES 
Appuhamy, P.A.H.N. (1995). New Extension Approach to increase income from 
Coconut estates, Coconut Bulletin 10,1/2:17-19 
Coconut Development Authority, 2002 [On Line] Coconut Industry in Sri Lanka 
<http.org.sg/SRILANKA.HTM> 
Gunatilaka, H.A.J. (1996). Progress of the Contract Research Project 12/233/171 
Adaptive Research Program on Crop/Farm Models: Report to the Sri Lanka 
Council for Agricultural Research Policy(lnternal Document) 
Liyanage, M.de.S. (1999). A guide to Scientific Cultivation and Management of 
Coconut, Coconut Research Institute of Sri Lanka 
Mahindapala, R. (1997). Technology transfer in Coconut Cultivation. 
The Quest for a Better Approach: Report to the Sri Lanka Council for 
Agricultural Research Policy. 
Official web site of Asia Pacific Coconut Community (www.apcc.org.sg.2002) 
52 


Persuasive extension program for coconut growers -a performance evaluation in Kurunegala district

Thanaraj, T.

Dharmasena, D.A.N.

Samarajeewa, U.

Copra drying in an improved solar dybrid system, CRI improved kiln and in the sun. a comparative study of drying characteristics

Ramaraju, K.

COCOS (2005), 17 53-56 
Printed in Sri Lanka 
A RAPID METHOD FOR POPULATION ASSESSMENT OF THE 
COCONUT ERIOPHYID MITE, ACERIA GUERRERONIS KEIFER 
(ERIOPHYIDAE: ACARI) 
K. Ramaraju 
Department ofAgricultural Entomology 
Tamil Nadu Agricultural University 
Coimbatore - 641 003, India 
ABSTRACT 
A simple, reliable and effective Water Wash Count Method to estimate the 
population of the coconut eriophyid mite, Aceha guerreronis on coconut 
buttons, is reported. 
INTRODUCTION 
Outbreaks of the coconut eriophyid mite, Aceria guerreronis Keifer, hitherto 
a serious pest of coconut in other parts of the world, were reported from 
Kerala and Tamil Nadu during 1998 by Sathiamma et a/., (1998) and 
Ramaraju et a/., (1999). Since then it has spread to almost all parts of Tamil 
Nadu and the level of infestation varies from 10 to 90 %. The attack results 
in both qualitative and quantitative losses in yield. The eriophyid mites are 
minute, about 250 // long and 50 u in width, and multiply rapidly. The mites 
feed on the meristematic tissue found under the perianth of growing nuts 
and also adhere to the inner surface of sepals. The mite infestation on nuts 
is patchy; not uniformly distributed. 
Two types of sampling methodSj non destructive and destructive, are widely 
used by many workers. In non-destructive sampling, mites are counted in 
situ allowing subsequent counts at the same site. However, non-destructive 
sampling methods cannot be employed in the case of gall forming eriophyid 
mites, since numerical estimates of individuals typically depend on removing 
the mite from the galls (Perring ef al, 1996). The major disadvantage of non­
destructive sampling is that sampling requires more time in the field and is 
very difficult to observe mites in concealed niches. Hence, destructive 
sampling methods that save time are used to assess mite populations. Of 
the several methods adopted for estimating mite populations by destructive 
methods, Yothers and Millers (1934) used a counting template, consisting of 
a 0.5 inch square, cut in a piece of paper, to estimate the densities of citrus 
rust mites on the upper and lower surfaces of leaves and on fruits. 
Ramaraju ef al., (2000 and 2001) estimated mortality of A. guerreronis either 
by counting only the live mite population or by counting dead and live mite 
populations found in a unit area of 4 sq.mm. 
53 
There is a need to measure the abundance of eriophyid mites without 
removing nuts from the tree. But since the coconut eriophyid mites, A. 
guerreronis are found concealed beneath the tepals, it has not been 
possible to accurately estimate the mite population on coconut by non­
destructive sampling methods. There is no uniformity in the infestation and 
no damage on the surface area. Even in the same plantation some trees 
may be free of infestation, and in a bunch few nuts may be completely free 
of damage. Hence, selecting and sampling nuts having different infestation 
levels is very difficult. Although not very precise, destructive sampling is the 
most widely used method of assessing eriophyid mite populations. 
It is very cumbersome to count mites present in a unit area, under a 
microscope and may possibly lead to biased sampling. Hence, a reliable 
and an effective method using water was developed to estimate the total 
mite population in coconut buttons. 
MATERIALS AND METHODS 
Assessing mite populations 
Water wash count method - The materials required for this method 
consisted of a 50 ml beaker, funnel, nematode counting dish, wooden stand, 
scalpel, 1 ml syringe and water. A few drops of soap solution or detergent 
were added into the water to facilitate washing. Infested samples (four-
month old buttons) were collected from the field and the 'tepals' were first 
removed separately with the help of a knife or scalpel. Place the funnel in 
the wooden stand and beaker under the funnel. Wash the inner surface of 
all the six tepals by forcibly ejecting the soap water solution using the 1 ml 
syringe and collect the different bio stages in the beaker through funnel. 
Then hold the nut upside down and wash the meristematic tissue (i.e. area 
covered by the tepals). Repeated washing (4-5 times) is necessary to collect 
all the bio stages. Approximately 10 ml of soap solution is required to 
completely wash the tepals and nut surface. If necessary, add a few ml and 
make up the solution to either 10 or 20 ml per sample. Shake thoroughly 
and take a one or two ml aliquot from the beaker, count the bio stages either 
separately or larvae + adult mites per ml using the nematode count dish 
under a stereo-zoom microscope and calculate the numbers in the total 
volume of water used. Other organisms like the predatory mites, mealy bug 
crawlers, predatory thrips etc. found within the tepals may also be washed 
out. If required these may be counted separately. 
Template count method - In this method the live eriophyid mite population, 
both nymphs and adults, was recorded in a 4 sq. mm area, using a 
template, on each of the innermost bracts (three observations on 4 t h, 5 t h 
and 6 t h bracts) and the nut surface (at three places), in each sample. The 
54 
observations were made at the places which appeared to have the largest 
populations. 
An experiment was conducted to compare the two methods described 
above. Twenty trees were maintained separately, for each treatment A 
single, infested, four-month old button was collected each month from each 
tree for population assessment, from January 2000 to December 2001. 
Thus, a total of 480 coconut buttons were assessed, in each treatment. The 
data were statistically analysed using correlation and regression 
methodology. 
RESULTS AND DISCUSSION 
The results of the wash method gave the total number of mites present in a 
nut, whereas the template count gave a proportion of the live mite 
population under bracts (tepals) and on the nut surface. A positive 
correlation was found between the live mite and total mite populations 
(Table 1). The regression equation was Y = 0.0038X + 13.812 (Fig 1). Both 
methods showed a similar trend in mite population indicating their reliability 
as methods of assessment. 
Table 1: Comparison of coconut eriophyid mite population assessed using 
template count and water wash count methods 
Palm No. No. of mites (Mean o f 24 nuts/palm) 
Template method (4 sq . mm.) Water wash method (10 ml) 
1 27.50 6720 
2 42.83 4960 
3 42.00 8480 
4 49.33 5280 
5 30.50 3680 
6 17.00 2880 
7 53.00 8160 
8 33.50 8960 
9 62.83 7680 
10 24.00 2880 
11 41.66 3680 
12 13.33 3360 
13 14.66 2880 
14 27.00 6720 
15 23.00 7360 
16 54.00 8640 
17 37.66 5280 
18 44.83 5280 
19 49.00 9280 
20 48.00 8670 
R value = 0.61 
55 
REFERENCES 
Perring, T. M., Farrar, C. A. and Oldfiekd, G.N. (1996).Sampling Techniques. In: 
Eriophyoid mites. Their biology, natural, enemies and control. E. E. 
Lindquist, M. W. Sabelis and J. Bruin (eds).Elsevier sciences, Amstertdam, 
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56 


A rapid method for population assessment of the coconut Eriophyid mite, Aceria guerreronis keifer (Eriophyidae : Acari)

Siriwardena, P.H.A.P.

Fernando, L.C.P.

A new method to estimate the population size of coconut mite, Aceria guerreronis, on a coconut

National Science Foundation of Sri Lanka

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