MSc

The present investigation entitled “Influence of nutrition and varieties on yield
and qualities of coconut inflorescence sap” was conducted at Instructional farm,
College of Agriculture, Vellayani and Nileswaram farm, RARS, Pilicode during
2014-2016. The objective of the study was to assess the influence of nutrition to
coconut as different levels of fertilizers and varieties on yield, nutritional qualities
and biochemical properties of coconut inflorescence sap.
The study consisted of two field experiments, both laid out in randomised
block design. The first experiment was to study the influence of different levels of
NPK fertilizers namely POP recommendation (T1), 125 % POP recommendation
(T2), 150 % POP recommendation (T3) and 175 % POP recommendation (T4) which
was carried out on west coast tall variety at Instructional Farm Vellayani under
rainfed condition.
The analysis of soil samples collected at the end of the experiment revealed
that the status of available primary nutrients (N, P and K) was significantly
influenced by the treatments. T4 recorded the highest value for all the 3 nutrients but it
was on par with T2 and T3 in the case of N and was significantly superior to T2 and
T3 in the case P and K. There was no significant difference between the treatments
with respect to secondary and micro nutrients.
The analysis of index leaf tissue of coconut revealed that there was no
significant influence of the fertilizer levels on the content of primary, secondary and
micro nutrients except for zinc where T4 (193.76 mg kg-1) recorded the highest value
which was on par with T3 (189.84 mg kg-1).
The yield of coconut inflorescence sap (CIS) was significantly influenced by
fertilizer levels. T4 (3.32 l day-1) recorded the highest yield, which was 134% more
over POP recommendation (T1). However, there was no significant influence of
treatments on sap production duration.
Analysis of CIS revealed that the pH of sap was significantly decreased by
increasing fertilizer levels while the total electrolyte concentration increased till T4
(3.96 dS m-1) but was on par with T3 (3.85 dS m1).
The quality parameters namely reducing sugar, non reducing sugar and total
sugar were significantly influenced by the treatments with T4 recording the highest
value. The alcohol content was highest in T4 (0.09 %) which was on par with T3
(0.08 %). The content of phenols, vitamin C and protein nitrogen were significantly
increased by fertilizer levels. The treatments significantly increased the content of
primary, secondary and micro nutrients in sap except for zinc, copper and
manganese.
The second experiment was to study the variability among coconut varieties
namely Malayan Yellow Dwarf (T1), Kerasree (T2), West Coast Tall (T3) and
Keraganga (T4) with respect to yield and quality of CIS. This was carried out at
Nileswaram farm, RARS, Pilicode under irrigated condition.
The varieties varied significantly with respect to CIS yield. It was maximum
in the tall variety WCT (3.14 l day-1) followed by the hybrid varieties Kerasree (2.09
l day-1) and Keraganga (1.80 l day-1). The dwarf variety MYD gave the lowest CIS
yield of 0.84 l day-1.
The analysis of CIS revealed that the variety WCT was superior with respect
to reducing sugar (0.52 g 100ml-1), total sugar (10.66 g 100ml-1), phenols (5.71 mg
100ml-1), vitamin C (1.87 mg 100ml-1) and total mineral content (2.32 %) while the
dwarf variety MYD gave higher non-reducing sugar (10.23 g 100ml-1) and alcohol
(0.09 %).
The study on changes in CIS during storage for 1 week indicated that without
any differentiation between varieties there was a decrease in pH, total sugar,
reducing sugar and non-reducing sugar while there was an increase in alcohol and
vitamin C content.
From the results of the study it can be concluded that, the yield, nutritional
qualities and biochemical properties of CIS can be significantly improved by
applying 75 % extra NPK fertilizers over and above the current POP
recommendation for palms maintained for nut production. The tall variety WCT
exhibited better sap yield and sap quality parameters and is more suitable for sap
production compared to dwarf varieties and hybrids.