Biochemical characterisation of coconut palms in relation to yield

Abstract

An investigation on the morphological and chemical components of yield in coconut palms was conducted at the College of Horticulture, Vellanikkara during 1981-83, in order to characterise the yield of palms based on these characters. Sixty palms of the cultivar West Cost Tall (W.C.T.) were selected from the existing Plantation at Agricultural Research Station, Mannuthy comprising twenty palms each under low, medium and high yield groups (< 40, 40-80 and 80 nuts/palm/year respectively). Observations on morphological characters such as number of leaves, length of leaf, length of petiole, number of leaflets, length of leaflets, periodicity of leaf emergence and girth at collar were recorded at bimonthly intervals. Analysis of leaf samples from the leaf position 14 were taken up to estimate the contents of nitrogen, phosphorus, potassium, calcium, magnesium, soluble sugars, starch, total phenols, free amino acids, total chlorophyll, catalase activity and peroxidase activity during March-April and September-October seasons. There was a significant positive correlation for number of leaves, length of leaves, number of leaflets, length of leaflets and girth at collar with the mean annual yield. The periodicity of leaf emergence had a negative correlation with yield. Among the mineral nutrients, nitrogen and potassium had significant positive correlation with yield. Phosphorus, Calcium and magnesium failed to show any linear relationship. The nutrient ratios viz., N/Ca, K/P, K/Ca, K/Mg and K/Ca + Mg also exhibited significant positive correlation with yield. The biochemical components such as soluble sugars and total chlorophyll content in the leaf lamina had significant positive correlation with yield. Total phenolic compounds present in the leaf lamina had a significant negative correlation with yield. Starch content in the leaf did not show such relations. The free amino acids present in traces in the leaf were identified. Leaf catalase and peroxidase activity exhibited no definite pattern of variation in relation to yield