Abstract:
Field experiments were conducted at the Instructional Farm, College of Agriculture, Vellayani to study the effect of nitrogen and potassium on growth and yield of Colocasia and uptake pattern of major nutrients under open and intercropped situations in coconut gardens. The treatments in the experiment consisted of a combination of three levels of N) 40, 60 and 80 kg/ha) and three levels of K (80, 120 and 160 kg/ha). The experiment was laid out in 32 factorial RBD.
Different growth attributes like plant height, number of leaves plant-1and LAI were maximum when N @ 60 kg/ha and K @ 160 kg/ha were applied under open condition. Under intecropped situations N @ 40 kg/ha and K @ 160 kg/ha recorded the maximum values for these characters.
The yield attributes viz., number of cormels/plant, mean weight of cormels, cormel and corm yield/plant, and harvest index gave maximum values when N @ 60 kg/ha and K @ 160 kg/ha were applied under open condition. In the intercropped situation, the highest values were obtained when N and K were applied @ 40 and 160 kg/ha. Nitrogen @ 60 kg/ha and K @ 160 kg/ha gave the highest yield of marketable tubers under open condition while K @ 160 kg/ha gave the maximum yield under intercropped situation.
Nitrogen had no influence on yield of marketable tubers under intercropped situations. Pottasium application increased the starch percentage of tubers and 160 kg K/ha resulted in the maximum value under open and intercropped situations. Plant uptake of N, P and K were influenced by increasing levels of K and was highest at the highest level of K in both open and intercropped situations. Available N and P content of the soil was not influenced by N and K levels under open condition, while the available K was maximum when 160 kg/ha was applied in both open and intercropped situations. Maximum benefit cost ratio and net returns were obtaining by the application of N and K @ 60 kg/ha and 160 kg/ha respectively under open conditions and 40kg/ha and 160 kg/ha respectively under intercropped situation with coconut.
