Influence of Pruning Levels and Fertilizer Rates on Growth and Yield of Jatropha curcas L. (Physic Nut)

Appropriate canopy management and proper application of fertilizer under different growing conditions and agronomic practices can obtain reliable yield of Jatropha curcas L. (Physic Nut). The objective of study was to determine the influence of pruning level in first year and fertilizer rate of combined NPK in the first and second year on growth and yield of Physic nut, conducted at Agricultural Research Station, Prabhunagar (Dharwad). The seeds were dibbled at 3 x 2m spacing apart. A split plot design with three replications was used. Four pruning levels of 100 cm, 150 cm, 200 cm and No pruning from the ground were assigned in main plots and combination of NPK fertilizers levels (40:40:40, 60:60:60, 80:80:80 N:P2O5:k2O g/ plant) were arranged randomly in subplots. All pruning levels from the ground did not have significant effects on number of branches and collar diameter, whereas application of fertilizer did increase number of branches, collar diameter, fruit yield and seed yield (15.77, 18.71cm, 316.65 and 727.96 g per plant respectively). Number of branches and collar diameter of Jatropha were significantly higher in pruning at 100 cm height from ground level (16.94 and 17.04cm respectively) as compared to other pruning levels. It is thus recommended to prune Physic nut at 200 cm from the ground and apply fertilizer at the rate of (80:80:80 g H:P2O5:K2O per plant) as it recorded maximum seed yield per plant (1142.95 g) and per hectare (1903.68 kg.) respectively over other treatment combinations.