Effect of defoliation on source-sink relationship in groundnut (Arachis hypogaea L.)

Abstract

A field investigation was taken up in groundnut variety Kadiri-6 to study the effect of defoliation on source sink relationship at Regional Agricultural Research Station, PJTSAU, Palem for two consecutive years i.e. Kharif, 2015 and Kharif, 2016. Defoliation was practiced at 90 DAS. Out of the five treatments, no defoliation has given best results over other four defoliation treatments. Among the two years 2015, 2016 and pooled, lower values were registered as the intensity of defoliation increased for all the characters. Near to zero values were registered for leaf area and leaf mass in 100 defoliation. For shoot mass (g/plant), root mass (g/plant), pod yield per plant (g/plant) and pod mass per plant (g/plant), among two years 2015, 2016 and pooled analysis, pod mass was highest in no defoliation followed by 25%, 50% and 75 % levels of defoliation. The lowest pod mass per plant was recorded in severe (100%) defoliation. The moderate and severe defoliation treatments significantly reduced all characters. Defoliation reduced the dry weight of root, shoot and pod mass. The adverse effect of defoliation was more pronounced when defoliation was complete than when half of the number of leaves were removed. The greatest reduction in yield occurred when the plants were defoliated during the early pod stage. Hence, in ground nut variety Kadiri - 6, no defoliation is the best to practice in realizing more pod yield per plant than defoliation.