CRITICAL PERIOD OF WEED INTERFERENCE ON SOYBEAN (GLYCINE MAX (L) MERRILL)

Abstract

Weeds are one of the important factors affecting agriculture production, weeds and inadequate weed control and management pose a detrimental factor affecting crop production. The experiment was conducted at the Teaching and Research Farm of Federal University Technology, Minna, Nigeria, to determine the effectiveness of different weeding regime and critical period of weed interference in the growth and yield of soyabean. The treatments were laid out in a Randomized Complete Block Design (RCBD) and replicated three times. There are ten treatments consisting of weed infested and weed-free as follows T1= soybean + weeding for 2 weeks, T2= soybean + weeding for 4 weeks, T3= soybean + weeding for 6 weeks, T4= soybean + weeding for 8 weeks, T5= soybean + weedy for 2 weeks, T6= soybean + weedy for 4 weeks ,T7= soybean + weedy for 6 weeks, T8= soybean + weedy for 8 weeks, T9= soybean + weed-free plot till end and T10= soybean + no weeding till end. Data were collected on weed cover score, weed dry weight, plant height, pod weight and grain yield. The Data were subjected to analysis of variance using SAS, software version 9, 2002. The results showed that soyabean with weed-free plot for 4, 6 8 and weed-free throughout significantly P<0.05 suppressed weed and increases yield by 70 % compared to other treatments The use of early maturing variety of soybean in addition to weed-free plot throughout the growth stage and weed-free for 8 weeks could be recommended in controlling weed interference in soybean for better soybean growth and yield.