Assessing the critical period of weed interference in groundnut Arachis hypogaea L. in Ogun State, south western Nigeria

Abstract

The critical period of weed interference in groundnut was investigated in 2018 and 2019 early cropping seasons at the Federal University of Agriculture, Abeokuta, Ogun State, Nigeria. The experiment consisted of ten treatments arranged in a randomized complete block design and replicated three times. Treatments includes keeping plots weed free initially for 3, 6, 9, 12, 15 weeks after planting (WAP) and keeping plots weed infested initially for 3, 6, 9, 12, 15 WAP. Data collected on weed cover score, weed dry matter production, crop vigour score, canopy spread, pod yield and numbers were subjected to analysis of variance and treatment means were separated using least significant difference at P ≤0.05. The results showed that total weed dry matter production increased with weed infestation period and decreased with weed free period. Also, there was significant increase in pod yield and count when plots were kept weed free for 6 WAP and more. Our findings showed that, the highest percent weed accumulation, weed removal, pod yield loss and pod yield gain all occured between 3 and 6 WAP. Therefore, the critical period of weed interference in groundnut is between 3 and 6 WAP. Also, there was 83.4% pod yield loss in groundnut when weed was allowed to compete freely with the crop throught crop life cycle.