Effect of nitrogen and weeding regimes on yield and yield components of maize (Zea mays L.) in the derived guinea savanna Agro-ecological zone of Nigeria

In the 2017 and 2018 wet seasons, field trials were conducted at the Teaching and Research Farm of the Faculty of Agriculture, Kogi State University, Anyigba to determine the effect of nitrogen and weeding regime (period of weed interference) on the yield and yield components of maize. The experimental design used was a split-plot in a randomized complete block design replicated three times. The main plot was assigned to four different levels of nitrogen 0, 40, 80 and 120 kg N/ha while the sub-plot was assigned to different frequencies or regimes of weed control. The results obtained from the study revealed that the application of 120 kg N/ha produced the highest cob weight, 100-seed weight and grain yield per hectare in both years. The study also showed that all the rates of nitrogen application resulted into increased grain yield in comparison to where there was no nitrogen application. Maize plant kept weed-free for 9 and 12 weeks after planting (WAP) and those weed infested for 3 WAP produced cob dry weight, 100-seed weight and grain yield (kg/ha) comparable to those kept weed-free throughout. From the two-year study conducted, it was found out that keeping the field weed-free for only 3WAP did not provide a satisfactory weed control situation for optimum crop performance owing to imminent re-infestation. Conversely, plants weed infested for 3WAP could ward off whatever damage that might have been inflicted initially through subsequent re-growth which could translate into impressive yield as observed in this study.