Growth attributes of extra-early maize (<i>Zea mays</i> L.) varieties as influenced by pre-and post-emergence herbicides in Northern Guinea Savanna of Nigeria

Abstract

Two field trials were conducted during 2016 and 2017 wet seasons at Kaduna State Agricultural Development Project (KADP) Maigana Research Farm, to assess the performance of three extra-early maize varieties (SAMMAZ-29, 32 and 33). Treatments were laid out in a split plot design consisting of 12 weed control treatment combinations nicosulfuron (0.075 and 0.15kg a.i./ha), Atrazine + pendimethalin (2.0 +2.0 kg a.i./ha) each of these was applied alone, followed by hoe weeding at 5WAS and followed by nicosulfuron (0.075kg a.i./ha) at 5 WAS. The parameters measured include leaf area index (LAI), crop vigor score, relative growth rate and grain yield ha^-1. The result showed that SAMMAZ-29 and SAMMAZ-32 had the highest LAI at 12 WAS in 2016, and hoe weeding (weeded at 3 and 6 WAS) at all the sampling periods in 2016, and at 4WAS and 12WAS in 2017, which was statistically similar to Atrazine (2.0 kg a.i./ha) followed by nicosulfuron (0.075 kg a.i./ha) at 5 WAS produced the highest LAI in 2017; SAMMAZ-29 produced the highest crop vigor score (CVS) at 4 and 12 WAS in 2016, similarly in 2017 SAMMAZ-29 and SAMMAZ-33 had the highest CVS at 8 WAS and nicosulfuron (0.15 kg a.i./ha) at 2 WAS followed by nicosulfuron (0.075 kg a.i./ha) at 5 WAS and hoe weeding at 3 and 6 WAS significantly produced the highest CVS at 12 WAS in 2016. Similarly, in 2017, nicosulfuron (0.15kg a.i./ha) at 2 WAS followed by nicosulfuron (0.075 kg a.i./ha) at 5 WAS, produced the highest CVS at all the sampling periods. SAMMAZ-29 with nicosulfuron (0.15 kg a.i./ha) at 2 WAS followed by nicosulfuron (0.075 kg a.i./ha) at 5 WAS produced the highest Relative growth rate (RGR) at all the sampling periods in both seasons. SAMMAZ-29 with nicosulfuron (0.15 kg a.i./ha) at 2 WAS followed by nicosulfuron (0.075 kg a.i./ha) at 5 WAS produced the highest grain yield/ha in 2016 and the mean. It could be suggested that SAMMAZ-29/SAMMAZ-32 with the application of Nicosulfuron (0.15 kg a.i./ha) at 2 WAS followed by Nicosulfuron (0.075 kg a.i./ha) at 5 WAS could be used by farmers for weed management during the production of maize in the northern Guinea savannah ecological zone of Nigeria.