Economic Evaluation of Methods of Weed Control and Insecticide (Lamdacyhalothrin) Rates in the Production of Cowpea (Vigna Unguiculata L)Walp) in the Southern Guinea Savanna of Nigeria

Abstract

Field trials were conducted in two locations, at the Teaching and Research (T&R) Farm of the College of Agriculture, Kwara State University and Ga-Alanu Village, Malete, in the 2015 cropping season. The aim was to determine the economic benefits of different methods of weed control applied together with insecticide rates in the production of cowpea. The experiment consisted of 18 treatments; three insecticide(Lambdacyhalothrin) rates, 0 ml, 175 ml (8.75 g ai/ha) and 350 (17.5 g ai/ha) ml/ha and six methods of weed control (pendimethalin at 1.5 kg a.i/ha, pendimethalin at 2.0 kg a.i/ha, pendimethalin at 1.5 kg ai/ha + one supplementary hoe weeding (SHW), metholachlor (1.5 kg a.i/ha) + Diuron (0.6 kg a.i/ha), hoe weeding at 3 and 6 weeks after sowing (WAS) and a weedy check. The treatments were laid out in randomized complete block design (RCBD) fitted into split plot arrangement and replicated three times. Results showed that insecticide rates at 175 ml and 350 ml/ha and pendimethalin at 2.0 kg ai/ha and pendimethialin at 1.5 kg a.i/ha plus one SHW at 6 WAS produced the maximum cowpea grain yield and were also more cost-effective and profitable in the production of cowpea in the southern Guinea savanna of Nigeria.