Weed control and cowpea yield under different tillage systems

Abstract

Field studies conducted in 2016 and 2017 in Calabar, Nigeria, evaluated the influence of tillage methods on weed control and yield of cowpea ( Vigna unguiculata [L.] Walp). These were split-plot experiments laid out in a randomized complete block design with three replications; involving no-tillage, plough + harrow, hoe tillage and SAMPEA 11, SAMPEA 12 and “ Kanannado ” cowpea varieties. Analysis of variance indicated significant ( P ≤ 0.05) tillage, cowpea varieties and their interaction effects on weed control and yields of cowpea. Tillage system did not change the soil texture. The results obtained could not be attributed to environmental changes as the weather data for the 2 years were not unique, rather they followed a similar trend. Longer pods with the highest number of pods plant −1 , seeds pod −1 , and seed yield (kg) ha −1 of cowpea were produced in ploughed plus harrowed plots. dry matter by 50.32% and 49.39% over SAMPEA 12 and SAMPEA 11, respectively. “ Kanannado ” combined with no-tillage (92.00 kg ha −1 ) was similar ( P > 0.05) to SAMPEA 11 combined with no-tillage (101.50 kg ha −1 ). However, the combination of SAMPEA 12 with ploughing and harrowing produced the highest seed yield (667.00 kg ha −1 ) and was recommended for adoption based on outstanding yield and satisfactory weed control in cowpea production in the study area.