Effect of cropping system induced shading on the grain yield and yield attributes of cowpea varieties intercropped with sorghum based systems in the Sudan savannah ecological zone of Nigeria

Abstract

Six cowpea varieties (IT98K-131-1, IT04K-227-4, IT89KD-288, IT93K-452 452-1, IT97K-499-35 IT99K-573-1-1) were intercropped with a local sorghum (Kaura) using four row arrangements (1C:1S, 2C:2S, Mixed crop and sole) in field experiments conducted at IITA Minjibir Farm and research farm of the Faculty of Agriculture Bayero University Kano located in the Sudan Savannah ecological zone of Nigeria during the 2015 and 2016 rainy seasons. In the field, the experiment was laid in a randomized complete block design (RCBD). Analysis of variance (ANOVA) showed significant difference on cowpea cropping systems and variety on the yield and yield attributes. Grain yield of cowpea was significantly higher at 2C:2S(663.0g) and sole (1323.8g) row arrangements in both seasons, the highest grain yield was obtained in one early variety IT97K-499-35(650.5g) and three medium varieties, IT99K 573-1-1(1060g), IT04K-227-4 (983.7g) and IT98K-131-1 (870.5g) as tolerant shading varieties. However, the late maturing variety-IT89KD-288 recorded the lowest grain yield and is considered to be susceptible to shading. Results of correlation coefficient showed that among the growth characters, a significant number of branches recorded positive correlation with yield (r=0.38) and 100 grain weight (r=0.32). Key words: Cropping systems, Cowpea varieties Grain yield, Intercropping and Shading.