Influence of Imazaquin Seed Treatment on Control of Striga gesnerioides and its Consequence on Yield and Yield Components of Selected Cowpea Genotypes

The effect of Imazaquin seed treatment on Striga control, yield, and yield components of cowpea were investigated in Nigeria, in 2010 and 2011 rainy seasons. Imazaquin at 0.00, 0.06, and 0.24 kg a.i. ha -1 was the main plot treatment; cowpea genotypes (Achishiru, IT97K-1263, IT97K-390-2, IT98K-133-1-1, TVU-1283, TVU-1542 and TVU-1908) were the subplots. The untreated control recorded the highest number of Striga m -2 which was 2.8 times higher than seed treatment with imazaquin at 0.06 kg a.i. ha -1 , and 6.8 times higher than treatment at 0.24 kg a.i. ha -1 . Achishiru had the most Striga infestation (4.29 m -2 ) in 2010 and TVU-1283 (5.61 m -2 ) in 2011; genotype IT97K-1263 had no Striga in 2010 and 2011. TVU-1542 and IT97K-390-2 recorded the highest grain yield in 2010 and 2011. Treating IT97K-390-2, IT98K-133-1-1 and TVU-1542 with imazaquin at 0.06 and 0.24 kg a.i. ha -1 reduced Striga parasitism in the field and increased grain yield and yield component of these genotypes. These treatment combinations are therefore recommended for Striga control. Keywords : genotypes, cowpea, imazaquin, Striga control, seed treatment