Screening for resistance to Striga gesnerioides and estimation of yield loss among Cowpea (Vigna unguiculata (L.) Walp.) progenies in the Upper East Region of Ghana

Abstract

Parasitic weed Striga gesnerioides (Willd.) is one of the major constraints of cowpea production. Host-plant resistance seems to be efficient and economical in controlling the pest. The objectives of this study were to evaluate recombinant inbred lines developed between IT97K 499-35 (Striga resistant parent,) and Sanzi (susceptible parent), by Single Seed Descent (SSD), for Striga resistance in Northern Ghana. The study also evaluated the promising Striga gesnerioides resistant lines and susceptible checks for yield loss due to Striga infestation. The studies involved a field and pot screening under artificial inoculation. Twenty-seven (27) recombinant inbred lines (RILs) out of the 251 RILs screened were resistant to Striga gesnerioides. The percentage reduction in the grain yield and dry biomass were lower in the resistant RILs (0.55 to 3.08% and 1.11 to 7.7%, respectively) than the susceptible ones (28.45 to 58.88% and 47.29 to 61.71%, respectively). The negative effect of Striga infestation on cowpea grain yield and dry biomass can then be reduced when resistant genotypes are used.