Evaluation of Two Sprays Application of Synthetic Pyrethroid in the Management of Maruca vitrata on Early and Late Sown Cowpea in Sudan Savanna of Nigeria

Field experiment was conducted at the Teaching and Research Farm of the Faculty of Agriculture, Bayero University, Kano (11058″ N; 8026″ E, 460 m above sea level) to determine the effect of a synthetic insecticide, Lambda Cyhalothrin [(Laraforce 2.5% E.C.] sprays application on the management of the legume pod borer (Maruca vitrata Fab.) on early and late season planted elite cowpea variety. Two crops cowpea were grown in a succession during the 2011 cropping season. The experiment was laid out in a Randomized Complete Block Design (RCBD), with each of the three treatments replicated four times. The treatments consisted of no spray (control), one spray and two spray regimes of the insecticide. Results showed that Laraforce 2.5EC sprays significantly (P<0.05) lowered population and damage of the Maruca larvae in both the early and late season planted crop compared with the untreated controls. The two-spray regime plots, however, had the lowest number of larval population and damage compared with those of the one-spray regime. The highest grain yield in the early (1400.01 kg ha-l) and late (768.05 kg ha-l) planted cowpea were recorded under two sprays regime treatments, followed by the one-spray regime and lastly the untreated control. Two sprays of Lara force effectively managed the population and damage of M. vitrata with resultant increase in yield of both the early and the late season planted cowpea in the study area.