EFFECT OF FOLIAR APPLICATION OF SOME FUNGICIDES ON SEPTORIA LEAF SPOT AND SEED YIELD IN COWPEA (Vigna unguiculata L. WALP)

Abstract

Field trials were conducted at Institute for Agricultural Research (IAR) farm, Samaru, Zaria during 2015 and 2016 wet seasons to determine the efficacy of three fungicides in management of Septoria leaf spot (SLS) of cowpea. The experiment was laid out as Randomized Complete Block Design consisting of fungicides: Mancozeb, Carbendazim, and Mancozeb+ Carbendazim applied at intervals of 7, 14 and 21 days on three cowpea varieties, replicated thrice. Fungicides significantly reduced (p ≤ 0.05) incidence and severity of SLS in both seasons; however, application of mancozeb + carbendazim gave highest reduction than their solo application. Spray intervals showed non-significant (p ≥ 0.05) difference in incidence and severity in both years. Incidence and severity of SLS significantly (p ≤ 0.05) varied with respect to variety, SAMPEA 10 had the lowest followed by SAMPEA 8 and SAMPEA 7. Fungicide applied plants showed significant (p ≤ 0.05) difference in seed yield, highest seed yield of 998.8 kg/ha and 836.9 kg/ha in 2015 and 2016 respectively were obtained following treatment with Mancozeb + Carbendazim, while lowest yield of 596.3 kg/ha and 435.8 kg/ha were obtained in 2015 and 2016 respectively from the control plots. Also, highest seed yield of 830.1 kg/ha and 683.1 kg/ha in 2015 and 2016 respectively, were obtained following a 7-day interval of spray. Overall, combined Mancozeb and Carbendazim application at 7- day interval exhibited great performance in both seasons, hence its potential can be exploited for successful management of Septoria leaf spot of cowpea and improve production in Guinea savannah of Nigeria.