Screening of Five (5) Varieties of Cowpea (Vigna unguiculata L.) for Leaf Spot Disease in Makurdi

ABSTRACT

The study investigated the seed health, germination and field reaction of five cowpea varieties namely: IT 99K-573-1-1, IT 99K-573-2-1, IT 90K-277-2, UAM 09 1055-6 and UAM 09 1051-1 to leaf spot incidence and severity in the 2018 cropping season. The laboratory experiment involved the use of the blotter method in isolating seed borne fungi in a Complete Randomized Design (CRD) while the field experiment was laid out in a Randomized Complete Block Design (RCBD) and replicated three times. The fungi infecting cowpea seeds were Fusarium solani, Aspergillus flavus, Aspergillus niger, Fusarium verticillioides and Curvularia lunata while those infecting the seedlings were Fusarium verticillioides, Curvularia lunata and Trichoderma viride. Results showed that variety UAM 09 1055-6 had the highest incidence of leaf spot at 5, 8 and 11 weeks after sowing, while variety IT 90K-277-2 had the least mean incidence of leaf spot. The germination percentage, germination rate and emergence percentage were significant for all cowpea varieties. The growth and yield parameters were significantly different across the varieties except 100 seed weight and number of branches for the various cowpea varieties. Variety UAM 09 1055-6 also had the highest leaf spot severity at 11 weeks after sowing, while leaf spot severity was not significant at 5 and 8 weeks after sowing. The study concluded that variety IT 90K-277-2 was the most resistant to leaf spot disease and was recommended for planting where leaf spot disease is prevalent.