Effect of Glomus Mosseae (Arbuscular Mycorrhizal Fungus) On Host - Parasite Relationship of Meloidogyne Incognita (Southern Root-Knot Nematode) on Four Improved Cowpea Varieties

Abstract

Effect of Glomus Mosseae (Arbuscular Mycorrhizal Fungus) On Host - Parasite Relationship of Meloidogyne Incognita (Southern Root-Knot Nematode) on Four Improved Cowpea VarietiesTwo pot experiments and a field study were conducted in a Randomized Complete Block Design (RCBD). The experiments were conducted to determine the effect ofGlomus mosseae, a mycorrhiza fungus, on the reaction of four improved cowpea varieties toMeloidogyne incognita.Cowpea plants were inoculated with a single or a combination of 5 000 eggs ofM. incognitaand 50 g ofG. mosseaeinoculum containing 5 spores/g of soil. The standardized method of screening and reporting resistance of crop germplasm to root-knot nematodes at 60 days after planting, and the modified version of including yield for resistance rating at harvest were used for this study. Root galling due toM. incognitainfection was significantly lower on all the cowpea varieties treated withG. mosseaeand more significantly on IT90K-277-2 and IT89KD-288 in the screenhouse.G. mosseae, suppressed root-knot nematode reproduction on all the varieties compared to cowpea plants infected only byM. incognitaboth in the screenhouse and field experiments. Also,G. mosseaemitigated the damage attributable to the root-knot nematode on all these varieties. Using Gall Index (GI), reproduction factor and yield,G. mosseaewas effective in improving the resistance of the cowpea varieties toM. incognita.IT90K-76 cowpea variety was consistently resistant to the root-knot nematode, while IT90K-277-2 was tolerant withM. incognitainfection but resistant withG. mosseaetreatment. IT90K-941-1 variety was resistant in the screenhouse. The results of this study also confirmedG. mosseaeas a potential bio-control agent forM. incognitaon these cowpea varieties.