The Effect of Mycorrhiza (Glomus Geosporum), Rhizobium and Meloidogyne Incognita on Growth and Development of Cowpea (Vigna Unguiculata L. Walp).

Cowpea (Vigna unguiculata) is a leguminous crop that thrives well on the tropical environment. Microbial activities especially in the rhizosphere have been shown to affect the growth and development of the crop. A screen house experiment was conducted to determine the individual effect of root-knot nematode, mycorrhizal fungus, rhizobium and combined effects of the three micro-organisms on the growth and development of cowpea (C.V giant black eye). The experiment was laid out in a 2x2x2 factorial in completely randomized design [CRD] with three replications. When nematode interacted with rhizobium in the soil in association with the cowpea roots, root nodulation was significantly increased but the interaction of mycorrhiza and nematode with rhizobium resulted in a higher increase of root nodulation. Mycorrhiza association with rhizobium produced higher root nodulation than rhizobium alone. The association of mycorrhiza and nematode with cowpea roots produced lesser galling of cowpea roots than nematode alone, but when Nematode was associated with rhizobium highest galling occurred on cowpea roots. Understanding different ways in which organisms interact in the soil in association with plant roots can help reduce the pathogencity of some organism. It is recommended that farmers should encourage activities which will enhance the establishment of these beneficial organisms especially in nematode infested soil.