IMPACT OF ARBUSCULAR MYCORRHIZAL FUNGI ON ROOT CALCIUM CONTENT OF COWPEA VARIETIES (Vigna unguiculata L. WALP) UNDER ALECTRA VOGELII INOCULATED SOIL

Abstract Biological control methods can play an important role in managing plant parasites affecting cowpea production particularly in the face of climate change. This research evaluated the effect of Glomus clarum on the root calcium content of four cowpea varieties in an Alectra vogelii inoculated soil. The four cowpea varieties used were: SAMPEA 7, IFE 82-12, IT97K-499-35 and TVX 3236. The sterilized sandy-loamy soil used for this experiment consisted of a mixture of top soil and sand in ratio 1:1 (v/v). Glomus clarum treatments was applied at five rates: the zero and without Alectra, zero and with Alectra, 10, 20 and 30 g/pot each with Alectra (3.3 g). The treatments were arranged in complete randomized design. The root of cowpea plants was sampled for calcium content at 5 weeks after planting (WAP). Testing with ANOVA, the two years data based on Glomus clarum treatments, the Glomus clarum at 30 g/pot treatment resulted in highest root calcium content which was only comparable with that due to 20 g/pot Glomus clarum treatment. In addition, Glomus clarum treatments resulted in the highest root calcium content in IT97K – 499 – 35 which was only significantly higher than the lowest root calcium content observed in TVX 3236. In conclusion, Glomus clarum treatments significantly increased root calcium content for the cowpea varieties on Alectra inoculated soil and thus recommended as a biological control agent in Alectra vogelii infested fields.