Response of Cowpea (Vigna Unguiculata) Varieties and Varying Levels of Phosphorus on Va-Mycorrhizal (Glomus Fasciculatum) Colonization and Nutrient Uptake

Vesicular arbuscular mycorrhizae, Glomus fasciculatum significantly enhanced the stem length, root and shoot weight ant uptake of NPK in cowpea plants. It also increased the per cent root colonization and mycorrhizal spore population in soil. Cowpea cultivars have shown variation in their response to mycorrhizal inoculations. Five cultivars of cowpea viz GP-75, RC-24, RCM-14, Pusa Barsati and EC-2851 gave positive response to VA-mycorrhizal inoculations. Cultivar EC-2851 was the best followed by Pusa Barsati. However, the response of other three varieties was not significant. The uptake of three elements was also maximum in cvs. EC-2851 and Pusa Barsati. The supplementary dose of phosphorus (along with mycorrhizae) as single super phosphorus @ 600 and 500 mg per pot supported better plant growth compared to 400 mg per pot. Similarly, the uptake of three elements by cowpea plants was also increased with the increase in phosphorus level in soil.