RESPONSE OF IRRIGATED MULBERRY (MORUS-ALBA L) TO VA-MYCORRHIZAL INOCULATION UNDER GRADED DOSES OF PHOSPHORUS

A field experiment was conducted for four years with Kanva-2 variety of mulberry, pre-inoculated with Glomus fasciculatum and Glomus mosseae at various doses of single super phosphate to examine their effect on plant growth, leaf yield and quality. The pooled data for 4 years revealed that the effect of inoculation of mulberry with Glomus mosseae in combination with 30 kg P ha(-1) yr(-1) was similar for plant growth, leaf yield and leaf chemical constituents with the control, which received the full dose of phosphatic fertilizer (120 kg P ha(-1) yr(-1)) without inoculation. This indicated a possibility to reduce phosphate fertilization in mulberry cultivation by 75%. Silkworm rearing (moulting test) also did not reveal any significant difference in the leaf quality even after reducing phosphorus application by 75% in mulberry inoculated with either Glomus mosseae or Glomus fasciculatum when compared with control. The root colonization was significantly higher in VAM inoculation at the lower levels of phosphorus compared to uninoculated control receiving the full dose of phosphate fertilizer (120 kg P ha(-1) yr(-1)) suggesting that low phosphorus levels in soil promote better VA-mycorrhizal symbiosis in mulberry.