GROWTH, ROOT ALTERATION, AND NUTRIENT UPTAKE OF NEEM TREE (Azadirachta indicaA. Juss) SEEDLINGS IN RESPONSE TO VESICULAR-ARBUSCULAR MYCORRHIZAL FUNGI AND PHOSPHORUS NUTRITION

Abstract

SUMMARY Growth and nutrient uptake of neem tree (Azadirachta indica A. Juss) seedlings were studied in response to vesicular-arbuscular mycorrhizal (VAM) fungi Glomus intraradices Schenck and Smith, and 2 levels of phosphorus (P). Extensive VAM colonization in neem roots occurred at both P levels: 0.65 and 1.30 mM P. Growth of VAM plants at both P levels was similar, while growth of noncolonized (Non-VAM) plants increased with increasing P supply. At the low P level, VAM plants had greater leaf area, shoot, root and leaf dry weight, and a greater root: shoot ratio than Non-VAM plants. Low P, VAM plants had a greater leaf area and root dry weight and a comparable leaf and shoot dry weight and root: shoot ratio, when compared with high P, Non-VAM plants. VAM inoculation also altered dry mass partitioning to root systems resulting in greater root length and dry weight of suberized roots in VAM plants. The length of nonsuberized roots increased with increasing P supply regardless of VAM inoculation. VAM inocu...