VAM FUNGI AND SOIL LIME CONTENT INFLUENCE ROOTSTOCK GROWTH AND NUTRIENT CONTENT

A factorial experiment was conducted to determine the interaction betw een vesicular-arbuscular fungi (VAF) inoculation (Glomus constrictus T rappe, G. deserticola Trappe, Blosse, and Menge, G. mosseae Nicol. and Gerd.) and sail lime content (0, 5%, 10%, 15%, 20%, 25%, and 30% acti ve lime). A control without fungus inoculum was set up for each medium . The mycorrhizal plants showed overall greater root and shoot growth than the control, independently of the soil lime content, and G. mosse ae and G. constrictus caused greater vegetative development than G. de serticola. However, plant growth was reduced by increasing soil lime c ontent. The absence of significant interactions between the two factor s of variability (fungi x lime concentration) on vegetative growth sug gests that mycorrhization, while increasing vine growth, does not redu ce grapevine susceptibility to calcium carbonate. Leaf chlorosis was f ound to be significantly higher in leaves of the inoculated cuttings, its incidence being greater at the higher lime rates. Leaf chlorophyll content (mu g/mg) was reduced by VAM, while chlorophyll content per l eaf area unit was also inversely correlated to lime concentration in t he substrate. Leaf mineral content was not influenced by soil lime, ex cept for magnesium which decreased with increased lime concentration. Inoculation of mycorrhizal fungi influenced the mineral content of P, Mn, and B and to a lesser extent Zn and Cu.