EFFECT OF IRRIGATION, WATER SALINITY AND ROOTSTOCK ON THE VERTICAL DISTRIBUTION OF VESICULAR‐ARBUSCULAR MYCORRHIZA IN CITRUS ROOTS

SUMMARY The effects of rootstock, irrigation regime and water salinity on the vertical distribution of vesicular-arbuscular mycorrhiza (VAM) of citrus roots were investigated in the field. Rootstocks differed in the uniformity of the vertical distribution of VAM, notably, Rough lemon exhibited a uniform vertical distribution and Sour orange a non-uniform distribution with decreased VAM infection at depth. Decreasing the interval between irrigations reduced VAM infection of Sour orange, especially in the upper layers of soil. Increased salinity of irrigation-water reduced VAM in deep layers of soil.