Variation in Nutrient Absorption by Thompson Seedless Grape (<i>Vitis vinifera</i> L.) on Different Rootstocks as Influenced by Soil Chemical Characteristics

Abstract

A survey was conducted to study the variation in nutrient absorption (petiole /Soil content) by Thompson Seedless grape as influenced by soil chemical characteristics on its own root, Dog Ridge and 110R rootstocks with an aim to provide guidelines in nutrient application with reference to the soil chemical characteristic and rootstock. Nutrient absorption was influenced most on own root followed by Dog Ridge and 110R roots. N followed by Zn, P and K were the most influenced nutrients on own root, while K, Mn and Zn on Dog Ridge; and Fe, N, K and Zn on 110R. All the soil chemical characteristics were ineffective in the absorption of Cu in vines on any root. Thompson Seedless root were more sensitive to soil pH in the absorption of P and S, and to CaCO3 levels in Ca absorption with a threshold level of 8.0 per cent. 110R root were independent of OC in N absorption, while Dog Ridge root exhibited dependence on OC for S absorption. Rootstocks in general, were more efficient in S beyond 1.5dSm-1. The ability to restrict the absorption of Na by rootstocks was dependent on the free calcium levels in the soil. 110R was most efficient in restricting the absorption of Na below 12.5 per cent, while Dog Ridge was equally efficient in the range of 12.5 – 17.0 per cent. Variation in the efficiency in nutrient absorption with the rootstock at different levels of soil chemical characteristics was attributed to the specific ion contributing to the chemical character, its interaction with other nutrient ions, their relative abundance and the preferential absorption by the roots.