Evaluation of growth, yield and elements uptake of grafted tomatoes on several Solanaceous rootstocks exposed to deficit irrigation

Abstract

A greenhouse experiment was carried out using seven Solanaceous species as rootstocks. Tomato plants were grafted on these rootstocks and after the healing and acclimatization period, were transferred to a soil-based greenhouse and exposed to three irrigation frequencies (3-day interval as control, 6-day and 9-day interval as moderate and severe drought stress) for four months. The results showed that shoot and root dry weight, daily dry matter production and yield were decreased with increasing irrigation intervals. At the same time, harvesting index was not affected by irrigation treatments in any of the grafting combinations. The concentration of N, Ca and Mg in leaf and root tissues were not influenced by irrigation intervals while P was increased in both leaf and root with increasing irrigation intervals and K was increased in leaf and decreased in root tissue. Leaf relative water content and electrolyte leakage were influenced by irrigation treatment. The applied rootstocks had a prominent effect on growth, yield, P and K concentration in leaf and root and reduction of leaf electrolyte leakage. Cherry tomato (Solanum lycopersicum var. cerasiforme) was superior to other rootstocks in terms of measured parameters, followed by Galapagus and Emperador. The positive role of these rootstocks in the mitigation of adverse effects of drought may be related to their vigorous root system. It is concluded that grafting as a healthy technique, since no chemical treatment is required, may increase the resistance of tomato plants against drought stress depending on the genotype of the rootstock.