Response of Two Tomato Cultivars to Field-applied Proline and Salt Stress

An experiment was carried out using saline water (6.57 dS.m-1) and subsurface drip irrigation (SDI) on two tomato cultivars (Solanum lycopersicum, cv. Rio Grande and Heinz-2274) in a silty clay soil. The former is a salinity tolerant and the latter a sensitive cultivar. Exogenous application of proline was done by foliar spray at two concentrations: 10 and 20 mg.L-1, with a control (saline water without proline), during the flowering stage. As a result of the proline applied, significant effects were observed on both cultivars of tomato, particularly with low concentration of proline (10 mg.L-1). It led to increase of leaf area, growth length and fruit yield. Regarding mineral nutrition, Ca2+ was higher in different organs while low accumulation of Na+ occurred. However, Cl- was very low significantly in all tissues of plants of Rio Grande at the higher concentration of proline applied