Evaluation of Physiological Indices of Tomato (Solanum lycopersicum) Plant Under Different Irrigation Intervals and Superabsorbent Polymer A200

Water deficiency stress as the most important abiotic stress plays an important role in the yield suppression of plants worldwide. Considering physiological indices to improve drought resistance is of paramount importance. The objective of present study was to evaluate the effects of different irrigation intervals (irrigation after 5, 7, 9 and 11 days) and rates of superabsorbent polymer (Nil, 0.2, 0.3, 0.4 and 0.5 percent of pot medium weight) on some physiological parameters of tomato (Solanum lycopersicum) plant under greenhouse condition. The study carried out at College of Agriculture, Ilam University during 2009-2010 using a factorial layout in randomized complete blocks design (RCBD) with three replications. Statistical analysis showed significant effects of the irrigation and superabsorbent polymer on total yield and plant physiological parameters including leaf relative water content (RWC), water use efficiency (WUE), total soluble solids (TSS), chlorophyll, proline and malondialdehyde (MDA) content. In drought conditions total yield, RWC, WUE and chlorophyll a reduced but MDA accumulation, proline content and TSS increased. Application of superabsorbent polymer significantly caused increasing of total yield, RWC, WUE, chlorophyll a and decreasing of MDA content, proline and TSS. Our results showed that superabsorbent polymers can absorb and retain extremely large amounts of water and decreased adverse effects of drought stress on the plants.