بهبود رشد و عملکرد میوه هندوانه با استفاده از قارچ مایکوریزا و سالیسیلیک اسید در رژیمهاي مختلف آبیاري.

Water scarcity is the main natural limitation for agricultural production in arid and semi-arid regions. The aim of this study was to investigate the effect of mycorrhizal fungi and salicylic acid on yield and quality of watermelon under water stress. For this purpose, a split factorial experiment was conducted with three replications based on a randomized complete block design in two years. Irrigation treatment at three levels of receiving 100%, 80% and 60% of water requirement were placed as the main factor in the main plots. Mycorrhizal fungus in two levels (including no inoculation and soil inoculation by 20 g m-2 ) along with spraying of salicylic acid in three levels (including 0, 50 and 100 mg L-1 ) were designated to the subplots. The highest amounts of proline concentration, peroxidase and catalase enzymes activities were recorded in 60% irrigation treatment. Electrolyte leakage decreased by salicylic acid application, though in each irrigation treatment the lowest electrolyte leakage was recorded in 100 mg L-1 treatment of salicylic acid. Electrolyte leakage was significantly reduced by mycorrhizal fungi application. The highest (9.12%) and the lowest (8.08%) level of total soluble solids were recorded respectively in 80% and 100% irrigation treatments. The highest amount of TSS (9.07%) was obtained with mycorrhizal fungi. TSS was significantly increased by 6.70% and 11.20% with 50 and 100 mg L-1 salicylic acid treatments, respectively, compared to the control. The lowest fruit yield (34.76 t ha-1 ) was obtained when the plants were exposed to 60% irrigation treatment and no mycorrhizal fungus inoculation conditions. Fruit yield increased significantly in the presence of mycorrhizal fungi inoculation across all irrigation treatment levels, with the highest fruit yield (68.82 t ha-1 ) being obtained when plants were grown under 100% irrigation treatment and mycorrhizal fungi inoculation conditions. It may be concluded that using mycorrhizal fungus as a biofertilizer and salicylic acid as a plant growth regulator can reduce the harmful effects of drought stress and, hence, it can be recommended to increase the fruit yield and quality of watermelon at least in arid-semiarid conditions. [ABSTRACT FROM AUTHOR]