Effect of Potassium Sulfate on Drought Resistance of Potato in Northern Fars Province

Potato is one of the sensitive plants to drought stress and it is one of the main crops in the north regions of Fars province. Since the planting time is simultaneous with wheat irrigation period, due consideration should be given to reduce irrigation consumption for this crop. This research investigated the effect of potassium sulfate on the drought tolerance of potatoes. Field experiment was arranged in split plot design with three replications. Irrigation intervals and potassium sulfates were allocated to main and subplots, respectively. Different treatments included various levels of potassium sulfate i.e. according to the soil test results, 20% and 40% below soil test results, and 20% and 40% more than soil test results, and irrigation intervals of 6 days, 12d, and 18 d. Plant measured responses included the tuber yield per hectare, means of weight and size of a tuber, tuber weight per plant, and also number of tubers per plant. Results showed that the highest yield was found in the 6-day interval irrigation and potassium sulfate at the rate of 40%> soil test results. However, in water deficit conditions, the 12-day interval and potassium sulfate use up to 40% > soil test results can be recommended as appropriate for avoiding potato yield decrease in the study area.