Effect of Irrigation Regimes and Fertilizer Combinations on Yield of Two Potato (Solanum tuberosum L.) Cultivars in Freidan

In order to determine the potato cultivars responses to irrigation regimes and fertilizer combinations, an experiment was conducted on Fereidan Research Farm, Isfahan Province in 2003. The trial was designed as split-split plot based on randomized complete block design with three replications. The cultivars (Arinda and Navita) were planted as main plots, and irrigated after 70, 140, 210 mm water evaporation from standard A pan surface that provided optimal watering, mild drought, and severe drought, respectively, as sub plots. Fertilizer combinations including of NPK + Zn, NPK+ Mn, NPK +Zn + Mn and NPK+ Manure were used as sub-sub plots. Results showed that the cultivar Arinda produced higher yield, mean tuber weight and total tuber number. By decreasing the amount of irrigation, the total yield and mean tuber weight were decreased. The highest amount of seed tubers (35-55 mm diameter) and marketable tuber sizes (diameter>35mm) and lowest amount of small size tuber numbers (diameter <35) were obtained in moderate drought. The use of NPK + Zn + Mn and NPK+ Manure produced the highest yield and mean tuber weight. Planting the cultivar Arinda with efficient irrigation is suggested in Isfahan province. Moderate drought is recommended for production of higher amount of seedy tubers. A combination of manure, Mn and Zn fertilizers are also suggested for potato farms of this district.