بررسی اثر سطوح مختلف نیتروژن بر عملکرد غده سیب‌زمینی در شرایط تنش خشکی و کنترل

In order to study the effects of different levels of irrigation and nitrogen on tuber yield and yield components of potato crop, a split plot experiment based on the randomized complete block design was carried out with four replications at Research Center of Agriculture and Natural Resources of Chahar Mahal va Bakhtiari province, in 2013. The levels of irrigation were Ir1, Ir2 and Ir3 (100, 75 and 50% of the water requirement of potato after emergence by the end of the growing season, respectively) as the main factors and nitrogen fertilizer treatments were N1, N2, N3 and N4 (100, 66, 33, and 0% of plant nitrogen requirement) as the secondary factors. The results indicated that with decreased levels of irrigation and nitrogen, tuber yield components also fell. Seed tuber yield was not affected by irrigation regimes, but the amount of seed tubers reduced greatly in N4 treatment. Marketable tuber yield was not different in Ir1 and Ir2 treatments (about 56 and 51 tons per hectare, respectively) but drought stress (Ir3) leads to the production of about 31.7 tones marketable tubers per hectare. Reduction of nitrogen application had the negative effect on tuber yield but due to the interaction of irrigation and nitrogen treatments, N2 yield was higher than N1 (52.8 and 50.4 tons per hectare, respectively).