بررسی تأثیر تنش‌خشکی و محلول‌‌پاشی پتاسیم بر برخی صفات فیزیولوژیکی و عملکرد سه رقم گندم

In order to evaluate the effect of drought stress and potassium foliar application on some physiological traits and grain yield of three wheat (Triticum aestivum L.) cultivars, an experiment was conducted in 2011-2012 at Seed and Plant Certification and Registration Research Institute (SPCRI), Karaj- Iran. The experiment was carried out using a split plot factorial based on a randomized complete blocks design with three replications. The water treatments included three irrigation regimes; normal, mild stress (warer withhold at the grain filling phase) and severe stress (water withhold at the ear emergence phase); potassium foliar treatments included, 0, 1.5% and 3.0% K2O applications and three wheat cultivars (Marvdasht, Pishtaz and WS-82-9). Net Photosynthesis, relative water content at two stages, after ear emergence and after grain filling, and grain yield were measured. The results showed that water stress significantly decreased these characters. Foliar application of potassium at the rate of 3.0% K2O gave the highest values of grain yield and net photosynthesis at second measurement stage. WS-82-9 had the highest value of grain yield as compared with the two other cultivars.