Response of maize cultivars to water stress at grain filling phase
Hosein Khoshvaghti1, Mohammad Eskandari-Kordlar1and Ramin Lotfi*2
Water deficit stress is one of the important factors limiting crop production in Iran. This research was conducted in 2012 to investigate field performance of three maize cultivars (S704, BC678 and H500) under well watering (50 mm evaporation from class A) and water stress at grain filling phase (90 mm evaporation from class A). Results showed that grain weight was more than that of grain number per plant affected by water stress during grain filling stage. Grain depth in cob and cob diameter under well watering was higher than that of water stress condition, indicating that grain volume and especially grain yield were decreased by increasing waster stress. Maximum grain yield per ha was showed in S704 in comparison to other cultivars. Superiority of S704 was attributed to be more of 100 grain weight, row number per cob, grain number per cob, cob diameter and length, cob weight. This research suggests that there is considerable variation between maize genotypes in tolerance to water stress and number and weight of grains are important traits for maintaining stable and high grain yields under water deficit conditions.
Keywords: grain filling phase, grain yield, maize, water stress