كليدواژه :
Wheat yield , كشاورزي , آبياري تكميلي , اجزاي عملكرد , گندم , Complementary irrigation , Growth indices , شاخص هاي رشد , drought stress
چكيده لاتين :
In order to study the growth rate, yield and yield components of four wheat cultivars under rain fed conditions and two irrigation regimes (I-at planting time and ear emergence , 2-planting time, ear emergence and grain filling), a factorial experiment on the basis of randomized complete blocks design with three replicates was conducted in Dry land Agriculture Research Institute at Maragheh during growing season of 1997-98. In this experiment wheat cultivars of Sabalan/l -27-56-4. Anza/3/Pi/Nor//Hys/4/sefid, 4493-P.1533-Bez and Sabalan were used. Several traits such as crop growth rate, relative growth rate, dry matter accumulation Per unit area, number of ears per unit area, number of grains per ear, 1000 grain weight, biological yield, grain yield, harvest index and productivity degree were determined . The results showed that drought stress led to the reduction of dry matter production, crop growth rate and relative growth rate. There was no significant differences between wheat cultivars, regarding green cover percentages, crop growth rate and relative growth rate. All traits( except grains per ear and harvest index) were affected by water deficit. However, irrigation x variety interaction was not significant for any trait. Considering traits studied in this research, no significant differences were found between two and three times of irrigation. Green cover percentage, plant height, crop growth rate, biological yield and productivity degree were significantly correlated with grain yield. Among these traits, mean green cover had the highest positive correlation with grain yield. Since this index could be determined easily and rapidly, it can be recommended as a suitable index for evaluating field performance of different crops.
