The effect of seeding rates on grain yield of some wheat varieties under rainfed condition

In order to evaluate effect of different seed rates on yield potential of newly released Iranian rainfed wheat cultivars under farmers' field, three separate trials based on factorial experiments were conducted using a completely randomized block design with two replications in the cold (Noorabad), moderately cold (Imanabad) and moderate (Koohdasht) regions of Lorestan province in 2016-17. Three commercial wheat cultivars including Azar2, Oahadi and Baran were used in the cold and moderately cold regions (Noorabad and Khorramabad, respectively), where in the moderate region (Koohdasht) three adapted wheat cultivars for this zone including Karim, Koohdasht and Qaboos were used. Seeding rate factor in all three experiments was four seeding rates of 120, 170, 220 and 270 kgha-1. Results showed that Baran cultivar by using up 170 kg seed per hectare in the cold and moderate cold zones of Noorabad and Imanabad, respectively; and Qaboos cultivar using 120 kg seed per hectare in the moderate zone of Koohdasht had the highest yield performance. Result of this study indicated that higher seeding rates will only increase costs of wheat production per hectare and also will result to waste certified seeds.