Abstract :
ABSTRACT: The effects of plant density on dry matter accumulation, grain yield and yield components of four maize hybrids were evaluated. The experimental design was split plot format based on a randomized complete block with three replications. The study was conducted of Islamic Azad University of Dezful (Iran) farming research station in 2010. The main factors were 4 levels of hybrids (Ks.c704, Ks.c700, K78 and K47) and plant densities 7, 8, 9 and 10 plants m-2 were used as sub-plot. The result showed with the increasing plant density of the whole hybrids increased amount of redistribution of dry matter. Because of increasing plant density were shade leaves high up on leaves and accelerate aging and was reduced its current photosynthesis. The maximum redistribution was obtained in hybrid KSC704 and 10 plant density. Results showed that the hybrid, density and their interactive on grain yield, total dry matter, 1000 seed weight and harvest index were significant. However, the number of rows per ear was not affected significantly by the plant density. Hybrid of Ks.c704 had the highest grain yield (8450 kg ha-1) due to greater leaf area index and its delayed durability compared to other hybrids. Highest grain yield for the same hybrid was obtained at plant density of 8 plants m-2. Both Ks.c700 and Ks.c704 hybrids at plant density of 8 plants m-2 reached their maximum grain yield and increased density in the grain yield and yield components. Therefore, the combination of KS.c704 hybrid at plant density of 8 plants m-2 was the best option to achieve the highest grain yield.
