Abstract

In order to study the effect of plant density on yield and yield components of grain corn hybrids, a field experiment was conducted in 2007-2008 in Firouz-Abad of Iran. The experiment was conducted in split plot base on randomized completely block design with three replications. Main plots were four levels of corn cultivars: Hybrid of late maturing 704 (V₁), hybrid of mid maturing 604 (V₂), hybrid of early maturing 370 (V₃) and hybrid of mid maturing 647 (V₄). Sub plots were four levels of plant density: 65000 plant ha^-1 (D₁), 75000 plant ha^-1 (D₂), 85000 plant ha^-1 (D₃) and 95000 plant ha^-1 (D₄). The result showed that, the most grain yield, 1000-grains weight, biologic yield, obtained from hybrid of late maturing 704; and the most harvest index achieved from hybrids of mid maturing 647 and early maturing 370. With density increasing, hybrids reaction were different for each one of factors; so that the highest grain yield of hybrid 704 obtained from 75000 plant ha^-1, for hybrids 604 and 647 obtained from 85000 plant ha^-1  and for hybrid 370 obtained from 95000 plant ha^-1.

Key words: Corn hybrid, plant density, yield, yield component.

Abbreviation

DM, Dry matter.