Effects of plant density on the quantitative yield of different corn (Zea mays L.) cultivars under the climatic conditions of Khorram Abad

An experiment was conducted to study the effects of plant density and cultivars on seed yield and yield components of corn (Zea mays L.) under the climatic conditions of Khorramabad at the Agriculture Research Station of Sarab Changaei. This experiment was a factorial on the basis of a randomized complete block design (RCBD) with four plant densities (6.5, 7.5, 8.5 and 9.5 plant/m2), three corn cultivars (301, 647, and SC.704) and 3 replications. Traits of seed yield, 1000 seed weight, corn cob weight, total dry matter, and row number per ear, seed number per row and harvest index were measured. According to the results cultivar SC.704 was the superior one relative to the other cultivars as well as the plant density of 8.5 plants/m2. Mean comparison showed that the highest seed yield was related to cultivar SC 704 with the plant density of 8.5 plant/m2 (7700 kg/ha) and the minimum seed yield was resulted by cultivar SC 301 and the plant density of 9.5 plant/m2 (3933 kg/ha). The highest 1000 seed weight was obtained from cultivar SC 647 with the plant density of 8.5 plant/m2 and the highest row number per ear (16.86) was related to cultivar SC 301 with the plant density of 6.5 plant/m2. Also, the highest seed number per row (28.03) and the highest seed number per ear (411.7) were resulted by cultivar SC 704 and the plant density of 6.5 plant/m2.