Abstract

In order to investigate the effect of tillage system and plant density on grain yield component in three varieties of corn, an experimental design, random complete block in a split factorial was used. Treatments arrangement was in quadruplicate in north of Iran in 2010. Main plot was subjected to tillage system in three levels: 1. Conventional system (CT). 2. Conservation system (RT) - chisel plough and multitiller. 3. No-tillage system (NT). Other factors were plant density in three levels (65000, 75000 and 85000 plant/ha) and three varieties of corn (500, 540, L.cv.sc 370). The results indicated that the grain yield and biological yield, which were affected by tillage system did not show any significant difference, while the grain yield and biological yield, which were affected by plant density and varieties showed significant difference. With the increase of density from 65000 to 85000 plants/ha, grain yield and biological yield decreased, respectively by an amount of 18.79 and 19.06. The reason for that was the decrease of some yield components, such as 1000 seeds weight, the number of grain in each row and the number of ear.

Key words: Corn, tillage system, density, variety, yield and yield component.