عنوان مقاله [English]
To evaluate the effect of row spacing, plant population and planting pattern on yield and yield components of corn (single cross 704) in the double cropping after paddy rice, a factorial experiment in a randomized complete block design with four replications was conducted in Research Gharakheil Agricultural Research Center of Qaemshahr, Iran in 2009. Treatments consisted of three row distances (65, 75, 85 cm), plant populations of 70000 and 800000 plants per hectare and two planting patterns (single-row and zigzag double-row). Results showed that maximum grain yield (9230 kg/ha) and harvest index (42.11 %) between row distance were obtained from 65 cm. Seed yield and yield components were not significantly affected by plant density. Seed yield of zigzag two-row planting pattern was 23.26 percent higher than single row planting pattern. All of the yield components in a single row were less than of zigzag double row planting patterns. The row spacing × plant density interactions for biomass, HI and ear length were significant at 5% level of probabilities. Planting pattern × row spacing interaction for biomass and number of rows per ear showed significant differences at the 5% level of probabilities. The lowest seed yield (6558 kg/ha) was obtained from 75 cm row spacing× single row planting pattern × 80 thousand density interactions and highest harvest index (46.86 %) from 80000 plants per hectare × 65 cm row spacing × double row zigzag planting pattern interaction. Grain yield was positively and highly correlated with all yield components, which may be due to delayed planting date (the first week of September) and proper growing condition for corn. It could be concluded that double cropping of corn after rice, results in yield stability and efficient use of water resources, in this area.