Effect of replacing ratios of maize: sorghum intercropping on yield and yield components

Intercropping system, increasing species number at area, is offered as way to increase production in agriculture. In order to investigate yield and yield components of maize and sorghum at different intercropping pattern, a randomized complete block design with four replications was conducted at the College of Agriculture and Natural Resources of Karaj, University of Tehran during 2014. The plants used in this system were fodder sorghum (Pegah cultivar) and grain maize (KSC600 cultivar). An alternative intercropping system was applied. The treatments consisted of sorghum monoculture, 75% maize: 25% sorghum, 50% maize: 50% sorghum, 25% maize: 75% sorghum and maize monoculture. The results showed that monoculture of sorghum produced the highest yield and intercropping of 75% sorghum: 25% maize produced the highest stem height and number of leaves per stem for sorghum. In maize, monoculture treatment obtained the highest grain yield (8.8 ton/ha) and 25% maize: 75% sorghum intercropping obtained the highest ear length (24 cm), number of rows per ear (18), number of seeds per row (42), and 1000 grain weight (157 g). LER was used to evaluate the efficiency of intercropping. The results showed that the index was affected by intercropping ratios. The highest level of LER = 1.8 was calculated in 25% maize: 75% sorghum. According to experiment data analysis, intercropping of maize: sorghum has useful resuls under Karaj climate.