Evaluation of grain yield and yield components of maize hybrids in double cropping with winter crops in temperate condition of Khorramabad, Iran

To study the effect of various winter crops on the morphological traits, grain yield and yield components of maize hybrids in double cropping systems, an experiment was carried out in the research field of Sarab-e Changayin 2006-2009 in Khorramabad. Split-plot arrangement in randomized block design with four replications was used. The winter crops included wheat, barley, berseem clover, annual medic and canola were assigned to main plots, and after harvesting them three maize hybrid (SC500) were randomized and sown in sub plots in summer. Results showed that maize hybrids had higher yield when were grown following berseem clover, canola and annual medic. The highest maize grain yield of 7769 kg.ha-1 was achieved following berseem clover because of its greater yield components, high harvest index (41.7%), grain.row-1 37.9), row.ear-1 (17.8) and 1000-grain weight (287.9 g). The lowest maize grain yield of 5809 kg.ha-1 was achieved following barley due to its low harvest index (36.5%), grain.row-1 (36.5), row.ear-1 (17.4) and 1000 grain weight (241.2 g) that had no significant differences with grain yield following wheat (6359 kg.ha-1). In general, maize grain yield as summer crop was higher following berseem clover, annual medic, canola, wheat and barley, respectively.