Evaluation of genes effect and combining ability in selected maize (Zea mays L.) lines

To evaluate radiation use efficiency and weed control, this experiment was conducted in two locations in Ahwaz, Iran, in a randomized complete block design with 14 treatments and four replications in 2016-2017. Treatments included: Sole sugarcane, Sole soybean, Sole cowpea, Sole soybean+rhizobium, Sole cowpea+rhizobium, Sole sugarcane+mycorrhizal, Intercropping sugarcane with cowpea, Intercropping sugarcane with soybean, Intercropping sugarcane with cowpea+rhizobium, Intercropping sugarcane with soybean+rhizobium, Intercropping sugarcane+mycorrhiza and cowpea, Intercropping sugarcane+mycorrhiza and soybean, Intercropping sugarcane+mycorrhiza and soybean+rhizobium, Intercropping sugarcane+mycorrhiza and cowpea+rhizobium. Results showed that radiation use efficiency in intercropping treatments was superior than sole cropping and the highest radiation use efficiency (1.9 g.Mj-1) and also the highest LER (2.06) and the highest stem yield of sugarcane (112.8 t.ha-1) was obtained in sugarcane+mycorrhiza and cowpea+rhizobium treatment. Weeds were well controlled without application of herbicides in intercropping treatments. Light extinction coefficient (K) for cowpea and soybeans was significantly different in two locations, but there was no significant difference for sugarcane. The highest LAI for cowpea (4.6) and the lowest K (0.427) were observed in the sole cowpea+rhizobium. The highest K for sugarcane (0.473) was obtained in sole cropping and the highest K for cowpea (0.595) was obtained in intercropping with sugarcane. Results of this experiment showed that the synergistic effects of mycorrhiza and cowpea and sugarcane on evaluated characteristics were positive, therefore the use of mycorrhiza and rhizobium and intercropping of legume crops improved soil fertility, land and radiation use efficiency. In addition, weeds were effectively controlled in intercropping treatments.