| Grain yield of maize would be increased and stable via double-genotypes intercropping, but the eco-physiological effect difference was observed in different intercropped model. In order to research the optimal model of variety combination and row ratio for maize intercropping with double-genotypes, in 2008 and 2009, field experiment was conducted on the farm of Henan Agricultural University, Zhengzhou, China, using six maize hybrids, Zhengdan 958(ZD958, compact plant type, susceptible to maize leaf south rust), Ludan 981(LD981, semi-compact plant type, highly resistant to maize leaf south rust), Xundan 20(XD20, compact plant type, medium susceptible to maize leaf south rust), Huafeng 9(HF9, semi-compact plant type, medium susceptible to maize leaf south rust), Denghai 602(DH602, compact plant type, medium resistant to maize leaf south rust) and Zhengnong 7278(ZN7278, semi-compact plant type, medium resistant to maize leaf south rust). The results are as follows:1) The eco-physiological effects were different in different plant type and row ratio intercropping system. In the intercropping system of ZD958‖LD981 (row ratio 1︰1 and 4︰2) and ZD958‖DH602 (row ratio 4︰2), the plant analyzer development readings (SPADR) of three-leaf near ear and leaf area index (LAI) of ZD958 decreased owing to shaded by LD981 and DH602 after silking, which result in grain yield decreased, and the land equivalent ratios (LER) less than 1 in the intercropping populations while the grain yield of LD981 and DH602 increased slightly. Grain yield of ZD958 increased owing to light condition improved in intercropping system of ZD958‖DH602 with row ratio 2︰2, and the LER >1 in the intercropping system. In the intercropping system of XD20‖HF9 (row ratio 1︰1) and XD20‖DH602 (row ratio 4︰2), HF9 and DH602 showed advantage competition while XD20 disadvantage competition, but the LER <1 in the intercropping systems. Meanwhile, grain yield of XD20 increased owing to growth condition improved in intercropping system of XD20‖DH602 with row ratio 2︰2, and the LER also more than 1. In the intercropping system of ZN7278‖DH602 with row ratio 1︰1and 4︰2, ZN7278 showed disadvantage competition, but which was better than ZD958 and XD20 in above intercropping systems. A significant advantage competition for ZN7278 was observed in ZN7278‖DH602 with row ratio 2︰2, and its grain yield increased significantly while grain yield decreased in DH602, and the LER also more than 1. The results from this study suggested that row ratio 2︰2 would be suitable to maize intercropping with different plant types.2) The leaf disease could be controlled via maize intercropping with different resistance hybrids. In this study, the resistance to maize leaf south rust was remarkable difference among the six hybrids. Compare to sole-cropping populations, the disease-index of maize leaf south rust all decreased significantly in intercropping populations.3) The agronomic characters would be changed in maize intercropping with double-genotypes. The result from this study showed that compare to sole-cropping populations, the plant height and ear height changed in intercropping populations, and the changes were different among six hybrids,but no significant change was observed in stem diameter and interval from anthesis to silking. |
