4Tollenaar, M. , Wu, J. Yield improvement in temperate maize is attributable to greater stress tolerance[ J]. Crop Sci. 1999, 39,1597 - 1604.
5Duvick,D. N. ,What is yield? In: Edmeades, G. O. , et al. (Eds.) , Developing Drought and Low N -tolerant maize[J]. CIMMYT, El Batan, Mexico, 1997. 332 -335.
6Pommel, B. , Bonhomme, R. , Variations in the vegetative and reproductive systems in individual plants of an heterogeneous maize crop[J]. Eur. J. Agron. 1998,(8), 39-49.
7Nafziger, E. D. , Effects of missing and two - plant hills on corn grain yield [ J ]. J. Prod. Agric. 1996, (9) ,238 - 240.