Abstract: Owing to the shading by wheat,the growth of spring cotton seedling was retarded in the inter-planted field. There were distinct reiations between irradiance and degree of shading by wheat. The degree of shading was aggravated with the increase of wheat height, and was improved by the spacing of cotton and wheat rows. Therefore, in order to get favourable growth Of cotton and increase production of wheat through interplanting,the suitable variety of wheat and rational spacing of cotton and wheat rows must be selected.

Key words: Pennisetum sp., plant diversity, insect diversity.