Abstract: The lodging resistance and related morphological and physiological traits of two super hybrid rice varieties Zhunliangyou 527 and Liangyou 293 at their late growth stage were investigated under three calcium application levels. The results showed that medium and high calcium application levels markedly improved the lodging-resistance of Zhunliangyou 527 at its late growth stage, but not benefited the decrease of the lodging index of Liangyou 293 at its ripening. There was a significant difference in the lodging resistance between the two varieties. The lodging index of test varieties increased obviously at their late growth stage, but their sensitive lodging stage differed. The lodging index had significant correlations with lodging resistance per plant, apparent lodging rate, plant height, aboveground biomass per plant, and dry mass and its transferring rate of stem and sheath.

Key words: Cinnamic acids, Allelopathy, Photosynthetic rate, Cucumis sativus, Transpiration rate, Root activity