Abstract: The content of chlorophyll and carotenoid in ginger leaves which were covered with green film, red film and blue film at seedling stage respectively was remarkably higher than that of the control in the whole growth period, but the effects of different treatments were different at different growth stages. At seedling stage, the sequence of the content of chlorophyll and carotenoid in ginger leaves from high to low was blue film, green film and red film treatments in turn, but there was no significant difference between blue film and green film treatments under condition of covering with colored plastic films, while with the ginger growing at vigorous growth stage that treated by green film became gradually higher, blue film in the second and red film was lower after film removal. In the whole growth period, the photosynthetic rate (Pn) of ginger leaves covered with films was all significantly higher than that of control, in which the Pn of ginger leaves treated by the green film was higher, followed by the red film and blue film, which increased by 28.0%, 16.3% and 8.9% respectively compared with the Pn of the control at 11:00 on July 19 during covering with films and increased by 21.3%, 12.5% and 5.9% on September 8 after films removal. Furthermore, covering with colored plastic films could create more suitable environmental conditions, alleviate the photosynthetic depression at noon without changing the diurnal variation of photosynthesis.

Key words: Ginger, Colored plastic film, Light quality, Chloroplast pigment, Photosynthesis