Abstract: Characteristics of radiant spectrum and reflection, transmission and absorption spectrums in rice colony at three weather condition, i. e. simulated cloudy, natural cloudy and sunny days during flowering-filling period, were analysed, to elucidate the reasons for impairment of rice production by light quality on cloudy days. The radiant energy with wavelength of 400-510 nm and 610-720 nmi. e. blue light and red light, greatly decreases and thus the radiant energy reflected by rice colony and transmitting through the colony increases in a greater amount, in the two wavelength range, which cause the radiant energy of the two parts of wavelength much less absorbed by rice colony.

Key words: Characteristics of radiant spectrum, Insufficient illumination impairment, Light quality

摘要： 通过对水稻开花灌浆期间模拟阴天，自然阴天和晴天光谱辐射能特征，以及这三种天气型下水稻群体反射，透射和吸收光谱辐射能变化特征的分析，揭示了阴天对水稻此阶段产生危害的光质原因即阴天促使400-510 nm（蓝光）和610-725 nm（红光）两个波段辐射能大幅度减少与水稻群体反射和透射这两个波段辐射能的比例大大增加，因而导致水稻群体吸收此两个波段的光谱辐射能显著减少所致。

关键词: 光谱辐射, 阴害形成, 灌浆, 开花, 水稻