【摘要】 通过对棉叶净光合速率 3a的研究 ,结果表明 :棉叶光合速率最大出现在盛蕾期至开花期。打顶前棉花主茎倒 4叶光合速率最大 ,打顶后倒 1叶和倒 2叶光合速率最大。开花期前倒4叶光合速率日变呈双峰曲线 ,峰值出现在 12 :0 0～ 14:0 0和 16:0 0～ 18:0 0且第一个峰值比第二个峰值高 ,盛花期后因品种不同而有所不同。盛花期前主茎叶光合速率较大 ,盛花期后果枝叶光合速率较大 ,不同叶位的叶片光合速率变化规律有所不同。棉叶展平 14d后光合速率达到最大值。化学调控、揭膜时期、追施尿素对棉花的光合速率均有较强的调节作用更多还原

【Abstract】 The results of three years(1998～2000) indicated that the maximum net photosynthesis rate of cotton leaf appeared from the full squaring stage to blooming stage. The photosynthesis rate of the forth leaf form top to bottom varied according to two peak curve in a day before the blooming stage. The peak value appeared in 12:00～14:00 and 16:00～18:00, the first peak value exceeded the second. The Pn of main stem leaf is high before the full blooming,the Pn of fruit branch leaf is higher after the full blooming. The Pn of leaf appeared maximum after the fourteenth days in life. The Pn adjust and controlled by DPC(mepiquat), the period of the covering of film plastic, fertilizer, etc.更多还原