不同氮素水平和密度下棉花群体光合速率的探讨

1986—1987年对不同氮素水平和密度条件下棉花群体光合速率进行了研究。结果证明,合理增施N素和适当的栽培密度能明显地提高棉花群体的光合能力,这种使棉花群体光合速率提高的效应,还随生育进程而增加。棉花盛花期群体光合速率日变化为“午休型”。棉花群体光合速率与皮棉产量无相关。

PHOTOSYNTHETIC RATES OF COTTON POPULATION UNDER DIFFERENT RATES OF NITROGEN APPLICATION AND PLANT DENSITIES

The photosynthetic rates ( PR ) in cotton population under different rates of nitrogen application and plant densities were investigaled. The results were as follows.(1) Among density rates of 2500, 3500, and 4500 plants per mu, 3500 plants per mu had the highiest PR; the plant population with N application at 20kg per mu, had highier PR than that at 20kg N per mu;(2) In Wuhan, changes of PR in both cotton population and single leaf ( functional leaf) showed a similar two peak curue ( i.e type of noon-rest) ;(3) From July 6 to August 13, the PR in cotton population increased sharply as plants grew;(4) The PR in cotton population was not correlated with the lint yield of cetton.