Effects of nitrogen application rate on spatiotemporal variability of biomass accumulation of cotton''s fruiting branch at flower and boll stage
施氮量对花铃期棉花果枝生物量累积时空变异特征的影响

Field experiments were conducted in Anyang and Nanjing, the typical representatives of ecological regions in the Yellow River Valley and the lower reaches of Yangtze River Valley in China, to quantitatively analyze the spatiotemporal variability of biomass accumulation of the fruiting branch of cotton variety Nucotn 33B at its flower and boll stage under effects of 0, 120, 240, 360, and 480 kg N·hm-2 (marked as N0, N1, N2, N3, and N4, respectively). The results indicated that both in Nanjing and in Anyang, the temporal variability of biomass accumulation of vegetative and reproductive organs at different positions of fruiting branch could be described by Logistic equation, but the spatial variability was obviously different. Under the nitrogen application rate of 360 kg·hm-2 in Anyang and of 240 kg·hm-2 in Nanjing, the biomass accumulation had the characteristics of earlier starting date, shorter duration, and maximal speed of rapid increase. These nitrogen application rates could accelerate the biomass accumulation to benefit the high lint yield and fiber quality, while excess or deficient nitrogen supply was disadvantageous to the biomass accumulation of fruiting branch. Therefore, it could be possible to apply appropriate amount of nitrogen to regulate the growth eigenvalues of different positions fruiting branch at its speed growth stage to obtain high lint yield and fiber quality.