棉 花 学 报     Cotton  Science   2010，22（1）：77-82

Above-ground Dry Matter Accumulation of Cotton Genetics at Different Nitrogen Applications
LIU Shao-dong¹，ZHANG Si-ping¹, ZHANG Li-zhen^2*
(1.Key Laboratory for Genetic Improvement of Cotton/Ministry of Agriculture, Cotton Research Institute, CAAS, Anyang, Henan 455000, China; 2.College of Agricultural Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China)

Abstract: Field experiments were conducted to analyze the dynamics of LAI, accumulation of above-ground dry matter and above-ground nitrogen content for three cotton varieties (Bt variety 33B, conventional variety CCRI 12 and Bt hybrid CCRI 46) under five nitrogen application levels (0, 90, 180, 270 and 360 kg·hm^-2) in a randomized completed block design in Anyang. The expolinear growth equation was used to simulate the dynamic of cotton above-ground dry matter; and a power function was used to describe nitrogen dilution. The results showed that: (1)the expolinear growth equation was well fitted to the growth of cotton above-ground dry matter, and the parameters could reflect the influence of interaction between cotton genetics and nitrogen applications. (2)The power function of dry matter and nitrogen content showed the declination of cotton above-ground nitrogen content with the dry matter accumulation, the parameter could be used to explore the ability of nitrogen uptake. (3)The analysis of above-ground dry matter accumulation and nitrogen dilution effect, showed that the appropriate rate of nitrogen application was 180 kg·hm^-2 and excessive nitrogen application had no effect with cotton growth and nitrogen uptake.
Key words：cotton; above-ground dry matter accumulation; nitrogen; expolinear growth equation;
nitrogen dilution function   [Full Text, 530KB]