The Effects Of Cotton Varieties For Resistance To Late Sowing On The Growth Characteristics In Short Planting Season

Early maturing cotton new variety "JX0010" was used in this research as test material.Three factors, application rate, density, sowing date,with five levels of each and were used in this experiment with quadratic regression design (311 designs) of quadratic regression combination design.The research was about short-season cultivation factors on the cultivation of cotton growing period, agronomic traits, characteristic changes in chlorophyll content, dry matter accumulation, distribution law, spatial and temporal distribution of cotton bolls, and the impact on cotton yield and fiber quality. The main findings were as follows:1.Cotton sowing is the main factor affecting growth period. Sowing every was put off 5d, seedling delayed 3-6d, budding delayed 2-5d, flowering delayed 2-6d, boll opening delayed 2-4d, but the sowing of cotton has little effect on the duration of two adjacent fertility.2.The density is the main factor affecting plant height,height of first fruiting branches, the number of fruit positions,then the amount of nitrogen, followed by sowing minimal impact; sowing is the main factor affecting the number of fruiting branches, density, followed by nitrogen levels on Min.3.Cotton aboveground plant dry matter accumulation, dry matter accumulation, dry matter accumulation per plant vegetative organs, reproductive organs dry matter accumulation trends substantially "S" type. Studies show that the correlations between total population of dry matter accumulation and yield of seed cotton were 0.7*?0.62*?0.60*, showing a significant positive correlation on July 16, August 5, August 25.With the advance of plant birth process, the proportion of vegetative organs reduced, while genital proportion gradually increased in dry matter distribution coefficient.4.Nitrogen is the main factor affecting the chlorophyll content of cotton.With the advance of cotton growth the chlorophyll content gradually increased, but nitrogen rate for processing 7.93kg/667m2 and 4kg/667m2 will lead to nitrogen deficiency the latter growth, lowering SPAD value.5.Cotton boll distribution showed that autumn peach appeared after the first decline in more than a rising trend over time with sowing delayed,indicating that early sowing and late sowing can lead to the proportion of autumn peach increasing, late sowing showing more prominent performance,and lacking of nitrogen excessively will bring about that peach boll increases; the spatial distribution showed that vertical boll was focused on the middle and lower and vertical boll was focused inner circle.6. Nitrogen is the main factor affecting the lint and the density is the main factor affecting boll weight and the number of bolls per plant. Mathematical models of a new line cotton "JX0010" of yield of seed cotton and nitrogen rates, density, sowing under short season cultivation were established. Single factor effect manifested as sowing> density> nitrogen rate,and two factor effect manifested as the interaction of nitrogen and density> the interaction of sowing and density> the interaction of nitrogen and sowing.From the regression equation,when nitrogen application was 13.49kg/667m2,the density was 4135 plant/667m2, sowing date was May 19, production was higher than 367.35kg/667m2.7.The order that cultural factors affecting cotton fiber quality traits was micronaire> elongation> breaking strength> upper half mean length> uniformity index. Sowing is the main factor that affecting micronaire, uniformity index and elongation, density is the main factor affecting the fracture strength and the upper half of the average length.