Effects Of Density And Sowing Date On Growth,Yield And Fiber Quality Of Early Maturing Direct Seeding Cotton

In order to explore the effects of sowing date and density on the growth and development of early maturing direct seeding cotton,determine the appropriate sowing date and planting density of early maturing direct seeding cotton in Hunan cotton area,and lay a theoretical foundation for the breeding and application of early maturing cotton varieties,the re split zone experiment was carried out with sowing date,density and variety as three factors to analyze the effects of different cultivation modes on cotton yield,physiological and biochemical indexes and fiber quality traits.The main conclusions are as follows:1.The sowing date has a significant impact on the plant height and fruit branch number of cotton.With the delay of sowing date,the plant height increases and the fruit branch number decreases at the cotton boll opening stage.There were significant differences in the height and number of the first fruit branch of cotton among varieties.The height of the first fruit branch of late maturing variety HN127 was better than that of other early maturing varieties,and the number of fruit branches of early maturing variety JX0010 was the most at the Bolling stage.Density has a significant effect on cotton plant height,and the density of2000 plants / mu is the highest.There was interaction between varieties and density.The higher the plant height of early maturing varieties with low density,the higher the plant height of late maturing varieties with high density;The height of the first fruit branch of Xiang K27 increased with the increase of density,and the height of the first fruit branch of JX0010 and HN127 decreased with the increase of density.There were significant interaction effects among sowing date,variety and density on plant height,first fruit branch height and fruit branch number.2.The sowing date has a significant impact on the number of bolls per plant.The number of bolls per plant decreases with the delay of sowing date.The sowing date and density have a significant impact on the single boll weight.Under the same sowing date,the single boll weight decreases with the increase of density.Early Maturing Cotton JX0010 had the largest number of bolls per plant,the largest single boll weight,and the highest yield of seed cotton and lint.3.Early maturing and late maturing varieties have significant effects on fiber quality indexes such as average length,fiber breaking strength and micronaire value in the upper half of cotton.The fiber quality indexes such as average length,fiber breaking strength and micronaire value in the upper half of Early Maturing Cotton Xiang K27 are the best.Sowing date and density had no significant effect on cotton fiber quality.Comprehensive analysis showed that the cultivation mode of Sowing on May 25,density of 2000 plants / mu and variety JX0010 had significant effects on the improvement of physiological and biochemical indexes of cotton plants,fiber quality traits and yield.