Effects of Planting Ways and Sowing(or transplanting) date on the Boll Development of the Summer Cotton in Wheat Summer Cotton Double Cropping

Cotton boll development of wheat summer cotton double cropping was affected by two factors which were planting ways and climatic condition that temperature factor was the leading role. When T(daily mean temperature in boll period)20℃, the boll development of interplanting summer cotton and field planting summer cotton after harvesting wheat was inferior to T single culturing summer cotton with normal seeding period which T20℃. Difference of boll development of interplanting and filed planting summer cotton with the same seeding period and T18℃ was insignificant. Boll development of interplanting and field planting summer cotton and single culturing summer cotton with normal seeding period which T20℃ was affected significantly by planting ways, under the condition of the same seeding period, difference of cotton boll development depended on planting ways and boll developing targets. According to the research, in this cotton production strict, it was appropriate for interplanting summer cotton seed sowinging before May 30, and it was unsuitable to adopt field planting method after harvesting wheat, and it would be optimum for seedling around May 15 and transplanting during June 10～15.