Application of Harvest Aids In Huanghuaihai Cotton Region of China

Cotton is one of the most important industrial crops of the Huanghuaihai Region in China, where cotton-winter wheat double cropping system is the main farming system. It is critical to harvesting the cotton in the relative short time for the planting of following winter-wheat. Normally, cotton is picked by hand in this region. However, changes in social economic condition have led to a shortage of workers to pick the cotton and in turn, most producers intend to introduce mechanized harvesting. Mechanized harvesting of cotton requires the application of harvest-facilitating defoliants. Developing efficient and safe harvest aid products and using technology are essential for this region. This study was conducted to determine the effects of different harvest aids on defoliation, boll opening, seed cotton yield, fiber quality and seed quality in Huanghuaihai Cotton Region. The treatments were as follows: Non-treatment (T1), Ethephon (T2), Dimethipin (T3), Thidizauron and Diuron (T4), Thidizauron (T5), Dimethipin + Ethephon (T6), Thidizauron and Diuron + Ethephon (T7), Thidizauron + Ethephon (T8). The results showed that ethephon had greater boll opening effect but poor defoliation effect, while three defoliants (T3, T4 and T5) had opposite effects. Greater than 90% abscission and about 75% boll opening were observed at tank mixes of ethephon and three defoliants, respectively. No differences of seed cotton yield among all treatments were observed, but approximately 83% of first picking percentage was recorded for T7 and T8. The upper boll weights of T2, T3, T4 and T5 were significantly lower than those in control (T1), while no differences among the treatment means for ginning percentage, 100-seed weight, and seed germination percentage. This study showed that tank mixes of ethephon and defoliants could be used for defoliation and boll opening of cotton with higher yield potential and less seed quality reduction, especially T8 due to lower cost.