缩节胺运筹对夏直播棉熟相的影响OACSTPCD

In order to clarify the effects of dimethyl-piperidinium chloride(DPC)operation on the ripening phase of wheat post direct-seeding cotton in the Yangtze River basin,the application amount and application period of DPC were designed in Yangzhou university experimental farm from 2018 to 2019.The CCRI 425 were used as the experimental ma-terials.Three levels of DPC amounts were set:0、180、360 g·hm-2.Two levels of DPC operation were set:DPC applied at full square and early flowering stage(the ratio of dosage was 1∶2)or at full square,early flowering and peak flower-ing stage(the ratio of dosage was 1∶2∶3).Production application(120 g·hm-2 DPC applied at early flowering)was used as CK.The results showed that under the conditions of 180 g·hm-2 DPC applied at full square and early flowering stage(the ratio of dosage was 1∶2)or at full square,early flowering and peak flowering stage(the ratio of dosage was 1∶2∶3),the intensity of flocculation was 59％-85.3％higher than that of the control.Regression analysis further showed that the yellow leaves was 9.0％-12.8％,the ratio of red stem for main stem was 52.8％-53.1％,the ratio of red stem for first fruit branch from the terminal was 28.3％-34.3％,the ratio for second fruit branch from the terminal was 27.5％-39.8％,the ratio of red stem for third fruit branch from the terminal was 34.3％-48.5％,the ratio of red stem for fourth fruit branch from the terminal was 49.1％-51.5％,and the position for opened boll from the top was 7.1-8.1,which was the most favorable for the formation of the highest flocculation intensity,that was,the most favor-able for centralized flocculation.Therefore,reasonable DPC operation can adjust the mature phase of centralized boll o-pening of direct-seeding cotton after wheat,and lay a foundation for mechanical harvesting.