Effects Of Redundant Buds And Top Of Fruit Branches On Source-sink Relation And Early Maturity Of Cotton

Nowadays,A tendency of simplified pruning in cotton are prevalent,redundant buds and decapitation fruit branches are important pruning measure of cotton production.The effects of redundant buds and decapitation fruit branches on cotton development,were researched in this study.For two years(2014 and 2015)in a row,Lumianyan28 was grown under field conditions in the Yellow River bottomland,Zhengzhou,Henan Province.Treatments of removal of redundant buds,removal of decapitation fruit branches,removal of redundant buds + removal of decapitation fruit branches were designed,with retained redundant buds and decapitation fruit branches as control,to explore effects of redundant buds and decapitation fruit branches on source-sink relation,early maturity,yield and fiber quality of cotton,which could provide scientific basis for simplified pruning.The main results were as follows: 1.Influence removal of redundant buds and decapitation fruit branches of the occurrence of cotton redundant budsBuds growing in cotton stem and fruit branches were measured in this study.The results showed that the more redundant buds growing in cotton stem and fruit branches were removed,the more redundant buds happened,which trended performance that removal of redundant buds+removal of decapitation fruit branches>removal of redundant buds > CK > removal of decapitation fruit branches,The study showed that redundant buds growing in main steam would drop down automatically with the treatment of retaining redundant buds with the advancement of reproductive period.2.Influence removal of redundant buds and decapitation fruit branches of source-sink relationLeaf area index,dry matter accumulation of source-sink,the SOD,POD activity and content of MDA,starch,soluble protein,IAA in cotton leaves and bolls were measured in this study.The results showed that removal of redundant buds and decapitation fruit branches could increase the leaf area index and total dry matter accumulation of cotton,which improved the ratio of source-sink in earlier growing stage and reduced the ratio of source-sink in latter growing stage,increasing the ratio of partition of dry matter to boll.Further analysis found that removal of redundant buds and decapitation fruit branches could also increase the SOD,POD activity and content of starch,soluble protein,IAA in cotton leaves and cottonseeds,which showed stronger activity of source and sink.It could improve the starch content of cotton fiber in summer boll and early autumn boll,increase percent of high quality boll,and reduce MDA content of cotton fiber;However,the reason that removal of redundant buds and decapitation fruit branches also reduced SOD activity and soluble protein,IAA content of cotton fiber was still unclear,which need further discussion.The study showed that regulation of removal of redundant buds + removal of decapitation fruit branches on source-sink relation outbalanced the removal of redundant buds and removal of decapitation fruit branches.3.Influence removal of redundant buds and decapitation fruit branches of early maturityIn this study,the spatial distribution of cotton bolls,pre-frost yield rate,the1st~2nd ratio of collecting cotton and ABA content in cotton leaves and bolls were surveyed.The results showed compared with the control,removal of redundant buds and decapitation fruit branches could increase the ratio of the 1st ~2ed fruit knots,reduce the ratio of the 3rd ~4th fruit knots bolls.In 2015,the pre-frost yield rate of removal of redundant buds + removal of decapitation fruit branches increased by 2.92% and 4.2% respectively,the1st~2nd ratio of collecting cotton of removal of redundant buds + removal of decapitation fruit branches separately increased 6.81% and 6.2% compared with CK in 2014 and 2015,Content of ABA in cotton leaves,cottonseeds and fiber of early autumn bolls and later autumn bolls were all increased in latter growth stage.Different treatments showed that removal of redundant buds + removal of decapitation fruit branches outbalanced removal of redundant buds or removal of decapitation fruit branches on early maturity.4.Influence removal of redundant buds and decapitation fruit branches of the yield and fiber qualityTotal bolls,boll weight,lint percentage,seed cotton yield,lint yield,length,tenacity,micronaire,uniformity an elongation of fiber were also surveyed.The results indicated that compared to the control,removal of redundant buds and decapitation fruit branches could improve total bolls,boll weight,lint percentage,leading to the increase of seed cotton yield and lint yield.Removal of redundant buds + removal of decapitation fruit branches,removal of redundant buds and removal of decapitation fruit branches increased by 6.62%,2.66%,3.7% compared with CK in 2014,removal of redundant buds + removal of decapitation fruit branches,removal of redundant buds and removal of decapitation fruit branches increased by 9.56%,5.26%,1.93% compared with CK in 2015,removal of redundant buds and decapitation fruit,there were smaller influence on cotton fiber quality,also reduced the economic benefits of farmers.To conclude,we suggest retained redundant buds and decapitation fruit branches to simplify pruning in the field under large-scale cultivation.