江淮棉区是我国重要的优质商品棉基地，横跨我国长江下游和淮河下游两大流域，年无霜期200-250天，≥10℃活动积温4500-5300℃。一般来说，该棉区降水量能较好地满足棉花生长发育的需要，近年的实际降水情况表明，降水的季节分配差异诱发该棉区棉花大田生长花铃期的涝渍灾害，不仅降低了降水有效性，而且造成棉花减产、降质。本研究针对江淮棉区涝渍性降雨对常规棉花栽培的影响，示范应用双秆棉的优化成铃优势，缩短棉花大田生长期、调节棉花生育进程最大可能避开涝渍性降雨对开花成铃的危害，实现稳产保收的高效栽培目的。示范分别于2006年、2007年在射阳，兴化、如东等地进行，以科棉3号为材料，设常规栽培（单秆，对照）、双秆栽培两种种植方式，研究双秆棉在涝渍性降雨胁迫条件下示范的产量构成、产量品质的形成，主要结论如下： 1.涝渍性降雨对常规单秆棉产量形成的影响 江淮棉区棉花大田生长期的涝渍性降雨主要集中在6月中下旬和7月上中旬，此阶段降雨主要表现以期间单日大降雨量为多，单日大量集中涝渍性降雨过程导致蕾铃大量脱落，雨后延续性涝渍显著降低现蕾强度，综合显示花铃期涝渍性降雨降低了成铃强度和成铃量，对品质之纤维长度和比强度的影响较大、其次是整齐度和伸长率，对马克隆值的影响最小。 2.涝渍性降雨逆境条件下双秆棉表现明显的成铃聚载效应 双秆棉大田生长期（移栽-拔秆）较对照缩短42天，全生育期缩短了35天。双秆棉现蕾强度高、果节量大，现蕾高峰期内现蕾强度高达14.54万个•hm-2•d-1，最终有效果节量达328.95万个•hm-2，显著高于单秆对照；双秆棉在高温富照期内平均成铃强度达4.42万个•hm-2•d-1，表现明显的成铃聚载效应； 在涝渍性降雨逆境条件下，2006年双秆处理的伏桃和早秋桃铃数高达104.65万个•hm-2，6-10台果枝铃数为49.03万个•hm-2，内围铃数为73.90万个•hm-2；2007年双秆处理的伏桃和早秋桃铃数高达104.58万个•hm-2，6-10台果枝铃数为46.70万个•hm-2，内围铃数为72.52万个•hm-2；涝渍性降雨逆境条件下双秆棉显示的内围果节高成铃率（2006年59.64％、62.60％），形成了较高的单铃籽棉和单铃经济系数， 2006、2007年双秆棉单铃平均籽棉重分别为4.85克、4.79克，单铃平均经济系数分别为73.36％、74.12％，均超过单秆对照。 3.涝渍性降雨逆境条件下双秆棉表现产量极显著超对照和纤维品质优化 双秆棉籽棉产量2006年较单秆棉增加15.09%，达显著水平，2007年较单秆棉增加20.17%，达极显著水平。双秆棉籽棉表现的增产优势主要为极显著的成铃数优势，单铃重和衣分并未表现出明显的优势。利用关联度方法对2007年单双秆处理的纤维品质指标值进行综合分析评判，表明双秆栽培处理总体棉花纤维品质优于常规单秆栽培处理，品质优势集中表现为纤维的比强度、整齐度较好，麦克隆值较适宜。

The Jianghuai cotton district is the important high-quality commodity cotton base of our country. It spans two major valley, the low reaches of the Yangzi River and the Huai River in our country, annual 200-250 days of frost-free period, accumulated temperature 4500-5300 ℃. Always, the rainfall of this cotton district could satisfy the growth and development of cotton, but the actual rainfall indicated that the differences of rainfall in different seasons resulted in the waterlogging disaster during flowering and boll-setting period in field; consequently, not only reduce the validity of rainfall, but also indicated reduction of output and quality of cotton. In this experiment, in allusion to the effect of waterlogging rainfall to conventional cotton cultivation in the Jianghuai cotton district, demonstrated the superiority of double-stem cotton budding, shorten its farm-growing period ,adjust the development course of cotton to avoid the harmfulness of flowering and boll-setting of waterlogging and achieve the high-effeciency cultivation of stable yield. The demonstration in Sheyang, Xinghua and Rudong during 2006 and 2007, the experiment matemial is Kemian 3, conventional (single-stem, CK) and double-stem cultivation, to investigated the yield components and the formulation of yield and qualitu of double-stem cotton demonstration in waterlogging rainfall stress. The main conclusion were as follows: 1 The effect of the formulation of conventional single-stem cotton yield by waterlogging rainfall The rainfall concentrated the middle and last ten days of June month and the first ten days of July month in Jianghuai cotton district. The further analysis indicated that the main behave formation was big daily rainfall, then resulted continue waterlogging disaster, significantly reduced the boll-setting rate of cotton. The main effect of waterlogging rainfall to cotton yield during budding boll tme was reduce the total boll number, to the length of fibre and specific intension was most significant, then was the uniformity and elongation, the least was micornaire. 2 The mass boll-setting effect gathering effect of double-stem cotton under waterlogging To compared with the single-stem cotton in the same planting period, the farm-growing period of double-stem cotton was shortened about 42 days, and the whole breeding period was shortened 35 days. In the square-emerging fastigium, the average square-emerging intensity is 14.54×105.hm-2.d-1, and the number of available square is 3.29×106.hm-2, were both evidently higher than that of sigle-stem cotton. In the best hot and light season, the average intensity of boll-setting of double-stem cotton is 4.42×104.hm-2.d-1, it showed obviously mass boll-setting effect. In waterlogging rainfall condition, the quantity of summer bolls and early autumn bolls of double-stem cotton is 1.04×104.hm-2, the boll number of the 6-10th fruit branches was 4.93×104.hm-2 , and the boll number of inside encircles was 7.39×104.hm-2 in 2006; and t the quantity of summer bolls and early autumn bolls of double-stem cotton is 1.04×104.hm-2, the boll number of the 6-10th fruit branches was 4.67×104.hm-2 , and the boll number of inside encircles was 7.25×104.hm-2 in 2007; In waterlogging rainfall condition ,The boll number of inside encircles of double-stem cotton on boll-setting rate is high(59.64% in 2006, 62.60% in 2007), The average of boll weight is 4.85g, 4.79g in 2006 and 2007, The SCR is 73.36%, 74.12%, both higher than single-stem cotton. 3 Compared with conventional cultivation, the yield of double-stem cotton under waterlogging is high and the fiber quality is fine. The seed cotton yield of double-stem cotton was 15.09% significantly higher than single-stem cotton in 2006, and was 20.17% extremely significantly higher than single-stem cotton in 2007. It was showed on the superiority of boll quantity, Grey correlation degree analysis to the fiber quality of double-stem cotton is overall superior to the treatments CK. The concentration demonstration showed that the specific intension, orderness and miclon of double-stem cotton were superior to CK.