温光和种植制度对棉花早熟性和纤维品质的影响

Effects of Climate and Planting System on Cotton Pre-maturity and Fiber Quality

研究了气候和种植制度对棉花早熟性和主要品质的影响,结果表明:棉花早熟性和纤维长细强指标受温光影响最大,熟制次之,栽培技术第三。进一步分析,气温中日最低温度对纤维品质影响最大。温光、熟制和栽培技术有互作效应,三者互作对细度影响最大,强度次之,长度影响最小;采用促早栽培,提高霜前花率有利于改进整体纤维品质。

The field experiments were carried out in Cotton Research Institute, CAAS in 2000 and 2002. CCRI 29, a hybrid cotton variety, was chosen for tests. Two planting patterns, single cropping and double cropping of wheat-cotton, were used. The tests were made in the same fields.The flowering stage in cotton fields in 2000 and 2002 was July 10, July 2 and July 10, respectively. Cotton in fields of single cropping was picked four times, and cotton in fields of double cropping was picked three times. Fusarium wilt and Verticillium wilt were investigated on July 10, July 4 and July 8, respectively in 2000 and 2002. The fiber quality was tested by HVI900 in Supervision Inspection and Test Center of Cotton Quality, Ministry of Agriculture, China. The span length, strength and micronaire value were tested. The weather station of Cotton Research Institute, CAAS offered the weather records in cotton growing season each year. All the data from the tests were analyzed by software of regression · correlation · path analysis system.In this study, the time from flowering to boll opening which was about 50 days was separated into three periods. The emphases of this study were the effects of climatic elements on the span length, strength and micronaire value in the periods of 0～20 d, 20～40 d, 40～50 d after flowering. The relations between climatic elements in the three periods, such as ≥20℃accumulated temperature, sum of daily maximum temperature, sum of daily minimum temperature, days of daily minimum temperature greater than or equal to 15℃, daily temperature range and sunshine hours, and earliness with fiber quality indexes were correspondingly analyzed respectively, in order to discover the correlativity between climatic elements and earliness, fiber quality indexes.The extent of influence of each index on the earliness of cotton was in turn that climatic conditions > cropping system > measure of early maturing culture. In the three indexes of fiber quality, the micronaire value was influenced most by outside surroundings, which varied in different years, cropping systems and harvest times. The strength and length varied in different years and harvest times, while unconspicuous between different cropping system.Thedifferenceofthethreeindexesoffiber qualityindifferentharvesttimeswasallverysig nificant.Itshowedthatthefiberqualitywasinflu encedmorebyoutsidesurroundings.Theplanting patternsanddifferentmeasureshadalesseffecton fiber qualitythanoutsidesurroundings.The length ,strengthandmicronairevalueoffiber ripenedfromeachtimewerecloselyinterrelatedto temperature,especiallythedailyminimumtemper ature .Thenormalgrowthoffiberwouldbeinflu encedifthedailyminimumtemperaturewasexces sivelow . Differentcroppingsystemhadlittleeffecton thelength ,moreonthestrength ,andthemoston themicronairevalue.Themainreasonwasthat, thecottonseedlingstageindoublecroppingwasin adversitywith quiteseriousconflictionsofsun shine ,temperatureandwaterresultingfromthe intercroppingcropofwheat.Whenbadclimatic environmentsuchaslowtemperature ,rainand lackofsunshinecame ,cottonwouldbeseriously delayedingrowthandlatematuring ,andtherate ofhighqualitycottonbeforefrostwouldbelow . Aninstanceoccurredin 2 0 0 2 .Therateofcotton beforefrostofdoublecroppingwas 2 0 .1 %,lower thanthatofsinglecropping .Amassofcottonafter frostandgreenbollcottonwereallthefiberoflow maturity,underdevelopedandlowmicronaireval ue .Theorderofthestrongorweakeffectofdis easedevelopmentinfieldsandconfigurationonthe fiberqualityneedsfurtherstudy . Keywords:cotton ;climate ;pre maturity ;fiber quality