极端干旱区棉花生育期变化特征及光热条件对其产量的影响

Variation characteristics of cotton growth and effect of light and thermal condition on yield factors in extreme arid region

利用敦煌市1983—2012年棉花生育期农业气象观测资料,研究不同播种期棉花的生育天数的变化以及棉花在不同阶段生育天数、气温、光照条件的差异及其对棉花产量的影响;构建了产量与生育天数、日照时数和平均气温的回归方程。结果表明:播种日期的迟早主要影响播种出苗期和苗期的生育天数,播种越迟,这两个阶段的天数越短。各发育阶段天数的变化直接影响着棉花的品质与产量,其中蕾期天数与吐絮期天数相关较好,蕾期天数短,吐絮期天数长,利于棉花的生长发育。近30 a来,日平均和总日照时数均有所增加,气候倾向率分别为0.12 h·10a-1和96.14 h·10a-1;平均气温呈上升趋势,气候倾向率达0.29℃·10a-1,近代气候光热条件的变化对喜热植物棉花是十分有利的。在不同生育阶段,棉花对光热条件的需求各异,如吐絮期的日照时数越多、气温越高,则越容易获得高产。根据早熟及抗病为主的品种对发育天数和光热条件的需求,结合当地气候,合理确定播种期,科学地利用气候因子对棉花各生育期的影响,是实现棉花高质高产的有效途径。

Using agricultural meteorological data of cotton growth period during 1983-2012 in Dunhuang ,this pa-per studied the difference of the number of days in each stage of cotton growth ,light and temperature condition and their effects on cotton yield ,and then built regression equation of yield and growth days ,sunshine hours and average tempera-ture .The results show ：the planting date mainly affects seeding stage and seedling growth dates;if the sowing dates de-lay ,the two stages will be shorter .The variation of stage days in every developing stage affects the quality and yield of the cotton .The shorter days of squaring stage ,the longer the days of wadding stage ,which is in favor of the cotton’ s growth .In recent 30 years ,both daily mean and total sunshine hours have increased ,and the climate tendency rate is 0 .12 h·10a-1 and 96 .14 h·10a-1 separately;the average temperature presents an increasing tendency ,and the climate tendency rate is 0 .29℃·10a-1 .The change of modern climate photothermal conditions is in favor of philotherm cotton . In different growth periods ,cotton has different demands on photothermal supply .During the wadding stage the more the sunshine ,the higher the temperature ,and it will be easier to obtain higher yield .According to the demand of early ma-turity ,disease-resistant cotton varieties on the light and thermal conditions and combining with the local climate ,control-ling the influence of climatic factors on cotton by scientific regulation are effective ways to harvest high yield of cotton .