配置模式对枣棉间作棉花光合及干物质积累特征的影响

Influence of allocation models on characteristics of photosynthesis and dry matter accumulation in cotton intercropped with jujube

在新疆自然生态条件下,研究了不同密度下宽窄行(45 cm+15 cm)和等行距(30 cm)配置模式对枣棉间作棉花光合及干物质积累特征的影响。结果表明:枣棉间作条件下,不同配置模式棉花在盛花期以前LAI、SPAD及Pn差异未达显著水平,盛花期后差异显著。棉花Pn全生育期呈抛物线形态变化,蕾期以低密度等行距较高,随密度增大各处理Pn呈下降趋势,Pn在盛花期达到峰值,中密度宽窄行最高,为34μmol·m-2·s-1,盛铃期、吐絮期以高密度宽窄行最高,各时期均以冠外区高于冠下区。高密度种植利于降低宽窄行t0,提高Vm,Vm最大值为269.8 kg·d-1,分别比中、低密度高11%、52.8%,而中、低密度等行距Vm高于宽窄行,高密度反之。■t、t1、t2表现为高密度>中密度>低密度。因此,枣棉间作棉花适宜宽窄行、高密度种植。

By using different planting densities with wide-narrow row （45 cm＋15 cm）and even row space （30 cm）,the effects of allocation models on characteristics of photosynthesis and dry matter accumulation in cotton inter-cropped with jujube were investigated in Xinjiang .The results showed that：（1）The difference of leaf area index （LAI）, SPAD and net photosynthesis rate （Pn）in cotton did not reach significant level before full-bloom stage among different allocation models,while it was opposite after full-bloom stage .（2）The change of Pn in cotton was parabolic,and it was higher in outer canopy than in lower canopy during the whole growth period .During bud stage,the Pn was relatively high under low density with even row space,and it tended to decrease with the increase of planting density .The Pn reached the peak values at full-bloom stage,in which the highest value was 34μmol·m-2·s-1 under middle density with wide-narrow row .During full-boll stage and boll opening stage,the Pn was the highest under high density with wide-nar-row row.（3）High planting density was beneficial to decrease t0 and increase Vm under wide-narrow row.The maximum value of Vm under high planting density was 269 .8 kg·d-1 ,being 1 1%and 52 .8%higher,respective,than that under middle and low planting density .The value of Vm under middle and low planting density with even row space was higher than that with wide-narrow row,but it was opposite under high planting density.The value of△t,t1 and t2 were se-quenced as：high density〉middle density〉low density .Therefore,it was suitable to plant cotton in high planting densi-ty with wide-narrow row in jujube-cotton intercropping system .