苗期喷施烯效唑对油菜生长及产量和品质的影响

Effect of uniconazole application on seedling growth and seed yield and quality in Brassica napus L.

为探索烯效唑在油菜机械化种植中的应用，2～4叶期用50 mg／L、75 mg／L、100 mg／L和150 mg／L的烯效唑喷施油菜幼苗（1或2次），研究烯效唑对幼苗生长调控、光合生理特性、植株抗倒性及其产量和品质的影响。结果显示：幼苗株高、最大叶面积和地上部干质量均随处理浓度和次数的增加而显著下降；当处理浓度≤100 mg／L，根干质量和根颈粗随处理浓度增加而增加。幼苗高、最大叶面积和根干质量随烯效唑处理时苗龄的增大而增加。叶片净光合率和叶绿素含量随处理浓度和次数的增加而增加。成熟期的株高和分枝点高度均随烯效唑处理浓度和次数的增加而降低，而根颈粗、根干质量和单位长度茎秆干质量增加，植株抗倒能力增强。烯效唑浓度≤100 mg／L，处理1次，单株角果数、千粒质量和种子产量增加。2～4叶期叶面喷施不同浓度烯效唑，种子含油量下降，蛋白质含量增加，脂肪酸组成及相对含量无明显变化。2叶或3叶期用≤100 mg／L烯效唑处理幼苗，可有效降低成熟期株高，增强植株抗倒性，有利于机械收获。

The effect of uniconazole on seedling growth of Brassica napus L. as well as seed yield and quality traits were investigated by foliar spraying once or twice at 2-4 leaf period with the concentrations of 50 mg/L,75 mg/L,100 mg/L and 150 mg/L in Nanjing. Seedling height （SH）, leaf area of the largest leaf （LAL） and dry matter weight of seedling shoots （ SDM） were decreased with the increase of applied concentrations and times of uniconazole. While the concentration was less than 100 mg/L, dry matter of roots （ RDM） and root collar diameter （ RCD） were increased with the concentration. The SH, LAL and SDM were increased as seedling developed bigger while uniconazole was applied. SPAD value, chlorophyll content and net photosynthetic rate （ NPR） of seedling leaf increased with the applied concentrations and times of uniconazole. At maturity, plant height （ PH） and the height of lowest branch point （ BPH ） were significantly decreased, however, root collar width, root dry weight and dry weight/stem length increased, and plant lodging resistance were improved. Seed yielding, pod number per plant and one thousand＆nbsp;seed weight were increased when the uniconazole was less than 100 mg/L and was applied once. Application of unicon-azole at 2-4 leaf age led to decreased oil content and increased protein content. All the results above indicated that uni-conazole applied at seedling stage gave a lower PH and BPH of the plant and a higher lodging resistantce at maturity, which were helpful for mechanical harvesting.