多效唑处理对直播油菜机械收获相关性状及产量的影响

以阳光2009与沣油520为材料,于封行期及蕾薹初期喷施不同浓度多效唑,测定倒伏、角果抗裂性及产量相关指标,研究多效唑对油菜产量和机械收获相关性状的影响,为高产及机械收获条件下油菜的多效唑调控提供技术支撑及理论依据。结果表明,不同时期多效唑处理均显著提高2个油菜品种的抗倒性、抗裂角性及产量,蕾薹初期喷施300 mg L–1多效唑后油菜抗倒与抗裂角指数增量大,封行期喷施150 mg L–1多效唑则后产量的增量大。多效唑处理降低每角果粒数,但增加油菜品种的单株角果数及千粒重,故而增加产量;且可通过增加油菜根颈粗、鲜重根冠比及抗折力降低株高和倒伏指数,提高油菜抗根倒与抗茎倒能力;通过增加角果含水量、延缓角果成熟度、增加角果皮干重提高油菜角果抗裂性。本研究认为封行期喷施150 mg L–1的多效唑是最佳喷施时期与喷施浓度,既可显著增强易倒伏而减产油菜田块的抗倒与抗裂角能力,最大幅度地提高产量,又可满足油菜机械化生产模式所需的高产、抗倒及抗裂角要求。

Effects of Paclobutrazol on Yield and Mechanical Harvest Characteristics of Winter Rapeseed with Direct Seeding Treatment

The aim of this research was to study the effects and mechanism of paclobutrazol (PP₃₃₃) treatments on rapeseed yield and mechanical harvesting. PP₃₃₃ was foliage sprayed with different concentrations at two stages (the closing of crop and the start of flower bud), on two varieties of rapeseed Yangguang 2009 and Fengyou 520. Our results demonstrated that PP₃₃₃ treatment significantly increased the rapeseed lodging resistance, silique shattering resistance and yield. PP₃₃₃ of 300 mg L^–1 at the bud beginning more significantly enhanced lodging resistance and silique shattering resistance, whereas 150 mg L^–1 PP₃₃₃ at crop closing period more significantly increased yield of the two varieties. PP₃₃₃ treatment reduced seed number per pod, while enhanced pods per plant, 1000-grain weight and yield. At the same time, PP₃₃₃ treatment increased root crown diameter, root-top ratio (fresh) and snapping resistance, whereas it reduced plant height and culm lodging index, resulting in reduced angle of plant lodging, which indicates an improvement in the resistance of root and stem lodging. Silique shattering resistance was increased due to increased silique water content, silique dry weight and delayed pod maturity. In summary, the crop closing period and 150 mg L^–1 PP₃₃₃ are the best treatment time and concentration for significantly enhancing the abilities of lodging resistance, silique shattering resistance and yield, which could meet rapeseed mechanized production.