叶面喷施多效唑对紫云英种子产量及结实特性的影响

【目的】通过花前叶面喷施多效唑，探讨多效唑对紫云英产量及其结实特性的调控效应，以期为增加紫云英籽粒数、提高产量调控技术的研究提供参考。【方法】试验以‘信紫1号’为供试材料，设多效唑喷施浓度0 (CK)、200 mg/L (T₁)、300 mg/L (T₂)、400 mg/L (T₃)、500 mg/L (T₄)、600 mg/L (T₅)，喷施溶液量均为750 kg/hm2，在开花前喷施一次。紫云英成熟期，按常规考种法调查单位面积株数、分枝数、不同层花序的花序数、结荚数、籽粒数等指标。【结果】与CK相比，喷施不同浓度多效唑处理的单位面积花序数、结荚数、单荚籽粒数和结实荚果率在不同层花序上均较对照有所提高，以T₃处理提高幅度最大。在第1～6层花序上，T₃处理的单位面积花序数较对照提高34.1%～59.0%，单位面积结荚数提高39.7%～68.4%，单荚籽粒数提高44.3%～53.7%，结实荚果率提高1.84～4.89个百分点。相关分析表明，紫云英种子产量与其单位面积花序数、一级分枝花序数、单个有效花序结荚数、结实荚果率及单荚籽粒数呈显著正相关。多效唑喷施浓度与紫云英种子产量及以上结实因子的相关性均达到极显著水平，以多效唑喷施浓度373 mg/L最优，种子产量最高。【结论】在紫云英花荚脱落高峰之前 (开花前)，叶面喷施多效唑可显著促进不同层花序单位面积花序数、结荚数、结实荚果率和单荚籽粒数的增加，尤其对促进第5、6层花序花荚结实成粒的效果显著，进而获得较高的种子产量。

Effects of spraying paclobutrazol on seed yield and seed-setting characteristics of Chinese milk vetch (Astragalus sinicus L.)

【Objectives】This study explored the influences of applying paclobutrazol on seed yield and seed setting characteristics of Chinese milk vetch (Astragalus sinicus L.), in expectation of providing reference for the efficient use of paclobutrazol in practical production.【Methods】Using Chinese milk vetch cultivar ‘Xinzi1’ as tested material, field experiment had six foliar application levels of paclobutrazol, as 0, 200, 300, 400, 500 and 600 mg/L, recorded as CK, T₁, T₂, T₃, T₄, T₅ in turn. The foliar application was conducted once at pre-flowering stage, and the spraying rate for all the six treatments was 750 kg/hm2. At the mature period of milk vetch, we recorded the number of inflorescence, pods and seeds at different inflorescence layers, the number of plants and branches per unit area using conventional test methods.【Results】In comparison with the control, the inflorescence and pods numbers in unit area, the seed-setting rates of pods and seeds per pod at all the six inflorescence layers were increased in different degrees in all the five paclobutrazol treatments, with the best effect in T₃ treatment. From the 1st to 6th inflorescence layer in T₃ treatment, the number of inflorescences per unit area was increased by 34.1%–59.0%, the number of pods per unit area increased by 39.7%–68.4%, the seed number per pod increased by 44.3%–53.7%, the seed-setting rates of pods increased by 1.84–4.89 percentage points. The seed yield of Chinese milk vetch was significantly and positively correlated with the inflorescence numbers per unit area, the inflorescence numbers per branch, pod numbers per inflorescence, seed set rates of pods and seed number per pod.【Conclusions】At pre-flowering stage, foliar application of paclobutrazol can significantly increase the inflorescences number, pod number, seed-setting rates and seed number per pod at all the six inflorescence layers especially at the 5th and 6th layers, and high seed yield was achieved at last. The best application concentration is paclobutrazol 373 mg/L.