叶面喷施硼肥对紫花苜蓿种子产量和质量的影响

在分析内蒙古额克托旗地区苜蓿种子生产基地土壤有效硼含量的基础上,连续2年在不同年限的紫花苜蓿(Medicago sativa)上采用质量分数为0.229%,0.371%和0.600%的硼砂溶液进行花期叶面喷施,研究其对苜蓿种子产量和质量的影响,旨在为苜蓿种子生产微肥施用方面提供科学依据。结果表明:硼对成熟期苜蓿单株叶重和荚果重、种子产量组分、种子产量和质量有一定影响,其中单株叶重以喷施0.600%的硼砂溶液效果最好,2013和2014年分别比对照增重80.77%和35.71%,0.371%的硼砂溶液对增加单株荚果重、单株结荚花序数、每花序结荚数、每荚果种子数以及种子增产效果最显著,2013和2014年种子单产分别为604.38和322.76 kg·hm^-2,比对照增产71.35%和37.37%,正常种苗百分比分别比对照提高10.24%和21.11%,种子硬实率分别比对照降低5.16%和10.55%。因此叶面喷施合适浓度硼肥可促进生殖分配,显著提高苜蓿种子产量和正常种苗数,降低硬实率,综合考虑以质量分数为0.371%肥液效果最佳。

Effects of Foliar Boron Application on the Yield and Quality of Alfalfa Seed

Based on the analysis of soil effective boron content in alfalfa seed production field at Eketuoqi area of Inner Mongolia, the mass fractions of 0.229%, 0.371% and 0.600% borax solution were used for foliar spray at flowering stage in different years of alfalfa (Medicago sativa) for two consecutive years. The effects of foliar spray on the yield and quality of alfalfa seed were studied to provide a scientific basis for the fertilizer application of alfalfa seed production. The results showed that boron affected the leaf and pod weight per plant, seed set, seed yield and quality of alfalfa in mature stage, and the borax solution of 0.600% had the best effect on the leaf weight, which increased by 80.77% and 35.71% compared to control in 2013 and 2014, respectively. The borax solution of 0.371% significantly increased pod weight per plant, racemes per plant, pod number per raceme, seed number per pod, seed yield and quality, the highest seed yield in 2013 and 2014 were 604.38 and 322.76 kg·hm^-2, increased by 71.35% and 37.37% compared to control. The percentages of normal seedling increased 10.24% and 21.11%, whereas hard seed rates decreased 5.16% and 10.55%, respectively. These results indicate that the foliar application of proper concentration of boron fertilizer can improve the reproductive allocation, seed yield and normal seedling ratio of alfalfa significantly, and decrease hard seed ratio. Based on overall consideration of the results, the mass fraction of 0.371% has the best effect.