Department of Agronomy, University of Missouri, Columbia, Missouri 65211.
Plant Physiol. 1990 Mar;92(3):602-7. doi: 10.1104/pp.92.3.602.
Our previous work demonstrated that boron (B) supplied to soybeans (Glycine max [L.] Merrill cv ;Williams 82') by a stem infusion technique increased the number of pods on branches and led to a significant yield increase. Therefore, research was continued to determine whether soil or foliar applications of B could be used to achieve the same results. Field experiments were completed with both soil and foliar applications of B. Only the foliar applications of B resulted in a significant increase in the number of pods/branch. When split foliar treatments were applied twice during flowering, the total application of 0.56 kilograms of B per hectare was the optimal treatment for increasing pods/branch. In a second field experiment in 1987, soybeans were treated weekly from flowering through podfill with six split foliar applications of aqueous H(3)BO(3) solutions so that total applications were either 0, 1.1, or 2.24 kilograms of B per hectare. Foliar applications increased the number of branches/plant at the end of the season and significantly stimulated the formation of pods on branches, with 1.12 kilograms of B per hectare being the optimal treatment for these variables. This rate also tended to increase the number of seeds/plant and seed yield/plant. A duplicate experiment with minor modifications was conducted during the summer of 1988, and again the 1.12 kilograms of B per hectare application rate resulted in significant increases in number of branches at harvest as well as number of pods on branches. The 2.24 kilograms of B per hectare application rate also significantly increased these parameters. Foliar B applications induced increases in leaf B concentration far above the 60 micrograms per gram level that was previously accepted as the upper level of tolerance for soybeans. Since optimal branching and per plant yield parameters were achieved by plants with B leaf concentrations greater than 160 micrograms per gram, the accepted range of soybean tolerance for B must be reconsidered when B is foliarly applied.
我们之前的工作表明，通过茎内灌注技术向大豆（Glycine max [L.] Merrill cv；Williams 82'）供应硼（B）可以增加枝条上的豆荚数量，并显著提高产量。因此，我们继续研究是否可以通过土壤或叶面施用 B 来达到相同的效果。我们进行了土壤和叶面施用 B 的田间试验。只有叶面施用 B 才能显著增加豆荚/枝条的数量。在花期进行两次叶面分裂处理时，每公顷施用 0.56 公斤 B 的总施用量是增加豆荚/枝条的最佳处理方法。在 1987 年的第二次田间试验中，从开花到结荚期，每周用 6 次叶面分裂处理用含 H(3)BO(3)的水溶液处理大豆，以使总施用量为每公顷 0、1.1 或 2.24 公斤 B。叶面施用可增加季末的分枝数/株，并显著刺激枝条上的豆荚形成，每公顷 1.12 公斤 B 的处理效果最佳。该处理方法还可增加每株种子数和种子产量。在 1988 年夏季进行了一项略有修改的重复试验，每公顷 1.12 公斤 B 的施用率也显著增加了收获时的分枝数以及枝条上的豆荚数。每公顷 2.24 公斤 B 的施用率也显著增加了这些参数。叶面 B 处理可使叶片 B 浓度远远高于之前被认为是大豆耐硼上限的 60 微克/克水平。由于最佳分枝和单株产量参数是通过叶片 B 浓度大于 160 微克/克的植株获得的，因此在叶面施用 B 时，必须重新考虑大豆对 B 的耐受范围。
