Webster Richard W, Roth Mitchell G, Mueller Brian D, Mueller Daren S, Chilvers Martin I, Willbur Jaime F, Mourtzinis Spyridon, Conley Shawn P, Smith Damon L
Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI 53706.
Department of Plant Pathology, The Ohio State University, Wooster, OH 44691.
Plant Dis. 2022 Apr;106(4):1183-1191. doi: 10.1094/PDIS-09-21-1931-RE. Epub 2022 Mar 30.
Soybean () farmers in the Upper Midwest region of the United States often experience severe yield losses due to Sclerotinia stem rot (SSR). Previous studies have revealed benefits of individual management practices for SSR. This study examined the integration of multiple control practices on the development of SSR, yield, and the economic implications of these practices. Combinations of row spacings, seeding rates, and fungicide applications were examined in multisite field trials across the Upper Midwest from 2017 to 2019. These trials revealed that wide row spacing and low seeding rates individually reduced SSR levels but also reduced yields. Yields were similar across the three highest seeding rates examined. However, site-years where SSR developed showed the highest partial profits at the intermediate seeding rates. This finding indicates that partial profits in diseased fields were reduced by high seeding rates, but this trend was not observed when SSR did not develop. Fungicides strongly reduced the development of SSR while also increasing yields. However, there was a reduction in partial profits due to their use at a low soybean sale price, but at higher sale prices fungicide use was similar to not treating. Additionally, the production of new inoculum was predicted from disease incidence, serving as an indicator of increased risk for SSR development in future years. Overall, this study suggests using wide rows and low seeding rates in fields with a history of SSR while reserving narrow rows and higher seeding rates for fields without a history of SSR.
美国中西部上游地区的大豆种植户经常因菌核病茎腐病（SSR）而遭受严重的产量损失。先前的研究揭示了针对SSR的个体管理措施的益处。本研究考察了多种防治措施的综合运用对SSR发展、产量以及这些措施的经济影响。在2017年至2019年期间，对上中西部地区的多个田间试验进行了行距、播种量和杀菌剂施用组合的研究。这些试验表明，宽行距和低播种量分别降低了SSR水平，但也降低了产量。在所考察的三个最高播种量下，产量相似。然而，发生SSR的地块年度在中等播种量时显示出最高的部分利润。这一发现表明，高播种量降低了病害田块的部分利润，但当未发生SSR时未观察到这种趋势。杀菌剂在强烈降低SSR发展的同时也提高了产量。然而，由于在大豆低价销售时使用杀菌剂，部分利润有所减少，但在较高销售价格时，使用杀菌剂与不处理的情况相似。此外，根据发病率预测了新接种体的产生，作为未来几年SSR发展风险增加的一个指标。总体而言，本研究建议在有SSR病史的田块使用宽行和低播种量，而在没有SSR病史的田块保留窄行和较高播种量。
