White mold caused by the fungus, Sclerotinia sclerotiorum is a devastating disease of soybean (Glycine max) and other leguminous crops, including dry bean (Phaseolus vulgaris). Previous research has demonstrated that no-till planting soybean into rolled–crimped cereal rye residue can enhance weed management, improve soil health and reduce labor requirements in organic production. However, there are limited data on the effects of cereal rye residue on white mold suppression in no-till planted soybean and dry bean. Two field trials were conducted in 2016–2017 (Year 1) and repeated in 2017–2018 (Year 2) to evaluate the potential of cereal rye cover crop residue to suppress white mold in these crops. In each trial (soybean and dry bean), the experimental design was a randomized complete block with two treatments: (1) rolled–crimped cereal rye residue and (2) no cover crop control. Treatment effects on plant population, biomass and yield components varied between the main crops. Compared with the control treatment, cereal rye residue reduced the incidence of white mold in soybean in both years and in dry bean in Year 2. The reduction in white mold in cereal rye residue plots was due to a combination of (1) decreased sclerotial germination (no stipes formed) and (2) increased nonfunctional sclerotial germination defined here as sclerotia that germinated but produced stipes without the expanded cup where asci containing ascospores are formed. Weed density and biomass were lower in cereal rye residue plots in soybean and dry bean, except in Year 1 in soybean when weed biomass was low in both treatments. Our findings indicate that cereal rye residue could help organic and conventional farmers manage white mold in no-till planted soybean and dry bean. Germination of sclerotia resulting in nonfunctional apothecia could potentially exhaust soilborne inoculum in the upper soil profile and reduce infections in subsequent crops.

中文翻译：

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卷曲谷物黑麦渣抑制免耕大豆和干豆中的白霉

由真菌引起的白色霉菌，核盘菌是大豆的一种毁灭性病害（最大甘氨酸) 和其他豆科作物，包括干豆 (菜豆）。先前的研究表明，将大豆免耕种植到卷曲谷物黑麦残渣中可以增强杂草管理、改善土壤健康并减少有机生产中的劳动力需求。然而，关于谷物黑麦残渣对免耕种植大豆和干豆白霉病抑制效果的数据有限。在 2016-2017 年（第 1 年）进行了两次田间试验，并在 2017-2018 年（第 2 年）重复进行了两次田间试验，以评估谷物黑麦覆盖作物残留物抑制这些作物白霉病的潜力。在每项试验（大豆和干豆）中，试验设计是一个随机完整区组，有两种处理：（1）卷曲谷物黑麦渣和（2）无覆盖作物控制。处理对植物种群、生物量和产量成分的影响因主要作物而异。与对照处理相比，谷物黑麦残留物降低了大豆和第 2 年干豆中白霉病的发生率。谷物黑麦残留物地块中白霉病的减少是由于（1）菌核发芽减少（没有形成菌柄）和(2) 增加的非功能性菌核萌发在此定义为菌核发芽但产生菌柄而没有形成含有子囊孢子的膨胀杯。大豆和干豆的谷物黑麦残留地块的杂草密度和生物量较低，除了在大豆的第 1 年，两种处理的杂草生物量都较低。我们的研究结果表明，谷物黑麦残留物可以帮助有机农民和传统农民管理免耕种植的大豆和干豆中的白霉病。