Abstract In organic agronomic cropping systems, the use of synthetic insecticides and transgenic varieties are prohibited and producers rely mainly on biological control, tillage, crop rotation, and other cultural practices to manage pests. We measured damage to organic corn (Zea mays L.) from multiple invertebrate pests, including slugs (Gastropoda: Mollusca), European corn borer (Ostrinia nubilalis Hübner), corn earworm (Helicoverpa zea Boddie), and fall armyworm (Spodoptera frugiperda Smith), early and late in the growing season in four cropping systems that varied in tillage frequency and intensity and in winter cover crop species. Specific management tactics included two cover crop mixtures preceding corn, the use of a roller-crimper or tillage to terminate cover crops preceding corn, and the establishment of interseeded cover crops after corn emergence. Prevalence of early-season damage was high, but severity of damage was very low and unrelated to corn yield. The proportion of corn plants affected by chewing pests early in the season was lower in plots in which tillage compared to a roller-crimper was used to terminate cover crops. Cropping system did not affect the numbers of late-season caterpillar pests or corn yield. Predation by natural enemies appeared to effectively maintain damage from chewing pests below yield-damaging levels. These results support the inclusion of winter and interseeded cover crops in organic agronomic crop rotations to gain environmental benefits without increasing risks of damage by insect pests.

中文翻译：

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以覆盖作物为基础的减耕有机系统中玉米早晚病虫害的流行情况

摘要 在有机农艺种植系统中，禁止使用合成杀虫剂和转基因品种，生产者主要依靠生物防治、耕作、轮作和其他栽培措施来管理害虫。我们测量了多种无脊椎动物害虫对有机玉米 (Zea mays L.) 的损害，包括蛞蝓（腹足纲：软体动物）、欧洲玉米螟（Ostrinia nubilalis Hübner）、玉米穗虫（Helicoverpa zea Boddie）和秋粘虫（Spodoptera frugiperda Smith） , 在四种耕作系统的生长季节早期和晚期，耕作频率和强度以及冬季覆盖作物种类各不相同。具体的管理策略包括在玉米之前使用两种覆盖作物混合物，使用滚压机或耕作来终止玉米之前的覆盖作物，以及在玉米出苗后建立间种覆盖作物。早季损害的发生率很高，但损害的严重程度非常低且与玉米产量无关。在本季早期受咀嚼性害虫影响的玉米植株比例在使用耕作而不是辊压机终止覆盖作物的地块中较低。种植制度不影响晚季虫害数量或玉米产量。天敌的捕食似乎可以有效地将咀嚼害虫造成的损害保持在产量损害水平以下。这些结果支持在有机农艺作物轮作中加入冬季和间种覆盖作物，以在不增加虫害破坏风险的情况下获得环境效益。但损害的严重程度非常低，与玉米产量无关。在本季早期受咀嚼性害虫影响的玉米植株比例在使用翻耕机终止覆盖作物的地块中较低。种植制度不影响晚季虫害数量或玉米产量。天敌的捕食似乎可以有效地将咀嚼害虫造成的损害保持在产量损害水平以下。这些结果支持在有机农艺作物轮作中加入冬季和间种覆盖作物，以在不增加虫害破坏风险的情况下获得环境效益。但损害的严重程度非常低，与玉米产量无关。在本季早期受咀嚼性害虫影响的玉米植株比例在使用翻耕机终止覆盖作物的地块中较低。种植制度不影响晚季虫害数量或玉米产量。天敌的捕食似乎可以有效地将咀嚼害虫造成的损害保持在产量损害水平以下。这些结果支持在有机农艺作物轮作中加入冬季和间种覆盖作物，以在不增加虫害破坏风险的情况下获得环境效益。种植制度不影响晚季虫害数量或玉米产量。天敌的捕食似乎可以有效地将咀嚼害虫造成的损害保持在产量损害水平以下。这些结果支持在有机农艺作物轮作中加入冬季和间种覆盖作物，以在不增加虫害破坏风险的情况下获得环境效益。种植制度不影响晚季虫害数量或玉米产量。天敌的捕食似乎可以有效地将咀嚼害虫造成的损害保持在产量损害水平以下。这些结果支持在有机农艺作物轮作中加入冬季和间种覆盖作物，以在不增加虫害破坏风险的情况下获得环境效益。