Spring dead spot (Ophiosphaerella herpotricha, O. korrae, O. narmari; SDS) is among the most destructive diseases of bermudagrass [Cynodon dactylon (L.) Pers.] and hybrid bermudagrass (C. dactylon x C. transvaalensis Burtt Davy) in the Transition Zone of the United States. Spring dead spot's primary causal agents in the United States, Ophiosphaerella korrae and O. herpotricha, infect bermudagrass in the fall with symptoms appearing in the spring when winter dormancy breaks. Patches of necrotic turfgrass often reoccur in the same location and expand into surrounding areas. Chemical control options are often expensive or provide inconsistent results. Our objectives were to develop SDS incidence maps, analyze these maps, and evaluate suppression efficacy of chemical applications guided by incidence-based maps. Digital imagery captured with an unmanned aerial vehicle (UAV) was used to create SDS incidence maps in the spring of 2016, 2017, and 2018. In the fall of 2016 and 2017, a targeted, site-specific penthiopyrad treatment was evaluated against blanket, full-coverage applications of penthiopyrad and tebuconazole, and a nontreated control. Treatments were compared using digital image analysis of diseased area (DA) and post-treatment SDS patch count (PC). Across both metrics, the penthiopyrad treatments had significantly less disease than both the tebuconazole and nontreated control in 2016–2017. Targeted penthiopyrad compared favorably to full coverage penthiopyrad for DA and PC in 2016–2017, but full-coverage penthiopyrad was superior to targeted penthiopyrad and tebuconazole in 2017–2018 for both DA and PC. Targeted penthiopyrad using SDS incidence maps required 51% less fungicides in 2016–2017 and 65% less in 2017–2018 when compared to full-coverage penthiopyrad.

中文翻译：

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通过航空测绘和精确制导杀菌剂应用研究有针对性的春季死点管理

春季死斑病( Ophiosphaerella herpotricha, O. korrae, O. narmari ; SDS) 是百慕大草 [ Cynodon dactylon (L.) Pers.] 和杂交百慕大草 ( C. dactylon x C. transvaalensis Burtt Davy)最具破坏性的病害之一美国的过渡区。美国春季死斑病的主要病原体 Ophiosphaerella korrae和O. herpotricha，秋季感染狗牙根，春季冬眠打破时出现症状。坏死的草坪草块经常在同一位置再次出现并扩展到周围区域。化学控制选项通常很昂贵或提供不一致的结果。我们的目标是开发 SDS 关联图，分析这些图，并评估基于关联图的化学应用的抑制效果。在 2016 年、2017 年和 2018 年春季，使用无人机 (UAV) 捕获的数字图像创建了 SDS 发生率图。在 2016 年和 2017 年秋季，针对毯子、吡噻菌胺和戊唑醇的全覆盖应用，以及未处理的对照。使用病变区域 (DA) 和治疗后 SDS 斑块计数 (PC) 的数字图像分析比较治疗。在这两个指标中，2016-2017 年，吡噻菌胺治疗的疾病明显少于戊唑醇和未治疗的对照组。2016-2017 年，靶向吡噻菌胺在 DA 和 PC 方面优于全覆盖吡噻菌胺，但在 2017-2018 年，对 DA 和 PC 而言，全覆盖吡噻菌胺优于靶向吡噻菌胺和戊唑醇。与全覆盖的吡噻菌胺相比，使用 SDS 发生率图的靶向吡噻菌胺在 2016-2017 年需要的杀菌剂减少 51%，在 2017-2018 年减少 65%。2016-2017 年，靶向吡噻菌胺在 DA 和 PC 方面优于全覆盖吡噻菌胺，但在 2017-2018 年，对 DA 和 PC 而言，全覆盖吡噻菌胺优于靶向吡噻菌胺和戊唑醇。与全覆盖的吡噻菌胺相比，使用 SDS 发生率图的靶向吡噻菌胺在 2016-2017 年需要的杀菌剂减少 51%，在 2017-2018 年减少 65%。2016-2017 年，靶向吡噻菌胺在 DA 和 PC 方面优于全覆盖吡噻菌胺，但在 2017-2018 年，对 DA 和 PC 而言，全覆盖吡噻菌胺优于靶向吡噻菌胺和戊唑醇。与全覆盖的吡噻菌胺相比，使用 SDS 发生率图的靶向吡噻菌胺在 2016-2017 年需要的杀菌剂减少 51%，在 2017-2018 年减少 65%。