Sweet basil is the most widely grown herb in the U.S. Downy mildew is the most common disease. Management is necessary because there is no tolerance for disease symptoms on leaves marketed for fresh consumption. Host resistance is a preferred management practice. Research was initiated to evaluate cultivars bred to be resistant to downy mildew when they started to become commercialized. Five replicated experiments were conducted between 2018 and 2022 with field-grown basil exposed to naturally-occurring wind-dispersed sporangiospores of Eleonora, which is one of the first resistant cultivars commercialized, exhibited limited suppression in this study (26 and 34% control based on AUDPC for incidence of leaves with symptoms compared to a susceptible cultivar). Amazel, the related cultivar Pesto Besto, and Prospera plus related cultivars from Genesis Seeds provided excellent to complete suppression (usually 100%). They have resistance gene . The four Rutgers DMR cultivars (Devotion, Obsession, Passion, and Thunderstruck) provided good to excellent control with some yearly variation (46–99% control). The recommended management program for downy mildew in field-grown sweet basil in an integrated management program with fungicides applied to resistant cultivar(s), plus weekly checking the crop for symptoms as well as staying current on knowledge about changes in the pathogen, commercialization of new resistant cultivars, and registration of new fungicides.

中文翻译：

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在露地条件下评估抗霜霉病的甜罗勒品种


甜罗勒是美国种植最广泛的草本植物，霜霉病是最常见的疾病。管理是必要的，因为新鲜食用的叶子对疾病症状没有耐受性。宿主抵抗是首选的管理实践。当品种开始商业化时，就开始研究评估抗霜霉病品种。 2018 年至 2022 年间进行了五次重复实验，将田间种植的罗勒暴露于 Eleonora 自然发生的风散孢子囊孢子中，Eleonora 是第一个商业化的抗性品种之一，在本研究中表现出有限的抑制（26% 和 34% 的对照基于AUDPC 表示与易感品种相比出现症状的叶子的发生率）。 Amazel、相关品种 Pesto Besto 和 Prospera 以及来自 Genesis Seeds 的相关品种提供了出色的完全抑制（通常为 100%）。他们有抗药基因。罗格斯大学的四个 DMR 品种（Devotion、Obsession、Passion 和 Thunderstruck）提供了良好到极好的控制效果，但存在一些年度变化（46-99% 控制）。推荐的田间种植甜罗勒霜霉病管理计划采用综合管理计划，其中包括对抗性品种施用杀菌剂，加上每周检查作物的症状以及及时了解有关病原体变化的最新知识，以及商业化新抗性品种、新杀菌剂登记。