Cercospora leaf spot, caused primarily by , is common on red beet wherever this vegetable crop is grown. The effectiveness of a conventional (propiconazole rotated with azoxystrobin) and an organic biofungicide ( mixed with copper octanoate) program were tested on four cultivars of beet that differed in susceptibility. Three inoculum densities were established by inoculating a 1-m portion of one row, allowing conidia to splash to the adjacent row, and not inoculating the remainer of the plot. Foliar severity was reduced by both fungicide programs compared to the water-treated control, but the conventional fungicides were more effective in the high inoculum area than the organic fungicides. The conventional fungicides also increased the fresh weight of healthy leaves compared to the water control, but the organic fungicides did not differ from the other two treatments. All cultivars except the most resistant one, Bull's Blood, had greater healthy weights in 2022 when the inoculum density was lower than in 2021. Cultivars sorted in the same order of susceptibility regardless of fungicide program. In all treatments, mean weight of diseased individual leaves was greater than healthy leaves. Partial cultivar resistance and fungicides or biofungicides had additive effects for integrated management of Cercospora leaf spot on red beet.

中文翻译：

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具有品种抗性的杀菌剂或生物杀菌剂对甜菜尾孢叶斑病综合治理的接种密度依赖性附加效果

尾孢叶斑病主要由 引起，在红甜菜上很常见，无论种植这种蔬菜作物。在四个不同敏感性的甜菜品种上测试了常规（丙环唑与嘧菌酯轮换）和有机生物杀菌剂（与辛酸铜混合）方案的有效性。通过接种一排的 1 米部分，允许分生孢子飞溅到相邻的排，并且不接种地块的其余部分，建立三种接种密度。与水处理对照相比，两种杀菌剂方案均降低了叶面严重程度，但在高接种量区域，传统杀菌剂比有机杀菌剂更有效。与水对照相比，常规杀菌剂还增加了健康叶片的鲜重，但有机杀菌剂与其他两种处理没有差异。 2022 年，除抗性最强的公牛血品种外，所有品种的健康体重均较高，当时接种密度低于 2021 年。无论采用何种杀菌剂方案，品种均按相同的敏感性顺序排序。在所有处理中，患病的单片叶子的平均重量大于健康的叶子。部分品种抗性和杀菌剂或生物杀菌剂对红甜菜尾孢叶斑病的综合治理具有累加效应。