ABSTRACT

The pathogen Erysiphe cruciferarum is an increasingly serious threat to cruciferous oilseed crops worldwide. In the present study, the severity of powdery mildew was evaluated on spring oilseed rape (Brassica napus) and five alternative oilseed crop species (B. juncea, B. nigra, Sinapis alba, Raphanus sativus, Eruca sativa). The main aim of the study was to identify plant species that are less susceptible to powdery mildew for possible application as cover crop, in trap cropping or seed production. Powdery mildew assessments were conducted in two growing seasons that were characterised by unusually warm and dry conditions for northern temperate climatic conditions. In both growing seasons, a heavy powdery mildew infection (over 80%) was recorded on B. napus and B. nigra plants, indicating that E. cruciferarum is an important pathogen for oilseed crops in northern Baltics. However, three other cruciferous species S. alba, E. sativa and R. sativus showed full resistance to powdery mildew, and thus, even under strong powdery mildew pressure, they can be cultivated without pesticide application in northern Baltic conditions. We suggest that in changing climatic conditions powdery mildew is expected to become a more serious problem in cruciferous oilseed crops in northern Europe, especially under intensive short-rotation farming practices.

摘要

病原体Erysiphe cruciferarum对全世界十字花科油料作物的威胁日益严重。在本研究中，白粉病的严重程度上春油菜（评价甘蓝型油菜）和五个替代油料种子作物物种（芥菜，黑芥，白芥，萝卜，芸苜蓿）。该研究的主要目的是确定对白粉病不太敏感的植物物种，以便可能用作覆盖作物、圈闭作物或种子生产。白粉病评估在两个生长季节进行，其特征是北温带气候条件异常温暖和干燥。在这两个生长季节，欧洲油菜和B. nigra植物上都记录到了严重的白粉病感染（超过 80%），这表明E. cruciferarum是波罗的海北部油籽作物的重要病原体。然而，其他三种十字花科植物S. alba、E. sativa和R. sativus对白粉病表现出完全的抵抗力，因此，即使在强烈的白粉病压力下，它们也可以在波罗的海北部条件下不使用农药进行栽培。我们建议，在不断变化的气候条件下，白粉病预计将成为北欧十字花科油籽作物中更严重的问题，尤其是在集约化短轮作耕作方式下。