Abstract Yield losses in wheat and barley cultivars varying in stripe rust reactions were determined under natural infection conditions in fungicide treated and untreated plots at Lacombe and Olds, central Alberta, from 2012 to 2014. Stripe rust caused by Puccinia striiformis was the major disease observed during the 3-year test. Moderate stripe rust severity caused significant yield losses of over 20% in a highly susceptible wheat, ‘AC Crystal’, while no severe yield losses occurred for resistant and moderately resistant cultivars/lines. However, a moderate level of stripe rust and the leaf spot complex caused reductions in thousand kernel weight (TKW) ranging from 5.4% to 13.5% for all wheat and barley cultivars/lines tested except for ‘Lillian’ wheat and ‘Seebe’ barley. When stripe rust developed early in the growing season resulting in severe disease, there were significant yield losses ranging from 17.6% to 91% for five wheat and two barley genotypes. Severe TKW and test weight losses also occurred for susceptible wheat and barley. The magnitude of yield losses in resistant and intermediate cultivars was smaller than in susceptible cultivars in the same tests. The present study demonstrated that one foliar-applied fungicide application was generally capable of protecting susceptible wheat and barley cultivars from stripe rust, while the use of resistant and intermediate cultivars was necessary for yield protection when moderate levels of disease occurred. Fungicide application was needed to reduce yield losses for resistant and moderately resistant cultivars when leaf spot diseases were prevalent and an early onset of stripe rust was observed, which can lead to severe stripe rust development even in resistant varieties.

中文翻译：

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阿尔伯塔省中部春小麦和大麦品种的产量反应，抗条锈病性不同

摘要 2012 年至 2014 年，在自然感染条件下，在阿尔伯塔省中部拉科姆和奥尔兹的经过杀菌剂处理和未经处理的地块中，测定了小麦和大麦品种在条锈病反应中不同的产量损失。由条锈菌引起的条锈病是在此期间观察到的主要病害。 3年的测试。中度条锈病严重程度导致高度易感小麦“AC Crystal”的产量损失超过 20%，而抗性和中度抗性品种/品系没有发生严重的产量损失。然而，中等水平的条锈病和叶斑复合物导致除“Lillian”小麦和“Seebe”大麦之外的所有小麦和大麦栽培品种/品系的千粒重（TKW）降低了 5.4% 至 13.5%。当条锈病在生长季节早期发展导致严重疾病时，五种小麦和两种大麦基因型的产量损失显着，从 17.6% 到 91% 不等。易感小麦和大麦也发生了严重的 TKW 和测试重量损失。在相同的测试中，抗性和中间品种的产量损失幅度小于易感品种。目前的研究表明，叶面喷施杀菌剂通常能够保护易感的小麦和大麦品种免受条锈病的侵害，而在中等水平的病害发生时，需要使用抗性和中间品种来保护产量。