alternaria leaf spot of crucifers

例句：

1. 1. This disease is a major threat to the health of crucifers, such as cabbage and broccoli.
   这种疾病对十字花科植物，如卷心菜和西兰花的健康构成重大威胁。
2. 2. Researchers are working on developing new treatments for this disease in crucifers.
   研究人员正在研究开发新的治疗措施来对抗这种病害。
3. 3.The outbreak of this disease has led to significant crop losses in the crucifers sector.
   这种病害的爆发导致十字花科作物损失严重。