hop downy mildew

例句：

1. 1. The farmer was worried about the damage caused by the hop downy mildew.
   农民担心跳蚤和虱子造成的损害。
2. 2. The gardener had to treat the plants with insecticides to control the hop downy mildew.
   园丁不得不用杀虫剂来控制跳蚤和虱子的侵害。
3. 3.The disease is a major concern for farmers, as it can cause significant crop losses.
   这种疾病是农民们的主要担忧，因为它会导致严重的作物损失。