alfalfa mosaic

例句：

1. 1. The alfalfa mosaic is a common disease that affects the growth of young plants.
   苜蓿花斑病是一种常见的疾病，影响幼苗的生长。
2. 2. The farmers are trying to control the spread of this disease by using resistant varieties of alfalfa.
   农民们正在尝试通过使用抗病的苜蓿品种来控制这种疾病的传播。
3. 3. The disease can be prevented by maintaining proper irrigation and fertilization practices in the fields.
   通过保持田间适当的灌溉和施肥实践，可以预防这种疾病。