needle rust of spruce

例句：

1. 1.The needle rust of spruce is a major concern for forest managers.
   针叶松的锈病是森林管理者们的一个主要担忧。
2. 2.The disease has been identified as a significant threat to the health of the spruce forests.
   这种病害已被确认为对针叶林的健康构成了重大威胁。
3. 3. Researchers are working on developing new treatments to combat this rust disease in spruce trees.
   研究人员正在研究开发新的治疗措施，以对抗针叶松树中的锈病。