是不是少了助动词？

It is crucially important to farmers that the herbicides they use to control weeds not damage their crops.

that之后的部分是不是应该加上一个do？

谢！

这是个主语从句 我看不出哪里要加do

that the herbicides they use to control weeds  < DO > not damage their crops is crucially important to farmers.

主语从句的否定形式，可以不用助动词吗？

谢谢！