烦恼的原因 meaning in English

scourge

The pesky weed is a problem for farmers because chemicals that kill it also damage the crops it feeds on
这种惹人的杂草使农民烦恼的原因是:一旦采用农药喷杀会破坏农作物生长条件
With your aid , that may be avoided , he continued ; and should there be danger of such an event - should he be the cause of adding a single trouble more to her existence - why , i think i shall be justified in going to extremes
“有你的帮助就可以避免， ”他接着说， “如果会有这么大的危险如果他就是使她的生活增加一种烦恼的原因那么，我以为我正好有理由走极端！