The herbicide pendimethalin can harm ginger plants if used in high concentrations. Low doses don't affect ginger growth, but high doses can damage roots and reduce photosynthesis. High levels of pendimethalin cause oxidative stress in ginger, leading to an increase in reactive oxygen species. However, the plant's defense mechanisms help maintain a balance. Pendimethalin accumulates in ginger roots but not in the edible rhizomes, so it's unlikely to harm human health when used in ginger fields.