Andy Robinson, Associate Professor and Extension Potato Agronomist at North Dakota State University and University of Minnesota, presents a comprehensive study on the effects of glyphosate on potatoes in his updated January 2024 bulletin titled “Glyphosate on Potatoes“.
Robinson points out that potatoes are highly susceptible to glyphosate, a widely-used herbicide in agriculture. Exposure to even low levels of glyphosate can result in reduced yield, poor quality tubers, and residual herbicide presence in potatoes. The herbicide is predominantly used for controlling weeds in crops like soybean, corn, canola, and sugarbeets, and as a preharvest treatment in various crops.
Glyphosate contamination in potatoes can occur through different means, including drift from spraying, tank contamination, or misapplication. This exposure can cause various symptoms in potato plants and tubers, such as yellowing or necrosis in young leaves, stunted growth, tuber skin cracking, malformations, and even death of foliage and tubers.
Robinson emphasizes the importance of careful application and mitigation strategies to avoid glyphosate injury in potatoes. This includes adjusting spray practices, ensuring clean water sources, and proper labeling and handling of herbicide containers.
The bulletin provides a thorough analysis of the potential effects of glyphosate residues in seed potatoes. High residue levels can completely inhibit sprout growth or cause abnormal sprout formations. Even moderate residue levels can lead to erratic and slow emergence, enlarged sprouts, and multiple sprouts from a single eye.
Robinson stresses the importance of careful herbicide application and recommends practices to mitigate glyphosate injury risks in potatoes. These include using specific spray techniques, ensuring clean water sources, and proper labeling and handling of herbicide containers.
The bulletin also advises growers to test plants for glyphosate residues in certified laboratories in suspected contamination cases.