Field trials were conducted to determine the effects of glyphosate and/or dicamba simulated drift rates on chipping potatoes (Solanum tuberosum L.) ‘Atlantic’ and ‘Dakota Pearl.’ Sublethal herbicide rates were applied at the tuber initiation stage and consisted of dicamba at 99 g ae ha−1 or glyphosate at 197 g ae ha−1 applied alone or the combinations of dicamba at 20 or 99 g ae ha−1 and glyphosate at 40 or 197 g ae ha−1, respectively. At 7 days after treatment (DAT), the high spray combination of glyphosate plus dicamba resulted in the greatest plant damage (28%). Plant injury from plants treated with the low combination of glyphosate plus dicamba did not differ from the nontreated control. At 21 DAT, visible injury increased to 40% for plants treated with the high combination of glyphosate plus dicamba. Total yield suggested that dicamba and glyphosate caused similar yield reductions as plants that received glyphosate at 197 g ha−1 or dicamba at 99 g ha−1 had lower total yields compared to the nontreated and plants that received the combination of glyphosate (197 g ha−1) and dicamba (99 g ha−1) had lower total yields compared to plants that received either herbicide alone. However, ‘Dakota Pearl’ plants were more sensitive to glyphosate at 197 g ha−1 than were ‘Atlantic’ plants, causing the interaction for most tuber grades. Tuber specific gravity was lower for plants that received glyphosate at 197 g ha−1, dicamba at 99 g ha−1, or this combination, but this reduction would not prevent chip processing. Results reinforce the need for diligence when applying these herbicides in proximity to a susceptible crop, such as chipping potatoes, and the need to thoroughly clean sprayers before application to a sensitive crop.

Increased use of dicamba and/or glyphosate in dicamba/glyphosate-tolerant soybean might affect many sensitive crops, including potato. The objective of this study was to determine the growth and yield of ‘Russet Burbank’ potato grown from seed tubers (generation 2) from mother plants (generation 1) treated with dicamba (4, 20, and 99 g ae ha−1), glyphosate (8, 40, and 197 g ae ha−1), or a combination of dicamba and glyphosate during tuber initiation. Generation 2 tubers were planted near Oakes and Inkster, ND, in 2016 and 2017, at the same research farm where the generation 1 tubers were grown the previous year. Treatment with 99 g ha−1 dicamba, 197 g ha−1 glyphosate, or 99 g ha−1 dicamba + 197 g ha−1 glyphosate caused emergence of generation 2 plants to be reduced by up to 84%, 86%, and 87%, respectively, at 5 wk after planting. Total tuber yield of generation 2 was reduced up to 67%, 55%, and 68% when 99 g ha−1 dicamba, 197 g ha−1 glyphosate, or 99 g ha−1 dicamba + 197 g ha−1 glyphosate was applied to generation 1 plants, respectively. At each site year, 197 g ha−1 glyphosate reduced total yield and marketable yield, while 99 g ha−1 dicamba reduced total yield and marketable yield in some site-years. This study confirms that exposure to glyphosate and dicamba of potato grown for potato seed tubers can negatively affect the growth and yield potential of the subsequently grown daughter generation.