‘Atlantic’ and ‘Dakota Pearl’ Chipping Potato Responses to Glyphosate and Dicamba Simulated Drift

Field trials were conducted to determine the effects of glyphosate and/or dicamba simulated drift rates on chipping potatoes ‘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 treatment. 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 ‘Atlantic’ 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 applications to a sensitive crop.

Current-Season Infection With Ordinary and Recombinant Strains of Potato virus Y Has Detrimental Effects on Chipping Potato Yield and Tuber Quality

Potato virus Y (PVY) is the most economically important virus infecting potatoes worldwide. Current-season spread of PVY occurs when aphids transmit the virus from infected to noninfected plants during the growing season. The impact of current-season PVY infection on yield and quality of chip processing potatoes is not well documented. In a replicated, greenhouse experiment conducted over 2 years, we measured the effect of current-season infection with four PVY strains (PVYO, PVYN-Wi, PVYNTN, and PVYN:O) on chip processing varieties Atlantic, Lamoka, and Snowden. PVY infection decreased yield and tuber specific gravity for some combinations of potato variety and virus strain but did not affect the appearance of chips including the prevalence of stem-end chip defects. This work suggests that current-season infection of chipping potatoes imposes a cost on producers and emphasizes the need for continued investment in seed certification and development of PVY-resistant cultivars.