Challenges from off-target herbicide incidents
Injury symptoms observed on grapevines damaged by volatile and off-target drift of phenoxy herbicides such as 2,4-dichlorophenoxyacetic acid (2,4-D) are commonly seen in Midwest vineyards. Damage severity varies, with grapevines generally recovering from the injury with more or less healthy re-growth following the damaging event. However, in extreme cases, significant epinasty, leaf and flower deformation and subsequent loss of yield can occur. Fruit quality and yield loss are especially noticeable if the incident occurs during early shoot growth and at cap-fall (anthesis). A unique combination of circumstances occurred in 2012 that led to exceptionally serious damage in a large number of vineyards in Nebraska. The winter of 2011-2012, one of the mildest on record, followed by unusually warm temperatures in the spring, led to bud burst taking place three or more weeks earlier than the average bud burst date for Nebraska. Two separate herbicide drift incidents damaged our NE-1020 planting at Dove Landing Vineyard, east of Lincoln. The first incident occurred during flowering and the second occurred midway between cap-fall and veraison. Sabervois, MN 1235 and Marquette sustained the most damage, while Chambourcin, Sauvignon Blanc, Vidal Blanc and MN 1258 were least affected. Frontenac, MN 1220, Valiant and Saint Croix exhibited intermediate symptoms. Further observations of the re-growth and general health of the vines were recorded in 2013.
Read, P.E. and Gamet, S.J. (2016). Challenges from off-target herbicide incidents. Acta Hortic. 1115, 167-170
phenoxy herbicides, epinasty, 2,4-D, grapevines, Vitis spp., volatilization