Spraying Dicamba and 2,4-D for Burndown

Mark VanGessel, Extension Weed Specialist; mjv@udel.edu

I noticed some grapes have started to leaf out, and flower buds are exposed. This prompts me to remind everyone who is spraying 2,4-D or dicamba to be mindful of your neighbors and adjacent properties. While new formulations of dicamba (Banvel) and 2,4-D are less volatile, they are not “volatile-free”. As temperatures increase, the risk of off-target movement increases as well.

New formulations are prone to physical drift same as the old formulations. The droplets moving off-target as soon as they leave the spray nozzles due to wind is still the most likely cause of off-target movement. Larger droplets are less prone to drift, but wind speed and temperatures above 85°F also increase the risk of spray drift. Temperature inversions allow droplets to remain aloft and very small droplets can move.

Finally, these new formulations are no safer to susceptible vegetation than older formulations. Injury to grapes, beans, tomatoes, and soybeans (and other broadleaf plants) is just as severe with these new formulations as with older formulations.

Be sure you are aware of surrounding fields and sensitive vegetation; read the label for all precautions and application restrictions; and do not spray when conditions favor off-target movement of 2,4-D or dicamba.