Overlapping applications may result in injury to blueberries. Place the herbicide properly. See the Velpar L or Pronone 10G supplemental list of weeds common in lowbush blueberry fields and the amounts of hexazinone needed for their control. Most lowbush blueberry clones are resistant to hexazinone at the suggested label rates. However, some are not.
Sourtop blueberry is more susceptible to injury from hexazinone than is low sweet blueberry.
Excessive rates of hexazinone will cause leaf drop beginning with the bottom leaves and moving to the top of the stems. Improper sprayer calibration or spray overlap will cause leaf drop when high rates of hexazinone are used. Injury increases with higher rates of hexazinone. Be-cause Velpar L is absorbed by the leaves as well as the roots, treating blueberries after they have emerged or leafed out will cause leaf drop and severe injury. As weeds are controlled, fewer plants are there to take up hexazinone, so injury to blueberries plants may occur.