The four active ingredients that are registered to control weed hosts (cherry, chokecherry, elderberry, mulberry, raspberry, etcetera) of spotted wing drosophila (SWD) are: 2,4-D, glyphosate, hexazinone, imazapyr and triclopyr. The table below outlines the best time to apply these herbicides and precautions that should be taken. Follow all label directions carefully.

Post-emergent herbicideHerbicide groupTarget weed speciesWeed growth stageNotes/precautions
2,4-D4Woody Species in non crop use areas (roadsides, fencerows, rights-of-way, airports, wastelands, in industrial parks) — non specified other than chokecherry.Apply at the time of rapid growth (usually May, June and/or September)
  • Control may be less effective during hot, dry weather when deep soil moisture is deficient.
Arsenal (Imazapyr)2Woody Species — raspberryFor maximum activity, weeds should be growing vigorously at the time of post-emergence applications.
  • Arsenal herbicide is readily absorbed through foliage and roots and is translocated rapidly throughout the plant. In perennials, the herbicide is translocated into, and kills, underground storage organs, preventing regrowth.
  • May be tank-mixed with glyphosate or Banvel VM herbicide in non-crop areas.
  • Keep Arsenal herbicide away from areas where tree roots may extend into the treated area or in locations where the chemical may be washed or moved into contact with their roots.
Fencerow (Triclopyr)4Woody plants and annual and perennial broadleaved weeds in fencerows and around farm buildings — cherry, chokecherry, raspberry.Applications should be made when woody plants and weeds are actively growing.
  • Use the high rate on the species listed.
  • Use higher rates for late summer applications when plant growth rates are reduced.
  • For woody plants exceeding the recommended height for foliar application, cut and spray regrowth or use one of the basal bark application methods.
Forza Silvicultural (Glyphosate)9Perennial weeds, woody brush and tree species in forest and woodland management areas — cherry, raspberry.Applications should be made when woody plants and weeds are actively growing.
  • Do not apply in autumn after leaf drop has started.
  • Do not apply under poor growing conditions; such as, drought stress, disease or insect damage, as reduced weed control may result.
  • Always use the higher rate on hard to control species or when vegetation growth is heavy or dense.
Garlon 4 (Triclopyr)4Woody plants and annual and perennial broadleaved weeds in pastures, rangelands, non-crop areas: rights of way, powerlines, fencerows, around farm buildings, etc. — cherry, chokecherry, raspberry.Applications should be made when woody plants and weeds are actively growing.
  • Use the high rate on the species listed.
  • Use higher rates for late summer applications when plant growth rates are reduced.
  • For woody plants exceeding the recommended height for foliar application, cut and spray regrowth or use one of the basal bark application methods.
Release Silvicultural (Triclopyr)4Woody plants and annual and perennial broadleaved weeds in forest and woodland management — raspberry.Applications should be made following full leaf-out, but before autumn colouration.
  • A rate in the upper end of the recommended range is suggested for control of basal sprouting and root suckering species and for tall, dense brush.
Remedy (Triclopyr)4Woody plants and annual and perennial broadleaved weeds on pastures and rangeland - cherry, chokecherry, elderberry, mulberry, raspberry.Applications should be made when woody plants and weeds are actively growing.
  • Use higher rates on hard to control species such as, chokecherry. If lower rates are used on hard to control species, resprouting may occur and retreatment may be necessary the following year.
Velpar L (Hexazinone)5Woodland Management Areas — raspberry.Applications to plants before leaves are fully expanded are more effective than later treatments.
  • Do not apply to extremely sandy or gravelly soils or to any soils with less than 1% organic matter.
  • Do not apply where the terrain does not permit even and accurate application.
Vision Silviculture (Glyphosate)9Forest road-side vegetation management — cherry, raspberry.Apply when the undesirable species are actively growing and the foliage is full and well-developed.
  • Repeat treatments may be necessary to control weeds that generate from underground parts or seed.
  • Applications may be made to undesirable deciduous species with some autumn colours, provided that major leaf fall has not yet occurred.