Definition: Gnatrol is a bacterial larvicide that paralyzes and kills fungus gnat larvae. It does not kill existing adult fungus gnats. 

Target Pests: Fungus Gnat Larvae

Frequency: Once every 3 weeks

Dosing Location: Directly to growing media

Dosing per Farm:

  • The ratio of Gnatrol powder to water is 1.25 grams : 1 L liter of water
  • For the SG: 2.5 grams Gnatrol to 2 L water 
  • For the Gym: 7.5 grams Gnatrol to 6  L water

Safety Equipment: Goggles, safety gas mask, rubber gloves

Dosing Protocol:

  1. DO NOT apply gnatrol spray without first putting on all safety equipment.
  2. Use a scale to measure out the designated dosing of gnatrol powder. Use a disposable seed prep cup. Compost or wash immediately after use.
  3. Fill the backpack sprayer with corresponding amount of water: 60-75 degrees Fahrenheit
  4. Add the measured gnatrol to the sprayer.
  5. Close and gently shake the backpack to dissolve the gnatrol powder.
  6. To disperse: 
    • The lever on the left hand side of the pack (when worn) operates the pressure pump for the sprayer. Pump the lever until you feel some resistance.
    • The handle on the right hand side of the backpack is the sprayer. Once enough pressure is built up in the unit, press the handle trigger to release the gnatrol solution from the nozzle.
    • To keep the sprayer at a consistent pressure, pump the lever while spraying.
  7. Before spraying be aware of your surroundings. There should be no one else present in the farm. 
  8. Application of gnatrol solution should be focused on the growing media. Avoid applying gnatrol on any plant flowers and leaves.
  9. For microgreens, the sprayer needs to be 1 foot away from the target. Focus on areas where there is a thin canopy. This is typically where the most algae will be found along with the highest density of nesting fungus gnats and blackflies.
  10. For mature plants, spray on mature plant medium and on any exposed root mass.
    • Be careful not to damage delicate mature plants (wood sorrel, violas, etc.)
    • As with microgreen application, focus on areas where there is a lot of algae growth and/or gnats.
    • All growing medium should be saturated with gnatrol solution.
  11. After applying gnatrol, DO NOT go back into the farm for 4 hours. Alert staff.
  12. To clean the backpack: 
    • Empty and rinse the pack with warm water
    • Pump clean water through the sprayer to remove any excess gnatrol
    • Make sure there is no standing water in the sprayer.