Before mixing any pesticide always check the pesticide label for instructions on compatibility of two or more pesticides. Some herbicides and carriers require a compatibility agent, some are not compatible with a compatibility agent.
Mixing Order Recommendation:
- Fill the spray tank with one-third of the carrier (water, fertilizer, or mix) to be used. Have the agitator on.
- Add ammonium sulfate for glyphosate products.
- Always add compatibility agent before herbicides, if compatibility problems exist. Refer to label.
- Use a defoamer if excessive foam is produced by the pesticide mixture. Refer to the label.
- If needed, add dry wettable powders (WP), dry flowables (DF) materials or water dispensable granules (WDG). Water soluble packets need time to soak with a small amount of water before being added to the tank. It is always recommended for pre-slurry wettable powders and dry flowables to be at a 2:1 ratio with water before being added to the partially filled spray tank. Some pesticides need presoaking.
- Agitation is used to uniformly disperse the added herbicides. Agitation means a rolling surface action. Be cautious of over agitating due to the possibility to reducing compatibility or excessive foaming.
- In most situations it is best to continue the agitation until the spray solution is applied. If agitation is stopped, make sure the suspension is satisfactory before application.
- After herbicides are dispersed, increase the carrier to 80 percent of the spray solution to be used.
- If needed add Liquids and flowables next.
- Then add emulsifiable concentrates (EC). Microencapsulated formulations should be added after the emulsifiable concentrates.
- Add surfactants and oils last. Some surfactants can cause excessive foaming. If applicator is concerned about the possibility of drift, a drift control agent could be added at this point.
- Add carrier to 100 percent of the spray solution to be used and make sure spray solution is mixed thoroughly before starting application.