By Tracey Lynn Harpster
Cleaning your sprayer to prevent potential crop injury is worth the time; learn how below.
What a spring — cool temperatures, rain, inaccessible fields, rain, equipment breakdowns, flooding, delayed plantings, and more rain. For most of you the crop is finally in, the plants are growing, and the planters are put away. Next on the list is the pesticide applications – fungicides, insecticides, and herbicides. All have short application windows, plus we have no control over the weather. With everything you have invested in this spring – time, money, equipment maintenance/repairs, and lost sleep – it would be a shame now to lose the crop, especially to something as avoidable as herbicide damage from pesticide residues left in the sprayer. Remember, now is not the time to cut corners – herbicides can damage susceptible crops when applicators do not thoroughly clean sprayer equipment before and after spraying different crops.
A quick, post-application, infield rinse may not be enough. Even very small amounts of herbicide residue left in tanks, hoses, screens, fittings, or booms can seriously damage crops. Some herbicide products still call for applying pints or quarts of herbicide per acre, but many herbicides now have application rates measured in ounces per acre. Residues from products with these lower application rates can affect crops even when trace amounts are left in the application equipment.
Furthermore, adjuvants may dislodge old herbicide residues that are embedded in tank walls or hoses, or may help break down particles in screens. When they do, the adjuvants may cause an old, unwanted herbicide residue to mix into the spray liquid. If the next sprayer load is Roundup or Liberty herbicide, the surfactants from those products can act like a powerful tank cleaner, reacting with plant-growth regulator residues and then causing unintended crop injury. Finally, many labels require the cleaning of sprayers before and after mixing and applying. Products with a label that states that the sprayer and equipment must be clean BEFORE mixing and loading means that you thoroughly clean the spray tank and all lines and filters, following the label directions on the previously applied pesticide prior to mixing the product. Remember the label is the law.
Below are the steps for sprayer cleanout procedure that are listed on the dicamba labels. Always read and follow all label guidelines of the specific product(s) you are applying. Also, don’t forget to wear the proper personal protective equipment (PPE) as stated on the product label!
- After spraying, drain the sprayer (including boom and lines) immediately. Do not allow the spray solution to remain in the spray boom lines overnight prior to flushing.
- Flush tank, hoses, boom and nozzles with clean water. If equipped, open boom ends and flush.
- Inspect and clean all strainers, screens and filters.
- Prepare a cleaning solution with a commercial detergent or sprayer cleaner or ammonia according to the label directions.
- Take care to wash all parts of the tank, including the inside top surface. Start agitation in the sprayer and thoroughly recirculate the cleaning solution for at least 15 minutes. All visible deposits must be removed from the spraying system.
- Flush hoses, spray lines and nozzles for at least 1 minute with the cleaning solution.
- Remove nozzles, screens and strainers and clean separately in the cleaning solution after completing the above procedures.
- Drain pump, filter and lines.
- Rinse the complete spraying system with clean water.
- Clean and wash off the outside of the entire sprayer and boom.
- All rinse water must be disposed of in compliance with local, state, and federal requirements.
Whether you are applying insecticides, fungicides or herbicides, application timing is always crucial. With a long to-do list and little time to spare, please do not gamble and only partially clean sprayers in order to save time and cover more acres. Your time-saving methods may be very costly in the end.