Now is a good time to clean field sprayers
Crop yield and quality depend on effective application of agricultural chemicals. Proper selection, use and maintenance of sprayers can save you money, improve the performance of the agrichemicals you use, and protect the environment, according to University of Missouri and Kansas State University specialists.
With the increased emphasis on custom application of herbicides, postemergence weed control, and use of herbicides that are active at low application rates, proper cleaning and maintenance of sprayers will be increasingly necessary to avoid injury to nontarget crop species. The issue will take on added importance as more producers use broad-spectrum herbicides such as Roundup and Liberty on their herbicide-tolerant crops. Postemergence applications sprayed directly on the crop foliage will generally have greater potential for crop injury than will soil applications. Serious crop injury can result from small amounts of herbicides remaining in the sprayer system.
In recent years there have been numerous occurrences of soybean crop damage with symptoms resembling injury from growth regulator herbicides. The injuries were attributed to various causes, including the use of other soybean herbicides and herbicide additives, but in many cases the spray tanks had not been cleaned properly before applying soybean herbicides.
Crop injury from sprayer contamination can occur up to several months after using the sprayer if it has not been cleaned properly. Injury from sprayer contamination can affect crop growth and development for several weeks after application and in severe cases can reduce crop yields. Herbicide residues in the sprayer can be redissolved through later contact with herbicides, their solvents or spray adjuvants. The objective of this publication is to present the appropriate cleanup procedures for sprayer equipment following the use of various herbicides in corn, soybean, wheat and cotton production.
Pesticides can settle to the bottom or cause rapid corrosion in the spraying system and thus should be washed from the whole system immediately after use. One should always try to end the workday with an empty tank. If you will be using the same agrichemical the next day, thoroughly flushing the sprayer tank and sprayer with clean water is sufficient and will help prevent drying and hardening of pesticide residues. If a different agrichemical will be used, then a more comprehensive procedure is recommended immediately after use.
When cleaning a sprayer, select a location where any spilled rinsate will not contaminate water supplies, streams, crops or other plants and where puddles will not be accessible to children, pets, livestock or wildlife. Preferably the area should be impervious to water and have a wash rack or cement apron with a sump to catch contaminated wash water and pesticides. If such a facility is not available, catch or contain the rinsate and spray the rinse water or the cleaning solution on a field in a manner consistent with the intended use of the agrichemical. Avoid discharging all the cleaning solution in a small area.