From BASF: The Chemical Company Website
The objective of any spray application of fungicides or insecticides is to provide a uniform distribution and deposition of active ingredient throughout the target area which will effectively control the intended insect or plant pathogen. Below are several guidelines that will help growers achieve optimal efficacy from these applications.
Apply pesticides that are effective at controlling the desired pest(s). It is best to properly identify the insect, mite, or plant pathogen before making applications to control these problems.
Make applications to interrupt the pest life stages that are most vulnerable. Many products do not control all life stages.
Use the right equipment for the job. It is important to use spray equipment as intended and to not use equipment that is not built for the type of applications you intend to make. Read the owner’s manual and follow all of the manufacturer’s recommendations.
Ensure consistent, thorough, and uniform coverage. Deliver chemicals to plants in such a manner that the spray solution is applied to both the upper and lower leaf surfaces uniformly. Leaves and stems that receive inadequate coverage are not protected as well as where adequate coverage is delivered.
Properly deliver chemicals to improve coverage and the effectiveness of these products. Growers should know in advance how much volume needs to be applied to any given area before the applications are made. They should also know the output [gallons per minute (gpm)], the application pressure [pounds per square inch (psi)], and the droplet sizes [microns] of the spray equipment being used. This information is helpful for growers to determine how much spray solution needs to be applied and the approximate time needed to make the applications.
CLEAN THE SPRAYER. This is one of the most important aspects of sprayer maintenance. Clean the equipment between every use by running lots of water, warm water, very diluted soapy water, or sprayer cleaning solutions through the pump, hoses, and spray orifices.
Set up a maintenance schedule. Routine maintenance schedules should be set up to inspect the equipment and to replace any worn parts. Be sure to inspect all hoses, filters, seals and tank lining for leaks fractures, cracks, and clogs. The pressure and spray pattern should also be routinely observed. Well-maintained and properly functioning equipment in combination with good application techniques will go a long way to maximizing the effectiveness of spray applications.
Growers should take steps to ensure that the equipment they use for their chemical applications (namely fungicides, insecticides, and plant growth regulators) is properly maintained. Failure to keep this equipment in good shape will result in the improper coverage of the chemicals being applied, inadequate pest control, the potential to cause injury to crops, and may reduce crop quality. Properly maintained spray equipment not only improves the efficacy of the applications and decreases the total costs associated with a pest management program, but will greatly extend the life of this equipment.
ALWAYS READ PRODUCT LABELS AND USE INSECTICIDES AND FUNGICIDES AS DIRECTED.