Sprayer Tips

Growers who want to make the most efficient use of crop protectants should turn their attention to their sprayers. Erdal Ozkan, an agricultural engineer and spraying technology expert with the Ohio State University Extension and the Ohio Agricultural Research and Development Center, offers 10 common-sense tips that will help growers improve the performance of sprayers.

1) Calibrate. Applying chemicals with a sprayer that is not calibrated and operated accurately could cause insufficient weed, insect, or disease control, which can lead to reduced yields, Ozkan says. Check the gallon-per-acre application rate of the sprayer.

2) Mind the nozzle. How the chemical is deposited on the target is as important as the amount
applied. Know what kind of nozzles are on your sprayer and whether or not their patterns need to be overlapped for complete coverage. Make sure the nozzles are not partially clogged.

3) Avoid streaks. In addition to clogging, other factors such as nozzle tips with different fan angles on the boom and uneven boom height are the most common causes of non-uniform spray patterns. They can all cause streaks of untreated areas that result in insufficient pest control and economic loss.

4) Check the boom. Setting the proper boom height for a given nozzle spacing is important in achieving proper overlapping. Conventional flat-fan nozzles require 30% to 50% overlapping of adjacent spray patterns.

5) Know your actual travel speed. Keep it as steady as possible. Increasing the speed by 20% may let you cover the field more quickly, but it also cuts the application rate by 20%. Similarly, a reduction of speed by 20% causes an over-application of pesticide by 20%.

6) Pay attention to spray pressure. Variations in pressure will cause changes in application rate, droplet size, and spray pattern.

7) Avoid drift. Spray drift wastes more chemicals than anything else. Use other drift-reduction strategies: keep the boom close to the target, use drift-retardant adjuvants, and spray in early morning and late afternoon when drift potential is less.

8) Be prepared. Carry extra nozzles, washers, other spare parts, and tools to repair simple problems quickly.

9) Calibrate again. Keep calibrating your sprayer periodically during the spraying season so it stays at peak performance.

10) Be safe. Read the chemical and equipment instructions and follow them. Wear protective clothing, rubber gloves, and respirators when calibrating the sprayer, doing the actual spraying, and cleaning the equipment.