Aerial application: A sign of spring crop production

Aerial applications are valuable for timing pest management regardless of soil conditions.

A crop duster plane.
Fixed wing aerial application performing spray calibration to ensure spray uniformity and reduce off-target drift. Photo by Nick’s Flying Service.

Beginning in late May, aerial applications are a relatively common sight in Michiana agriculture. Most pesticide treatments are applied by ground applicators and are not as visible as aerial application. However, aerial application offers the advantage of covering more acres per day by one applicator than ground application systems. Aerial applications are especially valuable during wet conditions, as the ground is too wet for ground equipment to pass without causing damaging ruts and compaction. In addition, aerial applications have higher clearance for tall crops such as late season corn, allowing fungicides such as those preventing tar spot to be applied at the proper time. 

The sandy and sandy loam soils under irrigation around the Michigan-Indiana border are preferable for seed corn and potatoes, leading to thousands of acres of each. Early planted potatoes emerge and reach row closure (where the leaves touch in the middle of the row) by late May. There are several diseases that affect potatoes, but the worst one is potato late blight (Phytopthora infestans). This is a highly contagious plant disease that travels in droplets of water carried on air currents and equipment and leads to almost total crop failure. Late blight is one of the greatest economic impacts in the world, as it is attributed to causing the Irish Potato Famine and continues to affect potato growers every year. late blight prefers cool, moist conditions. As potato rows close, those cool, moist conditions increase within the canopy. To prevent late blight and other pathogenic inoculations, growers apply preventative fungicides weekly. Row closure is generally the beginning of those weekly aerial applications. 

Many applicators participate in an annual aerial applicator calibration offered jointly by the Michigan Department of Agriculture and Rural Development (MDARD) and the National Agricultural Aviation Association. Aerial applicators utilize computerized systems that assist the pilot in delivering the chemical pesticide to the target while minimizing risk to off-target exposure. These systems also create a record of where the applicators have been and when the applicator systems were turned on and off and their correlation with local weather conditions. Although applicators work to reduce drift, aerial applications are still at higher drift risk than ground applications. Wind and humidity conditions must be watched closely to ensure adequate coverage. Other factors, such as tree lines, power lines, and houses can limit an applicator’s ability to consistently cover some areas. This is especially true for manned, fixed-wing aerial applicators, such as airplanes. 

In addition to weather conditions and physical obstacles, aerial applicators deal with spectators parking at the end of the field or standing in the field to watch the aerial display. This creates an additional risk for both pesticide exposure and pilot distraction. Because aerial applications are of such high visibility, applicators and growers receive several complaints throughout the growing season. One common misidentification of offsite pesticide application with airplanes happens when pilots make an abrupt climb at tree lines at the edge of the field. The climb, coupled with the propellor, creates a downdraft that shakes loose the dew on the trees creating the illusion of pesticide spray. 

Being able to apply pesticides at critical times is an important part of integrated pest management (IPM). In Michigan’s climate, soil conditions are often not conducive to a timely application. Humidity increases disease risks for all crops, but for high-risk crops such as potatoes, aerial applications improve pest management timeliness, treatment and prevention, and reduce compaction damage to the soil. 


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