Either ground or aerial equipment can be successfully used to apply fungicides for a SXS test. The main determining factors will usually be equipment and operator availability and cost.
Advantages of aerial application - Aerial applicators can cover acres more quickly and there is no crop damage due to equipment-crop contact. In addition to wheel traffic injury, ground equipment can also spread disease inoculum through a field if the boom or vehicle contacts wet foliage.
Advantages of ground application - There is less potential for spray drift with ground application due to lower boom height. In parts of North America growers may also have greater access to ground equipment which could provide more flexibility in scheduling the applications.
In any on-farm evaluation, the individual test strips should be as close to adjacent as possible. This is to insure that differences in crop performance in the strips are due to the treatment differences and not naturally occurring spatial variation. The larger the strips or the farther apart they are, the less confident one can be that differences in performance are real. In a fungicide vs. untreated SXS comparison it is necessary to include a buffer between the two strips to protect the untreated check strip from spray drift (Figures 1 and 2).
How to Minimize Spray Drift*
Pesticide usage should follow all label instructions provided by the manufacturer. Likewise, field application should be conducted by skilled professionals with adequate training and safe, well-maintained equipment (including protective clothing and swath-marking devices).
Do:
Don't: