However, the use of such nonselective herbicides produces devastating consequences when the product moves off target or is sprayed on the wrong field. Ideal spraying conditions are very critical when using these herbicides near traditional crops to avoid drift and resulting crop injury.
According to cases brought to the attention of the Farmland Insurance Company, many of the misapplication errors were related to equipment - 24%; drift - 33%; and tank mixing errors made by sprayer operators - 33%. Surprisingly, 8% of the applicators sprayed chemicals on the wrong field.
The objectives of this proposal were to:
1. To test the effectiveness of a number of anti-drift technologies in terms of their drift reduction response to various wind speeds and spray pressures.
2. To educate producers and spray applicators in terms of the importance of reducing drift and the selection and use of those technologies that are most effective in drift reduction.
3. To further develop and test the diagnostic capabilities of infrared photography as a tool to measure drift injury.
To achieve these objectives, six 30" rows of the following treatments were planted in side-by-side strip plots approximately 400 ft. long: 1. A Roundup corn variety, 2. A non Roundup Ready corn variety, 3. A Roundup Ready soybean variety, and 4. A non Roundup Ready soybean variety.
A sprayer was built with a variable rate fan located at one end of a six nozzle, 10 ft. spray boom. The boom was equipped with nozzle bodies capable of holding five different nozzles. Winds up to 20 m.p.h. could be produced depending on where along the boom the measurement was taken. Boom, fan, fan power supply (DC), spray tank, and other spray hardware were all mounted on a small flat trailer and pulled as one unit at a constant speed perpendicular across the four strip plots described. The following drift variables were tested as the sprayer was pulled across the plots using Roundup herbicide.
1. Anti-drift nozzle designs compared to flat fan including: drift guard nozzle tip, Turbo Teejet, Turbo Flood, turbo Drop nozzles.
2. Two different spray pressures - 25 and 40 p.s.i.
3. Normal wind speed (calm) versus a 10 m.p.h. wind speed created by the fan.
Aerial infrared photographs were taken of the plots seven days after they were sprayed.
Spray drift discussion utilizing these plots was a major educational topic at a Notill and Sprayer Technology Field Day held July 21 at the Fayette Co. Farm. The spray drift sessions were taught by Dr. Erdal Ozkan with approximately 85 producers attending. The topic, demonstrational plots, and introduction of new technologies were well received by participants. Infrared pictures of the plot area will be used at winter meetings to discuss spray drift problems and solutions. In general, the infrared photos do indicate visually that higher wind speeds and tank pressures increase chemical drift as we would expect and that the new anti-drift nozzles do reduce the amount of drift compared to the traditional flat fan nozzle. Visually, the turbo flood nozzle seemed to have the most effect on reducing spray drift.