AMES, Iowa – Spraying pesticides in apple orchards can be helpful in fighting pests and diseases. The question is what is the best method and spray time to have the greatest negative impact on the environment.
In collaboration with Ohio State University researchers and the USDA-Agricultural Research Service (ARS), Mark Gleson, a professor of botanical pathology and microbiology, explored ways to reduce the amount of chemicals used in fruit farming. , Maintaining Plant Health. The progress of their three-year research project was recently published in the Science Journal.
The first spraying method the researchers were studying was developed by the USDA-ARS agricultural engineer in Hepping Zoo, Western Ohio, and their team. This system uses a combination of laser beams and sensors mounted on an airplane to determine the location of the apple leaf. The spray tractor passes through the rows of trees, depending on what the laser and the sensors “see” and open the nostrils, especially for the target branches. This is contrary to traditional spraying methods, in which case all spray noses are actively sprayed along the entire line of the tree, resulting in an excess of liquid.
We are getting good application coverage and we are trying to see if we can keep pace with pests and diseases, ”Gleson said. “We don’t want trees dripping with pesticides, just enough cover to do the job.”
So far, researchers have found that this targeted spraying method reduces overall pesticide use by 30-70 percent. Gleason uses a small amount of pesticides that are environmentally friendly and have fewer trips to fill the spray, saving time and fuel.
Another technology you are evaluating is a weather-based disease alarm system that measures humidity in the garden for 90% or more hours. The warning system starts at the first cover stage after the flower petals have fallen off. After a total of 385 hours in such conditions, the spraying of the fungus is resumed to prevent fungal infections. Contrary to the anti-fungal spray schedule, which is used every 10 to 14 days each season, it has been shown to produce an average of 2.3 antifungal applications per year – a 25% reduction.
The researchers have collaborated with six orchards between the two states to conduct research and field experiments at the ISU Horticultural Research Center near Cambridge and Jefferson, Iowa, and north of Ames. Monthly meetings are held through Zoom to update all researchers, students and gardeners.
The team is innovating by sharing its research progress on websites, blog posts, podcasts and short videos.
One of the videos explains how the fungus on an apple was created by Olivia Meyer, a horticultural graduate student and a member of the Gleason research team. She divides the subject into a simple clip for two minutes.
“We are trying to explain different aspects of our research in interesting ways, to inform developers what we are doing,” Meyer said.
This is in line with the goals of the research project, which includes educating growers about these environmentally friendly pesticides. Iowa State Associate Professor of Economics Wendong Zhang and economics graduate Nian Cheng are working together to determine if any of these systems will save money for their work – another project goal.
“We are trying to get the growers interested in this. Much of the teaching is done by consumers. ”
The project is funded by the USDA Crop Protection and Pest Management Program.