Some commercial tree farm managers who are used to applying large volumes of pesticides to control insects and diseases on their operations are trying a new management system using half the amount. 

Horticulturalists with the University of Kentucky College of Agriculture are part of an effort led by The Ohio State University (OSU) to teach nursery and farm managers how to cover more plants with less pesticide, thereby saving money and becoming more environmentally aware.

At a recent field day at the Green Ridge Tree Farm in Elizabethtown Amy Fulcher, UK nursery crops extension associate, gathered a group of Kentucky nursery owners and managers together to learn about the Half-Rate Pesticide approach. The Half-Rate Pesticide Program started at OSU about seven years ago, and OSU educators  have traveled around the country ever since showing people how less spraying  can work for them.

 Participants listened to Heping Zhu, an agricultural engineer from the U.S. Department of Agriculture, and Randy Zondag, OSU extension educator, talk about calibrating sprayers to more efficiently apply pesticides. Zondag said many times growers have never calibrated their sprayer, and that leads to uneven coverage of the tree or crop. It may, unfortunately, also lead growers to believe need to spray more.

"But the issue is not how much can we reduce it (pesticide volume), it's what kind of coverage can we get on the plant to do the job," Zondag said. "Operators who have adopted the program have told us we are saving them somewhere between $200 and $400 per acre, per season by using this system."    

Understandably, many growers are skeptical of the program at first because if it doesn't work, they have a lot to lose, Zondag said.

Greg Goodpaster, tree farm production manager attending the field day, was one who started into the program with skepticism.

"We've just got our old ways because I have been in this business for 30 years," he said.  "We don't like taking risks on insects when it comes to spraying them; we want to make sure we get them killed.   I thought the half-rate program might not be as effective.  I thought I might have to go in there and spray again because it might not do what I wanted it to do.  Since I have been participating in the program, I have seen that it works."

Green Ridge Tree Farm has participated in the program for two years with an air-assisted sprayer on the 150-acre farm. Managers there have only targeted a portion of the farm with the program. Now, they are able to compare the results, and they're good.

"We saw what we wanted to see," said Ben Cecil, Green Ridge Tree Farm manager. "We saw no difference between the two application sites. If there is no difference, then that's what you are looking for, which was full control on both sites.  With the success that we have seen with the half-rate program, it only made sense to reduce our chemical costs again and use  in a more broad range of pest control."

Fulcher said it's important that growers become more sustainable, and the half-rate program can help them do that as well.

"The conventional 100 gallons (of pesticide) per acre is far beyond what is necessary, and that is what the program demonstrates in a very visual way with water-sensitive paper," she said. "We sprayed the half-rate and the full-rate on trees at Green Ridge, and growers were able to see how oversaturated the paper becomes with the full rate."

The demonstration was also a way for growers to see how a properly calibrated sprayer should look. Zondag emphasized that it's important for growers to understand their machinery, which could result in big savings.

"If we were able to implement this program across the entire farm, it would cut our pesticide purchases in half," Cecil said.

Fulcher said research shows promise for the program to be useful not only in tree crops, but other crops as well.