"Spray drift has wreaked havoc on wine grapes and kiwifruit in several NZ orchards recently, causing several hundred thousand dollars worth of damage.
 

“Agrichemicals can cause severe damage to natural ecosystems as well, especially when they land in surface waters, as most aquatic species are very sensitive to these chemicals.”
 

In an effort to address the issue, Lincoln Agritech’s Chemical Application, Research and Training group (CART) has conducted a six-year Government-funded research programme to find out more about pesticide spray drift movements and how to mitigate them.
 

The project, funded by the Ministry of Business, Innovation and Employment (MBIE), involved several tasks, including measuring pesticide drift on typical NZ crops, as well as analysing the effectiveness of drift-reducing technologies and training people in how to use them.
 

Project co-ordinator Scott Post says Lincoln Agritech was lucky to work with a high quality research team.
 

“We worked with scientists from SCION to model spray drift, with specialists from Plant Protection Chemistry in Rotorua to research how sprayed droplets land on leaves, and with scientists from the University of Otago to find out how pesticide vapour can drift from the applied area.”
 

Crops studied included kiwifruit, grapes, apples, potato and shelterbelts.

The team worked to improve mathematical models on drift and measured the vapour drift of 200 different pesticides.

Scott Post says the research has advanced knowledge about pesticide drift in NZ conditions and helped to improve AGDISP (Agricultural Dispersal), the internationally-recognised software for assessing drift risks in agriculture and forestry.
 

“AGDISP is used by many pesticide regulators around the world,” he says. “The software helps to evaluate the potential drift in a

large number of different spraying situations where no measurements are available.”
 

Lincoln Agritech shared its results and information with a wide range of stakeholders. “We interacted with producers, staff from councils and EPA, as well as spray contractors and manufacturers of sprayers and chemicals.
 

“This ensured that the project provided outcomes in line with the requirements of the primary sectors and the environment.”
 

The team also analysed the effectiveness of the latest Drift Reduction Technologies (DRT), which refer to small changes or additions to pesticide sprayers.
 

“We found that these technologies could reduce drift by 33 to 59 per cent,” says Post.
 

“Results like these encouraged us to start training people in the spraying business to use drift reduction approaches.”
 

Rory Roten says it was also important to work closely with organisations like GrowSafe, Zespri, Horticulture NZ and the Foundation for Arable Research, as well as aerial spray contractors in the agricultural aviation industry.
 

“This allowed us to reach many professionals and to educate them on the importance of working to reduce environmental impacts,” he says. “Nevertheless, we do not think that our job is over now that the project has ended. Our engagement in this kind of outreach will continue.”
 

Scott Post says new technologies are also needed, both to support the work of spraying professionals and to equip public authorities with tools that can help them to monitor drift.
 

With this in mind, the final part of the research programme involved a collaboration with specialists at the University of Auckland to develop electronic sensors that could detect and measure the amount of received drift on crops.
 

“Drift of agrichemicals can’t be avoided completely, whether in conventional or in organic farming,” he says.
 

“Nevertheless, we think it is possible to use our sensors to direct and improve sprayers’ performance when the operator knows how much drift is happening and where it is going.”