Researchers from the University of Kentucky found just how much and how often farmers need to apply a fungicide to fight foliar diseases.

Data estimated that foliar diseases caused between 19,029 to 244,149 tons of crop losses from 2012-2015 in Kentucky. In the past, farmers have used foliar fungicides to fight this problem. While these fungicides are effective, farmers are unsure when is best to apply it.

Author Richard "Cam" Kenimer harvesting the University of Kentucky corn hybrid trials. Source: APS

The team conducted corn fungicide research trials in nine farms around Kentucky over two years. This large dataset allowed the team to observe the effects of foliar fungicide and produce more solid results.

They evaluated a single fungicide application at the six-leaf collar stage, or the V6 stage, and the silking stage, or the R1 stage. They also evaluated single applications and double applications of fungicide at both stages.

The team found that treatment at the R1 stage had the best foliar disease control. Single application and double application at the R1 stage saw the same results. This means that farmers can rely on a single application of fungicide, which is the most cost-effective.

The study was also the first to show that the severity of Curvularia leaf spot, a new disease in Kentucky, was reduced with folar fungicide. This is a huge step toward creating a management plan to fight this disease.

A paper on this technology was published in Plant Health Progress.