---
title: UMD Researcher Helps Winegrowers Fight Infections With Less Fungicide
date: 2025-02-06T05:30:00-05:00
author: University of Maryland
canonical_url: "https://today.umd.edu/umd-researcher-helps-winegrowers-fight-infections-with-less-fungicide"
section: Articles
---
# UMD Researcher Helps Winegrowers Fight Infections With Less Fungicide

*February 6, 2025* — by [Kimbra Cutlip](/author/kimbra-cutlip)


> Work Developing Risk Model May Have Saved Cabernet Sauvignon as Viable Mid-Atlantic Crop

*Grapevine 1920x1080 — A UMD researcher conducted experiments in Maryland vineyards to determine when grapes are most susceptible to infection with the fungal disease ripe rot (below). The work resulted in a disease risk model that is reducing fungicide applications and saving money for farmers in Maryland and Virginia.*

Raise a glass to Maryland and Virginia winegrowers, who face a daunting challenge that that their peers in traditional wine regions like the Mediterranean or Northern California can mostly ignore: warm, humid summers that invite fungus to thrive.

Late in the growing season, fungal infections can invade and devastate a field of beautiful grapes after months of careful tending. To combat the problem, farmers often begin spraying chemical fungicide early in the spring, when grape vines flower, and continue regularly until nearing harvest in the fall. It still doesn’t prevent many grapes from succumbing to infection and rotting on the vine, especially the popular varieties like cabernet sauvignon and chardonnay.  
  
But recent work by plant pathologist Mengjun Hu in the College of Agriculture and Natural Resources has helped farmers pinpoint the pathogen responsible for a significant portion of late-season rots and identified the most effective window for applying fungicide. He and his team developed a disease risk model that is reducing fungicide applications, saving farmers money and improving grape harvests in Maryland and Virginia.  
  
“In my opinion, Mengjun’s work has made cabernet sauvignon viable again in the mid-Atlantic,” said Lucie Morton, an independent viticulturist and leading consultant to the North American wine industry. “Before this work, I had clients who lost entire seasons because they didn’t know what to spray for or when to spray.”  
  
As Maryland vineyards expanded from roughly 299 acres in 2002 to 1,200 today, along with more than 80 wineries, late-season rots had become a significant economic problem. “We didn’t know what specific pathogens were causing it, and growers were spraying broad spectrum fungicides and sort of guessing at when it was most effective,” said Hu, an associate professor in the Department of Plant Science and Landscape Architecture.


*shriveled grapes*




**Topics:** [Research](https://today.umd.edu/tags/research)


**Tags:** [Plant Science and Landscape Architecture](https://today.umd.edu/topic/plant-science-and-landscape-architecture), [Research](https://today.umd.edu/topic/research)


**Units:** [College of Agriculture and Natural Resources](https://today.umd.edu/topic/college-agriculture-and-natural-resources)