---
title: Rot Race
date: 2025-09-15T10:00:00-04:00
author: University of Maryland
canonical_url: "https://terp.umd.edu/rot-race"
section: Articles
---
# Rot Race

*September 15, 2025* — by [John Tucker](/authors/john-tucker)


- *Photos by Mengjun Hu*

> Researchers Help State’s Growers Save Vines, Fruit

*grapes on vines at vineyard — Unlike the dry, temperate climes of traditional wine regions of California, the DMV’s warm, wet summers invite fungus to thrive. By identifying the damaging pathogen, UMD researchers have developed a way to cut fungicide use while protecting grape quality.*

**WINE ENTHUSIASTS** are increasingly filling their glasses with products from Maryland vineyards, spurring an eightfold growth in the number of wineries since the 2000s and generating billions of dollars in the state.

But unlike the dry, temperate climes of traditional wine regions of California or Italy, the DMV’s warm, wet summers invite fungus to thrive. If just 5% of a grape bunch is rotting, the product can be ruined, pressuring growers to apply fungicide liberally throughout the six-month growing season despite high costs, potential environmental threats and health risks.

Associate Professor Mengjun Hu, a plant pathologist who assists growers through the University of Maryland Extension, discovered a way to cut fungicide use while protecting quality. He spent two years culling diseased grapes from more than 20 regional vineyards. In the lab, his team identified the pathogen responsible for most decay while understanding the control window of blight: the late growing season.


*rotting grapes*




**Issue:** [Fall 2025](https://terp.umd.edu/editions/fall-2025)


**Types:** [Explorations](https://terp.umd.edu/category/explorations)