Monitoring and Managing Fungicide Resistance in Grape Powdery Mildew

Sarah Lowder collecting samples

Sarah Lowder | PhD Student | Botany and Plant Pathology

No Fun(gi)

Grape powdery mildew is a worldwide disease of grapes and one of the primary reasons for fungicide use in the vineyard, as this disease is almost entirely controlled through preventative applications throughout the growing season. In recent years, growers have had disease control issues due to fungicide resistance, where the products that they use are no longer effective. This is often despite responsible fungicide use practices intended to help prevent resistance from developing, as this disease can disperse through the air from other vineyards. Previously, monitoring resistance in a vineyard was cost- and time-prohibitive at any scale that would be useful to growers.  However, we found that we can use a cotton swab to collect fungal spores off the gloves of workers already moving through the vineyard. Thanks to recent developments, we can look for a mutation in a particular segment of DNA which causes this resistance to one of the major fungicide groups. In turn, this allows growers to monitor resistance in their vineyard prior to applying a fungicide and at a fraction of the time and cost that could be done previously.

Perks of the Job

I love science and I love working with people to help solve problems.  Working in plant health not only lets me do both of those things but also lets me play a small part in helping to feed the world. There is nothing else I would rather do!

Long-Term Planning

My work helps monitoring fungicide resistance become a time- and price-effective option for growers. This allows growers to reduce the use of at-risk fungicides in disease populations with resistance, which, in turn, help prevent the use of ineffective fungicides that can be financially and environmentally costly. Large-scale monitoring also helps us understand more about how resistance develops and persists in a disease population, hopefully allowing us to prevent resistance development in the future.

Research Squad

I work in the Foliar Pathology Lab at the USDA-ARS facility with Dr. Walt Mahaffee and our collaborating groups across the USA, including the Fungicide Resistance Assessment, Mitigation, and Extension (FRAME) Network.