Clemson Plant Pathologist Tony Keinath believes Gatten, Vivando, Quintec and Procure fungicides provide the best management options for cucurbit producers managing powdery mildew. According to the The South Carolina Grower, a fungicide sensitivity bioassay was conducted between June 1 and June 10 to determine which fungicides can be used against the current outbreak of powdery mildew on squash, watermelon and …
Cucumber Downy Mildew Discovered in South Carolina
Cucumber downy mildew was discovered early last week in South Carolina, according to the South Carolina Grower. Clemson plant pathologist Tony Keinath attributed the discovery at the Coastal Research and Education Center on June 12 to a rain event that occurred the previous week. The plant, Straight 8, was observed with 50% diseased leaf area which suggests that infection started …
Clemson Extension Provides Weekly Crop Updates
Clemson Extension agents provide crop updates in The South Carolina Grower this week about the status of various specialty crops being produced throughout the state. Statewide Plant Pathologist Tony Keinath reports, “With the wet weather the past two weeks, gummy stem blight is spreading rapidly on watermelon. Because of widespread resistance to tebuconazole and the need for systemic fungicides, growers …
Biopesticides (Seem to) Perform Poorly Against Black Spot on Kale
From Clemson Plant Pathologist Tony Keinath in The South Carolina Grower . As part of a U.S. Department of Agriculture Organic Transitions Program grant, we tested 10 biopesticides on organic kale ‘Oldenbor’ to determine if any product controlled Alternaria leaf spot, a.k.a. black spot on kale. None look promising. No biopesticides reduced black spot on kale compared to the non-treated …
Resistance to Tebuconazole is Widespread in Gummy Stem Blight Fungus in South Carolina
South Carolina cucurbit growers should reduce tebuconazole applications in managing gummy stem blight. The pathogenic fungus has become moderately resistant to this very commonly used fungicide, according to Clemson plant pathologist Tony Keinath in The South Carolina Grower. Seven watermelon fields were sampled in 2019 (six fields) and 2021 (one field) in Beaufort, Bamberg, Barnwell and Hampton counties. Of 229 …
Managing Phytophthora Blight on Pepper
Phytophthora blight disease on pepper and tomato has been observed in South Carolina vegetable fields, according to Clemson plant pathologist Tony Keinath and Extension agent Andy Rollins in The South Carolina Grower. Heavy rainfall in the Upstate from May 23 to May 26 led to the disease emergence after June 1. The saturated soils provided an ideal environment for oospores …
Fungicides to Manage Cercospora Leaf Spot on Beets
Cercospora leaf spot disease, the most damaging disease on beet greens and bunch beets, can be managed just as equally with either conventional or organic fungicides, according to The South Carolina Grower, Clemson plant pathologist Tony Keinath. Based on previous research in New York with processing beets, Keinath evaluated the best conventional program – Tilt alternated with Quadris – and …
Early Cucumber Planting Protects Against Downy Mildew Disease
Early cucumber planting helps avoid downy mildew disease and increases yields, according to Clemson plant pathologist Tony Keinath in The South Carolina Grower. Keinath said producers should plant within one month of recommended planting dates which avoids downy mildew disease that is most prevalent between May 15 and June 15. In an experiment in 2021 at Clemson’s Coastal Research and …