green plant

Biopesticides (Seem to) Perform Poorly Against Black Spot on Kale

Jim Rogers Disease, Leafy Vegetables, South Carolina

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

Jim Rogers Disease, 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

Jim Rogers Disease, Peppers, Tomatoes

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 …

close up photo of beetroots on black background

Fungicides to Manage Cercospora Leaf Spot on Beets

Jim Rogers Disease, Research, Specialty Crops

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

Jim Rogers Cucurbits, Disease, Research

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 …