Tag: black spot

• Updated Fungicide Recommendations to Manage Alternaria Leaf Spot (Black Spot) on Brassicas

  

  By Tony Keinath, Clemson Plant Pathologist Despite some unusually cold weather in January and February, Alternaria black spot is active on overwintered brassicas. Although the brassica Alternaria fungus (Alternaria brassicicola) present in South Carolina supposedly prefers warm temperatures, I doubt that old information is accurate today. Growers should be on the lookout for tan to…

  Justin Ballew

  March 24, 2026

  Brassicas, Disease

  alternaria, black spot, Brassicas, effective fungicides for alternaria, fungicides, kale, managing alternaria in brassicas, managing black spot in brassicas, Managing black spot in kale

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

  

  From Clemson Plant Pathologist Tony Keinath. As part of a USDA Organic Transitions Program grant, we tested 10 biopesticides on organic kale ‘Oldenbor’ to see if any product controlled Alternaria leaf spot, a.k.a. black spot. Unfortunately, none look promising as no biopesticides reduced black spot compared to the nontreated control based on repeated greenhouse trials…

  Justin Ballew

  June 29, 2022

  Brassicas, Disease

  altermaria, biopesticides, black spot, Brassicas, disease management, kale