Temperatures have cooled down nicely, and rain is plentiful. Planting for fall crops continues around the state. The weather is perfect for disease development, including downy mildew, Southern blight, and anthracnose. See details below.
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Statewide
Tom Bilbo, Entomologist
If you grow okra or eggplant, be on the lookout for a new invasive insect pest that has been popping up in SC – the two-spot cotton leafhopper. It’s been detected in several counties on cotton and okra. It is a tiny insect, and you’ll likely see damage before seeing the insect itself. Leafhoppers have piercing-sucking mouthparts, just like stink bugs and leaffooted bugs, so damage will look somewhat similar, albeit primarily on the foliage. As their name suggests, they are usually found on the underside of leaves, and also have two distinct spots at the end of their wings. Some other host plants include cotton, peanut, roselle, sunflower, soybean, potato, and cowpea.
Close-up of an adult two-spot cotton leafhopper.
Photo by Daphne Zapsas, USDA-APHIS-PPQ, Biological Science Laboratory Technician
Midlands Region
Sarah Scott
- It has been hot and humid, and newly planted vegetable crops have been struggling to get established. This week, temperatures and cool down, hopefully give some relief to tender young plants.
- Peaches are still coming in at high volumes. Sap beetles are an issue in many fields, but there are very limited treatment options with harvest times being so close.
Newly planted pepper fields.
Sarah Scott, ©2025, Clemson Extension
Upstate Region
Andy Rollins
- Be on the lookout for downy mildew in all curcurbit plants in the Upstate. A few of these would be cucumber, squash, zucchini, pumpkin, cantaloupe, and watermelon. When inspecting plants, you will see yellow blotches on the tops of the leaves, but no sporulation (normally dry dust looking material). On some species, like cucumber, these areas will be angular and easier to identify. In cantaloupe, lesions can extend over the veins and have a more circular appearance. The real tell can be found when looking at the bottom of the leaves where the veins come together (hence “downy”). You can find a grayish, dusty look that is the spores. Under cool, wet conditions, normally occurring in the Upstate, I regularly start finding it during the first week of August. A 10x jeweler’s loupe would be needed to see this more easily. The pumpkin crop in the photos below was clean last week, but may not be by the end of this week. A list of the best fungicides for this disease can be found on the MyIpm Vegetable app. I would recommend the use of a protectant containing mancozeb and a systemic like Ranman. Just make sure to rotate the FRAC code when using systemic products to prevent resistance.
- We’re finding Southern stem blight in tomato and pepper.
- Growers are harvesting O’Henry peaches in the Upstate. Fruit may have some bacterial spot lesions on them, but the taste is excellent.
Downy mildew spots on the top of a pumpkin leaf.
Andy Rollins, ©2025, Clemson Extension
Symptoms of downy mildew on the bottom of a pumpkin leaf.
Andy Rollin, ©2025, Clemson Extension
