Category: Disease
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Fruit Rots on Pumpkins, Gourds, and Winter Squashes
From Clemson Plant Pathologist Tony Keinath As part of a new grant on cucurbit anthracnose with the University of Georgia, we sampled 68 pumpkins, gourds, and winter squash from “cull piles” at 7 pumpkin patches and small farms in South Carolina in October, November, and December 2023. Two-thirds of the 10 types of cucurbits sampled…
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Stem Rot on Transplanted Tomato in March 2024
From Clemson Plant Pathologist Tony Keinath and Food Crops Agent Zack Snipes “Stem and root rot” is the term used to describe a disease on recently transplanted vegetable crops, like tomato, pepper, watermelon, cantaloupe, and cucumber. Tomato transplants with stem rot were observed last week along the coast of South Carolina. A proper diagnosis of…
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Damping-Off on Direct-Seeded and Transplanted Vegetable Crops
From Clemson Plant Pathologist Tony Keinath “Damping-off” refers to root and stem rot on young seedlings of direct-seeded crops. “Stem and root rot” is used to describe the same disease on transplanted crops. I will use the term “seedling disease” when information below applies to both types of crops. In South Carolina, the water mold…
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White Mold on Kale and Other Cool-Season Vegetables
From Clemson Plant Pathologist Tony Keinath Sclerotinia white mold, a cool-season disease on several different vegetable crops, is present on collard and (probably) on kale. It is particularly common on over-wintered crops. The white mold fungus has a complex life cycle. The fungus, Sclerotinia sclerotiorum, survives long-term and over the summer as sclerotia in soil.…
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Fungicide Sensitivity of Cucurbit Powdery Mildew in Charleston, SC
From Clemson Plant Pathologist Tony Keinath A fall fungicide sensitivity bioassay was done in October 2023, to find out which fungicides are most effective against powdery mildew on squash, watermelon, and other cucurbits. Methods: ‘Early Prolific’ yellow summer squash plants with three true leaves were treated with fungicides, water, or not treated. The following day,…
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Cucumber Cultivar Response to Downy Mildew
From Clemson Plant Pathologist Tony Keinath This blog is an update on the preliminary cucumber cultivar reactions to downy mildew posted on June 16, 2023. Use the info in this blog to choose cultivars. Clearly, a few cultivars had temporarily “escaped” infection, although I don’t know how that was possible. In addition, the resistances originally…
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2023 Fusarium Wilt on Seedless Watermelon Experiment – Week 7 Observations
From Clemson Plant Pathologist Tony Keinath This year’s Fusarium wilt experiment includes 3 seedless cultivars, 3 fungicide treatments applied via drip irrigation, and grafting. This experiment is supported in part by a USDA SCRI grant. Transplants were set April 5 in a field infested with Fusarium races 1 and 2. These preliminary results are based…
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Fungicide Sensitivity of Cucurbit Powdery Mildew in Charleston, SC
From Clemson Plant Pathologist Tony Keinath A fungicide sensitivity bioassay was done between June 1 and June 10, 2023, to find out which fungicides can be used against the current outbreak of powdery mildew on squash, watermelon, and other cucurbits. Methods: Yellow summer squash plants ‘Early Prolific’ with three true leaves were treated with one…
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Cucumber Downy Mildew Found in Charleston, SC
From Clemson Plant Pathologist Tony Keinath One of the rainstorms the latter part of last week (the week of June 5) brought cucumber downy mildew spores with it to Coastal REC. On June 12, the most susceptible cucumber cultivar, Straight 8, already had 50% diseased leaf area. This amount of disease suggests that the infection…
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Basil Downy Mildew Arrives in Charleston, SC
From Clemson Plant Pathologist Tony Keinath. One of the rainstorms the week of June 5, 2023, brought basil downy mildew spores with it to Coastal REC. On Friday, June 9, all four cultivars in our demonstration were healthy and more than ready to harvest. On Monday, June 12, this is what we found. Basil downy…
The South Carolina Grower 