Tag: Watermelon
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Question of the Week – Blossom End Rot

This week, the question was: What’s going on with this watermelon? This watermelon is suffering from blossom end rot. This physiological disorder is also common in tomatoes and peppers. Blossom end rot results from a localized calcium deficiency in the fruit; however, this may not necessarily indicate a calcium deficiency in the soil. Blossom end…
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Resistance to Tebuconazole is Widespread in the Gummy Stem Blight Fungus in South Carolina

From Clemson Plant Pathologist Tony Keinath. Cucurbit growers should reduce the use of tebuconazole to manage gummy stem blight as the pathogenic fungus has become moderately resistant to this very commonly used fungicide. Seven watermelon fields were sampled in 2019 (six fields) and 2021 (one field) in Beaufort, Bamberg, Barnwell, and Hampton counties. Of 229…
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Fusarium Wilt Symptoms in Watermelon at Fruit Set Stage

From Clemson Plant Pathologist Tony Keinath and Extension Agent Rob Last. Watermelon growers may find new plants with symptoms of Fusarium wilt as the plants start to set fruit or as fruit sizes up. In the infested field at Coastal REC, 3-5% of the plants previously rated as healthy showed symptoms in the past 2…
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Preparing for Gummy Stem Blight in Fall Cucurbit Crops
From Clemson Plant Pathologist Tony Keinath. Gummy stem blight is more common and more severe on fall cucurbit crops than crops grown in the spring. The cooler weather and longer dew periods in the fall provide an ideal environment for the fungal pathogen to grow and spread. Gummy stem blight is most common on watermelon…
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Weekly Field Update – 7/6/21
Statewide Dr. Tony Keinath reports, “Basil downy mildew was found in mid-June in Charleston. Symptoms start as faint yellowing of leaves, which eventually show brown spots surrounded by yellow areas. To see the spores, look on the bottom of a symptomatic leaf. Sometimes it helps to hold the leaf up to a light source (but…
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Downy Mildew on Watermelon Found in SC
From Clemson Plant Pathologist Tony Keinath. Downy mildew was found on watermelon this week in Allendale and Barnwell counties. Although downy mildew does not infect fruit, it reduces sugar content once 1 in 4 leaves (25%) are infected. All watermelons should be sprayed with a fungicide effective against downy mildew. See pages 214-215 in the…
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Fusarium Wilt in Watermelon
From Clemson Plant Pathologist Tony Keinath. Fusarium wilt is showing up in watermelon fields and in research plots at Coastal REC in Charleston. The most telltale symptoms are wilting of a few leaves at the crown of the plant, wilting of one vine on a plant, or wilting without yellowing of a small plant. A…
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Downy Mildew Found on Watermelon in SC
Downy mildew was found yesterday, June 17, 2020, in one watermelon field in Bamberg County, South Carolina. All growers should immediately spray watermelon with Ranman, Revus, or Gavel to protect their crops from downy mildew. In addition to direct yield loss, loss of vine cover can expose fruit to sunburn (when the sun comes out…
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Field Update – 5/26/20
Statewide Dr. Tony Keinath reports, “Powdery mildew was found late last week on watermelon at the Coastal REC, Charleston. All watermelon growers should look at the photo below to be sure they can identify powdery mildew in the early stages. The spots are pale yellow, and, unlike squash, may not have white powdery growth under…
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Field Update – 5/18/20
Statewide Dr. Tony Keinath reports, “With the cooler-than-normal spring weather, two cool-season pathogens also may be active longer than normal. Downy mildew on brassicas, especially kale and collard, mainly affects the lower leaves. Sometimes it will move up onto the larger leaves in the middle of the plant. With a hand lens, you can see…