Tag: Watermelon
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Urgent: Powdery Mildew Found on Watermelon in Charleston, SC
From Clemson Plant Pathologist Tony Keinath. Powdery mildew was found on three cultivars of seedless watermelon at the Clemson Coastal REC on May 23, 2023. All watermelon crops in South Carolina should be 1) scouted for powdewry mildew and 2) if found, sprayed to prevent powdery mildew from reducing yields by up to 40%. When…
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2023 Fusarium Wilt on Seedless Watermelon Experiment – Week 5 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. Right on schedule, symptoms of…
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2023 Fusarium Wilt on Seedless Watermelon Experiment – Week 3 Observations
From Clemson Plant Pathologist Tony Keinath This year’s Fusarium wilt experiment includes three seedless cultivars, three fungicide treatments applied via drip irrigation, and grafting. This experiment is supported in part by a USDA SCRI grant. There also is a side experiment with SP-7 pollenizers grafted onto ‘Carolina Strongback’ rootstock and non-grafted SP-7 supported in part…
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How Seedless Watermelon Cultivars React to Fusarium Wilt: Average Results of 2021 and 2022 Trials
From Tony Keinath, Extension Vegetable Pathologist. As part of a large USDA Specialty Crop Research Initiative grant, I have been working with Dr. Jonathan Schultheis, Horticulturist at NCSU, to evaluate seedless watermelon cultivars grown in plots naturally infested with the Fusarium wilt fungus. The South Carolina trials were done in my Fusarium-infested field at the…
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2023 Gummy Stem Blight Control for Watermelon Growers: Early is on Time
From Tony Keinath, Extension Vegetable Pathologist. The recent freeze in the lower part of South Carolina more than ended the 2022 watermelon season. It’s not too early to plan for gummy stem blight control in 2023 to allow time to buy the right fungicides in case of shortages. As the saying goes, early is on…
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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…
The South Carolina Grower 