Category: Disease
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Sudden Wilt or Pythium Root Rot On Mature Cantaloupe
From Clemson Plant Pathologist Tony Keinath After a very dry April, the heavy rains in May triggered a case of Pythium root rot in one cantaloupe field in South Carolina in the past 2 weeks. Another name for Pythium root rot on mature cucurbits is “sudden wilt” to distinguish it from the more common damping-off…
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Cucurbit Disease Update for Mid-May 2025 (Downy Mildew Found in SC)
From Clemson Plant Pathologist Tony Keinath Despite relatively dry conditions this spring, two foliar diseases have shown up on cucurbits in different parts of South Carolina. Gummy stem blight was found on watermelon in the Central Savannah River Area, and downy mildew was found on cucumbers at Coastal REC. Five of 23 watermelon samples (that’s…
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Cucurbit Downy Mildew Fungicide Trial Report for Fall 2024: Part 1, Pickling Cucumber
From Clemson Plant Pathologist Tony Keinath In fall 2024, fungicide programs were tested on ‘Gershwin’ pickling cucumber to find out which programs worked best. Eight fungicide programs (plus a non-sprayed control) were used with various combinations of chlorothalonil (Bravo), Ranman, and Orondis Opti (Orondis + Bravo pre-mix). Cucurbit downy mildew (CDM) symptoms were noticed on…
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Field Scouting and Identification of Diseases on Cucurbits in South Carolina
From Clemson Plant Pathologist Tony Keinath For anyone who missed the Preplant Cucurbit Meeting on Feb. 7, 2025, at the Edisto Research and Education Center, here is a recap of the main points on scouting fields for cucurbit diseases. Table 1 shows which diseases are most likely to show up on different crops. Use this…
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Biologicals Made Easy: Grouping and Understanding Biological Fungicides
Johanna Wesche and Guido Schnabel, Clemson University Biologicals are gaining interest in modern agriculture for several reasons. They are used in organic farming to suppress pests and diseases and may have a place in spray programs used in conventional farming when disease pressure is low, when fungicide efficacy is threatened by resistance development, or when…
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Good Progress on Breeding a Downy Mildew-Resistant Pickling Cucumber, 2024 Update
From Clemson Plant Pathologist Tony Keinath I am part of an exciting collaboration with Dr. Michael Mazourek from Clemson University to help him complete the breeding and selection process for a new pickling cucumber with high levels of resistance to downy mildew. Field work at the Clemson Coastal REC in Charleston started last fall. We…
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Can Biological Products and Soil Amendments Help With Bacterial Disease Management in Peaches?
From Guido Schnabel, Hehe Wang, Juan Carlos Melgar, Ayodeji Idowu, Junaed Ahmed, Rongzhong Ye, and Michael Vassalos I think we can all agree that peaches produced in commercial peach orchards in South Carolina are special. They are sold locally at farm stands and many retail stores along the East Coast. You may not know that…
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White Mold is Active so Spray Now
From Clemson Plant Pathologist Tony Keinath and Extension Associate Justin Ballew The freezing weather the week of January 21, 2025, was just what the Sclerotinia white mold fungus was waiting for. While cold temperatures discourage most animals from being active, freezing temperatures trigger Sclerotinia sclerotia (the survival structures in soil) to germinate, produce tiny mushrooms,…
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And So It Begins…Neopest is Starting to Show Up.
By Guido Schnabel It is early October 2024 and as feared and expected, we are starting to see Neopestalotiopsis symptoms in strawberry fields. The leaf in Fig. 1 (left) displays leaf necrosis and was collected from a South Carolina farm October 4, 2024. Necrosis on leaves can be caused by many things, but if you…
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Efficacy Trials with Biofungicide Howler EVO against Strawberry Diseases
By Guido Schnabel, Jeffrey A. Hopkins, and Johanna Wesche Recently, the article Fungus-Based Biological Control Agents: How Useful Are They for Strawberry Disease Management? was published. The article reported our first experience with yeast-based biological control agents (BCA) against Botrytis fruit rot (BFR) and Anthracnose fruit rot (AFR) of strawberry. The trials were conducted at the…
The South Carolina Grower 