Category: Disease
-
Cottony Rot on Stored Carrots
From Clemson Plant Pathologist Tony Keinath. Stored carrots can rot if they are infected by one of several different fungi in the field. Among the culprits is Sclerotinia, typically known as white mold on beans, Sclerotinia stem rot and watery soft rot on brassicas, or timber rot on tomato. On carrot, the same disease is…
-
Pythium Damping-Off of Seedless and Pollenizer Watermelons
From Clemson Plant Pathologist Tony Keinath. Stand loss in transplanted spring seedless watermelons is usually not a serious issue in South Carolina, due to relatively sandy soils in the major production areas. Two pathogens that can cause post-transplanting damping-off and plant death are the fungus Fusarium and the water mold Pythium. Fusarium can kill seedlings…
-
Black Rot Review: How to Manage this Disease on Brassica Crops
From Clemson Plant Pathologist Tony Keinath. Black rot is the most common disease caused by bacteria on brassica crops. It was widespread in the Lowcountry in fall 2022, so it’s time for a review of this serious disease. Recognizing Black Rot Most often, black rot starts at the edges of the older leaves on brassicas.…
-
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…
-
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…
-
Fusarium Wilt on Okra
From Clemson Plant Pathologist Tony Keinath. Late summer is the time of year when Fusarium wilt shows up on okra. Because the fungus travels in the xylem, external symptoms are visible on all above-ground plant parts. Although the main stem may remain partially green, side branches turn brown, and pods dry completely. To diagnose Fusarium…
-
Cercospora Leaf Spot on Okra Looks Different than Other Cercospora Leaf Spots
From Clemson Plant Pathologist Tony Keinath and USDA Plant Pathologist Gabriel Rennberger. August is the time of the year when Cercospora leaf spot appears on okra. This Cercospora leaf spot doesn’t look like Cercospora leaf spots on other crops, such as beet. Most of the disease is on the leaf underside. On the top of…
-
Anthracnose Identified on Lima Bean in the Pee Dee Region of South Carolina
From Clemson Plant Pathologist Tony Keinath, Clemson Plant Breeder Jenna Hershberger, and Clemson Extension Agent Bruce McLean. Anthracnose on lima bean has been reported from the PeeDee area. Reddish brown blotches are found on leaves and pods. The disease appeared after a week of rain and, after another week of rain, quickly spread through the…
-
Choanephora Blight Found on Green Bean in Charleston
From Clemson Plant Pathologist Tony Keinath, Clemson Plant Breeder Sandra Branham, and Clemson Graduate Student Morgan Stone. Due to frequent rains, cloudy weather, and high humidity, Choanephora blight or wet rot was found throughout a one-acre planting of green bean cultivars and breeding lines at Coastal REC last week. Growers and home gardeners may see…
-
Biopesticides (Seem to) Perform Poorly Against Black Spot on Kale
From Clemson Plant Pathologist Tony Keinath. As part of a USDA Organic Transitions Program grant, we tested 10 biopesticides on organic kale ‘Oldenbor’ to see if any product controlled Alternaria leaf spot, a.k.a. black spot. Unfortunately, none look promising as no biopesticides reduced black spot compared to the nontreated control based on repeated greenhouse trials…
The South Carolina Grower 