Asparagus growers should consider scouting their fields during the summer months for foliar disease development. Important pathogens that growers need to scout for on a regular basis include Purple spot, Cercospora, and Rust. [Read more…]
Vegetable Disease Update: 5-27-22
- Neopestalalotiopsis on strawberry has been reported. Please click here to see the report from Penn State University Extension.
- Dickeya dianthicola has been reported in potato in Virginia.
- Botrytis and Anthracnose fruit rot is being reported in strawberry. For more information on controlling these two important diseases please click here.
- Cucurbit downy mildew has been reported on cucumber only as far north as Bamberg, County, GA (south central part of the state). To follow CDM reports in the U.S. please click here. Recent research has shown that oospores of the pathogen can overwinter in the southern US (North Carolina), but overwintering oospores were unable to germinate and cause infection the following spring. For more information please click here.
- Suncald has been reported in newly transplanted pepper fields. For more information please click here.
- Timber rot has been reported in tomato. For more information please click here.
- White rust has been reported in spinach.
- The 2022/2023 Commercial Vegetable Production Recommendations Guide is available for free online or for sale in hardcopy form at many County offices.
- For a quick review on managing fungicide resistance development using tank mixes and fungicide rotations, and information on FRAC group 4, FRAC group 7, and FRAC group 3 and FRAC group 11 fungicides please click on hyperlinks.
Anthracnose and Botrytis Control in Strawberries for 2022
Dr. Mengjun Hu, University of Maryland, and Kathy Demchak, Penn State University, have written an extensive article on effective strategies for Botrytis and Anthracnose fruit rot control for the 2022 season.
Managing gray mold (Botrytis) on strawberries is increasingly challenging because of fungicide resistance development, plus a new Botrytis species that is less susceptible to fungicides is becoming common in the mid-Atlantic region. Resistance to certain fungicides is also a problem in management of anthracnose fruit rot. This article describes disease management strategies designed to slow further resistance development, while also providing specifics for managing our two most common fruit rots.
The rest of the article can be accessed and downloaded as a PDF file by clicking on the following link: Botrytis and Anthracnose Mgt Strawberries final.
Anthracnose and Botrytis Control in Strawberries for 2022
Dr. Mengjun Hu, University of Maryland, and Kathy Demchak, Penn State University, have written an extensive article on effective strategies for Botrytis and Anthracnose fruit rot control for the 2022 season.
Managing gray mold (Botrytis) on strawberries is increasingly challenging because of fungicide resistance development, plus a new Botrytis species that is less susceptible to fungicides is becoming common in the mid-Atlantic region. Resistance to certain fungicides is also a problem in management of anthracnose fruit rot. This article describes disease management strategies designed to slow further resistance development, while also providing specifics for managing our two most common fruit rots.
The rest of the article can be accessed and downloaded as a PDF file by clicking on the following link: Botrytis and Anthracnose Mgt Strawberries final.
Understanding Protectant Fungicides
(FRAC groups M01 – M12) in 2022
Protectant (contact) fungicides, such as the inorganics (copper, FRAC group M01) and sulfur (FRAC code M02); the dithiocarbamates (mancozeb, M03), phthalimides (Captan, M04), and chloronitriles (chlorothalonil, M05) are fungicides which have a low chance for fungicide resistance to develop. Protectant fungicides typically offer broad spectrum control for many different pathogens.
Why wouldn’t fungi develop resistance to protectant fungicides? Protectant fungicides are used all the time, often in a weekly manner throughout much of the growing season.
Damping-off: Identifying and Controlling Pathogens in Transplant Production in 2022
It is extremely important to know which pathogen is causing damping-off problems and which fungicide to properly apply. The key to controlling damping-off is being proactive instead of reactive. Always refer to the fungicide label for crop use, pathogens controlled, and application rates.
Damping-off is caused by a number of important vegetable pathogens and is very common during transplant production. Damping-off can kill seedlings before they break the soil line (pre-emergent damping-off) or kill seedlings soon after they emerge (post-emergent damping-off). Common pathogens that cause damping-off include Pythium, Phytophthora, Rhizoctonia and Fusarium spp.