Vegetable Scouting Report: July 23, 2025
All crops: The break in heat has lead to slower maturation of cucurbits and tomatoes, and rain events throughout the region brought welcomed moisture to non-irrigated corn and pumpkin fields.
Alliums: Most of the garlic is in now, and early onions are going down. Make sure to remove garlic from drying areas once the innermost wrapper leaves are dry to the touch to avoid overdrying. As a reminder, refrain from handling onions when temperatures are over 90, and cover bulbs with tops during drying to protect from sun scald.
Brassicas: Reports of Swede midge in the eastern edge of the region continue to expand. Conventional growers can generally control Swede midge using existing flea beetle spray programs. Organic growers may need to keep brassicas covered to protect growing points until the edible portion has differentiated. Brussels sprouts are particularly susceptible to economic damage.
Cucurbits: Downy mildew continues to expand throughout the region. Maintain protective spray programs shared in previous blogs. Powdery mildew has not yet been reported as widespread in pumpkins, which are still setting fruit.
Nightshades: Late blight has been reported in the southern tier of NY. Current weather is not conducive to spread, but storms from the west may facilitate spread to our region as early as the end of the week. Make sure to apply protective sprays (chlorothalonil, copper) pre-emptively as soon as possible. Here is a brief overview of fungicides available from Dr. Meg McGrath for use if Late blight makes it to the region:
“Orondis Opti (49 + M5), Curzate or Tanos or Cymbol Advance or Cymbol Balance (all have same active ingredient in FRAC Group 27), Presidio (43), Previcur Flex or Cymbol Balance (28), Ranman (21), Gavel or Zoxium (22), Reason (11), Zampro (40 + 45), Revus (40), and Forum (40). These need to be tank-mixed with a protectant fungicide, except for Gavel, which contains mancozeb. Note that applying chlorothalonil weekly starting before disease onset has provided good control in fungicide efficacy experiments. This disease is extremely difficult to control with fungicide applications started after detection. Curzate and Tanos have good curative activity but short residual activity, thus another fungicide will be needed about 3-5 days after application. Previcur Flex has good systemic activity and thus protects stems and new growth. Ridomil Gold Bravo (or OLP) is very effective for sensitive pathogen strains like US-23, which has been the main one detected recently in the Northeastern USA. Strain identification can now be done in 1-2 days.”
Early blight is also increasing on field and tunnel grown tomatoes and is often associated with the stress of sustained fruit production. Early blight shows up on the lower leaves as lesions with concentric rings lined in yellow. Protective fungicides can help to slow the spread of this disease, as can optimized nutrient management.
For an overview of tomato disease management, please see this helpful article developed by Dr. Meg McGrath.
Sweet corn: Nothing new this week-make sure to reference the trap catches and scout your fields to determine the timing of spray applications.
