Vegetable Scouting Report: June 12, 2025

All/multiple crops: This might sound strange with the rain that we’ve been getting but, if you are using plastic mulches and drip irrigation, check under that plastic to make sure you don’t need to be irrigating. Although water will move laterally, those beds can still get dry even with brief glimpses of the sun and warmth. And it is very difficult to catch up using drip when beds get dried out. Over the years listening to different growers, researchers and irrigation company representatives, it is much better to run your drip systems more often with shorter durations then it is to run them once or twice a week for 5-6 hours. Short runs of 2-3 hours 3 to 4 times a week is optimal as long as your beds are already moist.

Alliums: Cool, wet weather has been conducive for the development of Botrytis Leaf Blight (BLB). Water-soaked lesions surrounded with a whitish halo typically develop on the oldest leaves first. If left untreated under conducive environmental conditions, lesions will coalesce, turn brown and result in early death of leaves and reduced yields. An application of Bravo alone, Bravo + Manzate, or Bravo + phosphoric acid or for organic production, Oso 5% SC OMRI-Listed) could help keep the BLB pressure in check.

The forecast is calling for hot and dry weather over the next 7 days, these conditions often increase thrips populations and damage, so get out there and scout. Check for thrips deep in the neck area. Best control will be obtained when treated at the recommended threshold of one thrips per leaf. Some labeled insecticides include Agri-mek, Radiant SC and Entrust SC (OMRI-Listed).

The first leek moth flight has ended in northern NY, and the second flight is expected to begin as early as next week. The second flight is usually the most damaging to onions. Stay tuned for more information in the coming weeks from our monitoring network. Pesticide applications are best timed approximately one week following peak flight, and netting should be set up in advance of the first trap counts.

Brassicas: Again, lots of Imported Cabbage Worm moths flying around this week and caterpillars chewing away on many of the different brassicas. Flea beetles are still abundant and need to be treated multiple times if using materials like pyrethroids that have little residual.

Swede midge damage symptoms in brassicas are now visible. Flight of the overwintered generation continues, and crops should be protected from transplant stage onwards.

Cucurbits: It’s nice to see some early, rowcovered green and yellow squash being harvested – gives a sense that summer might actually be coming. Striped Cucumber Beetles and Angular Leaf Spot continue to be the most active pests this week. For Angular Leaf Spot on squash that is not being harvested consider applying a copper product in a tank mix of mancozeb (5-day pre-harvest interval for mancozeb products). The addition of the mancozeb allows more of the copper ion to be active resulting in better control.

Two reports of bright yellow lower leaves in summer squash have been reported in the region, with uniform distribution across the plantings. Bright yellow leaves in certain cucurbits can be caused by environmental stress, such as cool temperatures, that triggers expression of the “precocious yellow” gene. This gene is useful for squash plant breeding because it enhances yellow fruit color and yield. The leaf yellowing response in varieties with this gene is usually temporary. See the University of New Hampshire’s article on this for more information and photos.

Nightshades: As we move forward with tomato growth, just a reminder that when pruning your tomatoes for trellising, be sure to remove the suckers when they are small (less than the thickness of a pencil). When suckers get too big and you remove them, it is a major shock to the plant and recovery is slow and worse yet, fruit may drop. The other issue with removing large suckers is the large wound that is left which allows for bacteria, botrytis and other pathogens to potentially get started. When pruning, staking or trellising, be sure to do it when the plants are dry as to limit the spread of diseases like Bacterial Canker, Speck and Spot. If you haven’t done so yet, stakes that are being re-used should be disinfected before they go out to the field. Clean as much of the organic matter as possible (dirt, dried plant debris etc.) in order for the disinfectants to work better. Do not pack stakes too tightly in washing container—allow solution to distribute evenly and contact all surfaces of the stake. Surfaces of stakes in the middle of a tightly packed group may not completely be soaked. Here are some thoughts about disinfectants that you can use:

Green-Shield (quaternary ammonium chloride salt)

• Recommended use rate is 1.5 fluid ounces per 5 gallons of clean water or 1 Tablespoon (= 0.5 fl oz) of Green-Shield in 1 gallon water.
• Allow surfaces to remain wet or submerged for 10 minutes before rinsing off with clean water.
• Very effective and economical: 1 gallon of Green-Shield is equal to 28 gallons of Clorox.

ZeroTol 2.0 (hydrogen peroxide + peroxyacetic acid)(OMRI Listed)

• Use a dilution of 1:300 or 0.5 fluid ounces per gallon of clean water and spray until runoff on greenhouse surfaces etc.
• Use a dilution of 1:50 or 2½ fluid ounces of ZeroTol 2.0 per gallon of clean water if surfaces have not been pre-cleaned.
• Use with a surfactant foaming agent, as described on the labels when using products containing Hydrogen peroxide plus peroxy¬acetic acid, such as Oxidate 2.0 and Zerotol 2.0 as it improves control on porous surfaces like wooden stakes.

Clorox/Bleach (5.25% sodium hypochlorite)

• Use rate of 1 part bleach to 9 parts of water (or 10% solution).
• Completely submerge stakes and allow to soak for at least 30 minutes before removing and rinsing.
• If possible, lower water pH to 6.5 – 5.8 to obtain the most activity from bleach.
• Add bleach or change water frequently when it becomes visibly dirty.
• Bleach is also short-lived after mixing in water, with a half-life of only 2 hours so replenishing often will be critical for the best activity.

Other materials: Hydrogen dioxide, hydrogen peroxide and peroxyacetic acid products such as an OxiDate or SaniDate can also be used to disinfect stakes (some are organic certified). Rates will depend on the formulation you choose.

Potatoes: Potato growth about doubled in fields I was looking at from last week from a couple days of warm weather; and with that the amount of Colorado Potato Beetles also increased with egg laying and hatching occurring all over the place. Materials to control small larvae include Rimon, Calantha (newly registered), Radiant/Blackhawk, Agri-Mek or other labeled formulations and Coragen. On Long Island, Rimon applied to first-generation larvae, applied 2X, 7 days apart at 50% egg hatch has been working well. Calantha, the newest product registered, should be used similarly as Rimon.  Organic choices include Entrust (spinosad) where resistance has not been documented, will provide good control. Other options include products containing azadirachtin (Azatin, AzaGuard, Azera, Molt-X, Aza-Direct etc.) and will probably need to be applied multiple times.  All of these products need to be applied to small larvae and at the highest labeled rates to provide adequate control.

Solanaceous flea beetles were also seen potatoes and eggplant this week in the north. The action threshold for flea beetles in potatoes is 15 feeding holes per terminal leaf. There are several products labeled for flea beetle control in potatoes, including some with overlapping labeling for Colorado potato beetle (e.g. Assail, Warrior, etc.).

Sweet corn: Corn Earworm (CEW) moths were caught at several lower Hudson Valley sites last week which seems pretty early, but not surprising with the weather patterns. Most of these moths are deposited here from storm fronts that move from the south into our region. There has been some discussion of overwintering populations here, but there have been no documented cases that I know of. If you have corn that was either in plastic or under rowcover that may be getting ready to silk, keep an eye on the trap catches to see if that corn may need to be treated. If eggs are laid on corn still in the whorl stage, the worms will act similarly to European Cornborer (ECB) burrow into the whorl to the tassel and feed there. As the tassel emerges, that is our opportunity to control CEW prior to silking and ECB.

For CEW control, Besiege (chlorantraniliprole plus lambdacyhalothrin) or Elevest (chlorantraniliprole plus bifenthrin) rotated with a pyrethroid plus Lannate is typically recommended. Do not rely on pyrethroids alone due to resistance issues. Trials in Virginia suggest that the most consistent pyrethroid products tested were Hero and Baythroid XL (both applied at the highest rates). Another option is to use spinosyns (Radiant, Blackhawk, Entrust) tank mixed with a pyrethroid.

Contributors: Cornell Cooperative Extension Specialists Chuck Bornt, Teresa Rusinek, Ethan Grundberg, Elisabeth Hodgdon and Crystal Stewart-Courtens.