Vegetable Scouting Report: June 25, 2025

All/multiple crops: The hot weather is increasing insect pressure across the board. The hotter it is, the faster insects’ metabolism works, which means they are more active and feed aggressively! We are seeing lots of general feeding by four lined plant bugs and tarnished plant bugs, and you’ll notice insects being a primary concern throughout the scouting report. A friendly reminder- spray flowering crops at night to protect bees.

Beans:  In our worry about Leafhoppers in potatoes, we often forget that beans, especially snap beans, are very sensitive to leafhopper damage and need to be scouted just as hard as potatoes.  There were definitely lots of leafhopper this week in beans so be sure to scout and treat as needed.  Multiple applications of pyrethroids may be required to control them.

Also, this week, while scouting beans, Pythium root rot was easily found in very early planted beans and without surprise.  This spring was prime conditions for root rots like pythium and Rhizoctonia, both like the cold, wet soil conditions we saw earlier.  The delay in germination and continued wet soil conditions are perfect for these diseases.  And now with a few dry days behind us, we see the wilting and leaf dropping that usually follows those infections as the root systems in these plants are heavily compromised.  Some plants this week could be found trying to send out some new roots higher up on the actual roots, but it probably won’t be enough to sustain the plant to harvest.

Brassicas: There have been localized outbreaks of cabbage aphids in brassicas this spring. Conventional growers have many options including Beleaf (flonicamid) and Assail 30SG (acetamiprid) but note the 7-day PHI.  Organic growers can use products containing Azadirachtin (neem) or pyrethrum.

Cucurbits:  This week the first adult Gray Squash Bug was observed on some very small pumpkins.  GSB prefers cucurbits such as Turk’s Turban, Hubbard and kabocha or buttercup types.  There are two reasons to pay particular attention to this pest – first, they damage plants by feeding on the leaves and stems, but more importantly, they carry or vector a relatively new disease for us here in NY called Yellow Vine Decline.  YVD is caused by a bacterium called Serratia marcescens.  Symptoms include yellowing leaves, stunted growth, and a gradual decline in plant health and under heavy pressure and the right environmental conditions, sudden plant collapse.  From my experience it is not worth trying to use insecticides for adults but focus on the young nymph stage instead.  Look for their coppery colored egg masses laid on the undersides of the crop leaves.  Once you’ve found a few, flag them and check them every day or every other day and when most of them have hatched and the small spider looking, grayish nymphs can be seen, that is when you can achieve good control with insecticides like Assail or Arvida(both acetamiprid) or pyrethroids like Warrior.  Organic growers can use azadirachtin containing products or PyGanic, but they need to be used early when the nymphs are small with multiple applications likely.

From Cornell Plant Pathologist Dr. Chris Smart – “Downy Mildew was identified on cucumber in Lenawee County Michigan (the southeastern part of the state) on June 24. Spore traps have identified spores of the pathogen in five counties. Cucumber is particularly susceptible so growers in Western NY with cucumbers should be protecting plants now. This is not entirely unexpected given the cool wet weather we have had, but it certainly is earlier than we usually see downy in NY.  It is important to report downy mildew outbreaks to the cucurbit downy mildew IPM Pipe https://cdm.ipmpipe.org/”

What does that mean for growers in eastern NY?  Cucurbit Downy Mildew can be a devastating disease and looking at the forecast for the next week, there very well could be the opportunity for spores to arrive in the area, riding on the stormfronts we might likely see.  Look for bright yellow spots on cucumber leaves and if flipped over, a grayish purplish fuzz might be seen, especially early in the morning.  If you suspect CDM, please contact your CCE ENYCHP specialist so we can confirm and report it on the CDM IPM PIPE website.  Protecting crops right now with chlorothalonil (Bravo, Initiate etc.) will be important through the next 4-5 days with the expected showers in the forecast.  Orondis Opti or Orondis Ultra and Ranman remain effective for CDM control for conventional growers and preventative applications of copper for organic growers.  For more control options click here.

Nightshades:  Leafhoppers and Colorado Potato Beetles are still the two primary insect pests in potatoes this week.  Leafhoppers seem to favor early maturing varieties, especially red ones like Dark Red Norland so concentrate scouting efforts on those varieties.

In tomatoes and eggplant, these last few days could start the buildup of Two Spotted Spider mites so be sure to spend some time scouting those crops.  Damage from mites can usually be found in the newer growth of the crop and appears as a sort of bronzing of the leaves.

Sweet corn:  Corn Earworm (CEW) moths are active at several locations this week and last week.  It is crucial in corn that is silking to maintain good insecticide coverage of the silk area and pay attention to trap catches for spray schedules.  CEW’s lay their eggs directly on the silks and when the egg hatches, it moves into the silk channel and then makes its way down into the tip of the ear so you have very limited opportunity to control it.  Most locations this week in the southern region were catching enough moths for a 4 day spray schedule.  Here is the thing – materials like Beseige or Elevest or Radiant (Entrust) do have good residual.  However, as the silk continues to emerge, that area will not be protected by previous insecticide applications because those insecticides aren’t systemic – yes they move into the plant tissue, but only translaminarly or essentially from the side they contact to the other side.  That is why multiple applications are or may be required to get good control.

With all the rain this spring, it might also be a good idea to think about sidedressing or topdressing sweet corn with a little bit of nitrogen.  Early plantings may have shallow rooting systems making them not as aggressive for nutrient mining.  However, additional nitrogen will probably not benefit corn that is either silking or starting to ear up, so concentrate on younger plantings.  And they may require additional irrigation during days like the last couple (hot, dry conditions) so pay attention, especially older corn that is silking or earing up.

Miscellaneous: Note that water pH and alkalinity can impact the stability and effectiveness of some commonly used organic and synthetic pesticides.  Water pH can be adjusted by using commercially available acidifying/buffering agents before adding the pesticide. There are OMRI listed products such as Leaf Life Organic Water Conditioner (Citric Acid) that can be used in organic production. The pesticide label usually states optimal pH ranges. If you are unsure, contact a technical representative of the product manufacturer. Applicators can test their water pH prior to a spray application using a pH litmus strip or a pH meter. Water alkalinity and pH adjustments are easy to make and can significantly improve crop health as well as the performance of pesticides and sanitizers. If you need help or have questions on the process, contact your local CCE Extension specialist.