Vegetable Scouting Report July 10, 2025

All/multiple crops: Cornell’s weed scientist, Dr. Lynn Sosnoski, passed along the following article that cautions against using AI weed control recommendations because they may be both wrong (read: kill your crop) and illegal. Find the story here.

Alliums: early garlic harvests are underway, but many growers are still determining when to pull their crop. If growing multiple varieties remember that each will mature at a different time, which may help you spread the harvest a little bit. Remember that garlic that reaches maximum size will store the best, because its wrapper leaves tightly seal in moisture and maintain bulb weight. Also keep in mind that curing at higher heat with good ventilation may help to prevent post-harvest disease development and suppress eriophyid mite populations. For more information see this comprehensive article.

 Brassicas: We are getting more reports of Swede Midge throughout the capital district. If you are seeing brassica plants failing to make proper heads, please reach out to us so we can confirm whether you have this emerging pest. To learn more about Swede Midge, visit the Swede Midge Informational Center.

 Cucurbits: Cucurbit downy mildew was observed in Dutchess County on July 2nd and in Columbia County on July 10th. There is also an unconfirmed report of CDM in Washington County on cucumbers. If you suspect CDM, please contact your CCE ENYCHP specialist so we can confirm and report it on the CDM IPM PIPE website. Growers should ensure that susceptible crops are protected with chlorothalonil (Bravo, Initiate etc.) for conventional farms or copper for organic farms. Orondis Opti or Orondis Ultra and Ranman remain effective for CDM control for conventional growers.   For more control options click here.

We continue to observe grey squash bugs laying eggs on pumpkins and squash. See last week for control measures. It’s also getting about that time to start thinking about Cucurbit Powdery Mildew.  Green and yellow summer squash are generally our first indicator crops for this pathogen.  We will be putting together the spray recommendations for next week’s newsletter.  There are a number of products labeled and effective for CPM including Procure, Proline, Vivando, Prolivo, Approvia Top, Miravis Prime, the Luna products (Flex and Experience and others.  These all should be applied with a protectant such as chlorothalonil or copper.  Options for organic producers include JMS Stylet Oil (use caution in hot, humid conditions), potassium bicarbonate products (if used early as a preventative) and sulfur (again, use caution under hot, humid conditions).  More next week on CPM control!

Nightshades:  With fruit set and starting to size up with field plantings, now is the time to start considering your Early Blight (EB) control.  EB usually shows up on older foliage first as a small blackish, brown spot and as it enlarges takes on a target board appearance.  Chlorothalonil (Bravo etc.) containing products do a good job until the plant starts to become stressed from fruiting and sizing those fruit.  Including another product such as Aprovia Top, Gavel, Luna Flex/Tranquility, Reason or other labeled materials is recommended.  Good coverage is also important. This is also a great time to take a foliar sample if you feel like you might need to fine-tune your plant nutrition. We often use Waters Ag Labs because they are fast and have easy to interpret results. We’re happy to look over your test results and help you develop a fertigation program. To take a sample, remove 10 of the most recently fully expanded leaves, rinse off any foliar feeds you have applied, and mail them with the submission form in a paper bag.

It’s that time of the season to also start noticing leaf rolling in tomatoes and the best explanation of TLR I’ve seen it by Jerry Brust, a Vegetable Specialist with the University of Maryland:

“Tomato leaf roll starts with upward cupping at the leaf margins followed by inward rolling of the leaves. Lower leaves are affected first, and can recover if environmental conditions and cultural factors are adjusted to reduce stress. Not all leaves on a plant roll, but eventually the rolling can involve most leaves on a plant and last through the season. In severe cases, whole plants can be affected.  The margins of adjacent leaflets may touch or overlap. Rolled leaves become rough and leathery but are otherwise normal in size and appearance.  There is no discoloration of leaf veins associated with this problem. The good news is that leaf roll rarely affects plant growth, fruit yield, or fruit quality.  Leaf roll is often seen just after plants are heavily pruned during dry soil conditions. If the tomato plant’s top growth is more vigorous than root growth and we are hit with a dry hot period the foliage may transpire water faster than the root system can absorb it from the soil, and the plant will respond by rolling its leaves to reduce the transpiration surface area.

Another cause of this disorder is growing high-yielding cultivars under high nitrogen fertility programs. Oddly enough leaf roll disorder also has been found to be caused by excess soil moisture coupled with extended high temperatures. Leaf roll severity appears to be very cultivar dependent. Cultivars selected for high yield tend to be the most susceptible. Indeterminate cultivars seem to be more sensitive to this problem than determinate cultivars.  It has been found that sugar and starch accumulating in the lower leaves cause the leaf to roll; the more they accumulate the worse they roll. Leaf roll is usually something we see when we have hot dry conditions in June or July, when plants are most actively growing. Leaf roll seldom

affects yield, therefore no corrective measures are needed.

 You can reduce symptoms by maintaining consistent, adequate soil moisture of about 1 inch per week during the growing season. This will also help with calcium up-take, reducing blossom end rot problems. Growers also should not prune heavily during hot dry conditions or over-fertilize with nitrogen.”

So, as you can see there are lots of things that can cause leaf rolling and probably most of it is what we’ve induced by pushing the plants hard or what Mother Nature has or hasn’t delivered in regards to moisture and temperatures!

New potatoes are being harvested as well and there is nothing prettier than seeing those tubers come out of the soil.  However, to keep them looking that nice be sure to handle them carefully as to not scuff off the skins.  If they vines can be killed a few weeks in advance, that will also help set the skins.  And if you wash them, please be very mindful of the water temperature that you are using.  Rule of thumb is the wash water should be no more than 10 degrees colder than temperature of the tubers.  Putting tubers directly from the field that are hot into cold water is a recipe for disaster.  Soft rot bacteria and other pathogens that might be on the soil on the tubers can easily be sucked into the lenticles (tiny pores on the skin of the potato that allow it to exchange gases) and cause the tubers to breakdown.  The breakdown does not happen right away, but usually within a couple days of washing and packing.

 Sweet corn:  Sweet corn harvest in underway in many parts of the region and Corn earworm (CEW) continues to be our biggest threat with a 4-5 day spray schedule indicated by most trap catches.  This week anywhere from 3-15 moths were caught at our trapping sites.  In addition to CEW, this week saw our first trap catch of Western Bean Cutworm (WBC).  This pest tends to prefer corn that is smaller in early whorl stage and behaves very similarly to European Corn borer with similar feeding damage.  We don’t necessarily see this pest on all farms in the region, but if you are not trapping on your farm for it you might not even know you have it.  Control timing is also very similar to ECB which is when 50% of the tassels have emerged and started opening followed a couple days later when the rest of the tassels have emerged and opened.  Once ECB or WBC get into the stalk, they become very, very difficult to control so time insecticides appropriately.

The hot, humid weather this week has also stared to stress some sweet corn with plants rolling their leaves to try and conserve moisture.  Corn just about ready to silk or in silk is probably most at risk to not developing a proper ear, so if you have the ability to irrigate, do so as soon as possible!

 Miscellaneous:  Japanese Beetles (JPB) are out and about as well feeding on many different crops including sweet potatoes, sweet corn, cucurbits, small fruits like raspberries and grapes.  JPB damage is characterized by the skeletonizing of leaves where they eat all the tissue except the veins of the leaves.  They can also feed on silks and husks of sweet corn.  In sweet potatoes and other root crops, that is not the part we worry about – what we do worry about is the eggs that are laid and the larvae or “grubs” that hatch and burrow in to roots.  The adults can be difficult to control, but is the stage to target as it is nearly impossible to control the grub stage once they are established.  Pyrethroids such as Warrior, Hero or Baythroid are the predominant materials to control JPB but other materials such as Assail (acetamiprid) can be effective if labeled for the crop.