All/multiple crops: As we approach peak u-pick season, it’s worth reading this short article from Rutger’s about what you can (and can’t) ask customers regarding service animals that they bring to your farm. Check out the short version here and the full length version here.

The herbicide Dacthal and all other dimethyl tetrachloroterephthalate (DCPA) containing pesticides can no longer be legally used in the United States. The manufacturer and product registrant AMVAC Chemical Corporation voluntarily cancelled all registrations of Dacthal in late August. More information on the voluntary cancellation can be found here. For growers with Dacthal in their inventory, AMVAC is accepting returns of unused product. Mike Helms from the Pesticide Safety Education Program shared this note:

“AMVAC is asking applicators to return the products to the place of purchase.  Dealers/distributors need to reach out to AMVAC directly to schedule a pickup, which they will cover the cost for and provide collection drums, if needed. The contact for this is Melina Garcia of the AMVAC Customer Service Team. Melina can be reached at 888-462-6822, extension 6053.”

Alliums:  Allium leafminer (ALM) activity was detected on 9/9 in the Hudson Valley. Beginning in 2017, ALM emergence has been carefully detected and recorded for the Hudson Valley and has occurred between September 3 and September 19. Emergence may occur a little later on farms north of the Hudson Valley. Growers with susceptible alliums such as scallion, chives, and leeks should cover these crops immediately with insect netting or row cover making sure there are no gaps along the edges. For larger plantings or other situations where row cover is not practical, there are effective OMRI-listed and conventional insecticides that can be used to reduce damage from ALM. More information on management options can be found here.

Brassicas:  Brassica downy mildew has been found in a broccoli and kale planting in the Hudson Valley. Lesions begin as small yellow leaf spots that later turn brown with blue or black lace-like markings. Under humid conditions, especially in the morning, look for white downy mold on leaf undersides. Dr. Chris Smart at Cornell University has conducted fungicide efficacy trials for downy mildew control on brassicas. Manzate Pro-Stick (mancozeb, FRAC M3, only labeled for broccoli and cabbage) is effective when used preventively and can be alternated with Champ Formula 2F (copper hydroxide, FRAC M1). Bravo Weather Stik (chlorothanlonil, FRAC M5) and Presidio (fluopicolide, FRAC 43, Presidio must be tank mixed with another fungicide with a different mode of action for resistance development prevention) are the other two fungicides recommended by Dr. Smart. For organic growers, avoidance is crucial. Increase plant spacing to improve air circulation and minimize leaf-to-leaf disease transmission. Make sure to rotate fields out of brassicas for at least three years and work to control cruciferous weeds that may also act as sources for inoculation. Most OMRI-approved fungicides have little demonstrated efficacy. Organic copper formulations, such as Badge X2 (copper oxychloride + copper hydroxide, FRAC M1) are the best bet, but products like Double Nickel 55 (Bacillus amyloliquefaciens strain D747, FRAC 44), Stargus (Bacillus amyloliquefaciens strain F727 cells and spent fermentation media, FRAC 44) and Regalia (Reynoutria sachalinensis extract, FRAC P5) are also labeled for downy mildew on most cole crops and have shown some reduction in disease severity in trials when used preventatively.

Alternaria leaf spot and head rot prevalence is increasing in the region as well. Cornell plant pathologist Dr. Chris Smart writes, “Under the right environmental conditions, the fungus can thrive and cause severe infection. Alternaria brassicicola produces spores after exposure to high relative humidity (~87%) and temperatures between 68-86 °F. The spores are then released during warm dry periods shortly after a rain. The spores are primarily aerially dispersed but can also be dispersed by rain splash. The optimal temperatures for new infections to occur are 55-75 F.  Alternaria brassicicola prefers cool weather and long periods of leaf wetness making fall weather in upstate New York an ideal environment.”  For fungicide information, consult Cornell Vegetable Program Vegetable Specialist Christy Hoepting’s Brassica Alternaria Fungicide Cheat Sheet for more recommendations.

Cucurbits:  Many pumpkins and fall ornamentals are moving into the market the last couple of weeks and the question arises every year around this time of when to stop spraying cucurbits.  The answer depends on how far along they are in their maturity, what kind of vine cover to you have, and when you will be harvesting.  If you still have good vine cover, but won’t be in there to harvest for another week or two, it would be beneficial to maintain a fungicide program including a copper as the bacterial diseases can become an issue on the fruit themselves this time of year with the heavy dews.  The weather this week and into early next week has lots of sun and 80 degree daytime temperatures, which could be a recipe for sunscald in some crops with a lack of vine cover, especially those dark green skinned varieties.  Just a reminder, you can click here for some tips on when to know if your crop is mature and how to best handle it.

Nightshades: The thing to be on the lookout for in the next couple of weeks is tomato fruitworm, which is the same species as corn earworm.  As sweet corn plantings start to become scarce, the moths will look for other suitable host crops and tomatoes are on that list of potential sites.  Keep an eye on the trap counts and scout regularly in your tomatoes.  Fall armyworm (FAW) can also attack tomatoes and we have seen several sites this week increase in the number of FAW moths.  Baythroid XL, Exirel, Coragen, and Lannate are all labeled with a 1 day PHI.

Potatoes:  Now that we are starting to see the soil temperatures start to drop, it’s time to start thinking about harvesting storage potatoes.  It all starts with proper vine killing!  Vine killing can be achieved by mechanical means (flaming, mowing, beating) or chemical means.  There are several chemical desiccants labeled in NY including Aim, Reglone, Rely and Vida.  All these materials are non-selective desiccants and most will also kill or at least hold back many late season weeds that may or may not be in your potato fields.  For the list and more information click here.  From Long Island Vegetable Specialist Sandy Menasha shares the following (Long Island Fruit and Vegetable Update, No 23, September 5, 2024):

Tips for Maintaining Tuber Quality in Storage: Ensuring and maintaining good tuber quality in storage starts in the field. Below are some of the common factors each year that lead to serious storage problems. The following points are made to help growers store and maintain high quality tubers:

• Vine-kill potatoes 2-3 weeks before harvest to ensure good skin set, making the tubers more resistant to skinning and bruising.
• Don’t begin to store potatoes until the latter part of September when tuber and air temperatures have cooled down. If possible, avoid harvesting when pulp temperature is above 60°F. Greater storage “prob­lems” usually occur in potatoes dug during the warm­er parts of September.
• Don’t store potatoes from wet areas of the field. Many potatoes from low areas are diseased or more prone to disease. Best not to even harvest these areas.
• Pad all deflectors and sharp points. Agitation chains should be minimized, and excessive bouncing should be avoided.
• During harvest maintain proper ground speed and chain speed ratio to keep the conveyors as full of potatoes as possible. This allows for the potatoes to “flow” from one chain to another reducing rollback and the potential for blackspot bruise.
• Reduce the height of drops to 6 inches or less during harvest and handling of potatoes.
• Remove all soil and debris during the harvest opera­tion and while conveying tubers into storage. Exces­sive soil in the storage will prevent proper air move­ment and increase the chance of storage rot.
• Provide enough staff and light to sort/cull tubers properly as they go into storage.

Corn:  Corn earworm (CEW) is still very active in most areas and the 80 degree days will continue to keep them very active!  Fall armyworm (FAW) catches in some areas are also on the rise. Targeted sprays for CEW should also control FAW.  Many areas will continue to be on a 3-5 day spray schedule.  Products include Coragen, Beseige (premix of Coragen and Warrior), Lannate and Radiant.

Miscellaneous: Several celery plantings in the Hudson Valley appear to be infested with the three primary fungal foliar diseases of the crop: early blight (Cercospora), late blight (Septoria), and anthracnose. Heavy dew sets and long periods of leaf wetness can contribute to these diseases continuing to spread in the field. OMAFRA has a helpful resource for identifying celery leaf disease that can be accessed here. Labeled azoxystrobin formulations (Quadris, Satori, OLF) and propiconazole products (Tilt, Fitness, OLF) can help manage all three diseases when applied in combination with a preventative fungicide like chlorothalonil (Bravo, Echo, Initiate, OLF). Labeled OMRI-listed copper formulations can be used by organic growers to manage the diseases. More information on celery anthracnose can be found here.