All/multiple crops:

Ozone damage sustained during the heat of the last few weeks continues to progress on damaged leaves and can look quite alarming. Beans, watermelons, and limited other crops are showing the most damage. If new growth is unaffected, it’s safe to assume damage was this environmental issue.

Dr. Steve Reiners wrote an article about the effects of smoke on vegetable crops. The conclusion of the story is that growers should not be worried about damage to plants but should make sure humans are protected. The full article is here.

Alliums: 

Many fields of transplanted onions in Orange County have high enough onion thrips populations now to be at the action threshold for insecticide applications. See previous updates for more detailed information on thrips management strategies for 2023 or refer to Dr. Brian Nault’s guidance here.

Onion maggots can be found causing some stressed transplanted onions to wilt. In fields of direct seeded onions that were treated with the FarMore FI500 package, the crop should be well-protected from serious maggot injury.

As we move into a period of wetter weather, folks who haven’t already removed insect netting for Allium Leaf Miner should consider doing so. We have anecdotally seen higher levels of bacterial issues in crops that remained covered. Since the flight is done, removal allows better air movement and infiltration of any sprays without any downside.

Brassicas:

Club root is showing up in some fields of cabbage. Take notes of the distribution of the disease in field to try to avoid planting into infested fields in the future. Club root can be easily confused with damage caused by root knot nematode feeding injury to radishes and root brassicas.

 Chenopods (Beets, Chard, Spinach):

The first generation of leaf miner is beginning to subside, potentially giving us a small break.

Cucurbits:

Many cucurbits (cucumbers in particular) transplanted in the field during earlier spring cold weather are stunted and flowering prematurely, reducing yield potential.

Cucumber beetle adults are now being found in large quantities, especially in cucumber fields in the Hudson Valley. Conventional growers using the FarMore seed treatment package or imidacloprid products in drench at planting should be sufficiently protected at this time. Organic growers can consider applications of kaolin clay (Surround WP) to small transplants that are more susceptible to bacterial wilt that is vectored by the beetles.

We are receiving scattered reports of pseudomonas on cucumbers. This is a seedborne bacterial disease that causes symptoms similar to downy mildew, minus the sporulation. If you see plants going down, even without cucumber beetle feeding, please let us know.

Cucurbit Downy Mildew has been found in cucumbers in Atlantic County in southern New Jersey.  With this week’s potential rainy forecast and current weather forecasting, you might want to consider being on a preventative fungicide program, especially with cucumbers and melons.  Chlorothalonil (Bravo, Initiate etc.), mancozeb or Gavel 75 DF which contains mancozeb plus another active ingredient would be good choices, especially for cukes and early green and yellow squash that are NOT being harvested yet – mancozeb has a 5 day Pre-harvest interval, so please be aware of that.  Copper is also useful for both organic and conventional growers.  Unfortunately, the CDM disease forecasting program that we relied upon to inform us of how the disease was going to move throughout the Northeast has been suspended due to a lack of funding.

Nightshades: 

Three-lined potato beetle adults and eggs observed on high tunnel ground cherries and eggplant. Tomatillos are another crop to keep an eye out for as feeding may become severe. Both the larval and adult stage will cause feeding damage.

Colorado Potato Beetle (CPB) adults, eggs, and larvae are all feeding on potato foliage in the Hudson Valley (don’t forget to scout those eggplant too – CPB loves eggplant!). Conventional growers who used an insecticide either in drench or on the seed piece at planting should not need additional foliar insecticide applications at this time. Research in NY has found that Entrust (spinosad) is the only OMRI-listed insecticide to significantly reduce large CPB larvae populations, but the pre-mix product Azera has also been found to reduce the severity of defoliation. More information can be found in Dr. Brian Nault’s presentation slides here.  If you did not use any insecticides at planting, applications should be targeted to larvae and not adults.  Flag a couple of egg masses and look at them every day until the hatch – once they have all hatched, that’s when insecticides should be applied.

Potato leaf hoppers (PLH) are also now active in the Hudson Valley on potatoes. Organic growers can use Pyganic to reduce the populations, but applications are more effective when the spray tank solution pH is reduced to around 6.  Applying later in the day so that the material stays active a bit longer might also improve control as sunlight breaks down Pyganic quickly.

Corn:

European corn borers (ECB) continue to be found in small numbers in traps in the northern region, but little damage is seen in the field.  Trap catches for the most part in eastern NY have yet to catch much apart from the Ulster County site.  Since a majority of early planted corn under rowcovers and plastic is at or near tassel, now would be the time to scout and look for the distinctive “window pane” feeding of ECB. From NYS IPM program: “Moths will be attracted to, and deposit the most egg masses in, the most advanced corn, especially fields started under plastic or row cover. Corn in late whorl to tassel emergence stage when egg masses are being laid does not show the typical larval feeding in the emerging tassel that we see in bare ground corn that is in the whorl stage during the flight. For this reason, tassel emergence scouting and thresholds have not been successful in plastic and row cover corn.  Target newly hatching larvae using the moth trap catches or scout for egg masses to determine when sprays are needed.  Growers have had good results when pheromone trap catches were used to time sprays for the first generation ECB in row cover or plastic corn. Growers waited until there was a significant increase in the ECB trap catches in their area and timed sprays to coincide with egg hatch.  ECB eggs require 100 degree days (base 50) from oviposition to hatch.  Two to three applications bracketing the peak moth flight are generally effective.”  Insecticides like lambda-cyhalothrin (Warrior II and many other generics) or zeta-cypermethrin (Mustang and other generics) still seem to do a good job with controlling them but as stated above may require several applications.  For early corn, a material like Coragen (chlorantraniliprole) or a pre-mix like Besiege (chlorantraniliprole plus lambda-cyhalothrin) may give better residual and require fewer applications.  Now would be a good time to check the pH of your water as many insecticides work better when the pH is below 6.0 – most labels will indicate this type of information.  Organic growers with transplanted sweet corn should also consider using a material that has residual like Entrust (Spinosad).

For more information go to  NY Sweet Corn Trap Network

Sweet potatoes

Most sweet potatoes are now planted and as usual are looking pretty rough (which is normal!), especially those that were planted during the first week in June with the high temperatures that we had.  Do not worry so much about what the foliage looks like as most of that is going to die off anyway – pay attention to the roots!  Sweet potato plants will usually root within a couple days of planting so gently pull a few out to check to see what they are doing.  If using plastic mulches, check the soil moisture in the beds and make sure it is adequate, especially if they were prepared when it was hot and dry out.  Once foliage takes off, we will need to prepare for deer feeding and Japanese Beetles.

Upcoming Event:

Free ! Agritourism Pricing Workshop:

How to figure out what your customers will bear

Tuesday, June 20, 2023 12pm to 1pm Via Zoom

Pre-registration Required:

https://cornell.zoom.us/meeting/register/tJIsce6tqDMuGddOrjKOe3k0mXCypafV0oao