Cornell Vegetable Program Enrollment

Program Areas

  • Food Safety
  • Variety Evaluation
  • Market Development
  • Pest Management
  • Cultural Practices

Enrollment Benefits

  • Telephone / Email Consultations
  • VegEdge Newsletter
  • Direct Mailings
  • Educational Meetings & Conferences
  • In-Field Educational Opportunities
  • On-Farm Research Trials

CVP Enrollment Form (PDF; 118KB)

Enrollee Login

Password:

Log In To Access:

  • Issues of VegEdge Newsletters
  • Helpful Diagnostic Tool:
      What's wrong with my crop?

Not an Enrollee? Enroll Now!

Online Enrollment Form

Determining Late Blight Sensitivity to Ridomil Takes Time

Carol MacNeil, Extension Vegetable Specialist
Cornell Vegetable Program

September 19, 2013

Determining Late Blight Sensitivity to Ridomil Takes Time
Late blight (LB) is present everywhere now, affecting most counties in WNY, Central NY, Southeastern NY, and the St. Lawrence Valley, in addition to all adjacent states and provinces. Destroy any LB hot spots, foliage in fields where LB is out of control, and abandoned plantings ASAP to reduce the population of spores present to infect late plantings! Continue fungicide sprays until all vines are dead and dry. If LB is present on your farm do not stretch your sprays beyond the shortest interval on the fungicide label for LB on your crop.

Aside from one sample each of US-8 in Erie, PA, and WI, a new strain in OH, and one sample of US-24 in ME, all samples submitted have been identified as US-23. Three LB samples were collected 9/2 from two nearby farms in Wayne Co. where two applications of Ridomil did not appear to control LB. A dozen samples collected from the same area 9/9, where LB had continued to increase, were all identified as US-23. While US-8 is resistant to mefenoxam (Ridomil, OLF), and US-24 has variable resistance, US-23, to date, has always been sensitive to mefenoxam. A preliminary test of mefenoxam sensitivity done a few days ago on the 3 original LB samples from the problem fields in Wayne Co. showed US-23 to be sensitive to mefenoxam, but a more definitive test is being done. Pure cultures of those LB samples are needed so the test will take a few weeks.

The % LB diseased foliage in a field significantly affects how well any fungicide works against it. From Bill Fry, Cornell, 9/16/13: "Years ago we did experiments on the effect of timing of Ridomil on the suppression of LB [on a sensitive LB strain]. The treatments included metalaxyl/Ridomil, mancozeb, or no fungicide. We initiated applications at ~0.5% disease or at 2-5% diseased [foliage]. The effects of Ridomil were apparent within a day or two, but the effects of mancozeb were not visible for at least one week. LB increased explosively in the mancozeb and untreated plots for the first week. Subsequently, mancozeb did slightly suppress disease relative to the water control. The effect of Ridomil was dramatically different with an immediate observable effect in [reducing disease development].  Nonetheless, the amount of disease in the Ridomil plots continued to increase gradually for the next four weeks. When we initiated Ridomil applications at 0.5% disease the final level of disease was less, and the rate at which disease increased was less, than when we began at 2-5% diseased foliage. There was inoculum from other plots that probably contributed to increased LB. Thus, once disease is established, it's really difficult to totally stop this pathogen. I suspect that given the wet weather and favorable conditions we've had recently, any fungicide may have been challenged."  

If mefenoxam (Ridomil, OLF) is not working on your farm rotate to a LB fungicide such as Previcur Flex plus protectant, Ranman plus, Revus Top or Forum plus. If you're close to potato vine-kill use a fungicide good against tuber blight such as Gavel, Zoxium plus protectant, Ranman plus, or Forum plus. (Info from T. Zitter, 7/12/13) 

If you think Ridomil is not working, or if you have questions regarding LB, contact Carol MacNeil


more crops
Asparagus

Asparagus

Beets

Beets

Broccoli

Broccoli

Brussels Sprouts

Brussels Sprouts

Cabbage

Cabbage

Carrots

Carrots

Cauliflower

Cauliflower

Cucumbers

Cucumbers

Dry Beans

Dry Beans

Eggplant

Eggplant

Ethnic Vegetables

Ethnic Vegetables

Garlic

Garlic

Horseradish

Horseradish

Kohlrabi

Kohlrabi

Leeks

Leeks

Lettuce / Leafy Greens

Lettuce / Leafy Greens

Melons

Melons

Onions

Onions

Parsnips

Parsnips

Peas

Peas

Peppers

Peppers

Potatoes

Potatoes

Pumpkins / Gourds

Pumpkins / Gourds

Radishes

Radishes

Rhubarb

Rhubarb

Rutabaga

Rutabaga

Snap Beans

Snap Beans

Squash - Summer

Squash - Summer

Squash- Winter

Squash- Winter

Sweet Corn

Sweet Corn

Sweet Potatoes

Sweet Potatoes

Tomatoes

Tomatoes

Turnips

Turnips

more crops

Upcoming Events

No upcoming events at this time.

Announcements

Lorsban is Banned: What Now?

Cabbage maggot (CM) feeds on brassica seedlings by tunneling into the stem of the plant just below the soil line. Their feeding can result in unsightly and unmarketable produce in the case of root brassicas like turnips, and in stunting, reduced stand, and reduced yield in head and stem brassicas like cabbage and broccoli. Lorsban and other formulations containing the active ingredient chlorpyrifos were the first line of defense for control of cabbage maggot in several brassica crops, because 1) at ~$10 per acre, it was affordable, and 2) it was easy to apply and avoided worker exposure as a directed spray at the base of the plant.

Unfortunately, Lorsban and all of its generic products for food and feed uses were banned in New York as of July 31, 2021, and in the United States as of February 28, 2022. In the absence of Lorsban and other chlorpyrifos-containing insecticides, NY brassica growers have 6 products belonging to 4 chemical classes available to manage cabbage maggot. This article, Lorsban is Banned: How to Control Cabbage Maggot in Brassicas Now?, written by Cornell Vegetable Program Specialist Christy Hoepting and Brian Nault of Cornell AgriTech, provides our "2022 Top Picks" to use instead of Lorsban plus results of Cornell research trial results related to application method, rate, and cabbage maggot control.


Propagating Strawberry Plants Through Runners

The production of strawberry plants is challenging due to the rigorous sanitation needs that must be met, especially in field propagation settings, but also in greenhouse settings. To add to that, growers in New York may find it more difficult to obtain their preferred strawberry varieties in the coming years, as fewer nurseries are propagating strawberries. The solution: strawberry plug plants propagated from runners in a controlled environment such as a greenhouse or high tunnel.

Plug production of rarer varieties that do well in New York State will fetch a higher price than dormant bare-root plants due to the higher cost of production and lower availability in the Northeast, especially if plants are available in August. Propagating Strawberry Plants Through Runners, written by Anya Osatuke of CCE Harvest NY and Brad Bergefurd of The Ohio State University, only discusses production and marketing potential of plug plants because successful field production of bare-root strawberries is very difficult to achieve without the use of highly restricted soil fumigants. 



Cornell Commercial Vegetable Guidelines Available

The 2022 Cornell Integrated Crop and Pest Management Guidelines for Commercial Vegetable Production are now available!

Written by Cornell University specialists, this publication is designed to offer producers, seed and chemical dealers, and crop consultants practical information on growing and managing vegetable crops in New York State. Topics include general culture, nutrient management, transplant production, postharvest handling, organic production, and managing common vegetable crop pest concerns. A preview of the Vegetable Guidelines can be seen online.

Cornell Crop and Pest Management Guidelines are available as a print copy ($43.50), online-only access ($43.50), or a package combining print and online access ($61.00). Shipping charges will be added to your order. Cornell Guidelines can be obtained through many local Cornell Cooperative Extension offices (call to confirm availability), or from The Cornell Store at Cornell University or call (844) 688-7620.


NEWSLETTER  |   CURRENT PROJECTS  |   IMPACT IN NY  |   SPONSORSHIP  |   RESOURCES  |   SITE MAP