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; 145KB)

Enrollee Login

Password:

Log In To Access:

  • Issues of VegEdge Newsletters

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

Mushrooms

Mushrooms

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

2025 Finger Lakes Auction Winter Growers Meeting

Event Offers DEC Credits

January 2, 2025
Penn Yan, NY

At this grower-focused meeting, ag industry experts will discuss pest control in vegetables, weed management strategies and best practices, seed germination, an introduction to foliar nutrient uptake in vegetables, and grouping flowers by growth needs. Plus we'll hear from a grower panel from Kutztown Produce Auction, moderated with NYS specific pest control from Judson Reid.

2.25 DEC recertification credits will be offered in categories 10, 1a, 23, and 24.

View 2025 Finger Lakes Auction Winter Growers Meeting Details

2025 Ontario Produce Auction Winter Growers Meeting

Event Offers DEC Credits

January 15, 2025
Stanley, NY

This grower-focused meeting will include information about pesticide applicator recertification and record keeping requirements, disease control in cole crops and vine crops, and using biocontrols for insect management in greenhouses. Several seed and ag input companies will be on-hand to share product news.

2.75 DEC recertification credits will be offered in categories 10, 1a, 23 and 24. CORE credits (0.5) offered too!

View 2025 Ontario Produce Auction Winter Growers Meeting Details

Intro to Food Safety and GAPs Training

February 19, 2025
via Zoom,

This virtual workshop will serve two purposes: 

  • For produce farms just interested in learning about farm food safety, this program will introduce principles and best practices.
  • For produce farms look for a GAPs (Good Agricultural Practices) training needed to meet buyer demands for audit/certification, this program will provide that as well.
View Intro to Food Safety and GAPs Training Details

Announcements

Winter Cover Cropping in High Tunnels

Cornell Cooperative Extension is researching cover crops for high tunnel growers to better manage fertility and improve soil health. Our work has shown that winter cover cropping in high tunnels has the potential to add organic matter, improve soil structure, support microbial activity, and help with nutrient management by scavenging leftover nitrogen and/or fixing nitrogen. This publication, Management Practices for High Organic Matter Soils: Winter Cover Cropping in High Tunnels, shares best practices for winter cover cropping in high tunnels including species selection, planting rates and dates, termination, and cultural management considerations.

Laser Scarecrows to Deter Birds in Sweet Corn

Are you considering the use of a laser scarecrow to deter birds on your farm? Cornell Cooperative Extension and the University of Rhode Island teamed up to test a research laser scarecrow on sweet corn farms.

A laser scarecrow is a device that has one or more laser modules connected to motors. The specifications of the lasers are optimized to the color and motion sensitivity of bird's eyes. When laser beams move across a field, birds become frightened and attempt to move away from the perceived threat. Light from the laser covers an area quickly and moves through the canopy without causing injury to the crop. Research demonstrates that birds do not readily become habituated to the laser.

A laser scarecrow used as the sole deterrent typically results in a significant reduction in crop damage. Combined with an auditory device, damage can be reduced even more. When used as part of an integrated management program for bird control that utilizes habitat management and multiple scare tactics, laser scarecrows can be useful tools for growers of multiple crops. All scare tactics must be deployed before birds find the field. The effectiveness of lasers depends on multiple factors such as bird species, bird populations, habitat and food availability. Lasers are not effective at deterring deer, racoons, coyotes or other mammals.

To learn more, the Laser Scarecrows to Deter Birds in Sweet Corn and Other High-Value Agricultural Crops fact sheet provides background information, research data, FAQs, and Advantages/Limitations on laser scarecrows.

NY Urban Farms Pest Management Fact Sheet Series

Cornell Cooperative Extension has partnered with dozens of urban farms across New York State to demonstrate and evaluate sustainable pest management strategies. Together with farmers, we found success using control methods that prevent or reduce crop losses through exclusion strategies, crop timing, host resistance, the introduction of beneficial organisms, and more. Regardless of management strategy used, common requirements for success include a knowledge of the pest and disease complex, preventative deployment and commitment to the process. The New York Urban Farms Sustainable Pest Management Fact Sheet Series includes case studies highlighting pest management techniques that New York urban farms have found valuable.

NYS Urban Growers Pest Management Needs Assessment

As part of a multi-year project exploring non-spray pest management options that are economically and environmentally sustainable for urban farms, we conducted a needs assessment with urban growers across New York State. The New York State Urban Growers Pest Management Needs Assessment presents findings on current pest management practices, challenges, and topics of future interest.

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