Vegetable Crops Edition

Seasonal updates and alerts on insects, diseases, and weeds impacting vegetable crops. New Jersey Commercial Vegetable Production Recommendations updates between annual publication issues are included.
 
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January 18, 2017

Corn Earworm Developing Resistance to Bt Toxins in Sweet Corn

Corn earworm caterpillar feeding on sweet corn tassel

New research from the University of Maryland indicates that corn earworm, also known as tomato fruitworm, has developed resistance to the Cry1 Bt toxins present in some sweet corn hybrids.  Based upon Galen Dively’s twenty-one years of research comparing non-Bt sweet corn varieties with Bt varieties in plot studies, the proportion of damaged ears in Bt varieties has dramatically increased over that time.

Syngenta sweet corn hybrids with Attribute® technology expressing Cry1 Ab toxins in 1996 showed less than 10% ear damage.  Those hybrids with Attribute® in 2016 averaged 84% ear damage.  Similarly, the amount of damaged area per ear had tripled.

Seminis produced sweet corn hybrids with Performance SeriesTM containing Cry1 A.105 and Cry2 ab for worm control.  When some of these hybrids were first evaluated in 2010 they provided 100% control of fall armyworm and 95% control of corn earworm.  In 2016, six plantings at research farm sites of these hybrids averaged 67% damaged ears.

[Read more…]

Filed Under: Vegetable Crops Tagged With: ,
November 9, 2016

Sources of Dickeya dianthicola in potato in 2016

Using PCR test results and North American Certified Seed Potato Health Certificates to track Lot no., Dickeya dianthicola has been reported in 16 states (DE, FL, MD, MA, NJ, NY, NC, PA, RI, VA, WV, OH, IN, MO, MI, and TX) on at least nine potato varieties to date in 2016. These varieties include: ‘Reba’, ‘Superior’, ‘Vivaldi’, ‘Norwis’, ‘Snowden’, ‘Yukon Gold’, ‘Beacon Chipper’, ‘Kennebec’, and ‘Atlantic’.  Known sources of infested seed found in potato fields on the East Coast have originated from at least two suppliers in Canada and a number of seed suppliers in Maine this past growing season. To better understand the scope and breadth of the pathogen affecting potato production on the East Coast, information on known varieties and lot numbers that tested positive for Dickeya this past summer have been collected. This information is now available. It’s important for potato growers using this information to know that this list is a working document and not all Dickeya dianthicola test results are known or have been made public or available by the Maine Potato Board or the Maine Department of Agriculture (or Canada). Dickeya testing is being done in Maine by the Maine Potato Board/Maine Department of Agriculture and independently by the University of Maine and other Universities and laboratories. Potato growers with any questions or concerns about Dickeya-infested varieties and seed lots in 2016 and sources of seed for 2017 should contact the Maine Department of Agriculture; or Potatoes New Brunswick, if purchasing seed from these regions.

Dickeya dianthicola has been detected in the US in the past, and because of this, APHIS  has designated the pathogen as a non-reportable/non-actionable pathogen despite its potential to cause 100% crop loss. A link to best management practices for managing Dickeya dianthicola in the Northeast (and mid-Atlantic region) can be found here. Importantly, there is no current policy in place designed specifically for regulating and/or controlling Dickeya dianthicola in seed potato coming into the US from Canada. The Maine Potato Board’s Executive Seed Council adopted their own Blackleg-tolerance policy last winter which is followed by the Maine Department of Agriculture. For more information on this policy please contact the Maine Potato Board or the Maine Department of Agriculture.

The best method for keeping your potato operation Dickeya-free is to adopt your own 0% Dickeya-tolerance policy.

 

Filed Under: Vegetable Crops Tagged With:
October 17, 2016

Credits! Get Your Credits!

Looking at the October calendar, many NJ licensed pesticide applicators finally realize that their 5-year license is almost at an end, and there’s hardly enough time or programs available to make their credit recertification requirements. Panic starts to set in and hurried calls are made across the state to find any source of recertification credits, whether CORE or in a specific category.

But wait – there’s the internet! Back in 2002, Rutgers Cooperative Extension launched an interactive web site, www.recert.rutgers.edu, to provide training and online licensure recertification opportunities in the CORE area of pesticide safety and storage.  Two CORE credits have been made available from two separate online modules for commercial applicators in NJ, NY, PA, and MD.  The web site features written and narrated script along with digital imagery designed for the general public (non-credit) and licensed professional audiences.  Pre- and Post- questions are also imbedded online to assess user knowledge prior to using the site, knowledge gained following completion, and the overall learning value of the site beyond the licensure credit.

Since 2002, nearly 500 individual licensed applicators have attained nearly 700 CORE credits through this web site for their state recertification needs. In addition, nearly 4,800 general use (non-credit) public views of the web site occur annually.

The NJDEP also hosts a list of approved online providers of CORE and category credits for NJ licensed applicators at www.nj.gov/dep/enforcement/pcp/bpo-recert.htm.   NJ licensed applicators should have received their annual statement in the mail recently, so you know where you stand and how many (more) credits you need for recertification, whether it expires this October 31 or in the near future.

So get on your computer and spend some quality time online adding to your knowledge of pesticide safety and category expertise (from turf to mosquitoes to trees, etc.), follow each site’s instructions, and avoid missing your recertification deadline. You’ll be glad you did, and so will the NJDEP!

Filed Under: Commercial Ag Updates, Fruit, Landscape, Nursery, & Turf, Vegetable Crops Tagged With: ,
October 14, 2016

Best management practices for Dickeya in potato production fields in the Northeast

Potato seed tubers harboring Dickeya dianthicola are the only confirmed source of this pathogen. It does not appear to be able to survive in soil (including in crop debris) from one growing season to the next. Consequently, rotating with a non-susceptible crop is not a necessary component of the management program. Best management practices listed below are encouraged to minimize potential losses from Dickeya.

  1. Select certified seed with negligible potential to be contaminated with Dickeya. This is best determined by talking with the seed grower about past occurrence on the farm and what is being done to manage it. There are growers who have not had Dickeya develop from their seed.
    • Select seed from farms where the pathogen has not been detected and seed marketed in previous years was not associated with Dickeya developing where the seed was planted. Check Certificates before purchase to determine if the seed was increased in previous years on a farm where Dickeya has been detected and so is at risk for being contaminated.
    • Select seed from farms where zero tolerance is being implemented.
    • Select seed with zero blackleg levels reported on the North American Seed Potato Health Certificates or the Winter Grow Out Test results for presence of Dickeya in ANY seed lot from ANY source. Seed lots with field readings of blackleg present should have reports that suspect plant samples were taken for testing and found to be Dickeya free. Check Certificates before purchase and require a copy be provided for your records.
    • Select seed that tested negative for Dickeya. Note that not detecting a pathogen in a sample of seed does not mean the pathogen is not present in the seed lot.
    • Ask for ‘references’ to contact: potato growers who purchased their seed in 2016.
    • Avoid seed lots that tested positive for Dickeya in previous years.
    • Avoid seed if its Certificate is unavailable. All certified seed has a Certificate.
    • Avoid seed from fields where symptoms of Dickeya were observed, even if affected plants were rogued out.
  2. Request from supplier (directly from grower or broker) PCR testing for Dickeya dianthicola using an independent laboratory.
  3. It is recommended that each truckload brought to a farm operation be sampled and re-tested for Dickeya once delivered. All results should be reported to your State Dept. of Agriculture or Potato Growers Association.
  4. All equipment during seed piece cutting should be disinfected on a regular basis (at least daily), and also between lot numbers.
  5. While it is recommended to rotate where potatoes are grown to manage most pathogens that can survive in unharvested tubers, this practice is not considered important for Dickeya because this pathogen does not readily spread in fields (thus a few tubers with Dickeya will not result in significant disease outbreak as can occur with late blight) and infected tubers are likely to rot while in soil.
  6. Inspect fields for symptoms regularly, starting when skips and affected plants are readily visible. Examine the crop for unevenness (erratic growth) and plants that are unthrifty. Dickeya can be present in a plant affecting growth but not causing its typical blackleg symptom.
  7. Avoid excess irrigation that results in standing water as Dickeya can move in this water. Note that surface irrigation water is not considered to be a possible source of Dickeya.
  8. Do not apply copper or other fungicide for Dickeya. They are ineffective being unable to reach the pathogen, which is inside stems.
  9. Growers are encouraged to submit suspect samples for testing promptly to their local extension office.
  10. All growers are requested to share information about Dickeya occurrence and absence in their production fields. This information is needed to improve understanding about this disease. Include variety, lot number (North American Seed Certificate), field location, and testing results.
  11. Dickeya has not been observed to continue developing in storage, which is as expected considering high temperatures are favorable, thus there are no management steps to implement after harvest for table-stock potatoes. However, it is prudent to make sure storages and pile temperatures remain cool, also reduce condensation and encourage airflow and exchange.

Prepared by Meg McGrath and Andy Wyenandt with assistance from Steve Johnson, Kate Everts, Beth Gugino, and Nate Kleczewski.

Filed Under: Vegetable Crops Tagged With: ,
October 10, 2016

Plastic Pesticide Container Recycling Dates

The NJ Dept. of Ag, Rutgers NJAES, Allied Recycling, and the Cumberland County Solid Waste Complex are offering October dates for free plastic pesticide container recycling disposal. These are offered to agricultural, professional, and commercial applicators holding a NJDEP Pesticide Applicators License. State, county and municipal government agencies may also participate.

Dates and locations are listed below. Questions? Contact:
Roberta C. Lang, New Jersey Department of Agriculture
Div. of Ag and Natural Resources, Phone: 609.292.2242
[Read more…]

Filed Under: Commercial Ag Updates, Cranberry, Fruit, Landscape, Nursery, & Turf, Tree Fruit, Vegetable Crops, Wine Grape
October 6, 2016

Vegetable Disease Briefs – 10/6/16

  • There have been no new reports of Late blight this this past week. All abandoned tomato fields should be mowed down or burned down with herbicide once harvesting is done.
  • Pepper anthracnose remains active. Weekly  maintenance sprays should continue as long as harvesting continues in fields where anthracnose is active.
  • Following the heavy rains and with more rain expected over the weekend, bacterial leaf spot in pepper and marginal necrosis and leaf spot in leafy greens are being reported. Fungal leaf spots are also being reported. Preventative fungicide programs will help reduce fungal and bacterial problems in leafy greens.
  • Cucurbit downy mildew has been confirmed on cucumber in New Jersey. Downy mildew is beginning to be reported on many other cucurbits in other parts of the country. All cucumber growers should continue with a downy mildew-specific fungicide to their weekly fungicide programs. All cucurbit growers need to scout on a regular basis and should mow or burn off fields when harvesting in done.
Filed Under: Vegetable Crops Tagged With: ,