Rutgers University | New Jersey Agricultural Experiment Station | Pesticide User Responsibility

Andy Wyenandt

This is an archive of Dr. Wyenandt's posts on the Plant and Pest Advisory.

April 21, 2015

Controlling purple spot in Asparagus

Purple spot, caused the soil-borne fungus, Stemphylium vesicarium, can cause problems in cool, wet springs as well. Symptoms, just like its name, include numerous, sunken oval-shaped spots on spears during the harvest season and more importantly on ferns and stalks during the summer months as long as conditions are ideal for its development.

Twelve hours of wetness is needed for infection and the disease is exacerbated by wind-blown sand injury. Heavy purple spot infection during the summer will lead to premature defoliation which will decrease carbohydrate reserves for the next production season. With the season we had last year and the wet spring we’ve had thus far this year season, pressure due to purple spot may be high. Control of purple spot can be difficult because of management issues (i.e., the mowing and chopping up and leaving of old fern material in the field) and because fungicides can’t be applied during the harvest season. Growers who had pre-mature defoliation issues last year may expect problems this spring. Controlling purple spot begins with preventative fungicide applications during summer and fall by reducing infections to ferns and stalks. Weekly scouting and timely fungicide applications once fern stalks are full size should be done. Apply and rotate azoxystrobin at 6.2 to 15.5 fl oz 2.08F/A or chlorothalonil at 2.0 to 4.0 pt/A.

Filed Under: Vegetable Crops
April 21, 2015

Suppressing Soil-borne Pathogens in Organic Transplant Production

Pathogens such as Fusarium, Pythium, Phytophthora, Thielaviopsis and Rhizoctonia that cause pre- and post-emergent damping-off can cause serious problems in organic transplant production.

Remember, Phytophthora and Pythium are more likely to cause damping-off in cool, wet soils. Conversely, Rhizoctonia and Fusarium are more likely to cause damping-off under warmer, drier conditions. In general, Pythium tends to kill seedlings before they emerge whereas Rhizoctonia and Fusarium tend to kill seedlings after emergence. There are exceptions to the rules, but none the less, all damping-off pathogens can cause serious losses if not identified and controlled properly. Remember seeds or transplants that sit in cold, wet soils for prolonged periods of time are more prone to damping-off. Outside weather conditions also play an important role in potential disease development in spring transplant production. Most importantly, daily watering schedules need to be monitored and/or adjusted so as not to overwater during cool, cloudy periods or underwater during bright, warm, sunny days. Always do your watering early enough in the day so leaves are dry going into the overnight. [Read more…]

Filed Under: Organic Production, Vegetable Crops Tagged With: ,
April 21, 2015

Early-season Pythium and Phytophthora Control in Pepper and Tomato Crops

“What should I do to help prevent Pythium and Phytophthora in my pepper and tomato crops early in the season?” is a question most often asked this time of year. In the past, the answer was simple. Apply mefenoxam (Ridomil Gold SL, Ultra Flourish, 4) or metalaxyl (MetaStar, 4). Problem solved, right?

Not exactly, with resistance development in Phytophthora (P. capsici) to both mefenoxam and metalaxyl, the correct answer isn’t as simple anymore. It’s important to remember that both chemistries will work very well as long as resistance hasn’t been detected on your farm. How do you know if you have resistance? The easiest way is to follow efficacy. [Read more…]

Filed Under: Vegetable Crops Tagged With: , ,
April 10, 2015 and

Commercial Vegetable Twilight Meeting April 23, 2015

The Rutgers Cooperative Extension Agricultural Agents of Atlantic, Cumberland and Gloucester Counties invite you to the first commercial vegetable twilight meeting of the 2015 season to discuss early spring crop pest control, label updates and management topics. Feel free to bring plant, insect, disease, or weed samples to the meeting to have them identified, or perhaps you can stump the experts. Please bring samples in sealed plastic bags.
Pesticide Recertification Credits have been requested for this meeting.

Date: Thursday, April 23, 2015 7:00 p.m. – 9:00 p.m.
Location: East Vineland Fire Hall, Landis Ave. across from the Savoy Restaurant
(park behind the building and enter conference room door in rear)

Agenda

  • 7:00pm Weed Control – Review of the Basics
    –Rick VanVranken, RCE Atlantic
  • 7:30pm Economic Benefits of Maintaining Native Pollinator Habitat
    –Elizabeth Schuster, Environmental Economist, The Nature Conservancy
  • 7:50pm NRCS Programs Supporting IPM/Organic Transition/Pollinator Habitat
    –Nicholas Saumweber, District Conservationist, NRCS
  • 8:10pm Early Season Insect Pests and Insecticide Updates
    –Joe Mahar, Vegetable IPM Coordinator
  • 8:30pm Vegetable Disease Control Options for Spring Crops
    –Dr. Andy Wyenandt, RAREC
  • 9:00pm Pesticide Regs & Worker Protection Standards Update for the Coming Season
    –Michelle Infante-Casella, RCE Gloucester
  • 9:30pm Questions & Answers
Filed Under: Commercial Ag Updates, Organic Production, Vegetable Crops
January 23, 2015 and

Confidence at your Fingertips:
Vegetable Production Recommendations

The new 2015 Commercial Vegetable Production Recommendations guide is now available.

Every year horticulturists, plant pathologists, entomologists and weed specialists from Penn State University, Rutgers, University of Delaware, Virginia Tech, University of Maryland and West Virginia University meet to discuss what changes should be made to the guide based on new research results and changes in the vegetable industry.     ~Elsa Sanchez, PSU

At NJAES, we are proud collaborators in the pursuit of evidence-based, environmentally-sound agricultural practices. We sometimes refer to the Recommendations as the $50-million growers guide because of the cumulative effort, scientific wisdom, and practical experience found within its pages; make no mistake, its a stunning return on investment for anyone who grows or eats vegetables in the mid-Atlantic states (Rabin did the math).

The guide is available online @ Rutgers NJAES | Commercial Vegetable Production Recommendations

For a hardcopy of the guide:

Filed Under: Vegetable Crops
January 21, 2015

Greenhouse Disease Management: Seed Treatment

Seed treatment and selected fungicides and bactericides labeled for greenhouse use tables can be found in the 2015 Commercial Vegetable Production Recommendations guide.

Hot Water Seed Treatment Photo: Meg McGrath, Cornell

Hot Water Seed Treatment
Photo: Meg McGrath, Cornell

All seed used in transplant production, as well as any transplants brought into the greenhouse should be certified ‘clean’ or disease-free. Important diseases such as Bacterial leaf spot of tomato and pepper can cause major problems in transplant production if introduced in the greenhouse. Bacterial leaf spot of tomato and pepper can be seed-borne and infested seed can be a major source of inoculum in the greenhouse and cause problems in the field later in the growing season.

As a rule for any crop, any non-certified or untreated seed should be treated, if applicable, with a Clorox treatment, or hot-water seed treatment, or dusted to help minimize bacterial or damping-off diseases.

For more information on seed treatments for specific crops please see Table E-14 on page E45 in Section E of the 2015 New Jersey Commercial Vegetable Production Recommendations Guide.
An updated table for selected fungicides and bactericides labeled for greenhouse use is available in Section E of the 2015 recommendations guide. The table includes a comprehensive list of fungicides and biological agents approved for greenhouse use. Table E-15 can be found on pages E46-48.

Filed Under: Vegetable Crops