- Quadris 2F from Syngenta, the first strobilurin (FRAC group 11) fungicide on the market, is coming off patent and a number of companies are expected to apply to manufacture and sell is under another name. Thus, in the 2015 Vegetable Recommendations Guide you will see references to Quadris (FRAC group 11) switched to azoxystrobin (FRAC group 11) much like we did with changing Bravo WeatherStik (M5) to chlorothalonil a few years ago. As more FRAC group 11 fungicides come off patent in the next few years we expect to do the same.
- Cucurbit downy mildew is presently active on acorn, butternut, yellow summer, cucumber, cantaloupe, and giant pumpkin in southern Florida. To track the progress of cucurbit downy mildew in the US please visit (http://cdm.ipmpipe.org/)
- Basil downy mildew is active in southern Florida.
April 22, 2015 Andy Wyenandt
Vegetable Disease Briefs – 4/22/15
April 21, 2015 Andy Wyenandt
Vegetable Disease Update 4‑20‑15
This week in the Vegetable Disease Update:
- Asparagus
- Cabbage
- Cole crops
- Leeks
- Lettuce
Note: The new 2015 NJ Commercial Vegetable Production Recommendations is available online.
Asparagus
Phytophthora crown and spear rot – In fields with low spots (poorly drained soils) or fields with a history of crown and/or spear rot apply Ridomil Gold 4SL (mefenoxam, 4) at 1.0 pt/A, or Ultra Flourish 2E/A (mefenoxam, 4) at 2.0 pt/A, or MetaStar 2E (metalaxyl, 4) at 2.0 qt/A over beds just before 1st harvest. For new plantings, apply the same after planting or after crown covering. Do not apply Ridomil or MetaStar one day prior to harvest or illegal residues may result. For more information please see 2015 New Jersey Commercial Vegetable Production Recommendations Guide.
[Read more…]
April 21, 2015 Andy Wyenandt
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.
April 21, 2015 Andy Wyenandt
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…]
April 21, 2015 Andy Wyenandt
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…]
April 10, 2015 Andy Wyenandt and Rick VanVranken
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
