Cucurbit downy mildew has been confirmed on cucumber near Cedarville in Cumberland County, New Jersey. This is the first report of cucurbit downy mildew this growing season. All cucumber growers who have not included a downy mildew-specific fungicide in their weekly spray program should do so. For more in formation on controlling cucurbit downy mildew please see the 2016 Mid-Atlantic Commercial Vegetable Production Recommendations Guide.
Archives for July 2016
July 11, 2016 Andy Wyenandt
Cucurbit downy mildew confirmed on cucumber in Southern New Jersey – ALERT – 7/11/16
July 11, 2016 Andy Wyenandt
Dickeya dianthicola affecting potato growers throughout Mid-Atlantic region and elsewhere – Updated 7/11/16
In addition to Dickeya dianthicola being found in ‘Superior’, ‘Reba’, ‘Snowden’, and ‘Norwis’ on 3 farms in New Jersey this year, the pathogen has also been detected in fields with seed originating from Maine on 5 farms on Long Island in ‘Reba’, ‘Vivialdi’, ‘Superior’, ‘Norwis’, and ‘Waneta’. Other varieties such as ‘Yukon Gold’ have also tested positive for Dickeya. The pathogen has been detected in MA, DE, PA, MD, VA, NC, WV, and FL this summer on seed from Maine and New Brunswick, Canada (NJ and VA). Maine potatoes are currently shipped to over 20 states across the country (CA, CT, DE, FL, ID, IN, KY, MD, MA, MS, NH, NJ, NY, NC, OH, PA, RI, TN, VT, VA, WA, WV, and WI). Potato growers, crop consultants, and Extension personnel in states which grow Maine potatoes should remain vigilant by scouting their fields for Dickeya symptoms on a regular basis and by submitting any suspect samples for diagnostic testing. Dickeya dianthicola has been detected in the US in the past, and because of this, APHIS just recently announced that the pathogen has been designated as a non-reportable/non-actionable pathogen despite its potential to cause 100% crop loss. A link to the USDA/APHIS website for information on Dickeya dianthicola detection and control can be found here.
For more information on Dickeya please see the following articles posted online – source(s) of information:
Dickeya: A new potato disease – Growing Produce
Blackleg is Once Again Being Observed in Potato Fields Across the Mid-Atlantic Region – Penn State University
Update on Dickeya detections in potato – University of Delaware
Dickeya Blackleg: New potato disease causing major impact. – Cornell University
Watch for Dickeya – a new potato disease – The Ohio State University
High security Aroostook farm advances tater technology. – Maine Potato Board
Slowing Dickeya, other pathogens in Canada. – North Dakota State University
Dickeya: A new threat to potato production in North America. – SPUDsmart
Dickeya is coming. – University of Wisconsin/North Dakota State University
Maine ‘Ground Zero’ for new potato disease. – Maine Department of Ag.
Maine seed potato growers looking to protect brand against disease. Maine Department of Ag./Maine Potato Board
July 11, 2016 Hemant Gohil
Size Peaches with Supplemental Irrigation
NJ peach orchards demand supplemental irrigation when drought weather patterns persist. Peaches gain up to 70% of their final volume during the last 30 days on the tree, so sizing fruit to their full potential requires supplemental irrigation. July and August are critical months for fruit sizing for most varieties. Inadequate irrigation during critical stages of fruit development results in smaller fruits and irreversible size/marketing losses. Irrigating closer to harvest will not increase fruit size. [Read more…]
July 10, 2016 Andy Wyenandt
Vegetable Disease Briefs – 7/11/16
- Basil downy mildew has been confirmed in southern and central New Jersey. All conventional basil growers should be on a preventative spray program prior to the arrival of the disease.
- Cucurbit downy mildew has been confirmed on cucumber as far north as Caroline County, Maryland and Sussex County, DE this past week. Cucurbit growers need to scout on a daily basis. All cucumber growers need to add a downy mildew-specific fungicide to their weekly fungicide programs.
- Reports of Dickeya dianthicola in potato continue across the east coast. Dickeya dianthicola has been confirmed in 10 states to date on potato seed originating from Maine and New Brunswick, Canada this growing season. All potato growers are encouraged to scout fields and report any suspect plants/tubers.
July 8, 2016 Cesar Rodriguez-Saona
Sparganothis Fruitworm Degree-Day Update: as of July 6, 2016
As of July 6, Sparganothis has accumulated 1,175 DD. Based on the DD model, Sparganothis has passed peak flight, and is laying eggs. Reminder that a single insecticide application, i.e., post-bloom application with Delegate, Altacor, Diazinon, or Intrepid, aimed at Sparganothis larvae will likely have the greatest effect if it is timed for peak egg-hatch/larval-emergence, which is approximately 1,400 DD and should coincide with early next week. I will keep you updated on these predictions as the season progresses.
Life history benchmarks for Sparganothis fruitworm and associated degree-day estimates (credit: Elissa Chasen and Shawn Steffan, USDA-ARS and UW Entomology).
July 8, 2016 A.Wyenandt, W.Kline, and J.Ingerson-Mahar
Potato | Tomato Disease Forecast 7-8-16
Click to View | Download Report 7-8-16
Potato Disease Forecasting Report
We will be tracking DSVs for Late blight development and calculating P-days for initiating the first early blight fungicide application.
The first late blight fungicide application is recommended once 18 DSVs accumulate from green row. Green row typically occurs around the first week in May in southern NJ. An early season application of a protectant fungicide such as mancozeb (Dithane, Manzate, Penncozeb) or Bravo (chlorothalonil) as soon the field is accessible is suggested. Please be vigilant and keep a look out for suspect late blight infections on young plants. No late blight has been reported in our region to date.
Remember the threshold for P-days is 300! Once 300 P-days is reached for your location early blight fungicide applications should be initiated. Growers who are interested in using this model should chose the location above that is closest in proximity to their farming operation and should regularly check the Cornell NEWA website (http://newa.cornell.edu/) where this information is compiled from. Click on Pests Forecasts from the menu, select your weather station, and click on tomato diseases, set accumulation start date and a table of daily and total DSVs will be generated.
Tomato Disease Forecasting Report
Disease severity values (DSVs) for early blight, septoria leaf spot, and tomato anthracnose development are determined daily based on leaf wetness (due to rainfall, dew) and air temperature.
On a daily basis DSV values can range from 0 to 4 where 0 = no chance for disease development to 4 = high chance for disease development.
DSVs are accumulated during the production season.Fungicide applications are based on an individually determined DSV threshold. The first fungicide application for the control of these three diseases is not warranted until 35 DSVs have accumulated from your transplanting date. After that, growers can base fungicide applications on different DSV thresholds.
Reports generated by Ryan Tirrell
