Archives for August 2018

August 22, 2018

IPM Update 08/22/18

Sweet Corn

European corn borer (ECB) moth catches remain unchanged.  The second flight is weak, with many traps catching no individuals.  Feeding signs in whorl corn have been exceptionally low.  There will be no map in this edition.  Second generation feeding is often obscured by fall armyworm (FAW) feeding.  Once plants hit full tassel, any ECB larvae present will move downward on the stalk and re-enter the plant near the area where ears are forming.  This can result in direct injury to the ear.  Growers should consider an insecticide application at the full tassel stage to target ECB larvae as they migrate downward.  This application can eliminate larvae that have escaped any earlier insecticide applications. [Read more…]

Filed Under: Organic Production, Vegetable Crops
August 20, 2018

Potato | Tomato Disease Forecast 8-21-18

Click to View | Download Report 8-21-18

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 as the field is accessible is suggested. Please be vigilant and keep a lookout 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 choose 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

Rutgers, The State University of New Jersey

Filed Under: Disease Forecasting Tagged With: ,
August 18, 2018

Monitoring for SLF Egg Masses

Spotted lanternfly egg mass

Spotted lanternfly egg mass – photo by A.L. Nielsen

Spotted lanternfly is a new invasive species in NJ. Egg masses are brownish grey and generally laid on bark in early fall and appear like a smudge of mud. Adults are expected to start egg laying in August and continue through November or the first hard frost.

SLF eggs overwinter and can be laid on multiple hard surfaces, including fence posts, trees, patio furniture, fruit bins, landscaping stones, railway cars, etc. Due to this they can be easily transported and represent a significant risk to SLF populations spreading. Vehicles, stones, agricultural equipment, and fruit bins coming from PA or VA should be inspected for egg masses beginning in August. Within state movement is also of concern to prevent new populations. If found, egg masses can be scraped into a plastic bag and frozen to limit spread and future impact of this pest.

Filed Under: Commercial Ag Updates, Fruit, Landscape, Nursery, & Turf, Plant Diagnostic Lab, Uncategorized, Vegetable Crops Tagged With: , , ,
August 15, 2018

Potato | Tomato Disease Forecast 8-16-18

Click to View | Download Report 8-16-18

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 as the field is accessible is suggested. Please be vigilant and keep a lookout 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 choose 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

Rutgers, The State University of New Jersey

Filed Under: Disease Forecasting Tagged With: ,
August 15, 2018

IPM Update 08/15/18

Sweet Corn

European corn borer (ECB) moth catches in black light traps remain very low.  The second flight is weak, with many traps catching no individuals.  Feeding signs in whorl corn have been exceptionally low.  There will be no map in this edition.  Second generation feeding is often obscured by fall armyworm (FAW) feeding.  Once plants hit full tassel, any ECB larvae present will move downward on the stalk and re-enter the plant near the area where ears are forming.  This can result in direct injury to the ear.  Growers should consider an insecticide application at the full tassel stage to target ECB larvae as they migrate downward.  This application can eliminate larvae that have escaped any earlier insecticide applications. [Read more…]

Filed Under: Organic Production, Vegetable Crops
August 13, 2018

Vegetable Disease Update – 8/13/18

  • Cucurbit downy mildew has been confirmed on cucumber, butternut squash, and pumpkin in NJ this growing season. Recent weather has been ideal for its development. All cucurbit growers should scout their fields on a regular basis and consider adding a downy mildew specific fungicide to their weekly maintenance sprays.
  • CDM has been reported in giant pumpkin and cantaloupe in MD this past week, and in acorn, summer squash, watermelon and butternut squash as far north as North Carolina to date.
  • Cucurbit powdery mildew is being reported.
  • The 2018 FRAC Table for Cucurbit Downy and Powdery Mildew Control in the mid-Atlantic Region can be found and downloaded for FREE here and is essential for developing control strategies for both diseases.
  • There have been no new reports of late blight in the region.
  • Basil downy mildew is being reported. Recent weather has been ideal for its development. For more information on Rutgers newly-released DMR sweet basils Obsession, Devotion, and Thunderstruck please click here. Follow the Rutgers Basil Downy Mildew Breeding Program on Instagram at #RutgersBasil
  • Bacterial leaf spot and Phytophthora blight have been reported in pepper and cucurbit crops.
  • Remember, copper applications on hot days with high relative humidity can cause phytotoxicity on a number of crops.
  • Cercospora leaf spot has been reported on swiss chard and beets.
Filed Under: Vegetable Crops