Sweet Corn
European corn borer (ECB) catches continue to be very low, and no map will appear in this edition. There have been a few traps that have begun to record minor increases, however. ECB feeding in NJ sweet corn plantings is also low. Check 5 plants each in 10 random locations for a 50 plant sample. Look for “shot-hole” injury, and consider treating when the number of infested plants in a 50 plant sample exceeds 12%. As infested plants proceed to the pre-tassel stage, live larvae and damage may be found in the emerging tassels. Once plants hit full tassel, ECB larvae 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…]
Archives for July 2017
Veg IPM Update: Week Ending 7/19/17
Vegetable Disease Update – 7/19/17
- Cucurbit downy mildew (CDM) has been confirmed on cucumber in northern and southern New Jersey. All cucumber growers should consider adding downy mildew specific products to their regular maintenance programs. CDM has been reported cantaloupe and Butternut squash in PA.
- Basil downy mildew has been reported in New Jersey.
- There have been no new reports of Late blight on tomato or potato in our region in the past week.
- Dickeya dianthicola has been reported in 6 states and in 9 potato varieties to date including Dark Red Norland, Red Pontiac, Silverton, Yukon Gold, Kennebec, Norwis, Superior, Marcy, and Vivaldi.
- Surveying for Dickeya dianthicola in potato fields and irrigation sources in NJ is currently on-going. If you suspect Dickeya, please contact your county agent. The best method for controlling Dickeya dianthicola in your operation is to adopt a zero-tolerance policy.
Potato | Tomato Disease Forecast 7-18-17
Click to View | Download Report 7-18-17
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.
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
Cucurbit Downy Mildew ALERT – 7/17/17
Cucurbit downy mildew was confirmed on cucumber in northern New Jersey (Hunterdon County) today in the cucurbit downy mildew sentinel plot at the Snyder Research and Extension Farm in Pittstown. This is the fourth report of CDM on cucumber in New Jersey this growing season. No other cucurbit crops were affected. All cucumber growers in NJ are encouraged to add downy mildew specific fungicides to their weekly maintenance spray programs. All growers should scout cucumber plantings as well as all other cucurbit crops for symptoms. CDM has also been reported on cucumber in MD, DE, and PA. To track the progress of cucurbit downy mildew in the US through the CDMpipe website through NCSU please click here.
Potato | Tomato Disease Forecast 7-14-17
Click to View | Download Report 7-14-17
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.
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
Fruit IPM for 7/13/17
Peach:
Oriental Fruit Moth (OFM): The 3rd OFM flight is well underway in all counties. These adults produce 3rd brood of larvae, which primarily infest the fruit.