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

Archives for June 2017

June 13, 2017

Sparganothis Fruitworm Degree-Day Update: as of June 13, 2017

Based on our degree-day model for Sparganothis fruitworm, first eggs laid are expected at around 681 DD (see chart). As of June 13, Sparganothis has accumulated 814 DD (using March 1 as biofix) or 774 DD (using April 1 as biofix). This indicates that egg laying has just started but eggs are not expected to hatch yet. 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 will most likely coincide with the 1st-2nd week in July. I will keep you updated as the season progresses.

Sparganothis fruitworm degree day benchmarks

Filed Under: Cranberry, Fruit
June 12, 2017

Potato | Tomato Disease Forecast 6-13-17

Click to View | Download Report 6-13-17

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: ,
June 8, 2017

Potato | Tomato Disease Forecast 6-9-17

Click to View | Download Report 6-9-17

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: ,
June 8, 2017

Fruit IPM Update for 6/8/17

Peach:

Tufted Apple Budmoth (TABM): The second TABM flight is well underway. Adults started to emerge in northern counties on 5/16 and in southern counties on 5/1. Although this has been a minor pest, this might be changing. Trap counts in northern counties are historically high, and indicate higher than normal populations. Timings are outlined below for anyone who had high populations last year.

 

Conventional,

Diamides

  

Conventional,

Diamides

 Intrepid, Rimon Bt
County Area AM EM EM EM
Southern 3rd-6/11-12; 4th 6/15-16 6/12-15 6/12-15 6/12-15
Northern 1st-6/10-13; 2nd 6/18-19 6/14-16 6/13-19 6/16-18

[Read more…]

Filed Under: Blueberry, Fruit, Tree Fruit
June 7, 2017

Veg IPM Update: Week Ending 6/07/17

Sweet Corn

European corn borer (ECB) catches have declined somewhat over the past week.  As this has happened, feeding signs in NJ sweet corn plantings have increased.  Overall, activity is lower than expected this year, likely due to adverse weather conditions.  The highest catches remain in southern Hunterdon County (see map at left), with lower activity elsewhere.  At present, infestation rates of 30% have been discovered in the Sergeantsville area of Hunterdon County, with rates of 16 – 22% from Somerset through Camden counties.  Feeding is likely to be occurring throughout the central and southern counties at this time, and will appear within the next few days in the northernmost areas.    Check 5 plants each in 10 random locations for a 50 plant sample.  Look  for “shot-hole” injury (see top photo at right, ), 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 (see bottom photo at right).  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…]

Filed Under: Vegetable Crops Tagged With: ,
June 7, 2017

Vegetable Disease Update – 6/7/17

  • Pythium root rot has been reported in multiple crops across the state. Unfortunately, the prolonged, wet weather across most of New Jersey has been ideal for its development. There are a number of options for early-season control of pre- and post emergent damping-off pathogens. For more information click here.
  • Downy mildew has been reported as far north as Northern Florida on multiple cucurbit crops and on cucumber in South Carolina and North Carolina on 6/6/17.
  • There have been no new reports of Late blight in the Southeast.
Filed Under: Vegetable Crops