Archives for June 2017

Potato | Tomato Disease Forecast 6-6-17

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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

Sparganothis Fruitworm Degree-Day Update: as of June 3, 2017

Based on our degree-day model for Sparganothis fruitworm, flight initiation is expected at around 596 DD (see chart). As of June 3, Sparganothis has accumulated 648 DD (using March 1 as biofix) or 608 DD (using April 1 as biofix). This indicates that flight activity has just started. Growers are advised to place pheromone traps for monitoring this pest at this moment, if they haven’t done so already.

Sparganothis fruitworm adult

Degree-day model benchmarks for Sparganothis fruitworm

Fruit IPM Update for June 1, 2017

Peach:

Tufted Apple Budmoth (TABM): The first of 2 flights of tufted apple budmoth have started. Adults started to emerge in northern counties on 5/16 and in southern counties on 5/1. Although this has been a minor pest, 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 1st-past; 2nd-6/3-6/5 5/31-6/3 5/30-6/5 6/3-6/5
Northern 1st-6/9-6/11 6/12-6/15 6/11-6/26 6/15-6/25

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