Archives for May 2013

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 New Jersey. 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.

Filed Under: Disease Forecasting

May 31, 2013 A.Wyenandt, W.Kline, and J.Ingerson-Mahar

Tomato Disease Forecasting Report 5-31-13

5-31-13 Tomato Report – Click to Download

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.

Filed Under: Disease Forecasting

May 30, 2013 Anne Nielsen

BMSB in Peaches

Beginning last night at RAREC (south Jersey) BMSB began moving in ‘larger’ numbers into peach orchards. They immediately were observed mating. This occurred at about 284 DD (base 57°F) at RAREC. Degree-day accumulations were slow this year and last week were delayed by the rain and cooler weather.

In north Jersey the degree-day accumulation should occur today 5/30 or tomorrow 5/31 for the dispersal into fruit orchards. We advise that you monitor the woods edge of orchards for stink bug activity and treat if BMSB is found.

Plum curculio is still active throughout the state but should be approaching the end of oviposition activity in south Jersey. If PC pressure is high, chose a compound that has activity against both PC and BMSB such as Actara (5.5oz), permethrin (16oz.) or Warrior (5.12oz). We are between generations for OFM but Codling Moth timings are upon us (see Dean’s pest report) for north and south.

Filed Under: Tree Fruit

May 29, 2013 Administrator

Dollar Spot Activity Flares Overnight

By Jim Murphy

The high humidity of last night (28-29 May) caused dollar spot disease to escalate. Until last night, symptoms on unprotected susceptible turf were minor.

The cottony fungal growth (mycelia) of dollar spot, which is easily seen at early morning hours during wet humid weather.

Cottony fungal growth (mycelia) of dollar spot, seen at early morning hours during wet humid weather.

This morning dollar spot mycelia was so profuse on this low maintenance turf that it looked like frost.

Susceptible grasses grown under low N fertility will typically havethe greatest damage from dollar spot. Annual bluegrass (Poa annua) is highly susceptible to dollar spot disease. In fact, you will often see annual bluegrass as the grass species with the most dollar spot damage in a mixed stand of grasses. Some varieties of creeping bentgrass have better tolerance to this disease and should be considered when selecting a variety. Colonial bentgrass is generally more tolerant of dollar spot than creeping bentgrass, although differences among colonial bentgrass can also be seen. The variety, Capri, had less disease this morning compared to older colonial bentgrass varieties. Perennial ryegrass is another species that will often be infected by dollar spot before other grasses, especially when is managed with low N fertility. Kentucky bluegrass can also be affected by dollar spot but many varieties have good tolerance to the disease.

Filed Under: Turf

May 29, 2013 Richard Buckley

Now You See Me, Now You Don’t

Four-lined plant bugs are tearing up in the home landscape this week. This true bug feeds on more than 250 mostly herbaceous and small woody ornamental plants. Like Jack Reacher, they are alert, quick, and difficult to detect.