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

Archives for August 2013

August 5, 2013

Potato Disease Forecasting Report 8-6-13

Potato Disease Forecasting Report 8-6-13 – Click to Download

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
August 5, 2013

Tomato Disease Forecasting Report 8-6-13

8-6-13 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
August 5, 2013

Touch of Gray

Everybody keeps asking me “any gray leaf spot yet?”  And I answer, “why yes, but not where you think.”  Gray leaf spot was diagnosed last week on samples of Hakonechloa that were submitted from a central New Jersey nursery grower.

Gray leaf spot on Japanese Hakone grass. Photo: Sabrina Tirpak, Rutgers PDL

Gray leaf spot on Japanese Hakone grass. Photo: Sabrina Tirpak, Rutgers PDL

[Read more…]

Filed Under: Landscape, Nursery, & Turf, Plant Diagnostic Lab Tagged With:
August 5, 2013

Befenthrin Labeled for Tree Fruit

We received notice on Friday 8/2, that 3 formulations of bifenthrin are now labeled for use in NJ peaches, nectarines and apples for control of brown marmorated stink bug (BMSB). This is the best product we have for BMSB, and although it is late in the season, growers should find it very useful. There is a 14 day PHI, with 30 days between applications. Do not apply more than .5 lb a.i. per acre per year.

Section 18 Bifenture 10DFBMSB 2013 NJ

Section 18 Bifenture EC BMSB 2013 NJ

2013-07-30 Brigade WSB BSMB Sec 18 NJ Final

Filed Under: Tree Fruit
August 2, 2013

Battling Green and False Kyllinga in New Jersey Turfs

By Jim Murphy

We are seeing and hearing about increasing problems with green and false kyllinga; both are very troublesome invasive weed species that have moved northward into New Jersey. Green kyllinga and false green kyllinga are very similar in appearance, and both are referred to as green kyllinga. Green kyllinga is very difficult to control once large mats form.

These weeds thrive under mowing and are prolific in areas that are poorly drained or frequently wet. If you do not have control over irrigation, encourage property owners to reduce irrigation when you find that the turf is frequently wet during dry weather; excess irrigation makes the problem worse.

Unfortunately for us, there are fewer herbicide options in the cool-season turfgrass market than in warm-season turfgrass market to our south. [Read more…]

Filed Under: Turf
August 2, 2013

Oriental Beetle Treatment Window Closes for NJ Nurseries

In most areas of NJ, the application timing of imidacloprid to nursery containers to achieve best efficacy against Oriental beetle grubs (Anomala orientalis) has now expired. The majority of eggs are laid during late June through early July and by the time August arrives, many of the grubs will have begun to molt into the 2nd instar stage. If imidacloprid is not applied until August, then some root feeding damage may have already occurred & furthermore, the larger instars will be more difficult to control. Generally, the preventative applications should be applied from early June to mid-July to achieve best results.

Next year, some nurseries may want to attempt the new Oriental beetle mating disruption pheromone that is discussed in the second half of this article.

Oriental Beetle & 3 Larvae Instars

Imidacloprid has good efficacy against Oriental beetle 1st instar grubs, but is significantly less effective against the 2nd & especially 3rd instar grubs

[Read more…]

Filed Under: Landscape, Nursery, & Turf