Archives for July 2018

July 24, 2018

Potato | Tomato Disease Forecast 7-24-18

Click to View | Download Report 7-24-18

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: ,
July 23, 2018

Summer Patch on Hard Fescue

Hot weather in early July brought on some severe summer patch (root disease) symptoms in hard fescue. This disease on fine fescues hasn’t been as thoroughly studied as it has been on other grasses.  So recommendations are based on knowledge learned in Kentucky bluegrass (Poa pratensis) and annual bluegrass (Poa annua) turfs. We are establishing plots […]

Filed Under: Landscape, Nursery, & Turf, Turf
July 23, 2018

Vegetable Disease Update – 7/23/18

  • Cucurbit downy mildew has been confirmed on cucumber in Warren County in northern NJ. This is the second report in the state this growing season. All cucumber growers should scout their fields on a regular basis and consider adding a downy mildew specific fungicide to their weekly maintenance sprays. CDM has been reported in cantaloupe in MD this past week, and in acorn, summer squash, watermelon and butternut squash as far north as North Carolina to date.
  • The 2018 FRAC Table for Cucurbit Downy and Powdery Mildew Control in the mid-Atlantic Region can be found and downloaded for FREE here.
  • There have been no new reports of late blight in the region.
  • Cucurbit powdery mildew is being reported.
  • Basil downy mildew is being reported. For more information on Rutgers newly-released DMR sweet basils Obsession, Devotion, and Thunderstruck please click here.
  • Bacterial leaf spot and Phytophthora blight have been reported in pepper.
Filed Under: Vegetable Crops
July 19, 2018

Potato | Tomato Disease Forecast 7-20-18

Click to View | Download Report 7-20-18

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: ,
July 18, 2018

Spotted Lanternfly in NJ

NEW PEST ALERT

Spotted lanternfly in grape

Spotted lanternfly in grape – photo credit E. Smyers

Spotted lanternfly (Lycorma deliculata, SLF) has been found in NJ. SLF is an invasive plant hopper species that could be very devastating to some NJ crops. Since its discovery in Pennsylvania in 2014, SLF has been placed under a state quarantine encompassing 13 Pennsylvania counties. Populations are also present in Virginia.

SLF adults and nymphs are phloem feeders that feed in large aggregations on woody tissue. Over 65 host plants were reported in Asia, many of which grow in the mid-Atlantic area. These host plants include hardwood trees such as Tree of Heaven, black walnut, and red maple and agricultural crops such as grape, apple, and hops. Feeding occurs on the trunk and limbs of plants, not on the fruit or leaf tissues. However, because they feed in aggregations and produce large amounts of honey dew (or sugar water), sooty mold can grow on plant surface and fruit, leading to reduced photosynthesis and plant vigor. In Pennsylvania, adults and nymphs have been observed feeding in commercial vineyards on cultivated grape. Economic estimates of injury are not available but growers report direct yield losses due to sooty mold and reductions in plant health and canopy coverage. Insecticides are effective but due to the high mobility of this pest, in highly infested areas, vines should be monitored closely for new bugs. Populations and injury are higher along vineyard edges, especially near Tree of Heaven. Interestingly, SLF tends to aggregate on a few trees or vines. Survey for SLF along the perimeters of fields and on Tree of Heaven, Black Walnut, Red Maple, and wild grapevines at the edges of wood lines. Aggregations of adults were found on commercial apple trees in PA near apples harvest in 2017, so apple growers need to be diligent as well.

The adults are large (~1” long) and quite colorful with a black head, grayish black spotted forewings and reddish black spotted hind wings. Adults may start to appear mid-late July (now) and will feed through the first hard freeze in the fall. Young nymphs hatch from eggs in late Spring/early summer and are black with white spots and as they get older they become red and black with white spots. While 4th instars have been reported in NJ, adults are present in VA, so be on the lookout for all life stages.

Spotted lanternfly on tree

Spotted lanternfly on Tree of Heaven – photo by A.L. Nielsen

If you think you seen or collected a spotted lanternfly please report it the New Jersey Department of Agriculture and the Department of Entomology at the Rutgers University School of Environmental and Biological Sciences by emailing slanternfly@njaes.rutgers.edu

Filed Under: Blueberry, Fruit, Landscape, Nursery, & Turf, Plant Diagnostic Lab, Tree Fruit, Uncategorized, Vegetable Crops, Wine Grape Tagged With: , , ,
July 18, 2018

IPM Update 7/18/18

Sweet Corn

European corn borer (ECB) moth catches in black light traps are showing signs of increase now.  This is an indication that the second flight is getting under way.  Catches overall are still quite low however, and there will be no map in this edition.  We expect to see increased feeding signs over the next two weeks, although this second generation feeding is sometimes obscured by fall armyworm (FAW) feeding.  Once plants hit full tassel, any ECB larvae present 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: Organic Production, Vegetable Crops