Cryptomeria samples have been coming into the Plant Diagnostic Laboratory with increasing frequency this spring. Their issues with winter damage, particularly this year, have been chronicled on this blog. We’ve also had a couple of samples diagnosed with Maskell scale in the lab this spring, too. Pretty routine set of samples, just a few more than usual, until last week that is… [Read more…]
Archives for June 2015
June 17, 2015 Dean Polk
Fruit IPM Report 6-16-2015
Peach
Brown Marmorated Stink Bug (BMSB): Adults are occasionally seen during orchard scouting. Knock down materials will be required for the remainder of the season in orchards with BMSB populations.
Oriental Fruit Moth (OFM): Second generation flights are very low in most areas. By all indications this generation should produce much lower pressure than the 1st generation. Any insecticides which are applied now should target this generation. Growers who have trap counts that are less than 6 moths per trap can skip insecticides that are intended for OFM. If trap counts are higher, then time your sprays according to the following table:
[Read more…]
June 17, 2015 Kris Holmstrom and Joe Ingerson-Mahar
Veg IPM Update: Week Ending 6/17/15
Sweet Corn
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Warmer evening temperatures have resulted in a slight resurgence of European corn borer (ECB) adults in the blacklight network. A residual first generation population remains in northern NJ, while the activity in the southwestern part of the state may represent the beginning of a second flight. The nature of the southern NJ activity should become clear over the next 1-2 weeks. Areas of highest activity include parts of Morris and Gloucester counties (see ECB map). ECB infestations continue to rise in sweet corn plantings. Feeding ranges from single digits to over 50% in areas where IPM personnel are operating.
[Read more…]
June 15, 2015 A.Wyenandt, W.Kline, and J.Ingerson-Mahar
Potato | Tomato Disease Forecast 6-16-15
Click to View | Download Report 6-16-15
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 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.
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.
June 14, 2015 Andy Wyenandt
Vegetable Disease Update – 6/14/15
Potato
Black Leg – Black leg is caused by Erwinia spp. which also cause ‘soft rots’. The bacteria which lead to the aerial phase of Blackleg are soil-borne (originate from old crop debris) and spread by rainfall, overhead irrigation and wind. The aerial phase of Blackleg does not originate from decaying seed pieces. The bacterium can enter the plant through wounds created by cultivation or through stems damaged by blowing wind, sand or hail. Dense canopies, warm weather and prolonged periods of leaf wetness favor the spread of aerial Blackleg. Fortunately, the disease rarely extends below ground and only causes dieback of stems over time. Symptoms of the aerial phase of Blackleg first appear as an irregular, water-soaked ‘green’ decay on stems that turns light-brown to black over time. Hot, dry weather will cause infected areas to dry out and become brittle. Do any cultivating when plants are dry, cultivating in the presence of dew or wet plants may help to spread the bacterium around.
June 14, 2015 Andy Wyenandt
Vegetable Diseases of the Week – 6/14/15
This week:
Sweet Basil – Basil downy mildew
Bell Pepper – Bacterial leaf spot
Symptoms of basil downy mildew infection
on Sweet Basil.
Basil downy mildew sporulating on
the underside of infected basil leaf.
Bacterial leaf spot of bell pepper.
