Since 2011 the vegetable working group has teamed up with Cornell University’s NEWA to bring tomato and potato late blight and early blight forecasting to vegetable growers throughout New Jersey. Over 30 weather stations from Sussex to Cape May County now offer disease as well as insect forecasting services for 19 specific pests. The website managed by the New York state Integrated Pest Management (IPM) program can be found at http://newa.cornell.edu/. Just click on the map and scroll down to New Jersey and chose a weather station within the closest proximity to your operation. Once you choose a location a new webpage will appear with the different forecasting options to choose from. Clicking on the potato early blight will automatically generate daily and accumulative P-day values for you for that location. Remember once 300 P-days are accumulated, spray programs for early blight control should be initiated. Clicking on either tomato or potato Late blight will bring up a table which will provide daily rainfall, average temperature, hours above 90% RH and daily and accumulative DSV values for that location. One important thing to remember for the disease forecasting is to track the accumulation of DSV or P-day values based on when you transplanted tomatoes or when potatoes emerged on your farm.
To track the progress of Late blight in the US please visit http://usablight.org/