| The recommended spray interval for today and later dates are based on FORECAST temperature, relative humidity, and rain. As updated forecast and then observed values change, the recommended intervals and NEXT spray dates can also change. Dates subject to change in forecast values are shown in red font. | |
| Today's date is highlighted by *** and yellow shading. The recommended date for first late blight fungicide application is in green font. Dates in the 'Daily Disease Severity points' column with gray shading were part of a wetting period that lasted beyond midnight into the next day. DSV points for a multi-day wetting period are assigned to the end of the period if there is no rain during the period (if all the wet hours are due to high relative humidity). If there is rain during a multi-day wetting period, DSV are assigned to the first date within the period that had rain. Some gray-shaded multi-day wetting periods are too short or too cool to generate DSV points. The date in the first row is set by the potato emergence date provided for this site. Late blight fungicide protection against late blight should begin when there have been 18 cumulative DSV points after emergence. The first spray date may occur before 18 DSV are counted if there is an extended wetting period right after emergence. | |
| If LATE Blight is active infections are in the area, symptoms can appear when there have been 70 DSV points after emergence. EARLY Blight control should begin at 300 cumulative P-Days. | |
| If total precipitation for past 7 days is < 1.2 inch, then if the 7-day DSV total is: >=6 then the maximum spray interval is 5 days. >=5 and <6, then the max. spray interval is 7 days. >4 and <5, then the max. spray interval is 10 days. <=4 and 7-day rain total is > 0 , the max. spray interval is 12 days. <=4 and 7-day rain total is 0, the max. spray interval is 14 days. |
If the 7-day total precipitation is >= 1.2 inch, then if the 7-day DSV total is: >=5, then the max. spray interval is 5 days. >=4 and <5, max. spray interval is 7 days. >3 and <4, then the max. spray interval is 10 days. <=3, then the max. spray interval is 12 days. |