06/24/05 Blight probable in Idaho potato fields

Because of the rain and cool conditions there's a 95 to 99 percent change that Idaho potato growers will see late blight this summer. University of Idaho's Phil Nolte says those values are higher than the late blight years of 1997 and 1998. NOLTE "The other thing that makes it even worse is the fact that we did have potato late blight last year in several of our production areas that which means that there are likely to be over wintering sources of the disease." Nolte said he personally diagnosed tubers with late blight in nine different storage facilities last fall. If thundershowers persist through the coming weeks, growers are advised to begin spraying at row closure and continue on a weekly schedule for 4 weeks. NOLTE "We have never found late blight in Idaho in a field before the plants are touching across the rows." And that's ideal for blight, especially in wet areas of a field. In southwestern Idaho some fields are near row closure but in eastern Idaho the plants are weeks away from closure. NOLTE "Of course if the weather turns hot and dry like it's supposed to in Idaho we could be having a conversation for no reason but all the indicators are the danger is very high." For the record, the earliest reported case of late blight in Idaho was July 5th, 1997 in Canyon County field near Caldwell. Today's Idaho Ag News Bill Scott