Grand Marsh

Weather data shown below is sourced from a NOAA data grid centered on 43.9, -89.7 and available on AgWeather. This data is used to run predictive disease severity models to give growers the information they need to mitigate disease risk in potato production.

DSVs: Late blight risk can be modeled using disease severity values (DSVs). On the chart above, highlight the date of your last spray and note the cumulative DSVs at that point. Then subtract that number from the most recent cumulative DSV value to get the accumulated DSVs since your last spray. When this value exceeds 18, late blight management action is recommended. You can download each chart by clicking on the menu button on the upper right corner. Visit VDIFN and select the Late Blight model for a statewide map of late blight risk.

P-Days: Early blight risk is elevated after 300 P-Days (physiological days) have accumulated since crop emergence. Early blight management actions are recommended beyond that point. On the chart above, note the cumulative p-days on the date of crop emergence and subtract that value from the most recent cumulative p-days to get the cumulative p-days for your crop. Visit VDIFN and select the Early Blight model for a statewide map of P-Days and early blight risk.