This is a widespread soil-borne disease of strawberries growing in cool, poorly drained soils. Symptoms show up as a burning of the outer margins of the leaves.
Young roots turn black at the tips and die back.
If Verticillium has been a problem in your area, consider a variety which has resistance to the wilt organism. Soil fumigation with a chloropicrin-containing fumigant is recommended when resistant varieties are not available. When using soil fumigants, follow manufacturer's directions and use caution in handling the material.