Bob Mulrooney, Extension Plant Pathologist; bobmul@udel.edu
Late blight Advisory
Location: Art and Keith Wicks Farm, Rt 9, Little Creek, Kent County
Greenrow: May 3
| Date | Late Blight | Early Blight | Spray Interval Recommendation | |
| DSV | Total DSV | Accumulated P-days* | ||
| 6/13 | 0 | 66 | 301 | 7-days |
| 6/13-6/15 | 0 | 66 | 318 | 7-days |
| 6/16 | 1 | 67 | 328 | 7-days |
| 6/17 | 0 | 67 | 336 | 7-days |
| 6/18-6/19 | 0 | 67 | 352 | 10-days |
| 6/20-6/22 | 1 | 68 | 377 | 10-days |
| 6/23 | 1 | 69 | 383 | 10-days |
| 6/24-6/26 | 0 | 69 | 407 | 10-days |
| 6/27 | 1 | 70 | 416 | 10-days |
| 6/28 | 1 | 71 | 424 | 10-days |
Continue to scout fields for symptoms of late blight. Conditions will continue to favor early blight. We have surpassed the 300 P-day threshold for initiating early blight sprays.
Late Blight was reported this week in DE, on the eastern shore VA, and Long Island, New York. The weather conditions have been favorable the past few days but the hot weather forecasted for this weekend should help reduce the threat. The Delaware find near Leipsic in Kent County was a small area at the end of a field next to woods and under power lines that obstructed the aerial application of fungicide applied to the whole field. Late blight specific fungicide has been applied.
For specific fungicide recommendations, see the 2011 Delaware Commercial Vegetable Production Recommendations Book.