Nathan Kleczewski, Extension Specialist – Plant Pathology; nkleczew@udel.edu and Phillip Sylvester, Kent Co. Ag Agent; phillip@udel.edu
Location: Art and Keith Wicks Farm, Rt 9, Leipsic, Kent County
Greenrow: May 5
| Date |
DSV |
Total DSV |
Accumulated P-Days |
Spray Interval Recommendation |
| 5/15 – 5/20 |
11 |
32 |
|
5-days |
| 5/20 – 5/23 |
2 |
34 |
|
5-days |
| 5/23 – 5/27 |
5 |
39 |
|
5-days |
| 5/27 – 5/30 |
0 |
39 |
|
10-days |
| 5/30 – 6/6 |
2 |
41 |
251 |
10-days |
| 6/6 – 6/7 |
10 |
51 |
261 |
5-days |
| 6/7 – 6/9 |
10 |
61 |
280 |
5-days |
| 6/9 – 6-13 |
4 |
65 |
314 |
7-days |
| 6/16 – 6/20 |
13 |
78 |
377 |
7-days |
| 6/20 – 6/27 |
6 |
84 |
420 |
7-days |
| 6/28 – 7/4 |
24 |
108 |
477 |
5-days |
Late Blight
The threshold of 18 DSVs has been exceeded. One hundred and eight (108) DSVs have accumulated so far for any potatoes that established green row (approximately 50% emergence) prior to and since May 5. Late blight was reported on a commercial potato field near Leipsic, Delaware as of July 2, 2013. Growers should aggressively scout their potato fields and apply preventative sprays at a 5-day spray interval. Any suspicious samples can be sent to the UD Plant Diagnostic Lab or dropped off at your local Extension office. See the 2013 Commercial Vegetable Production Recommendations-Delaware: http://extension.udel.edu/ag/files/2012/03/Potatoes.pdf.The website USABlight tracks tomato and potato late blight across the nation and can be found here: http://usablight.org/
Early Blight
The threshold of 300 P-Days has been exceeded. Four hundred and seventy seven (477) P-days have accumulated. A fungicide for early blight control is recommended. Commercial fungicide recommendations can be found in the 2013 Delaware Commercial Vegetable Recommendations Guide at http://extension.udel.edu/ag/files/2012/03/Potatoes.pdf