Potato Disease Advisory #3 – May 17, 2012

Late blight Advisory
Location: Art and Keith Wicks Farm, Rt 9, Leipsic, Kent County
Greenrow: April 20

Date DSV Total DSV Spray Interval Recommendations
4/20 – 4/30 12 12 None
4/30 – 5/1 8 20 7-days
5/1 – 5-8 15 35 5-days
5/8 – 5/10 4 39 5-days
5/10 – 5/13 0 39 10-days
5/13 – 5/16 5 44 7-days

The threshold of 18 DSVs has been exceeded. Forty-four (44) DSVs have accumulated as of Thursday, May 17. This includes any potatoes that established green row (approximately 50% emergence) prior to and on April 20. An additional five (5) DSVs accumulated during the recent wet, cloudy weather earlier in the week. While the spray interval has been lowered, the short-term forecast is predicting ample sunshine and warm temperatures. This should reduce the risk of late blight development.