dormant spraying

Asked January 26, 2013, 6:21 PM EST

Can I accomplish anything by spraying copper now in January and Lime Sulphur 3 weeks later. I have Anthracnose on some trees and was not able to spray copper before fall rains as late apple harvest into November. Is copper only for Fall clean up before rains? Makes it difficult here in the NorthWest.

Clark County Washington disease issues dormant spraying horticulture

1 Response

Good question. I do think a copper-based spray now would be a waste of time and money. Apple anthrancose infects in the fall but we typically do not see the symptoms until spring. For now, your time and effort would be better spent with an aggresive canker removal program. You have until next fall to remove and destroy (burn) those cankers. The fungus infects through wounds during harvest so a post harvest application, even after rains start, should be helpful in the long run. This is a difficult disease to manage in the PNW and requires a few years of sustained effort. Good luck.