Potato blight, how to treat Phytophthora infestans.

Liparis · Posted: Wed Jul 08, 2009 2:47 pm Post subject:

Phew!

Her Outdoors · Posted: Wed Jul 08, 2009 7:42 pm Post subject:

MaureenDillon · Rank attained: Hazel Tree Joined: 25 Jun 2009 Posts: 1

Hi,

I planted some Sarpo Axona beside some Robinta and Sante main crop potatoes.

I noticed a few leaves displayed blight symptoms last night, (mainly on the Sante crop) so in my panic, I sprayed with Dithane, (of course, Murphy's Law, it rained shortly after!)

I checked this morning and it's looking slight worse. Even the Sarpo Axona have been affected!!

Two queries:
1. How can the Sarpo Axona have blight when they are supposed to be blight resistant? I did read somewhere that if you pick the leaves off it, the leaves grow back quick enough.
2. As for the other two varieties, I read somewhere that you can pick all the affected leaves off and still spray the Dithane to prevent the blight spreading - is this true?

Thanks,
Maureen.

Liparis · Posted: Tue Jul 28, 2009 10:18 am Post subject:

The key word is resistant, they aren't blight-proof. Will be interesting to see if others who grow saporo and haven't sprayed get it.
Bill.

slugsaway · Rank attained: Hazel Tree Joined: 20 Apr 2010 Posts: 16

Ok so we're back to the blight problem and I'm not prepared! Just was out on my walk and collected some Horsetail to make the brew this evening, hopefully it won't rain till tomorrow. Going to use the boiling method, but don't have ant rainwater collected, can I use bottled water, I presume I can't use tap water because it has chlorine added... Also do I use this like the burgandy mixture, spraying the leaves top and underside? And final question, how soon does this need to be done before rain to be effective?