I've read that you can prevent Late Blight by spraying 50% milk and 50% water on the tomatoes. Has anyone tried this?
Also spraying with baking powder (natriumcarbonat) seems to work. Anyone tried this?
Did you mean to say using milk or baking soda for Late Blight or milk for Blossom End Rot where some have used it without much success?
I can't see either milk or baking soda as preventing Late BLight ( P. infestans) b/c I can't see how it would work to prevent infection.
Baking soda is used for powdery mildew on roses and Monarda and Zinnias and asters, etc., but it doesn't work against the fungi that cause powdery mildew on tomatoes.
Late BLight is a lethal disease that becomes systemic very quickly and I don't put it in the category of common typical foliage diseases although that's where the symptoms first appear.
But the fungus that causes it, P infestans, is not prevented from infecting by either milk or baking soda, that I know of and I've never heard of anyone using them, nor have I read of them being suggested.
Perhaps others might chime in here to the contrary and that's fine and perhaps you can share where you read about those treatments.
Here in Holland they are testing it as *preventive* use against late blight (with good results). It seems that the milk shifts to butyric acid on which the fungus which causes late blight doesn't grow.
For those we can read Dutch :-):
Er zijn goede berichten ontvangen over het preventief spuiten met verdunde volle melk. In een verhouding van 50% melk en de rest water. Navraag bij deskundigen leverde de volgende verklaring voor de werking: melk wordt (waarschijnlijk) omgezet in boterzuur waar de schimmel niet op wil/kan groeien.
I did a quick Google search and find that not so much milk but butyric acid itself is being tested against P. infestans on both potatoes and tomatoes .
So far I haven't come up with any results, though.
Butyric acid is a both a disinfectant and emulsifier so it will be interesting to see what happens as this unfolds.
Milk only contains about 2% butyric acid I found out, which is why several places have gone directly to using the acid itself.
Most reports European and not US.
Do you still have significant Late Blight problems in the Netherlands?
Here in the US it's mainly in pockets in various parts of the country and the origin is usually from potato cull piles. It's the new A2 strain that entered the US from Russia in about 1990 that's been causing the most problems since the A1 was never that much of a problem here before that.
Yes we still have significant problems with LB. Most growers have a rain shelter for the tomatoes. At this moment I don't. I try to grow strong species. Next year I will also select on earlynes.
Sir ,we have blight on tomatoes now done pulled some up ,breaking limbs off some don't seem like nothing we do helps .I am going to try Baking soda an milk hope this works it is just now first of June .thanks