Using Horsetail to keep Powdery Mildew under control.
A guide to reducing Powdery Mildew.
Powdery mildew has always been my #1 vineyard nemesis.
With the humidity and rain this season and reports of mildew already, I thought this bit of information would be useful for those interested in trying something more natural. This season I dug into the science behind a humble roadside plant, horsetail (Equisetum arvense), and the results blew me away. You can read the article on Horsetail for more valuable information.
🔍 What I found
In Italian split-plot trials, mixing a field-brewed horsetail extract with just half the usual wettable-sulphur rate kept mildew almost undetectable, while full-rate sulphur alone still let 40 %+ infection sneak in .
Silica from horsetail stiffens the leaf surface, sulphur still zaps spores, and the fermented brew seeds the canopy with friendly microbes for a three-layer defence .
💡 The easy on-farm test
Pick two similar vineyard blocks (4 rows each).
Block A: your normal full-rate sulphur.
Block B: horsetail extract + half-rate sulphur, sprayed on the same days.
Each week jot down mildew scores on ten flagged leaves—end-of-season you’ll have hard numbers on disease, berry quality, and spray cost savings .
👩🌾 Why bother?
Slash elemental-sulphur use by ~50 %.
Fewer spray passes, less labour, happier leaves in the heat.
Data you can trust because you collected it.
