|Rust mite bronzing on leaves in a biodynamic vineyard in February 2013.|
Agrochemical use is often seen as a cause of rust mites. For the record Rust Mite can be found in vines grown under minimal input regimes too (above & below).
|A Shiraz leaf in March 2014.|
Note that in McLaren Vale this year, vines grown by different techniques including biodynamic, organic and conventional management show signs of bronzing. In biodynamic or organic vineyards (which don’t use Mancozeb or insecticides) this is likely due to high rates of wettable sulphur which we use for powdery mildew control.