If you answered yes to these questions then look at a possible control measure below.
To limit the stunted & uneven shoot growth;
Application of wettable sulphur @ 500g/100lt (include non ionic wetter at label rate if not adding oil).
Water rates of 600 – 900 lt of water per hectare - do not use less than 500 lt/ha
Increased water rate should be used if worried about coverage.
Make sure coverage of the cordon and all spur wood is thorough.
Inclusion of Canola oil or Mineral oil at 2% (2lt per 100 lt) may improve control (10-15%) but should only be applied if the variety being sprayed is fully dormant (eg. Cabernet). Need to be aware that some Canola oils may contain GMO’s.
A period of 2-3 fine days and 15 degrees C or higher on the day of spraying is ideal.
Chardonnay is the indicator variety for timing of spraying in each region. Spraying should be done on all varieties when Chardonnay reaches 10% green tip (i.e. most buds woolly bud).
Look for services like McLaren Vale & Langhorne Creek CropWatch to advise of this timing.
Based on previous seasons we have some rough dates for your planning.
McLaren Vale Wine Region - Valley Floor
Our feelings are that spraying should occur from the last week of August to the end of the second week of September on all varieties/blocks that require rust mite treatment.
Currency Creek Wine Region
Spraying should occur from the last week of August to the end of the second week of September on all varieties/blocks that require rust mite treatment.
McLaren Vale Wine Region - Blewitt Springs & Clarendon
Spraying should occur from the first week of September to the end of the third week of September on all varieties/blocks that require rust mite treatment.
Adelaide Hills Wine Region
Mid-September through to the end of September. To get ideal timing find a block of Chardonnay in within your mesoclimate for exact timing.