Early sulphur worth its weight in gold
By Brandy Rawnsley
With budburst just around the corner, it’s time to get ready for the first spray of the season. Getting a sulphur spray on vines prior to budbreak is critical to prevent mite damage and reduce the risk of powdery mildew.
Rust mites over-winter in the bark of vines. From here, they move onto newly developed shoots in spring. Feeding damage causes leaf distortion, as well as stunted and uneven shoot growth. Severe infestations can lead to reduced canopy size and subsequent yield loss.
Cast your mind back to the January-March period. If there was any dark green-purple colouring of the leaves, these are the tell-tale signs of rust mite. Leaf bronzing is a good indicator of potential rust mite damage this coming season.
Applying THIOVIT JET® wettable sulphur is an effective yet inexpensive way to control rust mite. Timing is critical. Apply THIOVIT JET just prior to bud burst at mid-late woolly bud to target rust mite when they are exposed, emerging from the bark. Ensuring the temperature is >15°C at the time of application also improves efficacy of sulphur.
Single sprays of wettable sulphur at woolly bud or just after bud burst can also control low populations of bud mites. However severely infested buds can result in bud burst failure where feeding damage has already occurred.
THIOVIT JET should also be the first spray in your powdery mildew control program. Powdery mildew overwinters in buds. Commencing a preventative spray program soon after budburst with two early THIOVIT JET sprays significantly reduces both inoculum load and disease establishment, while laying the foundation for a sound resistance management program.
In trials conducted at Lenswood, South Australia, the inclusion of two early THIOVIT JET sprays, in a preventative fungicide program, significantly reduced disease development throughout the entire season.
In summary, consider using a quality sulphur product like THIOVIT JET this spring to get a head start on powdery mildew and mite control. The returns on your investment will be simply golden.
Dr Belinda (Brandy) Rawnsley is a Syngenta Technical Services Lead for Viticulture and Horticulture