Effects of Spraying Strategies Based on Monitored Disease Risk on Grape Disease Control and Fungicide Usage in Marlborough

Standard practice for grape disease management in Marlborough 10 years ago was to spray for diseases using calendar based spray programmes. Communication of grape disease management research has led to a change of practice for many grape growers. The key tool developed by the research programme was targeted spraying for diseases. This involved field monitoring for diseases and the use of decision support software, which contained the Bacchus Botrytis cinerea risk model. Adoption of targetbased spraying resulted in a reduction in fungicide usage of up to 50%. The research involved industry consultation, field trials on vineyards and communication of information to participants. The involvement of grape growers as advocates from the outset ensured that there was industry ownership of the outcomes. A change in practice by the Marlborough grape industry has resulted in financial savings for growers and environmental benefits for the wider community through reduced fungicide applications to wine grapes.