Varietal selection is important to ensure vigorous growth.
For example, Cassegrain (Port Macquarie, NSW) planted Chambourcin vines, a non-vinifera variety, because they are in a summer-rainfall area. Non-vinifera vines are not very susceptible to powdery mildew, whereas all Vinifera vines are.
One of the key strategies for any grower seeking to reduce chemical inputs is to understand the influence of sunlight on the vine. Row orientation, trellis design and the use of extra lifting wires, vine training, pruning and leaf trimming are all used to open up the vine to penetration of sunlight. Once again of all plants, vines most obviously demonstrate the effect of good sunlight exposure to the quality and character of the end product.
This practice is very effective at reducing the frequency of disease treatment and the quantity of any permitted chemical used to obtain a good coverage.