Last one... well, two
I found a PDF "final report" of that Australian grape research:
Applications of milk and whey generally increased the population of indigenous bacteria, yeasts and filamentous fungi on leaves and bunches, compared with vines treated with sulfur, but had no obvious effect on species diversity. While increased microbial populations may contribute to the reduction of powdery mildew on the vine surfaces, there was no evidence that they impaired grape or wine quality.
https://research.agwa.net.au/wp-content/ ... report.pdf
In summary, when disease pressure is low to moderate, commercially acceptable control of grapevine powdery mildew on cultivars that are not highly susceptible can be achieved using a range of novel materials including milk, whey and mixtures of canola oil plus potassium bicarbonate. As these compounds act as contact fungicides excellent cover of leaf and berry surfaces is required for effective control, and spray intervals should not exceed 14 days during flowering, early berry development and periods of rapid shoot growth.
I also found this if anyone wants to buy it and give us the highlights. Does it imply you should spray hydrogen peroxide in conjunction with the milk spray? At what %? Simultaneously or prior to milk?
Australasian Plant Pathology
September 2006, Volume 35, Issue 5, pp 487-493
Mode of action of milk and whey in the control of grapevine powdery mildew
P. Crisp, T. J. Wicks, G. Troup, E. S. Scott
$39.95 / â‚¬34.95 / Â£29.95 *
* Final gross prices may vary according to local VAT.
Grapevine powdery mildew, caused by the fungus Erysiphe (Uncinula) necator, is a major disease affecting grape yield and quality worldwide. In conventional vineyards, the disease is controlled mainly by regular applications of sulfur and synthetic fungicides and, in organic agriculture, by sulfur and botanical and mineral oils. Research has identified milk and whey as potential replacements for synthetic fungicides and sulfur in the control of powdery mildew. Electron spin resonance and scanning electron microscopy were used to investigate the possible mode or modes of action of milk and whey in the control of powdery mildew. Electron spin resonance experiments showed that various components of milk produced oxygen radicals in natural light, which may have contributed to the reduction of severity of powdery mildew on treated leaves. Milk and whey caused the hyphae of E. necator to collapse and damaged conidia within 24 h of treatment. Hydrogen peroxide, applied as a source of free radicals, also caused collapse of the hyphae of E. necator but did not damage conidia, and appeared to stimulate germination. Lactoferrin (an antimicrobial component of milk) ruptured conidia, but damage to hyphae was not evident until 48 h after treatment. The results support the hypothesis that free radical production and the action of lactoferrin are associated with the control of powdery mildew by milk.