Mitigating sunburn, dehydration and smoke taint in the vineyard : is there a role for sunscreens, antitranspirants and film forming barriers?

Warmer temperatures have resulted in compressed vintages, lower acidity and higher alcohol in Australian wines. The additional effects of extreme weather events, drought, limited water allocations and wildfires have exacerbated other negative consequences such as vine water stress, sunburn, berry shrivelling and smoke taint. Antitranspirants, reflective sunscreens and film-forming barriers are potential treatments that can be used to manage these negative consequences on both the foliage and berries. Di-1-p-menthene, derived from conifer resin, improves leaf water-use efficiency and reduces water loss from bunches. The reflective properties of kaolin, an inorganic clay, may lower canopy and fruit temperature and reduce the severity of sunburn damage and smoke taint. Chitosan, a natural biopolymer, elicits defence response mechanisms and has antioxidant properties. We review the preliminary findings and feasibility of these film forming products on vine response, berry composition and the resultant wine.