CONSUMERS will need to be educated in new wine varieties because the typical grape style grown in any given region is likely to have to switch because of climate change, warns a book on agriculture's future by 36 scientists.
Green oranges and yellow tomatoes may be another thing that consumers will have to get used to, as climate change affects the colour and nutritional value of horticultural produce, says the book, released today.
The CSIRO has published the book in an attempt to explain what agriculture can do to adapt.
Warming could change the areas suitable for cooler-climate wine grapes such as sauvignon blanc and pinot noir, while more climate-adaptable varieties such as shiraz and chardonnay might become more widespread, said Mark Howden, a CSIRO chief research scientist and an editor of Adapting Agriculture to Climate Change.
Mediterranean wine-grape varieties such as tempranillo and viognier, with which winemakers were already experimenting to target market niches, might become more commonplace in South Australia and other places set to become hotter and drier, Dr Howden said.
Grapes normally grown in hotter areas would move to cooler locations, and some regions not used for viticulture may be transformed into wine producers, he said.
Grapes' ''internal clocks'', run by temperature, were already leading them to ripen in the hot part of the year, which potentially compromised the flavour by increasing sugar and alcohol production, he said.
''It's only the skills of the winemaker keeping them under control at the moment,'' he said.
Two CSIRO scientists, Leanne Webb and Penny Whetton, also say in their chapter on horticulture that the sugar content and colour of citrus fruit is affected by warmer seasons, as they tend to ''re-green'' and cannot be left on the tree as long. Capsicums and tomatoes can turn yellow if they experience high temperatures when ripening, they write.
''Higher temperature can inhibit the formation of anthocyanin, the pigment causing colouration of apples and increase sunburn damage.''
Leafy crops such as lettuce and spinach may have reduced yields and be of poorer quality due to ''bolting'', which means prematurely forming seed heads or flowers, they say. Lettuce may have a shorter shelf life.
There may also be reduced sugar content in peas, strawberries and melons if the nights are warmer, while fruits may have less vitamin C, they warn.
But there may be benefits for producing dried fruit, such as sultanas, by sun-drying them as humidity and rainfall decrease in some regions. Certain annual crops, such as lettuce, may also have their growing seasons extended, they say.
The areas suitable for growing apples, pears and stone fruit, which require chilling, may be reduced by climate change, while the land area for subtropical fruit, including bananas, pineapples and avocados is likely to expand, they say.
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