Potted vines of Vitis vinifera L., cv. 9Cabernet Sauvignon9, 9Shiraz9, 9Rhine Riesling9 (9White Riesling9), and 9Clare Riesling9, were maintained in growth from 4 days after bud burst to berry set. Light intensity (2500 ft-c and day length (16 hours) were not varied. Temperatures (°C day/°C night) were 14/9, 20/15, 26/21, 32/27, and 38/33. The number of days from transfer to cabinets until flowering decreased from 70 at 14/9 to 24 at 26/21 to 20 at 38/33. Variation in the temperature range used to attain a mean daily temperature of approximately 18.3°C (as given by 20/15) had no effect on time to bloom. It is a matter for conjecture whether these results, obtained with small manipulated plants, would also be obtained with large field plants.
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Buttrose et al. (1973) studied this question.