Elevated root-zone temperature hastens vegetative and reproductive development in Shiraz grapevines
Article first published online: 26 DEC 2013
© 2013 Australian Society of Viticulture and Oenology Inc.
Australian Journal of Grape and Wine Research
Volume 20, Issue 1, pages 123–133, February 2014
How to Cite
Rogiers, S.Y., Clarke, S.J. and Schmidtke, L.M. (2014), Elevated root-zone temperature hastens vegetative and reproductive development in Shiraz grapevines. Australian Journal of Grape and Wine Research, 20: 123–133. doi: 10.1111/ajgw.12053
- Issue published online: 26 JAN 2014
- Article first published online: 26 DEC 2013
- Manuscript Accepted: 27 AUG 2013
- Manuscript Revised: 14 MAY 2013
- Manuscript Received: 9 FEB 2013
- Grape and Wine Research Development Corporation
- berry composition;
- canopy development;
- carbohydrate mobilisation;
- fruit ripening;
- soil temperature
Background and Aims
Springtime root-zone warming activates mobilisation of the root carbohydrate reserves, a critical source of carbon for early canopy and reproductive development in grapevines following winter dormancy. Seasonal variability in soil temperature during spring may result in inconsistent vegetative growth and fruitset with consequences for berry growth and ripening.
Methods and Results
We monitored flowering and berry ripening in Shiraz grapevines (Vitis vinifera L.) grown in large temperature-controlled pots. The vines were exposed to a cool, ambient and warm root-zone temperature from budburst to fruitset. Root starch mobilisation after budburst was linearly correlated to the cumulative heat units received by the soil. A warm root-zone temperature also hastened leaf expansion, net positive carbon assimilation, onset of flowering and fruit set, berry enlargement and the onset of veraison. At harvest, berry pH and nitrogen concentration as well as fresh and dry mass were higher for the vines exposed to a warm root-zone while berry acidity was lower.
Warm soil temperature in spring stimulated the mobilisation of carbohydrates in the roots and accelerated shoot and reproductive development, resulting in larger berries with lower acidity.
Significance of the Study
Because root-zone temperature is an environmental driver of berry size and composition, models predicting yield and berry composition can be fine-tuned to incorporate this critical parameter.