Abstract
High-light intensities and temperatures of the warm climate regions of Australia and elsewhere have a major effect on the growth and development of grapevines (Vitis vinifera L.). The objective of this research was to assess interactions between the light and seasonal temperatures by shading some vines
and comparing these with vines exposed to high-light intensities. Canopy temperatures were monitored using infrared radiometers and budbreak, phenology, growth, yield, berry ripening and gas exchange determined over three growing seasons. Results showed canopies were generally about 4 C cooler than air and shading extended this cooling. Irradiance, irrespective of seasonal temperatures, had no effect on time of budbreak, shoot phenology, stem growth, yield and bunch fresh weights while bunch and leaf dry
weights were reduced in low-light. Bunch ripening was initially delayed by low-light but thereafter the ripening process was highly temperature-dependent. Rates increased linearly with increasing temperature
in both low and high-light and were optimal at about 35 C. Maximum photosynthetic capacity was impaired by low irradiance, in accordance with shade leaf attributes, and attributable to stomatal closure.
No effects of the low photosynthetic capacity apparently carried-over to sugar accumulation, consistent with the strong sink capacity of bunches.
and comparing these with vines exposed to high-light intensities. Canopy temperatures were monitored using infrared radiometers and budbreak, phenology, growth, yield, berry ripening and gas exchange determined over three growing seasons. Results showed canopies were generally about 4 C cooler than air and shading extended this cooling. Irradiance, irrespective of seasonal temperatures, had no effect on time of budbreak, shoot phenology, stem growth, yield and bunch fresh weights while bunch and leaf dry
weights were reduced in low-light. Bunch ripening was initially delayed by low-light but thereafter the ripening process was highly temperature-dependent. Rates increased linearly with increasing temperature
in both low and high-light and were optimal at about 35 C. Maximum photosynthetic capacity was impaired by low irradiance, in accordance with shade leaf attributes, and attributable to stomatal closure.
No effects of the low photosynthetic capacity apparently carried-over to sugar accumulation, consistent with the strong sink capacity of bunches.
| Original language | English |
|---|---|
| Pages (from-to) | 59-69 |
| Number of pages | 11 |
| Journal | Plant Physiology and Biochemistry |
| Volume | 54 |
| DOIs | |
| Publication status | Published - May 2012 |