DIFFERENCES IN GAS EXCHANGE IN CV. TEMPRANILLO (VITIS VINIFERA L.) AS AFFECTED BY TRAINING SYSTEM

Field-grown Tempranillo vines grafted on IIOR were trained to four training systems (single curtain, vertical trellis, high head bush and short head bush). Daily evolution of net photosynthesis (A), transpiration rate (E) and Photosynthetically Photon Flux Density (PPFD) were measured in external leaves at phase I, II and III of berry growth in 1991 and 1992.

The diurnal pattern of A was the same for all treatments: photosynthesis increased from early in the morning until midday, and then it decreased towards the evening.

Differences in A were observed between training systems throughout the day, especially at midday.
Bush vines showed a higher A rates than vertical trellis due to a higher PPFD received by leaves and a more efficient response to PPFD levels.
However, vineyard net photosynthesis was the highest in vertical trellis, which had a higher canopy surface area (SA).

Intercepted PPFD, A, and transpiration rates were significantly higher in bush vines.
Transpiration rates seemed to be in agreement to PPFD levels, A and SA. The higher the SA, the lower transpiration rate due to reduced water availability.

V International Symposium on Grapevine Physiology

P. Baeza, C. Ruiz, M. Carmen Bartolomé, J. Lissarrague

Photosynthesis, surface area, transpiration

https://doi.org/10.17660/ActaHortic.2000.526.43