In this article:

The photosynthetic activity of single vine leaves was studied in a variety of outdoor situations using portable field equipment for environmental monitoring and CO2 analysis.

Field vine leaves showed a rate of CO2 assimilation comparable to other deciduous perennials.

Photosynthesis was light-saturated at intensities well below full sunlight and showed a temperature optimum near 30oC, but declined sharply, due to stomatal closure, when leaf moisture tension approached 15 b. Leaf photosynthesis, when light-limited, followed a cosine response to changes in the angle of incident light.

Under full sunlight the response curve was substantially displaced due to a generally higher level of solar radiation and to a component of diffuse radiation which became increasingly important at higher angles of incidence.

Effects of Irradiance, Temperature and Leaf Water Potential on Photosynthesis of Vine Leaves

1971, Photosynthetica, vol 5, issue 1, pages 6 – 15

csiro 213

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