Simulating three-dimensional grapevine canopies and modelling their light interception characteristics

Background and Aims The objective of this study was to develop a simplified approach to simulate three-dimensional (3D) grapevine canopies and model light interception. Methods and Results A re-sampling procedure was developed to generate a set of allometric parameters based on their sample mean and distribution derived from shoots of field-grown vines grown in response to variable amounts of irrigation and N fertiliser. A large number of 3D models of grapevine canopies was reconstructed with the plant architecture model YPLANT based on re-sampled allometric parameters. Approximately 80% of intercepted light by the canopies was shown to be captured by 20–30% of the leaves, with deficit-irrigated and N-stressed plants having a greater proportion of leaf area exposed to high and moderate light intensity throughout the day compared with that of non-stressed vines. The amount of daily absorbed light increased with increasing leaf area per vine and was highly affected by row direction. Conclusions Model predictions agreed with previously reported and measured amounts and patterns of light interception. Significance of the Study The approach described here simplifies previous attempts to represent the 3D architecture of a grapevine canopy, provides a good approximation to conditions vines may experience in the field and may be of practical use for field research and/or optimisation of canopy management practices in commercial production systems.