Coffee and vine are both perennial plants that are cultivated for their fruits on large areas in tropical and Mediterranean areas respectively. They are very similar in their structure with signicant areas of bare soil. Coffee is mostly grown in agroforestry systems, while vineyards are grown mostly as pure crops. Heavy pesticide use, soil degradation and loss of biodiversity are problems faced by both systems. Therefore, the use of trees in both systems may target some common problems, such as water contamination or pest control. In this paper we address two questions: 1) What lessons could be learned from coffee systems regarding the use of trees?; and 2) What are the differences in light competition with trees at different latitudes (Mediterranean versus tropical)? Shade is sought for coffee production in the tropics, but light competition by trees is considered detrimental for vine growing. However, vine was originally grown as an agroforestry system. The dynamic prediction of radiation patterns below the canopy of wide-spaced trees is essential to predict the outcome of agroforestry systems. A light competition model was used to calculate the impact of various tree canopy sizes and tree-row orientations on the distribution of the light at the coffee or vine level. For a given tree density and tree leaf area, the in!uence of the shape of the tree crown on the light availability for the crop is discussed. Surprisingly, erected and !at canopies were equivalent in the Mediterranean zone, but induced very different light patterns for the crop in the tropics. Tree-row direction was essential in Mediterranean latitudes and important in tropical latitudes to obtain a homogeneous radiation on the crop, which is counter-intuitive. Practical consequences for the choice and the management of shade trees with perennial crops are discussed