Light influences grapevine development in two main ways. Firstly, the quantity and quality of light intercepted by leaves influences the rate of photosynthesis and, in turn, the vine’s accumulation of sugars. Secondly, light intercepted by the developing fruit influences the composition of the berries and, in turn, the juice.
Photosynthesis by the vine during the growing season produces sugars which are either accumulated as sugars in the developing fruit or as storage reserves, in particular as starch in the roots and trunks of the vine. As early season development depends on these reserves, understanding the factors that determine the partitioning and subsequent utilisation of carbohydrates by the fruit, roots shoots and storage organs.
