From Wunsche, J.N. 1993. Fruit growers prune and train their trees to harness as much energy from the sun as possible for photosynthesis. As figure 2 shows, light has a major influence on final fruit yield. An overview of factors influencing the economic yield of apple production systems. Black lines indicate factors and processes which limit the productivity of healthy, well maintained orchards.
Blue lines indicate minor effects on orchard productivity.
From Wunsche, J.N. 1993. However, it is not necessarily the total amount of sunlight intercepted by the apple orchard which is important. The hypothesis is that the total light interception by the spur canopy, especially at about one month after full bloom, is the limiting factor for actual apple productivity. Carbon partitioning by the apple tree Carbon, obtained from carbon dioxide, is taken up by well illuminated leaves and converted into carbohydrates by the process of photosynthesis. How this carbon is utilised or partitioned by various leaf types at different stages of fruit growth is illustrated in Table 1.