The researchers studied how the amount of fruit on citrus trees affects their growth and fruit yield. They looked at 5-year-old satsuma mandarin trees in a field and found that trees with more fruit had smaller fruit size but higher fruit productivity. Trees with a normal fruit load produced around 1-1.1kg of fruit per square meter of leaf area. Lightly loaded trees had a dry matter productivity of leaves of 2.3-2.5kg per kg of leaves per year, while heavily loaded trees had a productivity of about 3.7kg per kg of leaves per year. The relationship between fruit load and fruit yield was similar to the relationship between planting density and yield per area.