Abstract: 【Objective】 The aim of the present experiment is to study the judgment parameter of canopy overcrowed for reformative high trunk open centre shape of Fuji apple with standard rootstock. 【Method】 The canopy was divided into 50 cm×50 cm× 50 cm and the relative light intensity, type and number of shoots, yield and quality of fruit were measured in different layers and positions of the canopy with twenty-year-old reformative high trunk open centre shape of Fuji apple tree in different growing seasons. 【Result】 The distribution of relative light intensity in the canopy was gradually descended from top to bottom in different layers, and was gradually increased from inner to outer of the canopy in the same layers. The relative light intensity below 2.5 m position of the canopy were less than 31.48%. In June when the leaf area first formed, the percent proportion of ＜30% relative light intensity in volume of the canopy was 47.62%. The yields mainly located in 1.5-2.0 m height of canopy and were calculated by 6.32×104 kg?hm-2. The branches(shoots) mainly distributed below 2.5 m height of the canopy and was 82.92% of total branches(shoots). The percentage of the branches(shoots) in outer, middle and inner positions of canopy was 53.08%, 36.92%, and 10.00%, respectively. The amount of total branches(shoots) and ratios of long, medium, spur shoots were 1.21×106 bars/hm2, 7.97%, 53.63% and 38.41%, respectively, in overcrowed canopy. 【Conclusion】 There are three judgment parameters of reformative high trunk open centre shape of Fuji apple that the percentage of ＜30% relative light intensity in volume of the canopy were 47.62% , total branches(shoots) were 1.21×106 bars/hm2 and shoots ratio in inner of canopy was ＜10% .

Key words: Fuji apple, reformative high trunk open centre shape, canopy overcrowed, judgment parameter