Relationships between distribution of relative light intensity and shoots and foliage in different tier of canopy of Red Fuji apple trees with modified open centre tree shape

Twelve-year-old trees of Red Fuji apple cultivar trained with modified open center shape were used for studying the relationship between the dynamic distribution of the relative light intensity and the types of shoots and leaf area index in different tier of the canopy.The results showed that the distribution of relative light intensity was gradually descended from top to bottom and gradually increased from inner to outer at the same tier of the canopy.The seasonal changes of relative light intensity in the upper tier of the canopy was stable from May to October,while in the middle and lower tiers were gradually descended from May to July and were stable after July.The diurnal change of relative light intensity in the canopy was low to high to low from morning to evening.The percent proportion of 30% relative light intensity in volume of the canopy were separately 15%,27% and 30% during May to June,July to August and September to October.The new shoots distribution in the canopy showed that ≥30 cm,15 to 30 cm,5 to 15 cm and ≤5 cm shoots were mainly located in above 2.0 m,1.5 to 2.5 m,1.0 to 2.0 m and 1.0 to 2.5 m height of the canopy.The total numbers of new shoots and percent proportion of ≥30 cm,15 to 30 cm,5 to 15 cm and ≤5 cm were 100.39 ten thousand/ha.,6.44%,5.52%,14.40% and 73.64% respectively and ≥6 leaves spur shoot more than 42.08%.The multiple statistic analysis was used to set up a regression equation,which were negative exponent relationship between relative light intensity value and accumulative shoots and leaf area index.The parameter of canopy structure for good qualities and high yield of Red Fuji apple trees were obtained,which were about 960 000/ hm2 shoots,with leaf areas index less then 3.9 and percent proportion of long,middle and spur shoots of 10.91%,13.70% and 75.39% respectively.