The Ecological And Physiological Responese Of The Main Shapes Of Apple In Southern Weibei Area

In order to study the physiological and ecological effects of three different shapes of Malus domestica cv Fuji in southern Weibei, we divided their canopy crowns into 0.5 m×0.5 m×0.5 m three-dimensional boxes and determined physiological and ecological indicators in each box of three different shapes (Small and sparse canopy shape, Freedom spindle shape, Low stem and open center shape) in 12-year-old Fuji apple orchard. The results were as follows:According to light distribution, the optimal light region of low stem and open center shape was the biggest, accounting for 74.39% of the total volume of the crown, 57.98% for small and sparse canopy shape,50.21% for freedom spindle shape and its inefficient light region of freedom spindle shape was close to 40%.There was even UV-B radiation intensity distribution in low stem and open center shape so as to ensure that fruits in each layer could receive UV radiation effectively; however, freedom spindle shape was weaker while the topper of small and sparse canopy shape was too strong.Considered the temperature,humidity and ventilation, the distribution and change of temperature and humidity were similar in the canopy of three different shapes generally, and higher temperature and humidity in the canopy of freedom spindle shape. For ventilation, the wind speed was ordered as small and sparse canopy shape > low stem and open center shape > freedom spindle shape. CO₂ concentration in the canopy of the different shapes was not significant difference.Think of canopy structure, total branches accounted 1648000/hm2 for freedom spindle shape, 1401000/hm2 for small and sparse canopy shape, 1303000/hm2 for low stem and open center shape. Relative light distributions in outter of small and sparse canopy shape were more even and the number of friuts was more.The friuts of composition of freedom spindle shape became less from bottom to topper. About photosynthesis ,low stem and open center shape was strongger than small and sparse canopy shape. And for freedom spindle shape, chlorophyll content was highest. For leaf area index, freedom spindle shape>small and sparse canopy shape>low stem and open center shape.LMA of three shapes were increasing both from bottom to top and from inside to outside. In yield and quality,this research showed that: characteristics of low stem and open center shape were 23.962kg/plant for yield, 19.94% for fruit onset, better fruit quality and higher hardness and soluble solid content, higher uniformity in fruit quality. For small and sparse canopy shape, fruit quality was not good and fruits in the upper and the lower part was not enough tidy, while for freedom spindle shape with smaller fruit, lower yield, some quality indexes, such as weight of single fruit, hardness, fruit rust, were inferior to the other two shapes. From the fitting of fruit and relative light with the polynomial, we found that there was notable positive relationship between most fruit quality indexes and relative light. When optimal light reached 38.64%, the weight of single fruit was the highest, and 67.08% for the hardness, 86.71% for soluble solid content, 87.56% for coloring, 40%～75% for optimal light in the crown.The comparison of results indicted there were more reasonable light distribution, higher fruit quality in low stem and open center shape and small and sparse canopy shape of the three, so the two shapes were suitable for extension and freedom spindle shape need to reform because of lower light interception on leaf curtain and lower yield and quality. This study revealed the effect of three shapes on physiological and ecological indicators, which provided a scientific basis for evaluating the tree structure and a theoretical clue and technique guidance for shape reforming in southern Weibei apple producing area.