| A series of experiments were done during 2006-2009 in Penglai (120.75E, 37.8N) and Jiaxiang (116.34 E, 35.41N), Shandong Province. With'Fuji'and'Gala'as test materials, it was systemically studied that the effect of bagging on characteristics of apple canopy, light environment and stem flow. And a new way of preventing sunburn after off-bagging was detected. The mainly results showed as follows:1. A new style of fruit paper bag which could prevent fruit from sun-burning efficiently after off-bagging was invented. This new style bag was easy to be made. First, a white paper was selected which is 10-17 g/m2 and the rate of light transmittance is about 60-90%. Second, make the paper into a cylindrical tube. Last, the tube was placed into common fruit paper bag (mainly yellow-stripe paper bag and single paper bag). And the way of using new style fruit paper bag was similar to that of common bags, except that when taking off common bags, the white cylindrical tube should remain around fruit, which was taken off at the same time as the apple was picked up. Applying this technology, not only could prevent fruit from sun-burning, for example, in 2006, only 3.4% of fruit was sunburned by new style paper bag, which was 47.70% less than CK, but also could improve surface smoothness, prolong the picking period of fruit, and improve fruit quality.2. Bagging changed the characteristics of canopy and worsen the environment of light at the early stage of after-bagging; in the last stage of after-bagging (maturity stage), bagging had little effect on characteristics of canopy. At the same time, the variation of the characteristics of canopy structure in different plant densities of bagging apple orchards was analyzed. Bagging could increase visual objects area index (VOI), and reduce coefficients for diffuse radiation and transmission coefficient in different degree and at different plant density orchards. In the orchards of 2m×4m and 4m×4m, after bagging, VOI was 2-2.5 times more than that of before-bagging. Bagging affected canopy light circumstance. In the canopy with six main branches, ineffective light densities (less than 30% natural light) were increased by bagging on middle-layer and under-layer, especially in under-layer, which was increased by 12%.But the characteristics of canopy of before and after off bagging have little changes, because the volume of apples are similar to the bag volume.3. Bagging could change the characteristics of apple canopy quickly and greatly. During the fast growing of new shoots, the characters of canopy had changed a lot. For example, the VOI and visual objects distribution (VOD) had increased a lot and the coefficient for diffuse radiation (TD) and coefficient for solar radiation penetration (TR) had reduced a lot. But bagging made the VOI and VOD increased rapidly, and the TD and TR reduced swiftly. After fruit bagged the characters of the canopy had changed little until fruit was picked up. During the last stage of fruit development the characters of canopy had changed little. While the VOI and VOD decreased rapidly and the TD and TR increased swiftly when fruit was picked up.4. The reflection capabilities of different color fruit bags effected the canopy light environment and the physiological indices of apple leaf. Different bag colors had different light reflection capabilities: snuff color |
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