关键词: 苹果再植, G系砧木, 矮化自根砧, 富士苹果, 树体生长, 果实产量, 果实品质

Abstract:

【Objective】 The effects of four dwarfing rootstocks (G935, G41, G11 and M9-T337) on the growth, early fruiting and yield quality of Fuji apple saplings under the replanting conditions were investigated for four years. The dwarfing rootstocks suitable for continuous cropping in Beijing were evaluated and selected, so as to provide a technical support for the renewal of the cultivation mode of old and inefficient apple orchards in China. 【Method】In the spring of 2016, 6-year-old apple trees (Fuji/SH6/ Malus prunifolia) were planed out and no soil improvement was carried out. 4 dwarfing rootstocks (G935, G11, G41 and M9-T337) Fuji apple seedlings (2-year-old roots and 1-year-dry) were directly planted in the original row, with a row spacing of 1 m×3.8 m. After planting, 4 dwarfing plants were investigated differences of tree growth, early fruiting, yield and quality of Fuji apple on rootstock for 4 consecutive years. 【Result】 The height of Fuji trees on G935 and G41 rootstock was higher than that of G11 and M9-T337; the number of main branches from high to low was: G935>G41>G11>M9-T337; the phenomenon of big feet of G41 and M9-T337 was higher than that of G935 and G11; the difference of height, diameter and number of main branches between G935 and G41 was significantly lower than that of G11 and M9-T337, with the neat garden phase. In the fourth year of continuous cropping, the chlorophyll content and net photosynthetic rate of leaves of G935 and G41 rootstocks were significantly higher than G11 and M9-T337, the fresh weight of leaves of G935 and G41 was significantly higher than G11 and M9-T337, and the dry weight of leaves of G935 and G41 was significantly higher than M9-T337. Within 4 years of continuous cropping, Fuji, the dwarfing rootstock of G935 and G41, grew normally, and the branch composition was in line with the change rule of dwarf rootstock fruit trees. From the second year, the proportion of long branches of G11 and M9-T337 trees was lower than 30%; from the third and fourth year, the proportion of short branches of G11 and M9-T337 trees was higher than 80%, the proportion of long branches was lower than 10%, and the tree vigor was obviously weakened. In the third year of continuous cropping, the flowering rate of G11 young trees was the highest, followed by G935 and G41, and M9-T337 had no flowering. In the fourth year of continuous cropping, the average yield per plant of Fuji on G935 and G41 rootstocks was significantly higher than that of M9-T337 and the average fruit weight and fruit shape index of G935 were significantly higher than those of other rootstocks. There were no significant differences in the soluble solid content, titratable acid content and solid acid ratio of the fruit of each rootstock. 【Conclusion】 Under the condition of replantation, the growth of young trees with G935 and G41 as rootstocks was significantly better than that of G11 and M9-T337. The branch composition was reasonable, the tree potential was moderate but not weak, the difference between single plants was small, and the garden was neat, which was suitable for continuous cropping in Beijing.

Key words: apple replant orchard, G dwarfing rootstocks, Fuji apple, tree growth, fruit yield, fruit quality