Studies on the dwarfing cultivation of peach tree

1.毛白李(矮化砧木)上的桃树需要相应的抚育和修剪新梢。在中央领导系统中，最重要的修剪可能是在第一年从主茎侧面出现新芽。在插穗的刺激下，出现了二次芽。当处理得当时，第2年产量为8公斤/株，第3年达到3米高的目标产量为2.6吨/株。冬季，毛白杨根部矿质营养含量高于桃树，但砂砾栽培条件下，毛白桃开花后对营养物质的吸收十分缓慢。砂培阶段RPP提供的养分越多，新梢越旺盛，果实生长越快。但果实成熟延迟，含糖量下降。另一方面，RPP在果实成熟初期施入较少的营养物质，果实早熟，含糖量增加。在实际种植中，应在前期给予足够的养分，在成熟期减少土壤养分。‘三洋水蜜素’的苦涩程度与果实总酚含量呈正相关。在易出现收敛的品种中，毛白杨和日本杨果实中的苯酚含量均高于桃树。在果实生长的第三阶段，剥皮、干旱和较低的温度增加了果实中的苯酚含量。以毛白杨、毛白杨为砧木的桃树，似乎出现了移栽失败的问题。

1. Peach trees on Prunus tomentosa (dwarfing rootstock) require relevant tending and triming of new shoots. The most important triming in a central leader system might be cutting (cutting back) new shoots appeared laterally from the main stem in the first year. Secondary shoots appeared by the stimulation of the cutting. When this treatment was made properly, the trees yielded 8kg/tree in the second year and 2.6ton/10are in the third year when they attained a target figure of 3m tall.2. The root of peach trees on P.tomentosa(RPP) contained more mineral nutrinets in winter than those on P.persica, but the absorption of nutrients in RPP was very inactive after blooming atage in a gravel culture. When RPP was provided more nutrients at the stage in a sand culture, new shoots became more vigorous and the fruit growth was promoted. However, fruit maturation delayed and the sugar content declined. On the other hand, when RPP was given less nutrients from the early stage of maturing, the fruits matured early and their sugar contents increased. In practical growing, it is necessary to give enough nutirients at the early stage and to reduce soil nutrients at the maturing stage.3. In case of 'Sanyo Suimitsu' the degree of astringency correlated positively with total phenol content in the fruit. The cultivars in which astringency tends to appear often, the fruits from trees on P.tomentosa and on P.japonica contained more phenol than that from trees on P.persica. Phenol content increased by girdring, drought and low femperatures at the third stage of fruit growth.4. It seems that the problem of replant failure occurs when P.japonica and P.tomentosa are used as rootstocks for peach.