黄土高原旱地苹果高接模式与品种更新技术研究

在黄土高原旱地进行了苹果高接换种技术试验。结果表明,对每公顷栽植1 260株的高密园,宜采用细长纺锤形整形,每公顷栽植834株的中密园宜采用小冠疏层形结构整形;单枝单芽贴干嫁接宜在4月中下旬进行,单芽腹接和地面蹲靠接应提前到3月下旬至4月上旬。细长纺锤形果树宜采用单枝单芽贴干嫁接,单株宜高接11个头,采用单芽腹接宜接12个头,地面蹲靠接以3个头为宜;小冠疏层形嫁接头数以30个较好。嫁接时砧枝截留长度为5～8 cm,嫁接不同枝段芽体接穗以调整平衡树体长势;依据树龄采用不同嫁接方法,1～5年生树选用单芽腹接,5～10年生树采用单芽枝接,11年生以上树宜采用地面蹲靠接;嫁接后采取封闭切口+套塑料袋的效果较好,单芽腹接芽眼包扎1层接树膜效果明显,地面插接及时包严用土培实保护,嫁接成活率平均在93．5％以上。嫁接后同步成形,树体生长旺,树冠恢复能力强,结果早,产量高,该技术已大面积推广应用,效益十分显著。

Research on top grafting pattern and technique for renewal cultivar in drought apple orchards of Loess Plateau

The experiment of top grafting technique for replacing cultivar was conducted in drought apple orchards of loss plateau. The results showed that slender spindle system was adopted in high density apple orchard with 1260 trees/hm^2,small stratified tree shape was adopted in middle density apple orchard with about 834 trees/hm^2. Grafting with one bud scion should be taken from middle April to late April, inarching at bottom part of trunk and side grafting with one bud should be taken from late March to early April. Grafting near trunk with one bud scion was selected for slender spindle system,the grafting number was 11 per tree. If side grafting with one bud was selected,the grafting number was 12 per tree. If inarching at bottom part of trunk was selected,the grafting number was 3 per tree. If improved spindle system was adopted,the grafting number was the age of tree multiplying 3,the selected limbs for grafting was cut back and only remained 5 to 8 cm long,grafting with different parts of a budwood was recommended for adjusting vigor of tree. Side grafting with one bud for 1 to 5-year old tree,grafting with one bud scion for 5 to 10-year-old tree,and inarching at bottom part of trunk for trees over ll-year-old trees were taken respectively according to different ages of trees. Protecting with oil and plastic bag was used after grafting with one bud scion. Protecting with a thin sheet of plastic was used after side grafting with one bud. Protecting with soil and enswathing with plastic was used after inarching at bottom part of trunk. In such a case,the survival rate of grafting could reach 93.5%. The tree would take shape and was vigorous. The top of the tree could recover quickly and the tree could bear fruit early and would be very productive after grafting. This technique has been extended on the large scale and yielded significant effect.