Rapid Propagation technique of Sweet Cherry by cannon twisting

Rapid Propagation technique of Sweet Cherry by twisting method

The breeding of traditional sweet cherry varieties usually takes at least 2 years to produce finished seedlings. Rootstocks are propagated in the first year and scions are grafted in the second year. In order to shorten the seedling breeding cycle and explore new ways of seedling propagation, the author has successfully propagated sweet cherries by using the traditional "twisting method" of Populus tomentosa in Hougezhuang Village and Dongge Street Gouxi Village, Liyuan Street, Pingdu City, respectively since 2013. the breeding cycle is one year shorter than the traditional method, and 10 seedlings can be produced from one rootstock, which greatly improves the breeding efficiency. The survival rate was high. 25000 sweet cherries were grafted with yellow honey, red lantern, ice sugar cherry, Meizao, Dihong, Samituo and other varieties, 23800 survived, the survival rate reached 95%, 22600 seedlings came out of the nursery, and the seedling rate was more than 90%. The main technical points are summarized as follows.

1 choose rootstock

The selection of rootstock is the most important in the breeding technique of "twisting method". The author uses the cherry rootstock king with strong rooting ability, also known as Okayama 16. The cuttage of this variety is very easy to take root, and very small branches can also be cut to survive. The root system of the seedling is very dense and grows rapidly, and the seedlings grow in the same year after cutting. The annual trunk and stout lateral branches were selected as rootstocks with the thickness of 0.8~1.3cm and the segments cut into length 13~15cm.

2 timely grafting

2.1 preparation of rootstocks and scions

In late November in autumn, the king branch of cherry rootstock was picked and cut back indoors after defoliation, and then the branches were cut indoors to grow 13~15cm branches for grafting as rootstock. At the same time, sweet cherry seedlings were cut into 18~20cm segments as scions indoors to keep moisture and keep fresh.

2.2 grafting

Grafting is suitable to be carried out from early December to early January. Before grafting, 3cm at the upper end of the rootstock and the lower end of the scion were soaked in 100mg/kg ABT1 rooting powder for 2 hours. After soaking, take out and dry and immediately seal with paraffin wax. The grafting method adopts double tongue grafting. The smooth surface is obliquely cut with a sharp knife at the upper end of the rootstock 3~4cm, and a vertical slit is cut at 3 places at the upper end of the slope, and the depth accounts for 1 / 2 of the slope. Select the scion whose thickness is roughly the same as that of the rootstock, cut the bevel with a quick knife at the lower end of the 3~4cm off-bud 1cm, and cut a slit vertically at the upper end of the bevel, accounting for 1 of the depth of the bevel, and then facing the bevel to align and tighten the rootstock and the scion formation layer; if the thickness is different, make sure that the cambium on one side is aligned with each other, and then wrap it tightly with plastic strips. Two buds were retained in the scion and cut at the 1cm above the apical bud.

3 grafted body storage

After the grafting, 50 grafts are tied up in a bundle. In the leeward direction, dig a storage cellar with a depth of 0.6m and a width of 1.5m (which can also be widened appropriately), and the length depends on the number of grafts. Fill the bottom of the cellar with clean aseptic sand 5cm or so, put the graft in the cellar vertically, place the scion upward, carefully fill with fine wet sand, and bury all the scions. Make sure that the wet sand is in full contact with the graft, and the upper part is basically flat with the ground; wet sand is covered with wet soil, gently pat and firm, and be careful not to trample on it. If the storage cellar is in the field, the wind barrier should be built with straw and film on the north side of the cellar.

4Graft planting

From late March to early April of the following year, take out the graft and remove the residual sand, when most of the scion and rootstock have healed together, do not artificially touch and loosen the grafting site in the process of transportation and planting. Planting according to row spacing 60cm and plant spacing 20cm. Three to five days before planting, the seedling land applied sufficient basic fertilizer to prepare soil moisture, and when the soil was moist, non-sticky and not hardened, the ditch was planted with a depth of about 20cm, and the furrow spacing was the row spacing. Handle it gently when planting, and strictly prevent the displacement of the grafting site. Then cover the soil and ridge. The suitable thickness of soil cover is about 3cm at the top of scion, and then watered along the ditch. After 3-4 days, furrows and ridges were further arranged and covered with plastic film.

5Seedling stage management

From 7 to 10 days after planting, the grafting began to sprout one after another, and the membrane was broken and the soil was pressed in time to ensure the normal growth of panicle buds. The sprouting of rootstock and the excess sprouting of scion were wiped out in time from May to July. In the middle of July, the quick-acting compound fertilizer was applied once, 666.7m2 was applied with 30kg, and the seedlings were watered in time according to soil moisture to promote the growth of seedlings. Weeding, watering, soil moisture conservation and pest control should be done during the whole seedling growth period.