Practice of stable yield Regeneration of Old Apple trees

Practice of stable yield Regeneration of Old Apple trees

With the sustained and rapid development of apple industry, there are more and more old orchards, some orchards are about 30 years old, many kinds of diseases and insect pests occur, the varieties are aging, the trees lack branches and branches, the tree is weak, the fruiting ability is declining, the fruit quality is poor, and the benefit is reduced year after year. If the garden is destroyed and rebuilt, there is a problem of replanting obstacles, and the interval is long, and the land utilization rate is low. For this reason, in recent years, we have transformed and renewed a number of old apple orchards through root grafting, with good results.

1 the advantage characteristics of the old orchard

Although the appearance of the old orchard is poor, the plants are uneven, lack of branches and few stems; the branches are thick, the branchlets are few, and there are many diseases; the tree is weak, the yield is not high, the quality is declining, and the benefit is very poor. However, the biggest advantage of the old apple orchard is that the root system is strong, and the rot mostly occurs in the upper and middle parts of the big branch and trunk, and there is less rot in the middle trunk below 20 cm from the ground. The new technology of renewal and transformation of the old apple orchard takes advantage of the advantage of the old apple orchard.

(2) the reliability of new technology for renewal and transformation of old orchards.

First, the tree which has been updated for more than 20 years has good performance. Through our investigation in Miganqiao Village and Caojiazhuang Village, Miganqiao Town, Fengxiang County, it was found that the new Hongxing orchard planted in 1986 was grafted into Huimin short branch in 1996 and yielded good results in the past 20 years. Marshal Huang and Old Hongxing Orchard, which was planted in 1988, was grafted into Liquan short-rich orchard in 1993. It has achieved good results in the past 23 years without any bad performance. At the same time, the orchard has been reformed and grafted for the second time since last year, and the trees grow well after renewal. Second, the high yield performance of the renewed orchard for 7 ~ 8 years is good (figure 1), and the fruit quality is high. Through the investigation in Fanjiazhai Village of Fanjiazhai Town of Fengxiang County and Qi Village of Tianjiazhuang Town, Fengxiang County, the updated orchard has good growth, high yield performance and strong tree growth, with a yield of 2 500 to 4 000 kg per mu and a full red fruit rate of more than 90%. Third, the orchard grows rapidly in 1 ~ 4 years after renewal, and enters the fruiting period and high yield period rapidly.

Fig. 1 Tree growth for 7 and 8 years after transformation

(3) the implementation of new technology for renewal and transformation.

3.1 preparation before renewal and transformation

Choose the orchard to be rebuilt, remove the main branches after the fallen leaves in the autumn and winter of the previous year, leave only about 1.5 meters of the trunk, clean up all the remaining branches and leaves, and apply chemicals (such as flake or seal cutting oil) to protect the trunk. On the basis of fertilization in autumn, winter irrigation should be carried out to keep the tree body with sufficient water. At the same time, prepare branches, varieties or dwarfing rootstocks to be replaced next spring. Prepare nylon grass, plastic bags, plastic film, and potions ready to smear the wound (such as flank, sealing oil, or tebuconazole).

3.2 Renewal and reconstruction of grafting techniques

The grafting of renewal and transformation can be carried out twice or at one time. The grafting speed of twice renewal transformation is relatively fast, the seed strips used are relatively few, the transformation technology is relatively simple, and the grafting difficulty is small. In the actual production, the two grafting methods are generally used, the first grafting is carried out before and after the apple tree sprouting (April), and the second abdominal grafting is carried out in the first and middle of June. When the renewal and transformation is completed at one time, the grafting is generally carried out before and after the sprouting of the apple tree. first, the new branches are grafted at the neck of the root of the tree to be renewed, and the grafted branches should be long. after the lower part is grafted, the abdominal grafting will be carried out at a distance of 25cm to 30cm, leaving only one trunk to grow upright upward.

When grafting before and after sprouting, one is to take out the prepared scion and choose the scion with strong branches, full buds and pure varieties. The second is to remove the old cut of 2cm to 3cm in the lower part of the scion, and then soak the scion in clean water for 24 hours to fully absorb water so that it can survive and grow. The third is to cut down the trunk of the orchard to be reformed. when cutting, it is best to remove the big branches on the tree first, and then cut down the tree at 10-15 cm from the ground (10-15 cm for dwarf trees and 5-20 cm for Arbor trees) (figure 2). When cutting the trunk, you should be careful not to hurt the cortex of the trunk section on the ground, and then scrape the wound on the trunk section on the ground. Fourth, there are 4 or 5 branches under the skin at the trunk section, the branch marriage interface should be smooth, the length is more than 2.5 cm, and the branch can be cut to 10 cm 15 cm when the renewal is carried out twice, and the branch can be relatively long at one time. After binding at the interface of the cross section, ventral grafting was carried out at 25cm and 30cm, and the whole grafting was completed at one time. Fifth, after the branches are grafted on the cross section, they are wrapped in plastic film or plastic bags to protect the wound, and then tightly bound with new nylon grass without leaving gaps, while all the grafted branches are bagged and tightly bandaged (figure 3). To speed up wound healing. Sixth, when grafting, make the first bud on the scion outward as far as possible, in order to facilitate the second abdominal grafting, and make the wound growth more firm and stable after grafting; generally, at least 4 or more scions should be grafted on a middle trunk, on the one hand, to guard against the death of the grafted scion, on the other hand, the middle trunk is thicker, the grafted branch is less than the middle trunk, the cortex and xylem of the grafting part are not healed well, and it is easy to be infected with diseases. Seventh, when the branch to be grafted reaches 40 cm to 60 cm, it is ventrally grafted at 25 cm to 30 cm in the scion. Abdominal grafting is usually carried out in the first and middle of June. At least four well-grown branches are selected after the grafting has survived (the orientation of the branches is as far as possible in four corners), and then they are grafted together. After the grafting is done, it is bandaged with a plastic strip 1 cm wide (figure 4). After the wound is fully healed, all the nylon grass, plastic bags, plastic film and plastic strips wrapped in the first or second grafting are removed in July and August of the same year. Then clean the wound and trunk of the first grafting site, spray 500 times of 25% propiconazole EC on it, or smear the wound and trunk with Shukang or flank, and then bury it in a mound 2 places away from the second marriage interface.

Fig. 2 cut down old trees

Fig. 3 after grafting, the branches are bagged and wrapped tightly.

Fig. 4 bandage with plastic strips after abdominal grafting

3.3 Graft transformation of special trees

When there is rot at the base of the big tree and cannot be grafted at the base of the trunk, the big tree can be dug up and grafted on the small roots under the big tree. After survival, the grafted branches are belly grafted together.

4 Management after receiving

4.1 timely removal of bags, unbinding, pile-up protection

After the completion of the renewal and transformation in the same year, the plastic bags should be removed in time after scion sprouting to prevent sprouting. From July to August, after the second grafting wound healed completely, the soil was removed and buried, the first grafting wound was cleaned, and the rot disease was prevented by spraying, and then the medium-dry soil was buried at the 6m ~ 8cm of the grafted branch to facilitate interface protection and promote growth.

4.2 strengthen the management of water and fertilizer

After the renewal and transformation is completed, it is necessary to apply fertilizer in time, using 100 kg of diammonium phosphate per mu, 35 cm of dwarfing apple and 45 cm of Arbor apple, and watering in time after fertilization. From July to August, urea was topdressing 50kg per mu before rain, and from September to October in autumn, basic fertilizer (farm manure) was applied to about 2000 kg per mu, and irrigation after application.

4.3 drawing and reshaping

After renewal and transformation, the apple tree generally does not need to set the stem, there are more main branches on the middle stem of the year, most of the main branches are more open, and there are also some competitive branches and some strong branches that need to pull branches and open angles. the opening angle of the main branch can be more than 90 °according to the growth condition, and the tree height can reach about 3 meters in autumn. The yield per mu can reach about 1 500 kg in the third year, it is very important to pull branches and promote flowers in the growing season, and the tree shaping is basically completed in the fourth year and begins to enter the peak fruiting period.

4.4 Disease and pest control

After the transformation of the old park is completed, attention should be paid to the prevention and control of diseases and insect pests, with emphasis on the prevention and control of beetles, top leaf rollers, aphids, longicorn beetles, red spiders, golden moths, big green leafhoppers, shell insects and rust, and early deciduous diseases. In the middle of May, 30% mimetidine 2000 times or 5% imidacloprid 2000 times and imidacloprid 3000 times were sprayed; from late May to early June, 800 times of Dasheng Mashi 45 was sprayed. From July to August, 20% of the solution was 4000 times of promethazine + 3000 times of Haolichi.