High-quality and High-yield cultivation techniques of low-yield Apple in barren mountainous area

In order to promote the development of Chengde fruit industry, improve fruit yield and quality, and accelerate the development of economic forest industry, since 2014, Chengde City Forestry Technology Extension Station has carried out the construction of demonstration base for improving quality and efficiency of low-yield apple orchard in Kuancheng County, and achieved good results. The technology is summarized as follows for reference.

1. High for high.

① Main varieties: 8 apple varieties suitable for high quality and high yield were popularized, including Hanfu, Yueyang Hong, Yueguan, Yuehua, Yueyan, Meimei 8, Hongjiangjun and Changfu 2.

(2) Time and method of top grafting: strengthen fertilizer and water management before grafting to restore tree vigor. The grafting methods in spring are cut grafting, split grafting, skin grafting and ventral grafting. The method adopted is selected according to the thickness of grafting parts, thin branches are grafted by cutting and splitting, thick branches are grafted by splitting and grafting, and trunk or main branch parts lacking branches are grafted by abdomen. The scion is sealed with wax, and the shaved surface is flat and long. After inserting the scion, tie the wound with plastic strips.

(3) Tree shape transformation: dense trees are transformed into tree shapes according to improved spindle shape or free spindle shape, and middle crown trees are transformed into tree shapes according to trunk sparse layer shape. First select the backbone branch, the diameter of the base of the main branch within 3 cm, leave about 10 cm for grafting, generally insert 2 scions; diameter more than 3 cm, from the base of the main branch 30 cm, select the branch axis of the twigs on both sides of the main branch for abdominal grafting, unilateral spacing distance 30~40 cm; too far there is no grafting bald part, adopt abdominal grafting.

2. Soil, fertilizer and water management.

① Soil management: Deep ploughing time is from autumn fruit harvest to fruit tree defoliation, depth is 30~40 cm, deep ploughing position is bounded by crown projection periphery, and shallow ploughing in inner chamber. Deep ploughing combined with organic manure. Cultivate and eliminate weeds, cover the orchard, spread straw and weeds 1000~1500 kg per mu, and the thickness shall not be less than 20 cm.

② Water management: combined with water collection facilities, irrigate key water such as pre-flowering water (germination to pre-flowering), post-flowering water (5~10 days after flowering) and frozen water. Drain water in time when soil reaches maximum field water holding capacity.

3. Increase organic fertilizer application: base fertilizer application in autumn is the main fertilizer application, and top fertilizer application in summer is the auxiliary fertilizer application. Organic fertilizer is applied after fruit picking, 1~2 kg organic fertilizer is applied for each kilogram of fruit produced, and appropriate calcium, magnesium and phosphorus are mixed, and the application amount per mu is 150~200 kg. N, P and K are used together during flower bud differentiation and fruit expansion; P and K are used mainly in late fruit growth period to increase color and increase nutrient storage.

3. Management of flowering and fruiting period.

① flower thinning and fruit thinning: after flower bud sprouting, do a good job of pre-flowering re-cutting, and keep the ratio of flower bud to leaf bud at 1∶4~5. Fruit thinning takes about 10 days after flowering and is completed within 3 weeks. The method of fruit spacing is adopted, and a center fruit with correct fruit shape is selected and reserved on the thick fruit platform according to 20~25 cm. The number of fruits reserved per mu is 10,000 ~ 12,000, and all redundant young fruits are thinned out.

(2) Fruit bagging: 1~2 days before bagging, use insecticide (mite)+ fungicide (protective fungicide + therapeutic fungicide)+ high-quality calcium fertilizer + agricultural water quality optimizer to control diseases and insect pests. When bagging, red Fuji and other red varieties use high-quality two-layer three-color paper bags, which begin to be set 45 days after flower drop.

(3) laying reflective film: in the middle and late August, laying silver-gray reflective film under the canopy.

4. Leaf picking and fruit turning: during the fruit coloring period, remove the leaves that shade the apple fruit and make the fruit directly exposed to sunlight.

4. Trimming key techniques.

Winter Scissors: First, thinning out over-dense branches, upright competitive branches and diseased branches, adjusting the opening angle and orientation of main branches, adjusting the tree structure from a large aspect; secondly, retracting branches that have not been pruned for many years; thirdly, adjusting the internal structure, thinning out strong branches on the back and thin and weak branches and overlapping branches that are too dense on the back to control competitive branches; The medium and small fruiting branch groups were selected and cultured by using auxiliary culture branches. For some parts with space, the 3~4 buds at the base of the annual branch were cut short, and the sub-full buds were stimulated to germinate, and the compact medium and small fruiting branch groups were cultured.

Summer shear: The main pruning techniques are support, pull, pry, do not, pressure, core, twist and so on. For the main branch with unreasonable opening angle, the method of bracing and pulling shall be adopted to open the angle to 70~80°; for the main branch with unreasonable angle, the method of different and oblique pulling shall be adopted to change the direction.

5. Pest control.

Adhere to the strategy of "prevention first, comprehensive control", promote the use of low-toxicity, non-residual pesticides and biological pesticides, and produce green pollution-free fruits. After pruning in winter, spray 5 Baume sulfur mixture to prevent rot, scale insects, rust, dry rot, etc. April with avermectins, imidacloprid and other pesticides to prevent insects aphid, moth, geometrid, spray triadimefon, carbendazim or carbendazim rust, powdery mildew. From late June to August, avermectins, pyrethroids and other insecticides were used to control chafers, longicorn beetles, psyllids, sting moths and other pests. After July, spray Bordeaux mixture for 4~5 times to prevent apple bituminous coal disease.

Chengde City Forestry Technology Extension Station Gao Jianli Jin Tiejuan Geng Jinchuan