High spindle shaping and cultivation techniques of double dwarf apple trees

High spindle shaping and cultivation techniques of "double dwarf" apple trees

National Modern Apple Industry Technology system Construction Project (CARS-28).

At present, the intensive cultivation mode of dwarf rootstock is mainly adopted in the advanced countries of apple production in the world, and [Jishan Huayao] is being vigorously promoted in our country. The "double dwarf" cultivation model of apple focuses on the double dwarfing advantages of short branch varieties and dwarf rootstocks, and is more suitable for highly dense planting, which can effectively reduce tree height, control tree crown, be easy to manage, and achieve early fruit and high yield. [2] However, in the area of the old route of the Yellow River, the intensive cultivation technique of dwarf rootstock in the "Shuangai" apple orchard failed to achieve the ideal effect, so the national apple industrial technology system Shangqiu Comprehensive Experimental Station carried out the technical research on the cultivation of "double dwarf". Successful experience and supporting techniques have been obtained.

1 general situation of the demonstration garden

The "double dwarf" densely planted demonstration park is built in Sunji Village, Zhangge Town, Liangyuan District, Shangqiu City, Henan Province (longitude 114 °49mm, longitude 116 °39m, latitude 33 °43m, 34 °52'). The area has a warm temperate and semi-temperate continental monsoon climate with four distinct seasons. The annual average temperature of the demonstration area is 12.5-15.5 ℃, the maximum and minimum temperatures are 39 ℃ and-9 ℃ respectively, the average annual sunshine hours are 1 944.5 hours, the frost-free period is 180-211 days, the annual precipitation is 600-950mm, the topography is flat, loam, pH value is 6.5, the drainage and irrigation is convenient, and the site conditions are basically the same.

The main varieties in the park are Fuji, a short branch of M26 interstock, and Malus balengensis as the rootstock; the "Shuangai" high-quality 2-year-old seedling is built with a height of about 1.5m, a basal diameter of 1.5~2.0cm, with 810 branches, an intermediate rootstock length of 25~30cm, and more than 5 lateral roots of the rootstock, and the marriage interface heals well. The interstock exposed 10~16cm on the ground, the plant row spacing was 2.5m × 4m, and the tree was of high spindle shape. The study of Gao Dengtao et al. [4] showed that M26 interstock had suitable dwarfing degree, good adaptability and excellent production performance in the old route of the Yellow River, especially the combination of short branch Fuji / M26 interroot. it showed good adaptability to the regional environment in terms of yield performance, fruit quality and disease resistance. The hedge system was established at the beginning of the garden.

2 shaping and pruning technology

The main branch is of high spindle shape, with a height of 3.3m to 3.5m, a height of 0.6m, an erect and robust central stem, a thickness ratio of 5 ∶ 1 to the main branch, a distribution of about 280m, no interlayer of the main branch, hollow arrangement, spiral rise, the angle of the main branch is 90 °110 °, the length of the main branch is 1.0m 1.5m, the plant does not connect, and the sagging three-dimensional fruit.

The main results are as follows: (1) after planting in that year, straighten the seedlings with bamboo pole, set the stem at the full bud, pull the longest branches with an angle of 90 °110 °, erase the 2nd to 6th buds at the top of the central trunk, and remove the strong shoots on the trunk in winter, the tree height can reach 2.0 × 2.5 m after pruning in the first year.

(2) pruning in the second year. In spring, all the lateral branches of the "double dwarf" fruit trees were removed, leaving only the central stem. In summer, the main work is to wipe buds and fix branches, pulling all the lateral branches above 25cm length below the level, and the base angle reaches 90 °110 °. In late August, the waist angle and slightly angle are enlarged to control their growth and promote the growth of the central stem, and the height of the tree can reach 2.8 to 3.3 m after pruning in the second year.

(3) pruning in the third year. In spring, all the lateral branches were still removed, only the central stem was retained; in summer, all the lateral branches above 25cm length were pulled below the level by wiping buds and fixing branches in summer, and the height of the tree could reach 3.5-4.0 m after 2 years of pruning.

(4) pruning in the 4th year. Cut off all the side branches whose thickness is more than 1x3 in diameter of the trunk of the bearing part, leaving a pile mouth that is short on the top and long on the bottom; remove the upper branches, disease and insect branches, weak branches, etc., choose the branches with moderate growth potential and large angle as the small main branches, do not hit the head, and truncate lightly to the middle stem; usually when there are two branches at the top of the lateral branches, remove the lower branches and remove the excess branchlets. Pruning in spring and summer is mainly by wiping buds and pulling branches, pulling all the lateral branches above the length of 25cm below the level, with a base angle of 90 °to 110 °, so as to control its growth and promote its vegetative growth to reproductive growth.

When the height of the tree is about 3m, it can bear a lot of fruit, and the flower bud can be removed every 15cm in spring, and the amount of hanging fruit can be reduced. In autumn, the new plants on the middle stem were pulled to 95 °120 °, and the new ones on the 1-year-old branches were twisted and pulled to ease the tree potential and increase the yield.

(5) regular pruning. To ensure the trunk advantage of the fruit tree, there is no too strong side branches to compete with it, remove all side branches whose diameter is more than half of the trunk diameter; prune all side branches so that the upper branchlets (hanging fruit branches) are arranged uniaxially, trim them with oblique pruning method: remove the side branches that are too low in the growth area or truncated, and generally remove the side branches below 60cm from the ground.

Pruning during the growing period is mainly to do a good job of pulling branches, coring and twisting branches, to remove competitive branches, overlapping branches, cross branches, disease and insect branches and upright branches, so as to solve the problem of ventilation and light transmission of trees. Fruit branch pruning: keep the strong, medium and short fruit branches, cut off the length of the long fruit branches, cut off the dense branches, and the short fruit branches should keep one branch every 10cm. The pruning in the later stage is mainly light pruning and slow release, leaving more flower bud branches to bear fruit.

(3) soil water and fertilizer management

Soil management focuses on deep ploughing and soil improvement, applying more organic fertilizer to improve soil structure to achieve the purpose of air permeability, water conservation and fertilizer conservation; continuous interrow grass growing, 30~40cm cutting, tree plate mulching and grass mulching can effectively stabilize soil temperature, maintain soil moisture and increase soil porosity.

During the establishment of the garden, the sufficient base fertilizer was applied, and the holes were expanded and turned deeply into 60cm every autumn. Nitrogen fertilizer was the main fertilizer in the early growth stage, phosphorus and potash fertilizer was the main fertilizer in the middle stage, and potash fertilizer was applied in the later stage. The average application rate of rotten high quality farm manure per 667m2 is 3000 ~ 5 000kg, commercial organic fertilizer 300~500kg, urea 45~70kg, potassium chloride 35~50kg, superphosphate 80~150kg, and full irrigation after application. Starting from the first and middle of July every year, the tree crown is sprayed with 0.3% potassium dihydrogen phosphate and 0.2% urea, once every 10 to 15 days, for 5 times in a row to prevent early defoliation and restore tree potential.

Popularize and apply the technology of integration of fertilizer and water, watering sprout water, post-anthesis water, inflated water and frozen water in normal years; watering according to special weather conditions, do a good job in the construction of orchard drainage facilities and rule out stagnant water in orchards at any time.

(4) Disease and pest control

Comprehensive application of agricultural, physical and chemical methods for prevention and control, the use of high efficiency, low toxicity, low residue and pollution-free pesticide and its pollution-free application technology. The main diseases and insect pests in the "double dwarf" dense planting demonstration garden are spot leaf disease, brown spot, anthrax leaf blight, ring disease, woolly aphid and so on. Use 48% chlorpyrifos 0.067% solution, or 75% mancozeb 0.125% solution, or 50% carbendazim 0.125% solution to control spot leaf blight; 60% Baitai to control apple anthracnose leaf blight; wheel Terminator to control ring disease; insect forest, avermectin and so on to control woolly aphid.

On the basis of strengthening the comprehensive management of soil, fertilizer and water, tree management, strengthening the tree potential, thoroughly clearing the garden and eradicating orchard pathogens, Bordeaux solution was applied to protect the whole process from bagging to September. Bordeaux solution is used alternately with organic fungicides such as pyrazolyl ester as the main active ingredient or oxime tebuconazole and other organic fungicides to control the infection of ring streak pathogen, rot pathogen, brown spot pathogen, etc. At the same time, the pathogens on the surface and surface of the branches were eradicated. Bordeaux liquid was sprayed four times in early July, late July, mid-August and early September.

At the same time, frequency vibrating electronic insecticidal lights are installed in the orchard, yellow boards are hung to control pests, and combined with pruning in winter and spring, branches of diseases and insect pests are cut off, cocoons of overwintering insects are scraped off, and burned out of the orchard. Strengthen cultivation management, enhance tree potential, increase the application of organic fertilizer, and improve the insect resistance of apple trees.