Standardized cultivation Model of dwarf (double Dwarf) Apple in Fengxiang County

Standardized cultivation Model of dwarf (double Dwarf) Apple in Fengxiang County

1 cultivation of dwarf (double dwarf) apple

At present, there are four types of seedlings used in dwarfing apple cultivation in China: dwarf self-rootstock seedlings, dwarf interstock seedlings, short branch seedlings and double dwarf seedlings (figure 1), of which dwarfing interstock seedlings are commonly used in production. In Fengxiang County, the cultivation area of double dwarf is larger, accounting for more than 80%. Double dwarf seedlings are seedlings bred by seeds, on which dwarf interstocks are grafted, and then short branch varieties are grafted on dwarfing interstocks. The establishment of gardens in areas with irrigation conditions is focused on the cultivation of double dwarfs. This is beneficial to speed up the development of dwarf apple in Fengxiang County, so as to improve land utilization, shorten production life, reduce production cost, improve management technology and improve fruit quality.

Fig. 1 dwarf (double dwarf) apple seedlings

2 cultivation standard of dwarf (double dwarf) apple

2.1 large seedling planting

Practice has proved that large seedlings (with many branches) can bear fruit in the same year. Moreover, the more branches of the large seedlings, the higher the yield in the second and third years; the seedlings planted with unbranched or too small stem diameter did not begin to bear fruit until the fourth and fifth years, let alone higher yields. The diameter of seedlings in dwarf (double dwarf) apple orchard should not be less than 16 mm, 10-15 branches, or at least 5 branches. It is suggested that the garden should not be planted with dry seedlings.

2.2 standardized establishment of garden

At present, dwarfing apple seedlings are mainly dwarfed interstock seedlings in the production of dwarfing apple plants. if you want to build double dwarf apple orchard seedlings, you should make an appointment in advance or reconnect them yourself. To build an orchard, we should choose places with superior site conditions, large temperature difference between day and night, 750-1300 meters above sea level, sufficient light, suitable climate, deep soil layer, fertile soil, gentle terrain, leeward to the sun, close to water sources, pure water quality and convenient transportation (figure 2). In line with the principle of "adapting measures to local conditions and suitable land for planting", according to market demand and ecological conditions, middle and late maturing varieties are the main varieties in the dry belt at an altitude of 820 meters. Fuji varieties with short branches such as Yanfu 6, Liquan short rich, Huimin short rich, Miyazaki short rich, Aomori short rich or well colored Fuji varieties are mainly planted. Chuanyuan Irrigation District, which is 760,800 meters above sea level, focuses on developing excellent early and mid-maturing varieties, such as Ligala, Shaanga 3, Honggailu, Qinyang and American No. 8, Mid-Autumn King, Asustek, Xinnonghong, Yuhua Fuji, precocious Fuji King and so on. After planting apple seedlings, plastic film mulching, plastic film bags and brackets were used to ensure the survival and upright growth of apple seedlings.

Fig. 2 standardized garden

2.3 planting density

The flat land has irrigation conditions, so it is suitable to choose M26 and M9 as dwarfing interstocks. The row spacing was (1.5 × 2.0) m × (3.5 × 4.0) m, and 95 plants per mu were planted. Under no irrigation condition, it is suitable to choose M26 and M9 as dwarfing interstocks.

2.4 planting depth of dwarf (double dwarf) seedlings

The planting depth of dwarfing rootstock is a key factor for the success of the garden. Dwarfing interstock seedlings with M26 as an example, in which the length of dwarfing interstock is 25 cm 30 cm, 3 cm 5 cm in semi-arid field block M26 in Fengxiang area, and 12 cm in M26 field with good water and fertilizer (figure 3). The dwarfing interstock takes M26 as an example of double dwarf apple seedlings, in which the length of dwarfing rootstock is 25-30 cm, and in the fields with better water and fertilizer, M26 is 5-8 cm above ground. Dwarfing interstocks exposed too much ground, dwarf trees, affecting high yield and efficiency; dwarfing stocks exposed too little, tall trees, and even similar to Arbor, can not normally play the high-quality and efficient performance of dwarfing apple trees.

Fig. 3 planting depth of double dwarf apple seedlings

2.5 reasonable pollination trees

Generally configure 20% of the pollination tree.

2.6 use of high spindle trees

Shaping objectives: the number of branches retained per mu of adult trees is 70 to 80 thousand, the proportion of long, medium and short branches is 1 ∶ 3 ∶ 6, the leaf area coefficient is 2.5 to 3.0, the ratio of branches to fruits is about 3 ∶ 1, the ratio of leaf to fruit is 25 to 30 ∶ 1, the ratio of flower buds to leaf buds is 1 ∶ 3, the number of flowers retained per mu is 14000 to 15000, and the coverage rate of orchards is about 70%.

The tree structure is 3 to 3.2 meters in height, 0.8 to 1 meters in height, the ratio of the thickness of the central leading trunk to the main branch in the same part is 5 to 6 ∶ 1, the trunk is equipped with 25 twigs, the length is not more than half of the row spacing, the lower layer can be longer, and the upper layer is shorter. The angle of the main branch is 110 °~ 120 °. There are fruiting branches on it, and there are no large and medium-sized fruiting branches. The whole tree is spindle-shaped (figure 4). After adulthood, the crown is small, the number of branches is abundant, the fruiting ability is strong, and there is no large main branch. light is sufficient and light energy utilization is high.

Fig. 4 High spindle tree

2.7 Orchard recommendation, grass mulching

Through our experiment and demonstration for many years, using orchard recommendation (figure 5) and orchard mulching to gradually increase the content of soil organic matter and activate soil nutrients; through full application of organic fertilizer and more application of biogas fertilizer to improve soil nutrients; through fine application of chemical fertilizer, topdressing compound fertilizer containing multi-element fertilizer to increase soil nutrition; through extra-root topdressing to supplement tree nutrients. It can greatly improve soil fertility and ensure the demand for soil nutrients for the growth of fruit trees. In particular, the recommendation of orchard and straw mulching can effectively improve the content of soil organic matter, accelerate the decomposition and transformation of minerals, and combine planting with raising land. According to the experimental determination, the soil organic matter content of the orchard planted white clover for 5 years increased from 0.87% to 1.72%, and the soil organic matter content for 7 years increased to 1.98%. The content of organic matter in 5cm soil covered with grass for 3 ~ 5 years can be increased by one percentage point.

Fig. 5 Orchard recommendation

2.8 Biological prevention and control

Adopt comprehensive technical measures to reduce the amount of chemical pesticides and fertilizers, reduce pollution, give full play to the advantages of biological control measures, comprehensively control diseases and insect pests, and produce green food. The use of low-residue chemical pesticides can not only effectively control the diseases and insect pests under the index that does not cause production harm, but also do not pollute the environment, and the residue on the fruit does not exceed the standard. There are mainly the following aspects:

(1) Agricultural prevention and control. It mainly includes fertilization and irrigation, winter and summer pruning (four seasons pruning), orchard ploughing, grass growing between rows, fruit bagging, bark scraping, insect trap control, armyworm board control (figure 6), manual killing, trunk whitening, winter garden cleaning and so on.

Fig. 6 armyworm board for pest control

(2) physical control. The use of pests to light, sugar and vinegar, extra-sexual hormones and other trends to predict and control. It mainly includes the methods of frequency vibrating insecticidal lamp trapping, sugar and vinegar trapping, sex attractant trapping, isotropic filament interference and so on.

(3) biological control. The measures for biological control of diseases and insect pests are mainly using natural enemy insects, bacteria, birds and microbial pesticides to control diseases and insect pests.

(4) Chemical control. To implement the plant protection policy of "prevention first and comprehensive control", in order to effectively, quickly and stably eliminate diseases and insect pests in years when a large number of diseases and insect pests occur, it is still necessary to combine the application of high-efficiency and low-toxic chemicals in order to achieve the goal of high quality, high yield and high efficiency of fruit trees.

3 matters needing attention in the cultivation of dwarf (double dwarf) apple

The construction of double dwarf seedlings must have irrigation conditions; dwarfing interstock seedlings have better irrigation conditions, no irrigation conditions, and must be watered and covered with plastic film when building the garden (figure 7).

Fig. 7 plastic film mulching after planting of double dwarf apple seedlings