After being discovered and propagated by grafting, Dongzao was planted under different site conditions. After many years and observation, it showed that the genetic characters were relatively stable, the fruit shape was beautiful, the fruit was large, the quality was high and the adaptability was strong, so it was suitable for planting in jujube areas in northern China. At present, it has passed the expert appraisal in Shandong Province and was named Zhandong 2.

Main Characters of Zhandong No.2, a Winter Jujube Variety

1. Botanical characteristics This variety has strong tree vigor, relatively open tree posture, longitudinally split bark, brown annual branches, large and sparse dermatomes (26 dermatomes per cm), and short distance between secondary branches of jujube head. The average number of young jujube stocks is 1.85, while the average number of middle-aged jujube stocks is 3.52, and the jujube stocks are short (generally about 20 cm in length). The leaves are broadly ovoid, with a leaf shape index of 1.85. The leaves are large and thick, with a dark green color, and the louver weighs 20.8g.. Flowers are large (average 3.2 mm? 3.5 mm), and the amount of flowers is also large.

2. The economic character of the fruit is large, with an average fruit weight of 21.09g and a maximum fruit weight of 57.5g. The fruit shape index is 0.9 18, and the fruit shape is regular. The fruit is oblate, apple-shaped, with short stalk, deep depression and flat and slightly concave top. The fruit is red and bright. The flesh is thick, the stone is small, the meat is delicate, crisp and sweet, the quality is excellent, and it is rich in nutrition. Tested by the Food Quality Supervision, Inspection and Testing Center of the Ministry of Agriculture, it contains 32% ~ 38% soluble solids (5% higher than Zhanhua Dongzao), and the edible rate is 97.9% (4.5% higher than Zhanhua Dongzao). It contains vitamin c 308 mg/100g, total acid 0. 17%, calcium 9.8 mg/100g, iron 3.6 mg/kg, water content 78.2%, fruit average hardness 8.7 kg/cm2, which is relatively resistant to storage and transportation and stored at room temperature/kloc.

3. Growth and fruiting habits The average growth of the new jujube head in the current year is 67.9 cm, and the crown is expanded quickly. The multi-head grafting is formed in the current year. Early fruit has strong high yield, which can be grafted in one year, produced in two years and produced in three years. The mature period of tree germination and fruiting is later (later than Zhanhua Dongzao 10 day), so it is suitable for protected cultivation. The first fruit bearing stage is mainly the middle and lower parts of new jujube heads, and the middle and upper parts of branches are the main fruits after the full fruit bearing stage.

4. Strong stress resistance and adaptability, salt and alkali resistance, high temperature resistance and cold resistance, showing high quality and stable yield in garden and field cultivation. It has stronger resistance to blind stinkbug scale and tetranychus urticae, stronger waterlogging tolerance and worse drought resistance than jujube rust and bacterial scab.

5. The phenological period began to sprout in Zhanhua, Shandong Province from April 22 to 26, and the leaves began to unfold on April 25 (lasting 8 to 9 days), and the flowers began to bloom on May 27, blooming on June 15, fading on July13 ~16, and the fruits began to color in the middle and late September.

Key points of cultivation techniques

1. It is advisable to plant the garden in spring, and the plant spacing is generally 2 meters? 3 meters, before planting, it is advisable to carry out unified planning, dot and locate holes, and dig holes with a square of about 50 cm (the surface soil is separated from the lower soil). Then, 2 ~ 3 shovels of decomposed loose farmyard manure and100 ~150g diammonium phosphate are fully mixed and backfilled with loose soil. When planting seedlings, it is necessary to dry, raise seedlings, protect, bundle, seal wax, transport, plant and water. Pay attention to the large-scale planting to be watered in batches according to the progress, and then compacted with water after planting. After the soil surface is painted (that is, when the soil surface is dry and wet, it can be hoed), the tree tray is arranged, ridged and covered with film.

2. Soil, fertilizer and water management mainly manages three fertilizers and four waters. The three fertilizers are base fertilizer in autumn, topdressing in time during the growing season and foliar spraying. /kloc-after picking the jujube fruit in the middle and late October, combine with deep ploughing and soil improvement, and apply 4000 ~ 5000 kilograms of high-quality soil miscellaneous fertilizer per mu. Top dressing 3 ~ 4 times before germination, flowering, young fruit expansion and after fruit picking, in which top dressing depends on the tree situation. Nitrogen fertilizer is the main fertilizer in the early stage of topdressing, and ternary compound fertilizer is applied in the later stage, generally about 0.5 kg per plant. During the growth period, according to the demand, the root dressing should be carried out every 15 days in combination with spraying. The four waters are water for accelerating germination, water for helping flowers, water for promoting fruit and water for wintering. Irrigation should be combined with topdressing, water racing in flowering period (flood irrigation should be avoided), and timely drainage should be carried out in rainy season to prevent waterlogging.

3. The modified small crown sparse layer shape can be used for shaping and pruning, which is also called a single layer and a heart-shaped tree. * * * is divided into two layers, with 3-4 main branches at the grass-roots level and 2-3 main branches or large bearing branches at the second layer, and the spacing between layers is1.0 ~1.2m.. There can be1~ 2 large and medium-sized fruiting branches (auxiliary branches) between layers, and they should be leveled. The extension of the upper main branch is1/3 ~1/2 of the lower main branch, and the tree height is controlled at 2 ~ 3 meters. Young trees are mainly lightly cut and slowly released, and the main side jujube heads are lightly cut to make the subordinate relationship clear, especially to avoid too many peripheral jujube heads, which will lead to the outward migration of the fruiting parts and poor ventilation and light transmittance, and pay attention to the timely update of the fruiting branches.

4. Protecting flowers and fruits is the most important cultivation technical measure in Zhandong 2 production, mainly including bud wiping, branch pulling, coring, nail opening, spraying plant growth regulators, fruit thinning and so on. Bud smearing, that is, after the winter jujube germinates in early May, the new jujube heads and long jujube heads that are not cultured with extended branches and fruiting branches are combined with shaping, and the most basal jujube heads are left to be wiped off. Bud wiping is often combined with bud retention, and the following methods are: leaving the bud at the base of the backbone branch and wiping the bud at the tip; Leave the secondary branch bud and wipe the axillary branch bud once; Leave secondary branches and lateral buds, and wipe back the upper buds; Wipe strong buds on the upper part of the trunk and weak buds on the lower part. Branching is to gradually pull the vertically growing jujube heads into a horizontal state with ropes from late April to late May. From late May to early June, the top bud or secondary branch of jujube head and the apex of jujube hanging in the early stage were removed in combination with the culture of fruiting branch group. Open nail means ring peeling. At the beginning of blooming in the first half of June, the trunk or main branch of the tree should be peeled off at the place where 1 is smooth, and then the nail opener should be used for ring cutting for two weeks to reach the xylem. Finally, the phloem tissue between the ring tangents should be peeled off. When cutting the skin with a knife, pay attention to the upward inclination of the upper knife and the downward inclination of the lower knife. The width of the nail opening must be different. Spraying1~ 2 times10 ~ 20mg/kg gibberellin and 0.2% boric acid at the flowering stage of winter jujube can significantly improve the fruit setting rate. From the end of July, artificial fruit thinning should be carried out, and the average 1 crane 1 fruit or 2 cranes 1 fruit should be determined according to the tree vigor, tree age and management level, thus creating conditions for high yield, high quality and high efficiency.