Rapid Propagation technique of Tree Peony

Peony is a traditional famous flower in China, which is deeply loved by people. if it can solve the problem of rapid propagation and reduce the production cost, it will greatly meet the needs of the market. The propagation methods of peony include ramet, grafting, cuttage, striping and so on. In comparison, grafting is still a better method for peony reproduction. However, the narrow sense of "grafting" can not solve the problem of rapid propagation of peony. In the production practice of Lushan Flower and Tree Seedling Farm in Luoyang City, Henan Province, after years of exploration, the traditional grafting method was improved, and a set of standardized rapid propagation technology of peony was formed, which accelerated the development of excellent varieties. The main points of this technology are introduced as follows.

I. selection of varieties

At present, there are more than 600 tree peony varieties in China. Through market investigation and observation of the biological characteristics of tree peony, four series of tree peony varieties were selected from the tree peony variety group and matched with Jackie Chan. First, varieties with colorful flowers, large number of flowers, "flower mouth" pine (easy to blossom), easy to reproduce and well-developed roots are selected as a series of flowering varieties, such as Luoyang Hong, Hu Hong, Oolong Pengsheng, meat hibiscus, similar lotus, cinnabar base, etc.; second, varieties with colorful flowers, large number of flowers and short plant types are selected as potted variety series, such as Huhong, peach red, coral platform, Yipin Zhu Yi, Wujin Yaohui, etc. Third, select varieties with colorful flowers, large number of flowers, long pedicels and strong germination as cut flower varieties, such as Zhaofan, No. 18, carmine, etc.; fourth, select varieties with both eight major colors, rich flower patterns, relatively valuable and strong adaptability, varieties with good intuitive effects as varieties for planting flower beds or establishing peony gardens. In this regard, the market abandoned the "large and comprehensive" approach, and only selected more than 100 fine peonies as "reserved varieties".

Second, establish ear picking nursery

There must be enough scions and rootstocks for grafting propagation of peony. For this reason, a spike picking nursery must be established for the purpose of cutting scions. The establishment of ear-picking nursery should choose the land with loose, deep and fertile soil, and the plant-row spacing should be large (1 × 1). After the selected fine varieties of peony were planted in the autumn of that year, all the branches on the ground were cut off (this is the so-called "flat stubble"), in order to stimulate the adventitious buds at the junction of rhizomes to germinate in the second year and grow into short branches (that is, scions). It is necessary to strengthen the management of fertilizer and water for the "mother plant" in the ear-picking garden. In this way, the scion can be cut once a year in autumn and make more and more short branches.

III. Timing

The grafting propagation of tree peony is very time-sensitive. The experimental results show that the best season is from early September to early October in the middle of the Yellow River basin. If the best grafting time is missed, the survival rate will decrease with the postponement of the season. At this time, if you encounter cloudy and rainy weather, you should also swing the time for grafting, which can be operated indoors, but you should pay attention to putting the grafted plants neatly and pay attention to ventilation (this still does not affect the healing of scions and rootstocks). Planting when the soil is suitable for cultivation after sunny days. Generally, ditches are dug and planted, with a width of 20 cm and a depth of 30 cm. The plant spacing is about 15 cm and the row spacing is about 35 cm.

IV. Improve the labor mix

In the case of mass production, it is important to seize the opportunity to improve the survival rate of peony grafting, but other factors can not be ignored, such as improving the grafting technology of operators and strengthening the sense of responsibility of grafters. As time is tight, tasks are heavy, and there are many varieties, special attention should be paid to the allocation of labor combinations. The practice of this farm is to hire surplus labor in local rural areas and take up posts only after strict technical training. Scions and rootstocks are provided by the field department. Generally, 2 people are a grafting group, and each batch is planted at a designated place by the grafter, and the reward is paid according to the survival rate of grafting in the second year (only living expenses are paid when grafting is done). Due to the improvement of the labor combination and the strict responsibility system, the grafting of 100000-150000 peonies can be completed in about 10 days a year. The average survival rate is more than 80%.

V. Establishment of variety files

Peony is a variety of flowers and trees, the slightest carelessness will cause variety confusion. Whenever the grafting breeding season, the field designated in the peony variety identification of technical experts, unified cutting scion, handed over to the grafting group for grafting. Follow up and record the varieties during planting. After the end of grafting, the variety distribution map shall be drawn uniformly and stored in the file for reference. In this way, it can be clear at a glance when checking the survival rate, transplant or sale.

6. Flat stubble pruning

Peony grafting is usually a stock and a bud (spike). After the second year of survival, if there is no flat stubble in the autumn of that year, the scion will only grow tall but not grow branches. Therefore, the surviving annual grafted seedlings should be cut above the interface (those whose length is more than 3 cm can still be regrafted as scions) to stimulate adventitious buds at the root buds to sprout branches. In this way, the 2-year-old grafted seedlings of peony can grow 4 short branches. Usually, peony 2-year-old grafted seedlings can be transplanted with a row spacing of 60 × 70 cm to cultivate large seedlings. In order to make the grafted seedlings quickly become large seedlings, flat stubble should be carried out immediately after transplanting in the same year (the cut short branches can still be used for grafting) to stimulate its multiple new branches. In this way, flat stubble pruning for two consecutive years and strengthening fertilizer and water management not only made the grafted seedlings quickly reach the specifications of the nursery, but also collected a large number of scions, which played an important role in the rapid propagation of tree peony.

The production practice of Luoyang Mangshan Flower and Tree Seedling Farm proved that no matter which peony variety series was calculated from the date of grafting, after 4 years of cultivation, it could grow into a large seedling with 7 Mel and 9 flower buds, which reached the specification of coming out of the nursery. It has the advantages of low cost, large quantity and quick coming out of the nursery, so it is a method of rapid propagation of peony which is worth popularizing.