2. Propagation method of Rosa roxburghii:
(1) Sowing: Seed is collected in September, sown in autumn or stored in sand until the following spring, and generally germinates 20-25 days after sowing. Seeds can be used to raise seedlings, but it is generally not recommended to use seeds to cultivate them because it is difficult to survive. Cutting seedlings are often used in production, which is easy to survive. Precious varieties are hard to cut.
(2) Cutting: It can be carried out in early spring or rainy season. Cutting, also known as cutting, is a common propagation method for cultivating plants. It is easy to survive by cutting seedlings with tender branches of that year. Choose strong branches without pests and diseases as cuttings. After selecting cuttings, handle them carefully. The tender cuttings should be cut immediately after harvest to prevent wilting from affecting survival. Generally, the lower incision of plant cuttings, such as some freshly burned plant ash, can prevent rot. Generally speaking, plant cuttings take root fastest at 20-25℃. Too low temperature will slow down rooting, and too high temperature will easily cause cuttings to rot. Therefore, if the temperature is artificially controlled, cutting can be carried out all year round. Under natural conditions, the temperature is suitable in spring and autumn. Care should be taken to keep the cutting substrate moist after cutting, but it should not be too wet, otherwise it will cause rot. At the same time, we should also pay attention to the humidity of the air, which can be maintained by covering it with plastic film, but we should pay attention to ventilation for a certain period of time.
3. Cultivation and management techniques of Rosa roxburghii: ensure sufficient fertilizer and water during cultivation, and apply fertilizer 1 time every month from early spring to early summer. Pay attention to properly thinning out the curved branches on the ground to facilitate ventilation and light transmission. In the process of growth, the base and trunk are easy to grow long branches, and the short branches can germinate, blossom and bear fruit in the next year.
(1) Watering: When planting wild roses underground, you should pay attention to pouring enough water in summer drought, especially in bud pregnancy and flowering period, and don't accumulate water in rainy season.
(2) Fertilization: human manure or decomposed organic fertilizer can be applied in winter ploughing and then turned into the soil. Roses and peanuts should be fertilized frequently for a long time, and topdressing 1-2 times of available fertilizer after flowering. Thin fertilizer should be applied during high temperature and drought, the last fertilizer should be applied before winter, and weeds should be removed in time before fertilization.
(3) Pruning: Pruning the wild rose in summer is mainly to cut off the budding flowers of the grafted rootstock, cut off the residual flowers after flowering, and sparse the redundant buds, so as to reduce the consumption of nutrients and create good conditions for the next flowering. In order to make the plant beautiful, the long branches 1/3 or half can be cut off, the middle branches 1/3 can be cut off, and the leaves above 1 cm can be cut obliquely. If the pruning is too light, the rose plant will grow taller and taller, the branches will grow longer and thinner, and the flowers will be smaller. Pruning in winter depends on varieties and cultivation purposes. When pruning, you should keep the branches and pay attention to the overall shape of the rose plant. Large-flowered varieties should have 4-6 branches with a length of 30-45 cm, and the upper branches should be cut off. For vines or vine varieties, we should dilute the old skills, cut off weak branches and diseased branches, and cultivate the trunk.
4. Control methods of Rosa roxburghii pests and diseases: Wild Rosa roxburghii has few pests and diseases, and sawflies, rose sawflies, scale insects, aphids, scorched leaves, canker, black spot and other pests and diseases often appear in artificial cultivation. In addition to spraying water, it should be used in conjunction with other flowers and trees, and it is not advisable to plant too much in one place. Every winter, pruning old branches and dense branches frequently, keeping light and good ventilation can reduce pests and diseases.
5. Distribution of Rosa roxburghii: Rosa roxburghii is distributed in Shaanxi, Gansu, Jiangxi, Anhui, Zhejiang, Fujian, Hunan, Hubei, Sichuan, Yunnan, Guizhou, Tibet and other provinces in China, and it is wild or cultivated everywhere. Japan also has it. This flower is cultivated and has high horticultural value.