How to choose eucalyptus seedlings?

How to choose eucalyptus seedlings? What are the ways of raising eucalyptus seedlings? What are the varieties of eucalyptus? Please introduce the choice of eucalyptus seedlings can be selected from the following points for reference. Choose from the way of raising seedlings: first, tissue culture seedlings: also known as gene seedlings, refers to the use of modern science and technology in the laboratory to make use of the totipotency of cells, through asexual reproduction, the production environment has been controlled, through the annual renewal of breeding materials, retain the excellent characters of quality and the best genetic gain. The characteristics of tissue culture seedlings are that the cultivation time is longer, the development of seedlings is more complete, the root system is developed, there is a main root system, the stress resistance is stronger than that of cutting seedlings, the survival rate of afforestation is higher, and the growth is relatively larger. Second, cutting seedlings: generally refers to the seedlings cultivated by cutting off the active lateral branches on the specially cultivated eucalyptus mother plant and soaking the rooting powder to promote the bark tissue to grow into roots. Cutting seedlings are characterized by low cost, short cultivation time and simple operation. On the whole, the growth activity and growth of tissue culture seedlings were slightly lower than those of tissue culture seedlings. Third, seed seedlings: refers to the eucalyptus seedlings cultivated with the fruits of eucalyptus. The operation of the seed seedling is simple and the cost is low, but because the genetic character is unstable, the variation is relatively large, and the activity of the seedling is relatively low, which will affect the overall growth and talent rate. Seed seedlings are gradually not being adopted by people. Suggestion: in most cases, the growth of tissue culture seedlings has more advantages than cutting seedlings and seed seedlings. Especially in the case of poor growth conditions, such as late planting time, high temperature, low moisture, poor soil and frequent termite activity, the survival rate of tissue culture seedlings is higher than that of cutting seedlings and seed seedlings. Selected from eucalyptus varieties: DH3229: the hybrid with Eucalyptus urophylla as female parent and Eucalyptus grandis as male parent has obvious excellent characteristics and better cold tolerance than Guanglin 9. The growth per unit area can reach 45 cubic meters / year * HM. Resistant to bacterial wilt and scorch wilt, and strong sprouting ability of cutting stakes. Generally, it can be closed into a forest in about a year, and as a short-term industrial raw material, it has faster economic benefits. It is suitable for planting in Guangdong, Guangxi and other areas with high temperature all the year round. Guanglin 9: the hybrid with Eucalyptus grandis as female parent and Eucalyptus urophylla as male parent has the excellent characteristics of parental parents. Good wind resistance. The growth per unit area can reach 45 cubic meters per year * HM, resistant to bacterial wilt and scorch wilt, and the sprouting ability of cutting stumps is strong. Generally, it can be closed into a forest in about a year, and as a short-term industrial raw material, it has faster economic benefits. It is suitable for planting in Guangdong, Guangxi and other areas with high temperature all the year round. Eucalyptus camaldulensis No. 3: it is a new fast-growing and cold-tolerant variety selected by natural hybridization between Eucalyptus urophylla and Eucalyptus camaldulensis, which can withstand a low temperature of minus 10 degrees Celsius. The growth per unit area can reach 45 cubic meters / year * HM. Resistant to bacterial wilt and scorch wilt, and strong sprouting ability of cutting stakes. Generally, it can be closed into a forest in about a year, and as a short-term industrial raw material, it has faster economic benefits. It is suitable for planting in areas with long frost time. Note: eucalyptus seedlings are prone to scorch blight and bacterial wilt. Eucalyptus seedlings should be identified so as not to buy diseased seedlings. Scorch blight often occurs in the cutting nursery, harming young leaves, twigs and shoots. When the disease is serious, the seedlings die quickly. Scorch blight is mainly characterized by light brown to brown, round or irregular spots on branches and leaves. When wet, the edge of the disease is waterlogged, and the spot seems to have been scalded by boiling water; when dry, the boundary of the spot is obvious, and the downy mildew on the back is not easy to see. Scorch blight mostly occurs in high temperature and humid season, and cuttings are more vulnerable, because in the seedbed, the disease is more prevalent because of high temperature and relative humidity. Eucalyptus scorch blight and bacterial wilt can also be controlled: 1. Select the nursery: the nursery should be located in the place of air circulation, not close. 2. Strengthen the management: control the moisture of the seedbed. In summer, proper shading and grass mulching can reduce soil temperature, appropriately increase fertilizer, promote seedling growth and improve disease resistance. In hot and humid summer, 0.5-1% Bordeaux solution should be sprayed once a week to protect seedlings or 75% chlorothalonil 600-800 times. The cuttings of the cuttings should be disinfected, generally soaked with 0.2-0.3% potassium permanganate for 6 hours, and then washed with clean water before being inserted into the nutrition bag. The first application began the next day after entering the bag, first disinfected with 0.2% potassium permanganate, then washed the seedlings with clean water, and then sprayed with 75% chlorothalonil 600-800 times, once a week. 3, and the treatment of diseased plants: when diseased seedlings are found, they should be removed, and 0.2-0.3% potassium permanganate is used to spray seedlings to inhibit the further spread of the disease. Wash the seedlings with clean water after spraying. Click to get more eucalyptus planting techniques click to get more flower planting techniques