First, willow cultivation.
1. Tree species selection. There are many kinds of willows all over the country. There are dozens of willow varieties in China, among which weeping willows, dry willows, yellow willows, long-leaved willows and river willows are the most common, and the growth habits of each willow are different. Therefore, when choosing willow tree species, we should choose according to the local climate conditions and soil texture. Generally speaking, the soil thickness suitable for willow growth should be above 0, 7 meters, and the PH value should be below 8.
2. Planting density of willow. Willow planting should not be too sparse, which is easy to cause floating soil phenomenon and can not effectively improve the climate conditions; It should not be too dense, which is not conducive to the growth and photosynthesis of willow trees. Therefore, the planting density of willow should be 4~5 meters, and the floating range should not be too large.
3. willow planting. The common willow planting method is cutting propagation, which can maintain the advantages of the mother tree. Usually in winter, the hibernating willow branches are cut off, and the length of each branch should be about 17 ~ 18 cm, and it should have more than three teeth. Then, the branches are cultured in water for a period of time, about ten days. Finally, inserting branches into the soil can improve the survival rate of willow, reaching more than 70%, and water it in time after planting in the soil.
4. willow irrigation. Water is a necessary condition for willow growth. Therefore, after planting saplings, it is necessary to ensure that the soil moisture is sufficient. Trench irrigation is generally used in irrigation, which is beneficial to water infiltration and avoids flooding, which will cause the loss of nutrients in the surface layer of soil, and the phenomenon of rotten roots and soil hardening will appear.
5. Fertilization of willow. In order to ensure that the soil has enough nutrition, fertilization should be done well before sowing seedlings to ensure soil fertility. After planting saplings in spring, a shallow annular ditch is dug around the willow, with urea as the main fertilizer, and phosphate fertilizer, slag fertilizer, compost and farmyard manure are applied in the ditch. In the choice of fertilizer type, if root irrigation is selected, water-soluble fertilizer is used; If you choose foliar fertilizer, choose foliar fertilizer.
6, willow loosening soil to weed. After planting the willow, you should take good care of it. Regularly loosening soil can maintain soil fertility, break hardened soil, loosen soil structure, increase soil permeability, and make tree roots breathe smoothly. In addition, regular loosening can also reduce the evaporation loss of water. Regular weeding can uproot redundant weeds and seedlings, and prevent these weeds from robbing willow of nutrients and water, resulting in insufficient nutrient absorption of willow. In addition, weeding can increase the growth area of willow, increase the photosynthesis of willow and reduce the erosion of pests and diseases. It should be noted that when selecting herbicides, we must be careful not to let chemical drugs affect the health of willow trees.
7. Pruning and sprouting of willows. Under normal circumstances, when pruning the side branches, the annual seedlings can't prune all the side branches, which may cause the willows to grow crooked, so they should be reserved when pruning the side branches; Two-year-old seedlings can prune all the side branches above the trunk when pruning. Willow branches should be pruned frequently to prevent redundant branches from absorbing nutrients, ensure that the nutrition of the trunk can be sufficient, and improve the overall illumination and air permeability of the willow. Pruning branches often can also make willows grow well.
Second, willow pest control,
1, willow rust. Willow rust is a common willow disease, which usually occurs in May and June in summer. In summer, the summer roe deer grows behind the leaves, and the newly grown summer roe deer is round and small in shape. The protection of willow rust is generally in the seedling stage. When raising seedlings, willow seedlings with strong ability of flying pests and diseases should be selected, and the density should be appropriate when planting. In addition, weeding is also a key factor. Weed regularly in spring and summer to prevent other weeds from spreading diseases and pests to willow trees. Once the disease occurs, it should be treated in time. 25% triadimefon wettable powder can be sprayed 800 times, about 3 times, 20 days/kloc-0 times. In this way, willow rust can be well treated.
2. pear psylla. Pear psylla is a common pest, especially harmful and contagious. Adult psyllid sucks the sap of willow buds, leaves and twigs, among which nymph is the most harmful, which can cause chloasma on willow leaves, and in severe cases, it can fall off early. In addition, the larvae of psyllid can secrete a lot of mucus, which in turn causes other diseases and insect pests of willow trees. The best time to control psyllid is mainly in early spring. On the one hand, the old bark of willow trees should be torn off; On the other hand, weeds and branches and leaves of dead trees accumulated in a winter should be cleared in early spring to prevent the adults of psyllid from doing harm to willow trees. Once the willow is eroded by psyllid, 40% dimethoate emulsion 1000 times solution and 20% pyrethroid emulsion 3000 times solution can be sprayed on the affected area, which can effectively kill psyllid and protect the healthy growth of willow.
Other auxiliary methods:
1. Trees and dead branches that have died or been seriously infected should be cut down or pruned in time, and the cut trees and dead branches should be burned centrally to prevent the spread of germs. It is necessary to select suitable disease-resistant tree species and update the clearing section of diseased trees in time.
2. Strengthen post-planting management to promote the robust growth of trees. Poplars and willows on both sides of roads, rivers and ditches should be coated with white paint to prevent sunburn or frostbite.
3. When necessary, apply 50% carbendazim wettable powder or 25 times solution of 10% lye and a small amount of diesel oil to the broken skin of the diseased trunk. For larger lesions, antirust paint, 5% anthracene oil emulsion stock solution, arsenic solution, oil absorption without dephenolization or 3 times alkaline water can be used for treatment.
4, advocate the use of anti-corruption 1. Scrape the diseased scar on the tree into a stubble prism with a scraper, and scrape it into the bark for 0, 3~0 and 5cm. After scraping, apply the liquid medicine evenly on the diseased scar with a brush. The original drug 1 kg can treat 200~250 lesions and scars. During prevention and control, the original drug can be diluted 20~25 times and evenly coated on the trunk or side branches. Generally, young trees should not be coated with the original medicine to avoid phytotoxicity.
Third, the conclusion
In recent years, due to the serious damage to the ecological environment, the state has put forward the initiative of returning farmland to forests and protecting natural vegetation, and issued corresponding vegetation protection policies. At the same time, due to the advantages of willow itself, large-scale cultivation of willow can not only increase the green area in China, but also meet the economic and social demand for wood, which can be described as killing two birds with one stone. We advocate protecting the environment, protecting green vegetation and taking the road of sustainable development. I hope that the willow cultivation methods and pest control methods discussed in this paper can help forestry workers.
1, propagation, cultivation and management
Variety selection 1. 1
There are many kinds of willows all over the country, and each kind of willow has different growth patterns and habits. Therefore, the selection of willow varieties should be based on the actual situation, and the varieties that meet the local soil conditions and climate environment should be selected. Generally speaking, the most suitable soil for willow growth is more than 0.7m thick, and the PH value of the land is less than 8.
1.2 planting density
When planting willows, they should not be too thin or too dense. Sparse planting or dense planting are easy to cause floating soil, which can not adjust the climate and improve the environment. Therefore, when planting willows, the density must be controlled. The planting density is generally controlled at 4-5m, and the floating range cannot be too large. Controlling the planting density of willow plays a great role in photosynthesis and improving climate conditions.
Cutting propagation of 1.3
The most common propagation method of willow is cutting propagation, and it can also be sown to raise seedlings. Cutting in early spring, choosing good plants with fast growth and less pests and diseases as cutting mother trees can not only retain the original advantages of willow, but also improve the survival rate. During overwintering, willow branches are cut into cuttings with the length of 15 ~ 17 cm, and directly inserted into the soil, and the row spacing of the cuttings is 20 ~ 30 cm.
1.4 Irrigation and fertilization
Water is a necessary condition for willow growth. In the process of willow irrigation, it is necessary to ensure sufficient water in the planting soil to avoid willow root rot and soil hardening. Therefore, it is forbidden to flood irrigation, and it is better to use furrow irrigation, which is helpful to water infiltration, improve soil moisture and provide sufficient water for willow growth.
In addition to the necessary water supply, it is also necessary to apply corresponding fertilizers as nutrient supply at all stages to make willow grow healthily and rapidly. In order to ensure soil fertility, the corresponding soil fertilization work can be done well before seedling raising; In addition, a shallow annular ditch can be dug around the willow, and urea is the main fertilizer. At the same time, farmyard manure, slag manure and phosphate fertilizer can be applied in the ditch, and more water-soluble fertilizers can be selected when selecting fertilizers, and some foliar fertilizers can be sprinkled on willow leaves when necessary.
1.5 loosening soil and weeding
In order to maintain soil fertility, reduce water evaporation and loss, and break the hardened soil, you can loosen the soil regularly to make the roots of trees breathe smoothly. In order to prevent weeds from robbing willows of nutrients and water, it is also possible to reduce the breeding of pests and diseases by regularly removing redundant weeds and seedlings.
1.6 Pruning and terminal bud of willow
Under normal circumstances, annual seedlings can't prune all the side branches, which may lead to willows growing crooked. When two-year-old seedlings are pruned, all the side branches above the trunk are pruned. Willow branches should be pruned frequently to prevent redundant branches from absorbing nutrients, ensure the nutrition of trunk, and improve the overall light transmittance and air permeability of willow.
2. Common pests and diseases and their prevention and control
2. 1 Common pests and diseases and their control
2. 1. 1 willow rust
Willow rust is a common willow disease, which mostly occurs in May and June. In order to prevent willow rust, it is necessary to choose seedlings with strong resistance to pests and diseases, master appropriate planting density and choose appropriate weeding methods when raising seedlings, and weed in time in spring and summer to avoid the spread of pests and diseases among seedlings.
Main treatment method: 25% triadimefon wettable powder can be sprayed 800 times, about three times, once every 20 days.
2. 1.2 psyllid
Pear psylla is a common pest, which has the characteristics of "extremely fast damage" and "fast infection" Adult psyllid sucks the sap from willow buds, leaves and twigs. We must grasp the best control time when controlling. In addition, the larvae of psyllid can secrete a lot of mucus, which will lead to other diseases and insect pests of willow trees. Mild willow leaves will appear chloasma, and severe willow leaves will fall off in advance.
Main control methods: early spring is the best time to control psylla pyrifolia, one is to clean up weeds and dead leaves accumulated in winter, and the other is to use white paint. If necessary, break dead or seriously infected trees, dead branches and old barks, and smear them with sterile 1 ... If willow is eroded by psyllids, it is recommended to use 20% pyrethroid emulsion 3000 times and dimethoate emulsion 100 times, and spray them on the diseased parts of willow after preparation, so as to effectively kill psyllids and promote the healthy growth of willow. .
2. 1.3 root rot
Once suffering from root rot, the roots of willow will rot. When the illness is mild, diseased spots will appear on the branches, and when the illness is serious, the whole willow will dry up. At this time, it is necessary to pull out the whole willow and isolate the diseased willow from other disease-free saplings, so as to effectively control the spread and spread of willow pests and diseases.
Main control methods: A common and effective control method is to select some agents with good antibacterial effect, such as triadimefon, chlorothalonil, carbon disulfide, sanfumei, copper sulfate, tridemorph and so on, for the control of willow root rot. It can be treated twice a year in early spring and late summer when bacteria start to move. At the same time of chemical control, measures such as soil disinfection with 20% formalin solution and replacement of exotic soil can be used to cooperate with control. Another simple way is to take the soil near the focus of root rot, remove the rotten roots, cover it with plant ash, and then cover it with new soil. This method is simple, economical and effective. Generally speaking, after careful operation and management, the control effect of the above measures is above 95%.
2. 1.4 poplar gray leaf spot willow is the most susceptible to poplar gray leaf spot at seedling stage, and the occurrence of this disease is closely related to rainfall and air humidity, mainly in the hot and rainy season from June to July. Many kinds of willows and poplars, from seedlings to young trees to big trees, can suffer from this disease. Seedling stage and young trees suffered the most, and the common symptoms were premature falling of diseased leaves and dead shoots. If the disease occurs on leaves and twigs, water stains will appear on the leaves, and dark green protruding hairy spots will appear at the umbilicus of the pathogen in the later stage. After the disease, the tops of seedlings and young trees will turn black, lose support and droop.
Main control methods: spray sterilization with carbendazim and thiophanate-methyl. , every month 1 time, 3 ~ 4 times; Implement crop rotation, do not reuse the same piece of land as a nursery, and the cuttings should not be too close [4].
3. Conclusion
The prevention and control of diseases and insect pests of willow should be carried out at all growth stages, and suitable disease-resistant tree species should be selected and diseased trees should be planted in time; The cut trees and branches should be burned centrally to prevent the spread of germs; After planting, strengthen management and maintenance, paint the trunk with white paint to prevent sunburn or frostbite, and promote the robust growth of willow; You can also use omethoate solution for prevention and control, and take prevention and control measures twice a month, which can promptly eliminate common summer pests and diseases such as longicorn beetles, ladybugs and leaf curl moths; But don't apply the original medicine to the girdling mouth of the young flourishing tree to avoid phytotoxicity.