Propagation of Magnolia denudata and afforestation techniques for pest control

Propagation and Pest Control and Afforestation techniques of Magnolia Magnolia

1 Biological characteristics and value of Magnolia mandshurica

1.1 morphological characteristics

Magnolia Magnolia, crown ovate, leaves alternate, leaf tip short and pointed, leaf base cuneate, large leaves Obovate, surface luster. The shoots and buds are covered with short villi, the branches and buds are dense in winter, and there are grayish green long hairs outside the buds. The whole plant blossoms first and then leaves, the flowers are pure white and fragrant, the petals and calyx are similar, and the florescence is 8-10 days. It blossoms from March to April and ripe fruit from September to October. The fruit is a black aggregate follicle with a heart-shaped seed. When the site condition is good, the height of the tree can reach more than 15 m.

1.2 Ecological habits

Magnolia prefers light, moisture, waterlogging, shade tolerance, fertile, well-drained and slightly acidic sandy soil, so it is one of the better greening tree species to prevent air pollution. Planting Magnolia should choose slightly acidic soil with elevation below 200 m, sunny slope and deep soil layer. When the soil is poor, the growth rate is slow.

1.3 Economic value

Magnolia magnolia has a certain medicinal value, which contains volatile oil, mainly citral, clove oleic acid, alkaloid, decanoic acid, rutin, oleic acid, vitamin A, etc., which can be used for headache, nasal congestion, acute and chronic sinusitis and so on. at the same time, it also has an inhibitory effect on common skin fungi; because of its thick flesh and unique fragrance, the petals can be eaten fresh or dried.

2 raising seedlings

Magnolia Magnolia is often propagated by sowing, grafting, striping, root division and other methods, and the survival rate of cutting propagation is low. Magnolia Magnolia is routinely propagated by seed to raise seedlings. In the vegetation restoration of ecological public welfare forest, it is very important to select seedlings propagated from excellent provenances for afforestation.

2.1 seed harvesting and storage

2.1.1 seed collection

It is appropriate to choose middle-aged trees with more than 20 years old, straight stem shape, healthy growth, no diseases and insect pests and more fruit. When the pericarp of Magnolia magnolia hardens, turns red, and slightly cracks to reveal the red aril, the seeds can be collected and fully mature seeds can be collected. Seed collection began in late August and ended before September 20 in Anqing area. If the seed is collected too early, the immaturity of the seed will affect the germination rate; if the seed is collected too late, the aggregate fruit will crack completely, and the seed will fall off and is not easy to be collected, and it is easy to be gnawed by rats.

2.1.2 seed modulation

(1) threshing. After the fruit is picked, it should be spread out to dry. When the pericarp is cracked by itself, the seed can be removed and the red seed can be obtained. Avoid moisture in the drying process, the seeds will no longer crack after moisture, so it is necessary to avoid rain and dew.

(2) soaking seeds. When the seeds that have been removed are immersed in water, the full seeds will sink to the bottom of the water, and the empty grains and sundries will float on the surface to remove sundries such as empty grains. The time of soaking seeds is generally 1-2 days, not more than 2 days, during which the seeds should be turned frequently. 3% to 5% sodium hydroxide can be added during seed soaking, which helps to accelerate the softening of aril to facilitate cleaning.

(3) cleaning. Scrub repeatedly with plant ash to prevent mildew during storage. If there are obvious white spots in the hilum, it means that the seed is not washed clean, it is easy to cause mildew in the future and needs to be re-washed.

(4) Yin dryness. After cleaning, put the seeds in a ventilated place, the beach is thin and dry. The faster the process of drying, the better. In case of high humidity, you can use an electric fan to dry the surface of the seed and turn it by hand every half an hour. Taboo seeds are directly exposed to the sun, otherwise they will lose their vitality. Normal seeds are dark yellow to black. Seeds with light yellow and white colors should be picked out. The seeds will be basically dry after 20 days of shade drying.

2.1.3 Storage

Magnolia seeds are mostly stored in low temperature wet sand. Wash the ordinary river sand and disinfect it with 0.2% potassium permanganate. The humidity should be kneaded into a ball and dispersed. Storage method: one layer of sand and one layer of seeds are stacked indoors, and the thickness of each layer of sand is 2: 3 cm. Turn every 1-2 weeks during stratification to aerate. Check the humidity of the sand and pick out rotten seeds with more gravel on the seed coat.

2.2 selection and treatment of nursery sites

Sowing seedbed production. Magnolia fleshy root, afraid of waterlogging, the nursery should choose sandy loam with high terrain and good drainage and irrigation conditions, achieve three ploughs and three harrows before sowing, apply sufficient basic fertilizer (the amount of fertilizer is rotten cake fertilizer or compound fertilizer 3000 kg/hm2), disinfect the soil with carbendazim or carbendazim to make a high bed with a flat bed. The surface of the bed is covered with yellow soil about 10 cm thick.

2.3 sowing and management

Sow seeds at the end of March and the beginning of April. Sowing seeds for 60 kg/hm2, covering sawdust or burning ash soil 0.2cm thick after sowing, spraying water to cover straw or sunshade net to keep the bed moist.

2.4 Disease and pest control

The seedling stage focuses on the prevention and control of seedling blight and root rot. There are many Rain Water in the plum rain season from June to July, and the humidity is too high, so it is easy to get sick. It is necessary to remove the diseased plants in time and burn them centrally; spray 300 times 600 times Bordeaux solution or 65% 600 times Dysen zinc solution when the disease occurs, or irrigate with 70% methyl thiophanate 1000 times wettability solution.

3 afforestation

3.1 site selection

Magnolia should choose the middle or lower sunny slope with medium or deep soil layer, and the loose acid or slightly acidic soil in valleys and foothills should be avoided, and the lowland with stagnant water and the flat land with poor drainage should be avoided.

3.2 afforestation and land preparation

The cave soil preparation is adopted, and the specification is 40 cm × 40 cm × 40 cm. Remove tree roots, stones, weeds and so on. When preparing the soil, it is necessary to separate the topsoil from the core soil, and backfill the topsoil first and then the core soil when backfilling. Backfilling can be carried out at the same time as fertilization.

3.3 planting density

The planting density of ecological public welfare forest should refer to the crown width of this tree species and be planted densely appropriately. In the afforestation of local ecological vegetation restoration, the planting density of Magnolia Magnolia is 3 m × 4 m.

3.4 mixed forest construction

In the subcompartment selection of vegetation restoration afforestation, mixed afforestation was carried out with two or more native tree species. Locally, choose magnolia and maple incense block mixture. Magnolia magnolia is planted deeply in the soil layer and maple incense is planted shallowly in the soil layer.

3.5 afforestation time

The best afforestation time of Magnolia is before sprouting or before spreading leaves in the early stage of blooming. The seedlings were watered once 4-5 days before seedling emergence, so that the plants could absorb sufficient water, which was beneficial to the survival after planting and the soil ball formation when the seedlings were taken out. The root system should be damaged as little as possible when digging, and the soil ball should be taken when taking seedlings, and the diameter of the soil ball is 8-10 times of the ground diameter of the seedling. The earth ball is tied up with straw rope to prevent it from falling apart during transportation.

3.6 Technical requirements for afforestation

In the afforestation technology, we should do the following: with planting, shorten the time as far as possible and keep the roots moist; trim the necessary roots and branches before planting; big seedlings should be planted with soil balls, dig big holes, re-apply base fertilizer, and set up supports in time after planting; proper deep planting can inhibit tillering and is beneficial to growth; watering should be done immediately after planting.

4. Tending and management

4.1 weeding and loosening the soil

In order to promote the growth of young forest, green shrubs can be interplanted from afforestation to canopy closure. Combined with the water and fertilizer management of green seedlings, the young forest was loosened and weeded from May to August to promote the growth of young forest.

4.2 Water and fertilizer management

Magnolia likes fertilizer, in addition to the application of base fertilizer when planting, it should be properly fertilized every year since then. Fertilization was carried out four times a year, that is, applying nitrogen, phosphorus and potassium compound fertilizer once before flowering to improve flowering quality and beneficial to spring growth; applying nitrogen fertilizer once after anthesis to increase plant growth and expand nutrient area; applying phosphorus and potassium compound fertilizer once from July to August to promote flower bud differentiation and improve the Lignification degree of new branches; applying circle fertilizer with ripening fermentation before winter can improve soil activity and soil temperature.

4.3 plastic pruning

Magnolia mandshurica has strong sprouting and fecundity, and often sprouts to form multiple dry strips, which affects the formation and growth of the trunk. In order to control the growth of sprouting strips, the sprouting strips can be chopped off, the stem shape can be arranged and the trunk growth can be maintained within 1-2 years before and after canopy closure. Pruning period should be selected after flowering and before a large number of sprouting, pruning to remove diseased branches, overdense branches, redundant branches, parallel branches and long branches, usually should remove sprouting at any time.

4.4 Disease and pest control

Magnolia magnolia is a tree species with strong disease resistance, which is mainly harmed by longicorn beetles and occasionally underground pests such as grubs. Green Weilei 500 times solution can be selected to kill longicorn beetles, 50% zinc parathion emulsion 1000 times liquid root irrigation to kill grubs.