"Cultivated Techniques for Rapid Growth and High Yield of Larix principis-rupprechtii"

4. The test area of ​​the test area should be located near the office area for easy observation and management at any time.

(B) Planning of auxiliary land

The planning of auxiliary land should be based on the ability to meet production needs, and occupy as little land as possible. It should generally not exceed 15% of the total area of ​​the nursery, including road network, irrigation pipelines, office areas, and conditional or large-scale nurseries. Also consider the setting of windbreaks and hedgerows.

1. The setting of the road network road network should pay attention to the division of main roads, sub-roads and trails. The main road is the main transportation line running through the center of the nursery. It should be connected with the nursery gates, seedling screening sheds and main warehouses. The width depends on the size of the nursery, but it must not be less than 4m. The roadbed is slightly higher than the ground. The secondary roads are located at two main roads, which are perpendicular to the main road. The width of the roads may be smaller than the main road. The number of sub roads should be determined according to the daily operation of the nursery. The trails are mainly used for the passage of workers, with a width of 0.5 to 1m, and an alternative trail with a bed ditch.

2. Irrigation system In order to save water and occupy land, the main pipelines and culverts are mainly set up, and the main pipelines and branch pipelines are divided. The specific specifications vary with the area of ​​the nursery and the amount of one irrigation. The pipeline should be laid below the maximum permafrost to prevent freezing in winter. If sprinkler irrigation, should be reasonable configuration, there is enough Yang Cheng's water pump, outlet pressure above 3kg/cm2, nozzle density is generally 15m ~ 20m. Drainage systems should be located on the edge of the nursery and on the outside of the road, with access to rivers or other low-lying lands.

3. The windbreak forest belt windbreak forest belt shall be set perpendicular to the main wind direction, and the windbreak belt setting of the network format shall be carried out conditionally. The cultivation of Larix principis-rupprechtii should not be used as a windbreak forest to prevent the spread of pests and diseases, especially to increase the host of certain pathogens.

4. The setting of office area and warehouse office area and warehouse shall be determined according to the size of the nursery area. The principle is to choose the place where the soil conditions are poor and easy to operate. The land area is about 1% to 2% of the nursery area.

Section 2 Soil Preparation, Soil Fertilization, Sterilization, Bedding

One, site preparation

Soil preparation is to create favorable conditions for seed germination, seedling growth and root development, including arable land, alfalfa and repression. Soil preparation is conducive to loosening the soil, enhancing ventilation and water permeability, increasing ground temperature, facilitating the activities of microorganisms, promoting the decomposition of organic matter, and maturing of soil, eliminating weeds and diseases and pests, and is an important measure to improve soil fertility. The northern region is relatively arid, mainly autumn ploughing, with the depth of the roots of the seedlings of two-year-olds as the standard (about 30cm), with the ploughing and hoeing, destroying the wintering sites of underground pests. Repression in the early spring to facilitate the protection. After the site preparation, it will be fine and flat, and there will be no large clods and debris to prevent the accumulation of water after the rain.

Second, soil treatment and fertilization

In order to improve the soil and increase the content of organic matter, the pathogenic bacteria and the underground pests in the soil will be eliminated, and a good growth environment will be created for the cultivation of high quality seedlings. Soil fertilization and disinfection must be done before sowing.

1 Base fertilizer (also known as base fertilizer) Base fertilizer can provide long-term nutrients needed for seedlings, that is, it can fertilize the soil and improve the soil. It mainly uses organic manure such as green manure, compost, farmyard manure and applies 3-4 tons of organic fertilizer per acre. . Fertilization method: Before the bed is made, the base fertilizer is transported to the nursery ground. The base fertilizer is spread evenly on the basis of the site preparation. In the nursery of phosphorus-deficient fertilizers, to supplement the phosphorus content, the superphosphate can be crushed and evenly sprinkled on the surface with 25kg per acre, and plunge into the soil with a depth of 20 to 30cm with an iron plow. If the organic fertilizer is insufficiently prepared, diammonium phosphate (15kg per mu) or compound fertilizer (20kg per mu) can be used instead of inorganic fertilizer as the base fertilizer. Organic manure must be sufficiently cooked to kill weed seeds and germs.

2 The improved soil is reclaimed from sand at the planting time, accumulated year by year, and the nursery is desertified. The use of inorganic fertilizers increases the degree of soil compaction. In order to keep the nursery soils soft and fertile for a long period of time, every continuous crop should be soiled for 8 to 10 years. For improvement, it is best to use pine needle soil. Pine needle soil has mycorrhizal bacteria and can increase the root absorption area after inoculation. The application amount is 5 tons per acre, and the depth is 20-30M deep after spreading. L. Mycorrhizae exist in the nursery of old nursery larch and larch forest soil. The inoculation of mycorrhizal fungi is mainly accomplished through the use of indigenous soil. In the inoculation process of mycorrhizal fungi, mycorrhizal fungi should be prevented from being exposed to high temperatures and sunlight, and they should be watered after application to maintain a certain humidity, which is conducive to survival and reproduction.

3 The commonly used pesticides for soil disinfection include quintozene, ferrous sulfate, formalin, dexamethasone, Suhua 911, phoxim, etc. (which can all be synchronized with fertilization). Ferrous sulphate is a commonly used soil disinfectant, not only has a bactericidal effect, but also regulates soil pH, and can increase iron in the soil. Formalin is a very effective soil disinfectant. It can cultivate valuable nursery stocks with small area or can be treated with formalin to treat soil. Pentachloronitrobenzene has a good bactericidal action against Rhizoctonia and has a long potency. Therefore, in the nursery with Rhizoctonia as the main pathogen, the use of this agent has a good effect on soil treatment. However, it has no good effect on Fusarium, so it should be mixed with other fungicides, such as Dexon, Suhua 911 and so on. The use method (amount) is shown in Table 3-1.

Table 3-1 Soil disinfection methods

Pharmaceutical name

Instructions

effect

Ferrous sulphate

Each square meter is sprayed with 2% solution 5kg on the surface of the soil, or 20kg per acre. After crushed, it is evenly spread on the surface and turned into the soil through the arable land.

Sterilization, effective in preventing and treating damping-off

Pentachloronitrobenzene

Use 40% powder 5.5kg per acre, mix evenly with fine soil

Sterilization

Formalin

After spraying with 40% of the drug 200 times, it will be sealed for 3-5 days, then it will be sown in the sun for 2-3 days.

Sterilization

Phoxim

Apply 1 to 1.5 kg of medicine per acre into soil

Insecticide

Third, make a bed

Larch nursery takes the bed as the main, the layout of the seedbed extends from the east to the west, and the north and south direction of the seedlings is appropriate, so that the seedlings are well ventilated and evenly distributed, which is beneficial to photosynthesis. The seedbed is divided into three types: high bed, low bed, and high bed (to bed). The new breeding (sowing) area should be based mainly on high beds, and the transplanted seedlings can be used as low beds. High bed: The bed is 10-20 cm higher than the trail, the width of the bed is 120 M, the width of the trail is 30 cm, and the length of the seed bed is determined according to the size, shape and irrigation method. The advantage of the high bed is to increase the thickness of the nutrient soil layer of the seedbed, which is conducive to raising the temperature of the soil, drainage is good, and it is convenient for the side irrigation, the bed surface is not easy to be compacted, and the mechanical operation is convenient. After the high bed is completed, the sunken bed should be poured so that the bed body has sufficient impact resistance, which reflects the fact that the upper jaw is solid and is conducive to sowing. Lower bed: The bed is lower than the trail 15-20cm, the trail is 30cm wide, 5-10m long, and a drainage ditch should be left between each row of beds. Its advantage is that it is easy to irrigate and is beneficial to drought.

Section III Seed Treatment and Germination

First, the purchase of seeds and the determination of the amount of sowing

(1) Seed purchase

It is better to use the seeds of the seed gardens and mother trees in this area. If the locals cannot really meet the requirements, the purchased seed must be the same or similar to the climate and soil conditions in the nursery area. To purchase seeds, the quality of the seeds should be tested first, and the seed supply units should be requested to include the seed sources, seed harvest time, seed quality, grade, and quarantine certificate.

(II) Determination of seeding rate

After the above tests (see Chapter 3, Section 3), the seeding rate is calculated using the following formula.

X=( A・W/P・G・10002・)C

In the formula: X: Actual required sowing amount per unit area (kg)

A: Planned seedling yield per unit area

W: Thousand grain weight (g)

P: Clarity

G: germination rate

10002 is a constant

C. The loss factor varies with seed size, soil conditions, and technical level. Larix principis-rupprechtii generally ranges from 1.7 to 1.8.

Second, seed disinfection and germination

Treating seed can promote seed germination, increase seed germination potential, make emergence of young shoots and seedling emergence neat and robust, reduce occurrence of seedling pests and diseases, seed treatment is the center work before sowing.

(I) Seed disinfection

Seed disinfection commonly used agents and methods.

(1) Use 0.3% potassium permanganate solution to soak seeds for 30 minutes, remove and wash with water, and soak in fresh water for 24 hours to perform winter storage or germination. It should be noted that potassium permanganate has Disinfection and promote the germination of seeds, but the seeds of the radicle has broken through the seed coat should not be disinfected with potassium permanganate solution to prevent phytotoxicity.

(2) Use 0.15% formalin solution, soak for 20-30 minutes, remove the seal for 2 hours and then wash the seeds with clean water for winter storage or direct germination.

(3) Soaking with 0.3% to 1% copper sulfate solution for 2 to 3 hours, remove and wash with clean water.

(4) Before the seeding, the seeds are mixed with Dixan, and the enemy is equably mixed with 10 to 15 times of fine soil and then mixed with the seeds with the equivalent of 0.2% to 0.4% of the seed weight. The enemy can effectively prevent and cure damping-off. happened.

(B) Seed cold treatment

Larch seeds are suitable for low-temperature treatment by stratification method, which can effectively improve the germination potential. The stratification method is also divided into sand and snow.

1. Sand pits are selected for digging seed pits in places with good sun, leeward and well-drained water. Pit depth is controlled within 1.5m, length and width are determined based on topography and seed amount. In sand traps, we first wet the sand on the bottom of the seed pit by 10 to 15 cm to mix the disinfected seeds with the wet sand. The ratio of seed to sand is 1:3, and the humidity after mixing is 50 to 60% of the saturated moisture content. , that is, no water in the hands, and the loose hands can be immediately scattered, and the mixed sand seeds are placed in the seed storage pits. The upper cover is covered with 20cm or more fine wet sand, and the cover is then covered with 2 to 3 layers of straw shades. A grassy handle is erected every 1m away from the seed pit, and straw or wheat straw can be used. The straw length is higher than the thickness of the seed pile to facilitate ventilation.

2. Before and after the snow is left for snow (no snow can be used to smash the snow in the screen), the volume ratio of the seeds and snow is 1:3, and the snow is 20cm thick in the pit. After solid, it is put into a mixed seed. Flat, 40 to 50cm from the pit fill snow and surface level, and then covered with straw, higher than the ground surface 10 ~ 20cm, in order to maintain the low temperature inside the pit. Regardless of sand and snow deposits, insect repellent and rat poison should be sprayed on the surface around the storage pit, and diligently checked during the winter storage to avoid harm to humans and animals. When spring comes, pay attention to temperature changes in the seed pit to prevent seed germination in the pit.

The role of seed cold treatment is mainly to promote the seed to absorb enough water, prolonged low-temperature storage promote seed coat softening and release the seed dormancy, and promote seed germination. By germination at low temperature, the seeds germinate neatly and increase the germination potential.

Seeds that have been treated at a low temperature are generally taken out of the storage pit 5 to 7 days before sowing, and the fine sand is placed directly in a germination shed at 25°C to 30°C. The germination shed can be temporarily erected with plastic sheeting, depending on the seed size. Canopy cloth can not be directly contacted with seeds to prevent the surface temperature from being too high, causing burns to the seeds and affecting the germination rate. Pre-emergence in the warm shed on the surface of the horse mat fecal 15 ~ 20cm, horse feces on the upper shop mat or straw curtain, the seeds evenly placed on the mat, the seed thickness of 10 ~ 15cm, often turning the seeds, so that the seeds can be uniform temperature , neat germination. Generally once every 1 to 2 hours flip once, when the seed surface is exposed to dry, use 20 ~ 25 °C warm water humidification, if the number of days of germination is too long, it should be regularly rinse with water. When the temperature in the booth is too high, it is necessary to ventilate the air and lower the temperature so that the temperature in the booth can be maintained at 25°C to 30°C, until about 30% of the seeds germinate white (when most seeds are twisted). .

Seeds without cold treatment, warm water soaked seed specific practices: Pour 40 °C warm water into the seeds, the ratio of water and seeds is 3:1, with the back with the stirring, so that the seed temperature is uniform. Until the temperature is lowered to room temperature, add fresh water to soak seeds for 24 hours. After the seeds are completely swollen, remove and drain the purified water, and put the seeds into a container containing ABT rooting powder solution for treatment. Using ABT3 or ABT4 rooting powder, soaked in 400PPM solution for 2 hours, washed and washed for germination. After the test, the seeds treated with ABT rooting powder increased the germination potential by 5 to 7 percentage points.

Sowing in the fourth quarter

Larch seedlings are often planted in spring. The specific time is as early as possible. When the temperature reaches 12°C, the soil can be sown at a temperature of 5cm deep and stable at 8°C, and cold regions should avoid late frost and late spring to avoid damage.

First, sowing

1. Spread the bed with enough water before sowing, sow the seed evenly on the seedbed and gently repress the fine sand (or mixed soil) on the screen. The sowing has the advantages of high yield, sufficient land use, and uniform distribution of nutrient space in seedlings. Because seedlings are not ridged or bred, the management of weeding, soil loosening, and pest control are inconvenient. The seedlings grow taller, affecting the ventilation and light transmission, and adversely affecting the growth of seedlings in later stages. , is not conducive to mechanical operations.

2. Drilling is based on a certain distance, a certain amount of broadcast, sowing soil and repression, according to the mechanical program once completed. Drilling has a series of management and operation procedures, such as saving seeds, facilitating ventilation and light, facilitating the weeding, weeding, and preventing pests and diseases. The row spacing can be flexibly mastered. For many years, the row spacing of each nursery in the Mengfu Forest Management Bureau is generally 10 cm, and the broadcast width is 10 cm, which is conducive to improving the utilization rate of the nursery. The direction of the sowing line is best in the north-south direction, which is advantageous for ventilation and light transmission, and the seedlings can shelter each other against sunburn.

Second, cover soil

Cover soil thickness is a key part of the entire planting. After rubbing the seeds, the soil is covered with sand immediately after sowing, and the thickness of the covering soil is generally 2 to 3 times of the diameter of the short axis of the seed. In addition, it should be based on climate, soil, and seeding period. The thickness of Larix principis-rupprechtii is generally 0.3-0.5 cm. Cover soil is suitable, the normal unearthed seedlings, seedlings stand upright, the top of the seed shell, take off the seed shell, showing purple stem green leaves, belonging to healthy seedlings. Overly thick soil, seedlings can not be successfully unearthed, combined with multiple watering caused by surface compaction, the seeds in the soil to form axillary buds, when the amount of seeding is large, the concentration of group strength (top cover) can unearthed, but because the seeds stay in the soil For a long time, the nutrients in the embryos have been consumed in the soil. After the soil is unearthed, the shells are not topped, the stems and stems are bent, and the yellow leaves are easily killed by high temperature or unfavorable external factors. If the soil is too thin, the soil is easy to dry or the seeds are exposed to the outside of the soil after being watered to dry and die, which affects the bud rate. Cover soil must be uniform, thickness appropriate, immediately after the cover should be watered, watering should not be too much, then connected to the bottom can be, after sowing is best shaded with curtains, etc., light transmission coefficient of 30%. Covering the curtain, that is, preventing the wind from blowing away the cover soil and the seeds, can prevent the mechanical spray from spilling the seeds and causing losses.

Third, seedling management

The whole growth process of 1-year-old planting seedlings can be divided into seedling stage, seedling stage, fast-growing stage, and seedling growth stage (hardening stage).

(A) The main features of each stage and management measures

1. Seedling stage from seeding to seedling emergence, about 15 days. At this time, the seedlings extend downwards from the main roots of the exoskeleton and the seedlings themselves cannot produce nutrients, mainly relying on the nutrients stored in the seeds. Controlling moisture and temperature at this stage is the main management measure. Watering should grasp the principle of a small number of times to keep the bed moist, which is conducive to raising the temperature and promoting the seeds to be unearthed as soon as possible. After more than 80% of the seedlings are unearthed, the seedlings need to increase the number of light hours. The shading time is usually between 10am and 4pm. After the seedlings are adapted, the cover is gradually removed. Improper management of shading and waste materials will also affect the quality of seedlings. Conditional nurseries must promote early sowing in due time. Before the arrival of "Apricot Flower Frost" (night cream), all seedlings will be unearthed. When the temperature is high, sprinkler irrigation and other measures can be used to fully implement all-ray nursery. In addition, due to seedlings unearthed often with seed shells, vulnerable to damage by birds, precautions should be taken.

2. In the initial stage of growth (seedling stage) After emergence from the seedlings, till the emergence of lateral roots, new shoots, and the appearance of the second round of true leaves, this stage is the initial stage of growth. At this time, the growth of underground roots began to accelerate, and the seedlings were able to produce nutrients themselves. However, the shoots and leaves of the seedlings were still growing slowly on the ground, they were resistant to high and low temperatures, and were sensitive to soil moisture. This stage was about 40 days. This period of seedlings prone to damping-off, is the key period of seedling protection, if the growth of seedlings and the external environment is not adaptable when the heart is easy to occur, so that the seedlings prematurely capped. In order to avoid occurrence of heart disease at the seedling stage, according to the phenological habits at the seedling stage, various factors required for the seedling stage should be adjusted. Under conditions of continuous high temperature, it is necessary to constantly cool water to meet the suitable temperature for seedling growth; A small amount of topdressing nitrogen fertilizer can be used to promote the shoots to shoot new shoots. Watering should be carried out in a timely and appropriate manner. Regular inspection of the soil moisture should be carried out. The roots of the seedlings should be kept in the wet soil layer, and the bed surface can be slightly dry. The soil moisture content should be 15 to 20%. When the seedlings grow out of the lateral roots, after the new shoots are drawn out, the seedlings should be properly grown to promote the growth of the roots of the seedlings and enhance the stress resistance of the seedlings. When the local surface temperature reaches 35°C, there is a risk of sunburn. Water should be lowered to prevent sunburn. After the rain, the seedlings and stems are easy to “wear soil trousers”, and should be sprayed with water before the high temperature comes on the next day to prevent the seedlings from being exposed to high temperatures due to “soil trousers”. This period is a disease, especially the high incidence of damping-off. Prophylaxis should be carried out when 2 or 3 lateral roots of seedlings are grown. In the production of the following chemicals are commonly used to prevent lice and root rot.

Table 3-2 Seedling Disease Prevention Methods

Pharmaceutical name

Instructions

effect

potassium permanganate

Spray with 0.4% solution for 3 minutes with clean water

Every 7 to 10 days

Ferrous acid

Spray with 0.5% solution, should strictly control the concentration of the solution to avoid the use of iron utensils to prevent the production of high-priced iron

Every 10 to 15 days

Bordeaux mixture

With 1% Bordeaux mixture sprayed on seedlings, the liquid must be ready for use

Every 5 to 10 days

After the seedlings grow out of the second round of needles, a second round of lateral roots has been formed, which has a certain resistance to the external environment. To loosen the soil, cut off the capillary in the surface soil, regulate the temperature and humidity, reduce the number of watering, and promote the growth of seedlings. At this time, the first loose soil weeding can be performed. The principle of loose soil is the first time that the loose soil should not be too deep, and the loose soil made of wire is used to break the top soil 0.3 to 0.5 M. With the growth of the seedlings, the depth of loose soil goes from shallow to deep to 2 M. The new seedlings are generally 3-5 times loosen and can be combined with manual weeding at the same time. The principle of weeding is to remove early and small, prevent weeds from growing too much and affect the growth of seedlings. Otherwise, weeds are too late and the roots of the weeds are too large. When weeding, they bring out seedlings. People call them "end-pots", which cause the roots of the seedlings to ventilate, affecting the growth and yield.

3. Fast-growing period The period from the high growth of seedlings to the decline of high growth, this stage is the fastest growing period of seedlings, usually in June to July. At this time, it is also the time for the strongest transpiration of the seedlings on the ground. The amount of fertilizer needed to be increased increases. Nitrogen fertilizers should be applied to ensure the synthesis of protoplasms with protein as the main component and accelerate seedling growth. By the end of July, nitrogen fertilizer should be stopped, and some phosphorus and potassium fertilizers can be applied. Watering of seedlings in the fast-growing period should master the principle of a large number of times and less time, which will help increase the temperature of the ground. Watering should be sufficient to meet the needs of seedlings. During this period, it was hot and rainy, and it was prone to gray mold. Generally, it appeared as a lumps, and the young shoots of the seedlings changed from purple to yellow and drooping. They should be combined with Dingmiao to timely improve the air and light conditions of the seedbed. For diseased seedbeds, use 0.3% potassium permanganate solution or 1% ferrous sulfate solution for spray control. This period is also a high incidence of pine rust, should be treated with 1% triadimefon as early as possible, such as spraying within 8 hours of rain should be sprayed. After June, it is necessary to pay attention to prevention and control during the active period of underground pests.

4 Late growth period (also known as seedling hardening period) High growth from seedlings significantly decreased until the roots ceased to grow into hibernation. During this period, the overall lignification of the seedlings, the accelerated growth of the diameter, and the gradual closure of the winter buds, reduced the water content in the body, and the nutrients were transferred to the storage state. The resistance was strong. Stop the application of nitrogen fertilizer, increase phosphorus and potassium fertilizers, promote lignification of seedlings, prevent seedlings from being greedy and grow in order to increase cold resistance. The corresponding control of watering, to minimize the number of watering, this period lasts about 1-2 months. By cutting off the main roots of the seedlings and the long lateral roots, the water absorption of the seedlings can be controlled to prevent leggy growth.

(B) Seedling fertilizer and water management

1, fertilization

(1) One-year-old seedlings, with top-dressing N-fertilizers in summer, divided into 1 to 3 times. When the seedlings produce 3 to 4 lateral roots, the first top-dressing will be performed, 2.5 to 3 kg of ammonium sulfate per mu. Every 10 to 15 days thereafter, the amount of fertilizer is gradually increased to ensure that the vigorous growth of seedlings on the nutritional needs, but not more than in late July. The application of phosphorus and potash fertilizers began in early August in order to promote the radial growth of seedlings and increase the storage of phosphorus and potassium elements in the seedlings and promote the lignification of seedlings. For two-year-old seedlings and transplanted seedlings, the top-dressing period is about 20 days earlier than that of the one-year-old seedlings, and the amount of fertilizer can also be increased. However, at the end of July, nitrogen fertilizers are also stopped and potassium phosphate is topdressed.

(2) Determining the fertilization type according to the symptoms of seedlings. When the supply of certain elements in the soil is insufficient during the growth and development of the seedlings, the metabolism of the photosynthesis of the seedlings is affected, and the external morphology immediately undergoes certain symptoms. According to these symptoms, the target can be selectively selected. Fertilizer varieties, targeted nutrition for seedlings.

1 Nitrogen deficiency: The main role of nitrogen is an important element that constitutes protein and chlorophyll, and when there is a lack of photosynthesis, it affects protein formation. The seedlings showed yellow, green and thin leaf color, short stems and weak stems, yellow leaves of the lower old leaves, and stagnation of branch shoots. Recovery of acidic nitrogen fertilizers such as ammonium sulfate and ammonium nitrate was beneficial to the growth of larch.

2 Phosphorus deficiency: Phosphorus is an important element that constitutes the nucleus and plays an important role in cell division and meristem formation. In the absence of seedlings, leaf color is purple and bronze, and begins with the tips of the lower leaves. The seedlings are thin and the bud develops. Bad, faded lateral buds, very few and slender, mainly superphosphate and dibasic calcium phosphate can be added. Most of the northern sandy soils lack phosphorus.

3 Potassium deficiency: Potassium is mainly adsorbed in the protoplasm of the cell fluid in an ionic state, which can increase the cell fluid concentration and enhance the cold resistance of the seedlings. When the potassium is lacking, the leaf color is dark green or dark green, and the growth is slow, the stem is short and the degree of lignification is low. Low, mainly followed by potassium chloride, potassium sulfate, etc. to supplement.

4 Calcium deficiency: affecting the formation of cell walls, cell division was blocked, and showed new roots were short, curved, tip withered and died. The leaves were small, pale green, and young shoots and young shoots died severely. Soil acidity is too large, too much potassium can easily lead to calcium deficiency, commonly used calcium fertilizers are lime, hydrated lime and superphosphate.

5 Iron deficiency: Iron is the main component of synthetic chlorophyll. In the absence of iron, seedlings appear yellow or even white and gradually develop downwards, but the veins often remain green. In severe cases, the veins are yellow-green, and brown spots appear on the edges until Withered. In the northern regions, the utilization of iron is generally low when the ground temperature is low or the ground temperature is too high, and alkaline soil that contains too much calcium can cause iron deficiency. Fertilizers include ferrous sulfate and ferrous ammonium sulfate.

6 Manganese deficiency: Manganese can promote the activation of various enzymes and play multiple roles in metabolism. In the absence, the seedlings were initially slightly yellowed and gradually expanded to the whole. When the soil is alkaline, excessive humidity is prone to occur. Because manganese and iron can be absorbed and used by seedlings in a certain proportion, they are often lacking at the same time. Fertilizer varieties are manganese sulfate, manganese chloride and so on.

Nitrogen, phosphorus, potassium, and other major elements are often the symptoms from the lower part of the old leaves began to occur, and trace elements such as iron and manganese are often spread from the new upper and lower leaves. It should be noted that the deficiency of seedlings is different from that of pests. The infection of seedlings by pests and diseases usually occurs in the nursery plots, spreading from point to block, and the deficiency of the disease is limited to only one point and one block does not spread outward. the difference.

2, fertilization should pay attention to the combination of loose soil weeding and coordination with irrigation after soil fertility, weeding loose soil can weaken the degree of soil consolidation. Water is one of the necessary conditions for the decomposition of organic manure in soil, and it is a regulator of the osmotic pressure of soil solution. It can regulate the concentration of soil solution normally absorbed by seedlings, especially in the drought and high temperature period, and it has an irreplaceable role in preventing physiological drought water. . If too much water will dilute the concentration of the solution in the soil and reduce the effect of the fertilizer material, it is necessary to ensure the rationality of the water supply. The loose soil has a drainage effect on continuous rainy days, but in the case of drought and high temperature, there are Drought protection.

IV. Chemical weeding and thinning

1. Chemical Weeding Weeds Because of its strong rootstock, well-developed root system, rapid growth, and strong fertility, it competes for nutrient and growth space for seedlings. Weeds are also a host to many pests and diseases. Manual weeding is a heavy and long-term task. Work, but also will damage the seedlings due to weeding, and chemical weeding has the advantages of simple, timely, long period of effective, effective, low cost, labor-saving, easy to mechanized operation, but in the production applications, must choose a suitable chemical drugs To master the performance of drugs and the preparation of concentration and use methods, otherwise, it is prone to produce phytotoxicity, which is not worth the candle. Therefore, chemical weeding should be treated with caution. Larix principis-rupprechtii seedlings are available in the following medicines.

(1) Fluorologue: When the root length of the new nursery seedling grows to more than 5cm, 48% trifluralin is applied to the site above the lateral root of the root. Amount of 30 ~ 100ml per acre, applied to the depth of the soil in the less than 2cm is appropriate, one can be. Two-year-old seedlings can be divided into two times, each time the use of 30 ~ 60ml, medication should not be sprayed on a windy day, can not use ultra-low sprayer application.

(2) Sodium pentachlorophenol: This agent is suitable for weeding in coniferous nurseries and has both bactericidal and insecticidal effects. Before sowing 5 to 7 days, 75% of sodium pentachlorophenol powder per acre 500 ~ 800g, watered 70 ~ 90 liters, evenly sprayed on the bed can be done well.

(3), cut grass (Gour): Before sowing 5 to 7 days, 50ml diluted into 1000 times per acre sprayed on the bed surface, the amount of 20 ~ 30ml per acre seedling spray, after pouring Washing with water, precautions, avoid using under the condition of daily temperature below 20 °C, should maintain uniform spraying, make the surface form a complete film.

2. The size of seedling density of seedlings determines the quality and cost of seedlings. It is one of the important measures to control the quality of seedlings. It should follow the principle of “early seedlings and late seedlings”. Generally, it is divided into 2 to 3 times, and the seedlings must be poured before seedlings. water.

The first seedlings of larch were carried out before entering the fast growing period. At this time, the second and third rounds of needles were released from the seedlings, and the lateral roots were 2 to 3 layers. The seedlings basically stabilized, which provided a favorable environment for the growth of the seedlings. The first time the seedlings are mainly opened up dense clusters of dense seedlings, increase the light transmission coefficient, to provide a good growth space for the retention of seedlings, and promote growth and development. The seedling density after the first seedling should be greater than 25% to 30% of the planned seedling production. After the fast growing period, the second thinning usually occurs rapidly through seedlings. Under strong competition, the individual shows a marked differentiation. Going between small seedlings and bad seedlings is a major process of selecting the best, and the purpose is still to promote. Lime growth and development. The number of post-seedling post-emergence plants is greater than the planned production of 15% to 20% for later damage.

V. Staying in bed management

1. Root cutting Root cutting is a technical measure to cut off the main root and promote the growth of lateral roots and hair roots during seedling cultivation. For seedlings with developed main roots at the seedling stage and with few transplanted roots and no plan to transplant for more than two years, root cutting measures must be taken to promote the lignification of seedlings, inhibit high growth, and cultivate commonly known as “dwarf, bearded” seedlings. In other words, the seedlings have thick diameter, many lateral roots, and a small ratio of height to diameter, and they are easy to survive after afforestation. The time and depth of root cutting directly affect the rooting effect and is the key to cutting root technology. The depth of cutting should be determined according to site condition of nursery and growth potential of seedlings. The conditions of the nursery are good, the seedlings grow vigorously above the ground, and the depth of the cuttings must be shallow. Larch seedlings in the north are usually kept in the early spring of the second year of the bed seedlings. When the soil is thawed to about 20M, the roots are cut (mechanically cutting roots with the cutting root plow). The root cutting depth is controlled at 18-20 M. The cutting roots are not only beneficial to the lateral roots. The development, but also easy to grasp the root depth. Immediately after cutting roots watering to prevent ventilation, resulting in the death of seedlings.

2. The cultivation of second-year-old larch seedlings of Dingmiao seedlings. After the operation and management and the two seedling-seeding processes in the current year, the third seedling belongs to the seedling-seeding process, and the seedling-setting time is generally determined in the second year of the spring. Dingmiao is still a form of seedling selection, and seedlings and seedlings are proposed on the rooted seedbed. The number of seedlings per mu after seedling is greater than the planned seedling yield by 5% to 10%. The proposed seedlings can be transplanted or Fill the container for incubation and use.

Wiping and snoring. The annual larch seedlings generally have only one trunk, no branching, leaving the bed (biennial) seedlings, giving birth to multiple lateral branches on the annual trunk, that is, one bud is divided into one side branch, so that the seedlings develop into Straight, non-scarred, non-scarred, and seedlings with appropriate height-to-diameter ratios are generally expanded in early spring (after the root recovery), and all the lateral buds on the dried seedlings are removed before the high growth period. 2 or 3 buds will be destroyed when entering the fast-growing period. The buds and snoring time should not be too late. They should be completed before lignification. Delaying the snoring time, lumbering takes time and effort, and pruning with scissors will have an impact on the healing of seedlings. Through the snoring operation, the ventilation and light transmission conditions of the seedbed can be adjusted to improve the yield and quality of seedlings.

The cultivation of cutting seedlings in section V

The all-optical self-controlled spray cutting and seedling raising technology is the successful shaping technique of Hebei Academy of Forestry in Longtoushan Nursery. Having passed the appraisal, this technology has reached the leading domestic level. Larix principis-rupprechtii is one of the main coniferous species that has been included in the research project for the selection and breeding of improved varieties due to its strong cold resistance, rapid growth and good material quality. However, its robust instability has seriously hampered the progress of sexual improvement of the tree species. Therefore, cutting propagation as an important way of breeding fine varieties has been closely watched by the forestry community. Since 1988, the Mengzi Forestry Bureau and the Hebei Provincial Academy of Forestry have jointly studied, in the case of no precedent in the country, in the area of ​​200m2, using all-optically controlled spray cutting to propagate the progeny of the progeny of the larch mother tree. In 13970 strains, the rooting rate reached 100%, the cutting density increased from the original 200 plants/m2 to 800 plants/m2, and the transplanted plant survival rate in the year was 100%. Cuttage seedlings have the following advantages: First, they have high yields and yields. All light fog can fully exert the comprehensive effects of matrix, light, temperature, and humidity, and are convenient for intensive management. As many as 800 cutting seedlings are produced per square meter, which is suitable for strong seedlings. Large-scale production of seedlings. Second, seedling quality was excellent. Lateral cuttings had more lateral roots than seedlings. The stems were robust, with high degree of lignification, full top buds, large stem and leaf absorption area, and high survival rates for transplanting and afforestation. Thirdly, cutting seedlings belong to the category of asexual reproduction, which can maintain the excellent characteristics of the female parent, and should be widely promoted in the construction of fast-growing and high-yielding forests.

First, cutting equipment and slotting construction

(1) The all-optical fogging device is assembled from "double long arm self-pressure rotary scanning device" and "SL-Z type leaf wet automatic control device" to implement automatic spray control.

(2) Construction of slotting machine: round slotting machine with diameter of 12m, with 35cm wall height (wall width is width of horizontal brick, cement jointing) and the drain hole at the base. The bed is laid with a pebble 15cm from bottom to top, 3~5cm coarse sand, and a 15cm cutting matrix (sand pebbles, etc.).

(3) Water supply system: pumping water from deep wells and a simple water tower, and supplying water to the insertion bed and medicine tank through the main pipeline and branch pipelines. Control accessories include water tower main valve station and filter, main pipeline valves, branch pipeline manual valves, electromagnetic valves and micro-electric pumps.

(4) Storage Irrigation: volume 1 ~ 1.5m3, equipped with valves, filter nets and water injection scales, used for plugging aseptic, foliar fertilization, automation through micro electric pump and spray device.

Second, cutting

(a) Preparation for cuttings

On the mother tree, the semi-woody shoots of the first branch of the plant from 1.5 to 2.5 years old were selected for cutting. When the new shoots are drawn up to 15 to 20cm (in the paddock area from late June to mid-July), the strips will be picked up sooner or later or on cloudy days. Select a fully developed semi-woody tender to take a slight section of about 13cm, and cut it down in a bucket of water about 5cm deep. Beware of loss of water. Temporary storage of cuttings should be placed in a cool place. Before cutting, shoots are cut by 10 cm slightly for cuttings. Cuttings for cuts should be treated with ABT rooting powder for 3 to 5 seconds at a depth of 1.5 to 2 cm.

(b) take a shady shed

The arbour is a movable type, all cover the slotting machine, the awning material is a shade net for sale in the market, the shed light intensity is more than 50% smaller than outside the shed, the awning diameter is 14m, it is yurt-like, the highest point of the center is 2.1m, and the slot is set around Fixed wooden stake erection and fixation.

(c) Matrix disinfection

Before the plug, the substrate is sprayed with water, then sprayed with 0.15% potassium permanganate solution, and thoroughly disinfected until the water out of the plug outlet flows out of the red potassium permanganate solution, and then sprayed with clean water to the outlet of the water and then the water can be plugged. .

(4) Cutting and post-insertion management

First use a hard object with a depth of 4 cm to mark the hole on the substrate. The diameter of the hole is 0.6-0.8 cm. Then insert the cuttings treated with the rooting powder. Plant spacing 2 × 6cm, density 800 / m2, while inserting artificial spray, to prevent loss of wilting cuttings. After the cutting is completed, the 1500 mg/kg trehalose solution is sprayed on the bed surface to disinfect 0.4 kg per square meter, and thereafter is sterilized periodically at an interval of 7 days. The spraying device was in the normally open state within 2 days after insertion, and the automatic spray was performed on the third day.

After 10 days of cutting, the nutrient solution was sprayed at intervals of 10 days. 0.54 mg/kg of triacontanol was sprayed in the early stage of rooting, 0.8% KH2PO4 solution was sprayed in the later stage, and spraying was prohibited within 2 to 3 hours after spraying to facilitate the absorption of foliar surfaces. Spraying nutrient solution should be done in the evening.

Within 30 days after insertion, the formation period of tissue primordial and radicles is also the key period of the whole cutting process. The temperature of the substrate in 5cm depth is controlled below 30°C, and is higher than the bed surface temperature of 2~3°C. Once the temperature exceeds 30°C, frequent spraying is required to reduce the temperature until the temperature of the substrate is stabilized below 30°C. 30天后,插穗进入生根发育期,根系生理机能和有机物质的交换逐渐趋于正常,要逐渐调节减少喷雾次数和喷雾量。生根前期保持叶面有水珠,生根后期保持基质表面湿润。至于床面相对湿度及温度可顺其自然。

三、扦插苗的越冬管理

平床扦插苗越冬,在上冻前清除落叶,用洗净细河沙粒(直径小于1mm)覆于床上,覆沙厚度15cm左右,以完全盖上苗为宜。沿床周围用土把排水孔封住,扦插苗即可安全越冬。翌春清除覆沙即可上山造林或圃地移植培养大苗。

第六节、移植苗、容器苗的培育

一、移植苗培育

移植苗是培育优质壮苗的重要途径,苗木经过移植,扩大了苗木生长空间,苗木根系发达,侧根增多,冠根比更加合理,发育健壮,可大幅度提高造林成活率。

落叶松移植,多在早春进行,在土壤解冻后,树液尚未开始流动,枝芽也未萌发前完成,秋季移植应在地上部分停止生长后立即进行,移植过迟不利于根系恢复,在冬季土壤冻结严重地区,不宜秋季移植,移植时间最好在阴天或早晨、晚上进行,尽量避免雨后或土壤过湿时移植,以免造成土壤板结,影响苗木根系舒展和破坏土壤的结构,降低苗木成活率,。苗木移植前对根系要进行适当修剪,以促进须根生长,减少窝根。移栽一年生苗,一般修剪后根系保留7~10cm,移植时要用保水剂或泥浆蘸根,用ABT生根粉等生物激素调节剂浸根可以大大提高苗木成活率,缩短缓苗期,移植后立即浇水。

二、容器苗培育

容器育苗越来越受人们所重视,孟滦林管局大面积推广和应用阶段是在1983年通过生产实践,总结和技术更新,无论是苗木培育、造林技术等方面都得到了不断的完善,造林比重越来越大。由于苗木在容器中形成完整的根团,栽苗时根系不易受到损伤,延长造林季节,而且造林后缩短缓苗期,生长快、郁闭成林早、育苗周期短,节省种子等优点。培育容器苗有播籽和植苗两种方法。

(一)容器杯

1、营养基质。常用的营养基质有泥炭、堆肥、苗圃或林地菌根土、森林腐殖土、山地草皮土、火烧土等,营养基质选好后,粉碎或过筛,拣净草根石块,按一定比例充分混合,将PH值调制在6.5~7.0之间为宜,并进行消毒,其方法有:

(1)用0.15%浓度的福尔马林溶液5~10kg,消毒1m3营养土搅拌,密封24h,打开后即可装杯使用。

(2)用1%硫酸亚铁溶液5~10kg消毒1m3营养土,充分混合后可立即使用。

2、把营养土装入容器,分层压实;装至距容器口1M为度。

(二)容器播种苗

1、 要按设计将装好基质的容器放入苗床,容器要排列整齐。一般每床宽为10或20个容器,长1000或5000个容器不等。排列前,床底要铲平,排好后要用沙或土填实容器间的空隙并培好床边。容器排好后可供直播育苗。

2、 播种时,种子必须提前催芽。每容器播种量应根据种子质量、催芽程度而定。一般播2~3粒,播后用沙土或腐殖质土覆盖,有条件的苗圃可盖苇帘。然后淋水,经常保持湿润。幼苗出土后,及时揭去苇帘。并作好除草、施肥和防治病虫害等工作。如果一个容器有多株苗时要及时间苗,缺苗的应补苗。待苗根将要穿出或已经稍微穿出容器时抓紧雨前、雨后连同容器造林。如为塑料容器,应先行浇水使土壤湿润,然后紧握容器,挤压土壤,脱去容器后,再行栽植。

(三)容器栽植苗培育:容器栽植苗技术容易掌握,省工省时,是见效快的一种苗木培育措施。从移植培育至造林只用3个月左右时间,造林成活率和裸根造林比有大幅度的提高。通常应用的容器规格根据造林类别和运输难易成度进行灵活确定,有12×20M和8×15M不等,一般容器移植苗多选用一年生容器小苗为培育对象,将准备好的营养土装入容器1/3时挤紧,手提苗放入容器的中心位置,填土挤实,防止窝根,然后将移植好苗的容器排入苗床及时浇水,适时进行中耕除草、施肥、打药。在造林的前3天浇足底水,运到造林地进行造林。

第七节病虫害防治

一、病害

落叶松幼苗常见的病害有猝倒病、松杨锈病、植苗高温伤害、早期落叶病等。

1.猝倒病又称立枯病症

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