Propagation and cultivation techniques of hardwood cuttings of rhododendron

Azalea plants beautiful shape, colorful flowers, high ornamental value, broad market prospects, so widely used in landscape engineering. How does the following study azalea hardwood cuttings propagation cultivation?

Cuttage is the main propagation method of deciduous, semi-evergreen and evergreen rhododendrons, and widely used, but due to the difficulty of rooting rhododendrons, and cuttings transplanted slow growth. Therefore, in view of the large demand for Rhododendron seedlings and the difficulty of cutting rooting and slow growth, scholars at home and abroad have carried out cutting seedling experiments in recent years. It is found that cutting rooting is affected by endogenous factors such as endogenous hormones, rooting auxiliary factors, nutrient levels and antioxidant enzyme activities, while exogenous auxins can regulate the physiological activities of cuttings, induce enzyme activities and auxiliary factors, thus promoting cell elongation, division, root primordium differentiation and adventitious root formation. Cuttage time is closely related to lignification degree and physiological characteristics of cuttings, which is another key factor affecting rooting of cuttings.

1. Seedbed laying

The seedbed is arranged in a glass greenhouse or a plastic greenhouse, red bricks or cement bricks are adopted for the bed edge, a drainage hole is reserved at the bottom of the seedbed every 100cm, stones, pebbles and coarse sand are sequentially added from bottom to top to improve drainage and ventilation of the seedbed; a culture substrate with a thickness of 10 - 15cm is laid on the coarse sand, and the seedbed is leveled and watered by raking and light pressure; In order to control the temperature, humidity and light of the seedbed environment, an arc plastic shed was set up on the seedbed, automatic spraying facilities were equipped in the shed, and a sunshade net was set up at 30cm above the plastic shed; after the seedbed was made, the substrate and the surrounding environment were disinfected with 500 times of multi-bacteria solution.

2. Cutting collection and production

selecting mature plants of eastern azalea with an age of about 5 - 2 ~ 5 years and vigorous growth as stock plants for picking ears, collecting woody branches (also called hard branches) of the previous year of the plant canopy in June, spraying water to keep moisture, and transporting them indoors in time; selecting twigs with strong and upright branches, no diseases and insect pests, and no flower buds (with bud buds), cutting into cuttings with a length of 10 - 2 ~ 5cm, keeping 2 - 5 branches on branch points, and removing tender buds at the top ends of 2 - 3cm branches; Remove the leaves at the base of cuttings, keep 3~4 upper leaves, and then cut off 1/2~2/3 according to the size of leaves to reduce water evaporation; cut off the cortex and cambium of 1.0 ~ 1.2cm long at the base of cuttings by grafting knife, and form a surface with branches at an angle of more than 45°, so as to facilitate the absorption of rooting agents and the formation of large area callus.

3. Callus treatment

1000mg/L IBA aqueous solution is used for treating cuttings for 1min, then NAA 500mg/L aqueous solution is used for soaking the cuttings base for 1min, natural air drying is carried out for 12h; the cuttings are placed in an environment with a temperature of 23 - 26 DEG C and a relative humidity of 60 - 70% for 6h; then the cuttings are placed in an environment with a temperature of 10 - 15 DEG C and a relative humidity of 40 - 60% for 2h; and finally, the cuttings base is immersed in ABT rooting agent solution.(ABT rooting agent: water = 1g: 2kg) for 3 - 5 seconds, and placed in an environment with a temperature of 23 - 26 DEG C and a relative humidity of 50 - 60% for 24 hours.

4. Cutting and management

Cutting immediately after cutting treatment, cutting first with small bamboo sticks to lead a small hole to reduce the mechanical damage of the matrix to the cutting tissue; the plant spacing between cuttings is 15×15cm, the cutting depth is 1/3~1/2 of the cutting length, and water is sprayed after cutting. During the experiment period, automatic intermittent spraying system was used to replenish water and humidify: 5min/4h in the daytime, 2min/4h in the evening, and gradually reduce the number of spraying after 40 days; the temperature and illumination intensity in the shed were adjusted by ventilation and shading net on both sides of the plastic shed according to the weather conditions (The temperature in the greenhouse is controlled at 20.0 ~ 30.0 ℃ and the relative humidity is 80.0 ~ 95.0%); when the temperature is higher than 30.0 ℃, open the plastic greenhouse for ventilation and reduce the temperature; in order to reduce pollution, remove the leaves and rotten cuttings of the seedbed in time, and spray 500 times of carbendazim or 1000 times of thiophanate-methyl aqueous solution alternately once every 7~10 days.

After 50 days, observe the rooting situation of rhododendron and check it every 10 days. When more than 3 roots are rooted at the bottom and the root length is more than 2 cm, transplanting can be started. The planting medium for transplanting was peat soil: yellow loam soil: pearlite: vermiculite 4:1:1. When transplanting, irrigate root water thoroughly, set up sunshade net 50cm away from the ground, the sunshade rate of sunshade net is 50%, cover sunshade net from 9:00 a.m. to 5:00 p.m., remove sunshade net at other time, remove sunshade net after transplanting and planting for 2 months.

The callus formation rate is up to 95%, the rooting rate is up to 90%, each plant has more than 3 roots, and the root length is more than 2cm. In the second year, the height of growth reaches 30~50cm, and the branches are strong and can be taken out of the nursery. The technology lies in that lignified branches of the previous year are selected as cuttings, the front ends of the lignified branches are provided with transition branches from the current year to the lignification, the length of the cuttings is more than twice that of the traditional cuttings, the cuttings are plants with a plurality of branches after rooting, the cuttings are rooted and transplanted in the current year, and the seedlings can be taken out of the nursery in the second year after rooting, so that the situation that the branches are taken out in the second year after the original cuttings survive is solved, and the seedlings can be taken out of the nursery after the third year; and the seedlings of the technology have strong branches and the whole plants grow rapidly.

This technology breaks the traditional concept in cutting time, cutting in June to July, which is conducive to rapid rooting and rapid development of seedlings after rooting. The problems of difficult rooting, low propagation rate, slow production and the like of rhododendron cuttings are solved, and the rooting rate and rooting quality are effectively improved. The technology does not need special treatment, is simple and easy to operate, is an effective method for large-scale rapid propagation of rhododendron, and is especially suitable for industrialized seedling of evergreen rhododendron.

How does rhododendron grow?

How does rhododendron cuttage breed, it is to point to rhododendron cuttage method. So how does the rose grow? Here we tell you how to cut azaleas propagation bar!

How does rhododendron grow?

Rhododendron propagation, can be used cutting, grafting, layering, sub-plant, sowing five methods, of which cutting is the most common, the largest amount of propagation; layering into seedlings the fastest, grafting propagation is the most complex, only cutting is not easy to survive the varieties with grafting, sowing mainly with cultivated varieties.

Cuttage propagation, cuttage pots to 20 cm diameter of the new shallow tile pots as well, because of its good permeability, easy to root. Culturing soil mixed with 20% humus garden soil, 40% horse manure and 40% river sand can be used as substrate. Cutting time in spring (May) and autumn (October) best, when the temperature between 20-25℃, the most suitable cutting. When cutting, select the half-lignified branches of the current year as cuttings, press the knife with extremely sharp pliers; cut 6-10 cm with nodes, cut smoothly and neatly, cut off the lower leaves, leaving only 3-4 leaflets at the top. Buy vitamin B12 injection 1, after opening, the cuttings dipped in the liquid medicine, take out for a while can be cut. Before insertion, the culture soil in the pot should be sprayed with a watering can the day before, but it should not be sprayed too much. The next day, it is just moist, which is most suitable for cuttage. The depth of insertion is 3-4 cm. When planting, first save a hole in the soil with chopsticks, then insert the cuttings, compact them with hands, make the pot soil fully contact with the cuttings, and then pour water once. After inserting, the flowerpot had better be covered with a plastic bag, and the bag mouth should be tied with a belt. When watering is needed, open it again, and tie it again after watering. Cuttings of the pot should be placed in the direct sun without sunlight, cuttage pot soil every day within 10 days to spray water, in addition to rainy days, cloudy days can be sprayed once, dry climate should spray twice, but the amount of water should not be too much every day. 10 days later, always pay attention to keeping the soil moist. 4-5 Shed during the week until germination and then gradually let it receive some sunlight. It usually takes about 2 months to root. After that, it only needs shade for 2-3 hours at noon, and the rest of the time can be allowed to receive light to facilitate its own production of nutrients in photosynthesis.

The cultivation method of azaleas

The cultivation method of azaleas-soil:

General plant flower cultivation methods are inseparable from good soil environment, for azalea cultivation methods, soil environment is more important. There are many ways to cultivate azalea culture soil, due to different varieties of cultivation, but first or have the following conditions: loose, smooth drainage, good ventilation, acidic soil, humus rich, sufficient base fertilizer.

The cultivation method of rhododendrons-watering:

As we all know, watering is a very important job. For the cultivation method of rhododendrons, watering skills are very important. Because the azalea root fine, so in the watering time to pay attention not too much of course not too little, appropriate on the good. And watering time is best in the morning and evening, which is conducive to azaleas very good absorption of water.

The cultivation method of azaleas-fertilization:

Azalea is a very atmospheric flower, she does not need too much fertilizer to grow, so pay attention not to too much fertilizer, too much fertilizer will make azalea difficult to absorb and die, appropriate fertilizer can make azalea grow well, open beautiful flowers.

Azalea cultivation method-sunshine:

Azalea breeding methods are also a very important indispensable is the absorption of sunlight, for plants and flowers, to promote photosynthesis is necessary. Therefore, the growth of rhododendrons is also inseparable from the sunshine, but it cannot be exposed to the sun all day long. Suitable sunlight can make rhododendrons bloom more beautiful and moving flowers.

Propagation Methods and Soilless Culture Techniques of Rhododendron

Azalea is a famous flower in the world, one of the top ten famous flowers in China. There are about 900 species of azalea in the world, and more than 530 species in China. Because azaleas are short plants, flowering all the year round, flowers for double petals, ornamental value is extremely high, in residential areas and squares can often be seen, and today's small series to say is azaleas breeding methods and soilless cultivation technology points.

1 Morphological characteristics

Rhododendron is evergreen, semi-evergreen, deciduous shrub or small tree, plant height 0.4~4m, shoot often very short brown or brown hair. Flowers terminal or axillary, funnel-shaped or bell-shaped, bract flowers, corolla diameter of 2~6cm, white, yellow, pink, orange, green lotus red, rose red and other colors, stamens 5~10. Fruit a capsule, ovary 3 - 5-loculed, seeds minute.

2 Ecological habits

Azalea like sparse shade environment, avoid sunlight exposure, its cold resistance due to different origins and vary greatly. Rhododendron is a typical acid soil plant. It grows well in the environment with hydrogen ion concentration of 31.63~316.3 μ mol / L (pH 5.5 ~4.5). In the gardens of northern China, there is no piece of azalea cultivated in the open field. In alkaline environment, azalea leaves yellow due to lack of iron and manganese, resulting in falling and dying. The mechanism of alkali-to-leaf chlorosis is still unclear.

3 Methods of reproduction

Propagation methods are sowing, cuttage, layering, grafting, sub-plant and other methods. Cuttage and grafting can maintain the heredity of varieties and form commercial production technology; sowing is conducive to cross breeding, breeding excellent single plant; cutting green branches, select semi-lignified branches, high survival rate in plum rain season. Cuttage substrate is also one of the key factors affecting its survival. Azalea cuttings require rich nutrition, good ventilation and water conditions around the base of cuttings, which can be provided by means of fog culture and pearlite culture. Grafting method can give full play to the advantages of rootstock root system and scion fine characteristics, cultivate a set of advantages of both individual trees. The scion takes the tender shoot of the excellent variety, removes the lower leaf, only leaves 3~4 leaflets at the top, cuts the base into wedge shape, and cuts the surface to be 0.5~1.0cm long. The rootstock used is "imperial concubine drunk""jade butterfly""purple butterfly", generally do not use white azalea seed.

4 Soilless culture management

4.1 matrix

4.1.1 Provide acidic environment: pine needles, peat, sawdust, etc. are acidic substrates.

4.1.2 Root systems in the substrate do not dry out due to dry weather: azalea roots are easy to die due to drying, so it is best to choose a mixture of peat and vermiculite or perlite.

4.1.3 Soil and fertilizer conservation and ventilation: properly handle the relationship between acidity, ventilation and water and fertilizer conservation. When planting, consider that the acidity of the substrate should be at a hydrogen ion concentration of 3.16~31.63μ mol/ L (pH 5.5 ~4.5) under the condition that the bottom of the pot does not leak. At the same time, keep good ventilation. Nutrition and water can be guaranteed by watering and irrigating nutrient solution.

4.2 hydroponic requirement

4.2.1 pH: hydrogen ion concentration 3.16~31.63 μ mol/ L (pH 5.5 ~4.5), keep the most suitable environmental acidity for azalea roots.

4.2.2 Total nutrition: supply all kinds of nutrients needed according to the growth needs of western cuckoo, otherwise it is easy to cause single salt toxicity.

4.2.3 Large acid-base buffer capacity: The hydrogen ion concentration of nutrient solution does not decrease significantly due to the addition of alkaline substances.

4.3 watering

Western cuckoo is not alkali resistant, usually the hydrogen ion concentration of groundwater used in cities is lower than 100nmol / L (pH higher than 7), and it is easy to cause rhododendron leaves to yellow and fall off when watering with groundwater. Therefore, in order to avoid this situation, you can set up a water tank in the place where rhododendron is planted, and the water in the water tank will be exposed to the sun for a few days. At the same time, vinegar or vinegar can be used to adjust the hydrogen ion concentration of water. About 1 tablespoon of vinegar is added to 500mL of water.

4.4 management

Azalea management methods for the main shade avoid exposure, like cool avoid sultry, like acid avoid alkaline, like thin fertilizer avoid fat.