Key Points of Seed Propagation Techniques and Pest and Disease Control Methods for Redbud
How do you propagate redbud from seed? The bark, fruit, wood and flowers of the redbud can all be used as medicine. It is grown in many provinces of China and blooms in early spring. The flowers come in pink, bright red, purple-red and other colors, and their shape resembles a butterfly.
1 Growth Habits
It likes sunlight and is fairly tolerant of summer heat. It prefers deep, fertile, well-drained soil, has strong cold resistance and drought resistance, but cannot tolerate waterlogging. It has strong sprouting ability and is fairly tolerant of pruning. The tree form is clustered with branching at the base. It is suitable for a wide range of planting sites and can be planted as a specimen in courtyards or grown in parks, green belts and other areas.
2 Sowing and Propagation
2.1 Seed Treatment
2.1.1 Seed Collection
Redbud fruit ripens from late October to early November. Select superior mother trees that grow vigorously, have good yield performance, are free of pests and diseases, and produce plump seeds. After the pods mature, they should be collected promptly. After drying, remove the pod skins and collect the clean seeds. The 1000-seed weight is about 30.3 grams.
2.1.2 Seed Storage
For seeds collected in autumn and intended for sowing the following spring, the dry storage method can be used. First dry the selected redbud seeds, and once they reach an air-dry state, put them into paper bags and store them in a low-temperature, dry, ventilated, cool warehouse at 0°C to 5°C. Be sure to check frequently in order to prevent insect damage and moisture-related deterioration.
2.1.3 Seed Germination Promotion
Before spring sowing, the seeds should be treated to promote germination, in order to help them emerge quickly and uniformly with a high seedling rate. Water soaking and stratification are commonly used for germination promotion. The seed coat of redbud is thick and hard. Germination promotion is carried out ten days before sowing the seeds the following year, using warm water soaking to promote germination. The redbud seed shell is relatively thick, so the soaking water temperature is 40°C to 60°C. After pouring in the seeds, stir until the water cools naturally, then leave at room temperature, changing to cool water once every two to three days. Once the seeds swell after absorbing water, scoop them out and place them in a clay pot, mix with two to three times their volume of river sand, and place in a wind-sheltered, sunny spot to promote germination (note that the wet sand should be kept at a moisture level where it forms a ball when squeezed by hand without dripping water). It is best to seal the flower pot with plastic wrap. Seeds undergoing sand storage should be turned every day so they are heated evenly. After about 7 days, when more than 40% of the seeds have split and shown white, they can be sown.
2.2 Land Preparation
2.2.1 Selection of Seedling Raising Site
Choose flat terrain with convenient irrigation, shelter from wind, exposure to sun, good drainage, and sandy loam or medium loam soil, with a soil pH of 6.8-7.5. It is not suitable to raise seedlings on continuously cropped land or in nurseries where vegetables or fruit trees have been grown for a long time.
2.2.2 Land Preparation
The main procedures of land preparation include deep plowing, fine harrowing and leveling. The root system of seed-grown seedlings is distributed at a depth of 0 to 25 cm in the soil layer, so deep plowing to 25 cm is appropriate. After the first plowing, irrigate once thoroughly. When the soil is no longer sticky, carry out the second plowing and fine harrowing, keeping the sowing site's soil moist, fine and loose in order to meet the needs of seed germination, then level it. The more carefully this work is done, the more favorable it is for the seedlings to emerge after sowing. After the sowing site is prepared, it should be loose on top and firm below. A loose surface helps the seedlings absorb oxygen and emerge while reducing evaporation of soil moisture from the lower layer; a firm lower layer allows the seeds to closely contact the moist soil below, ensuring the seeds' soil moisture requirements during germination. During land preparation, apply sufficient base fertilizer, with 3-5.0 m3 of decomposed organic fertilizer per mu.
2.2.3 Bed Making
The seedling bed should be made as a low bed running north-south, with east-west water channels between the seedling beds. The bed surface should be 15-20 cm lower than the paths, the bed surface width should be 80-120 cm, the path width should be 40 cm, and the length of the seedling bed is generally 10-20 m. The advantages of a low bed are labor savings, convenient watering, water savings and good moisture retention. The disadvantage is that the bed surface tends to crust after irrigation, so timely loosening of the soil is needed. Before sowing, apply 70% quintozene powder in furrows at a rate of 1.5-2.5 kg per mu. Also use a 2.0%-3.0% ferrous sulfate solution, which can be poured over the seedling bed with a watering can. The amount of medicinal solution is 9 L per square meter of nursery land.
2.3 Sowing
2.3.1 Sowing Time and Sowing Rate
The sowing time is in late April, and the sowing rate is 4-4.5 kg per mu.
2.3.2 Sowing Method
Use manual drilling, with a sowing depth of 1.50 cm-2.0 cm and a row spacing of 25 cm-30 cm. The day before sowing, water thoroughly to soak the soil. After sowing, cover with fine sandy soil to a thickness of 1.50 cm, and finally cover with plastic film. The edges of the plastic film should be pressed down firmly. The advantage of doing this is that when the seeds break through the soil, they will not come into contact with the plastic film, which can effectively prevent the young shoots from being scorched by high afternoon temperatures.
2.4 Seedling Management
When the seedlings reach 3-4 cm tall or have grown 4-5 true leaves, weed and thin the seedlings once as part of the weeding. When the seedlings enter the rapid growth stage, thin them a second time, taking care to maintain a reasonable density, with plant spacing kept at 10-12 cm. June to August is the rapid growth stage of the seedlings, and strengthening topdressing is very important. In June, when the seedlings have grown 4 true leaves, carry out the first topdressing, applying 4 kg of urea, 11 kg of phosphate fertilizer and 1.5 kg of potassium fertilizer per mu. In July, carry out the second topdressing with 9 kg of urea, 14 kg of phosphate fertilizer and 2.5 kg of potassium fertilizer. In August, carry out the third topdressing with 5 kg of urea, 17 kg of phosphate fertilizer and 4.5 kg of potassium fertilizer.
3 Division Propagation Method
Taking advantage of the redbud's habit of readily producing suckers from its roots, in October each year or before germination, a sharp knife can be used to cut the lateral roots connecting the sucker shoots to the mother plant before planting them out, giving a relatively high survival rate. Seedlings divided in autumn should be heeled in for winter protection, then planted out in the nursery in March, and they can bloom the following year.
4 Pest and Disease Control
4.1 Redbud Angular Leaf Spot
Redbud angular leaf spot mainly occurs on leaves. The lesions are polygonal in shape and range in color from yellowish-brown to dark red-brown. In severe cases, the lesions cover the leaves and often merge into patches, eventually causing the leaves to wither and fall off. Under normal conditions, this disease occurs from July to September. When the disease occurs, spray 50% carbendazim wettable powder at 700-1,000 times dilution, 70% mancozeb wettable powder at 800-1,000 times dilution, or 80% zineb at 500 times dilution. Spray once every 10 days, for 3-4 consecutive sprays, for a good control effect.
4.2 Redbud Wilt
This is a systemic disease. It first appears on branches and then develops until the entire clump dies. Peeling back the bark, a yellow-brown concentric-ring-shaped necrotic spot can be seen on the cross-section. Under normal conditions, the disease is more severe from May to July. For control, strengthen maintenance and management, improve tree vigor, and enhance the plants' disease resistance. Rotate crops in the nursery land to avoid continuous cropping, or before sowing apply 70% quintozene powder in furrows at 3-5 jin per mu. Promptly prune out dead diseased branches and plants, burn them in a centralized manner, and disinfect with 70% quintozene or 3% ferrous sulfate. Root drenching can be done with 50% thiram wettable powder at 200 times dilution, 50% carbendazim wettable powder at 400 times dilution, or 100 ppm of 120 agricultural antibiotic solution.
4.3 Redbud Leaf Blight
Redbud leaf blight mainly damages leaves. In the early stage, the lesions are red-brown and round, then merge and expand into irregular large spots; when most or the entire leaf turns red-brown, it dies. Under normal conditions, the disease begins in June. Corresponding control methods: after leaf emergence, spray with 50% carbendazim at 800-1,000 times dilution, or 50% thiophanate-methyl at 500-1,000 times dilution, spraying once every 10-15 days, for 2-3 consecutive sprays.
The above is all the content about redbud cultivation techniques. If you also want to know how to propagate redbud, come to Huinong.com to learn!
Seedling Raising Techniques and Seedling Stage Management of Chinese Pine in Northern China
Many seedling growers in northern China cultivate Chinese pine. Recently, some farmer friends have been asking how to propagate Chinese pine seeds and how to manage Chinese pine saplings. Therefore, the editor below has compiled an article on seedling raising techniques for Chinese pine in northern China!
1 Site Selection and Land Preparation
Chinese pine prefers fertile, loose plots with relatively deep soil, and also requires good drainage and convenient irrigation. For sowing and seedling raising, choose sandy loam or loam, with a pH value required to be neutral or weakly acidic. In northern China, for mountain seedling raising, one can generally choose flat terrain with a relatively small slope on a shady slope or semi-sunny slope, and it should have a relatively high humus content. Because Chinese pine seedlings have root fungi on their roots, continuous cropping can be used when raising seedlings, and the continuous cropping effect is very good. In addition, seedlings can be raised on plots where conifers, redbud and similar crops were previously grown; however, the effect is poor when raising seedlings on land where elm, black locust, or previous crops of corn, potatoes, melons, fruits or vegetables were grown. After selecting the site, plow the plot in the autumn of the year before sowing, with deep plowing required, and the plowing depth should preferably be 30-50 cm.
2 Seed Treatment
In order to increase the seed germination rate and reduce the occurrence of pests and diseases, before sowing Chinese pine seeds, disinfection, soaking and germination promotion treatments are needed. For disinfection, generally use a 0.5% formalin solution or a 0.1% potassium permanganate solution for soaking, with a soaking time of 30-60 min. After disinfecting the seeds, rinse them clean with water. Soaking is mainly to eliminate the effect of the waxy layer on the surface of Chinese pine seeds on seedling emergence. Generally, soaking in warm water at about 35°C for 24 h is sufficient. After soaking, take out the seeds and place them in an environment of 25-30°C for germination promotion. When 4/5 of the seeds have split, they can be sown.
3 Sowing and Seedling Raising
In northern China, sowing is generally done in April. Before sowing, clear debris from the seedling raising site, then prepare the land and make beds, generally making beds about 1 m wide, while the length can be determined according to the terrain. A 30 cm walkway should be left between bed strips to facilitate weeding, soil loosening and other operations. In addition, in order to reduce the occurrence of soil pests and diseases, chemicals (about 375 kg/hm2 of ferrous sulfate and about 45 kg/hm2 of 3% trichlorfon powder) can be mixed with soil and evenly spread into the plot, then plowed in, or the chemicals can be mixed evenly with base fertilizer and applied to the seedling raising land. When sowing, the base fertilizer applied should preferably be decomposed farmyard organic fertilizer at an application rate of 30,000 kg/hm2. In addition, appropriate amounts of urea at 225 kg/hm2, phosphate fertilizer at 375 kg/hm2 and potassium fertilizer at 225 kg/hm2 can also be applied.
4 Seedling Stage Management
After Chinese pine seeds are sown and emerge, the seedlings grow for a relatively long time, generally requiring about 3 years of growth. During the seedling growth stage, if management is improper, their growth rate will slow down. Therefore, during the growth stage of Chinese pine seedlings, management must be done well.
4.1 Protection Before Emergence
Because Chinese pine seeds have a fragrant aroma, they easily attract some insects, birds or mice to feed on them. After the seeds germinate and before the seedlings emerge uniformly, protective measures should be taken, especially the control of birds and mice, which can be done through manual guarding, placing rodenticide and other methods, until the seedlings have all emerged.
4.2 Water and Fertilizer Management
Chinese pine seeds differ from other forest tree seeds that germinate easily. After sowing, they need sufficient water as a guarantee, so after sowing, sprinkle water on the seedling raising field once each morning and evening, but be careful not to sprinkle too much and not to allow waterlogging; the soil only needs to be moist after each watering. After the seedlings emerge uniformly, irrigation can be done according to soil moisture conditions. Regarding fertilization, under normal circumstances, because sufficient base fertilizer was applied before sowing, no further fertilization is done that year; in the second year, topdressing can be done according to seedling growth. If the seedlings show obvious signs of malnutrition such as thin stems and yellowing needles, or when the seedlings are in the rapid growth stage, timely topdressing is needed. Topdressing should mainly be nitrogen fertilizer, appropriately combined with phosphate fertilizer and potassium fertilizer.
4.3 Weeding and Soil Loosening
After the seedlings emerge uniformly, if too much water is sprinkled on the surface or there is a lot of rainfall, the soil will crust. Because the root system of Chinese pine seedlings is not well developed and their growth is weak, after the soil crusts it is difficult for them to absorb enough nutrients. Once soil crusting occurs, the soil should be loosened promptly to promote the growth of Chinese pine seedlings. At the same time, when there is a lot of rainfall or watering on the plot, it will also accelerate the growth rate of weeds. The growth of weeds not only competes for soil nutrients but also occupies growing space, affecting the growth of Chinese pine seedlings. Therefore, when weeds are found, they should also be removed promptly.
4.4 Overwintering Protection for Seedlings
Winters in northern China are cold, and because Chinese pine seedlings have poorly developed root systems and weak growth, their cold resistance is weak. In order to ensure the overwintering survival rate of the seedlings, scientific and reasonable cold protection measures are needed. Before overwintering, when the surface soil of the plot freezes at night and thaws during the day, carry out one winter irrigation, which can reduce the impact of freezing damage. In addition, in very cold areas, seedlings can be covered with soil, or wheat straw, straw and other materials can be used to cover the seedling bed, or plastic film can be used to cover above the seedling bed.
5 Pest and Disease Control
The main diseases that Chinese pine seedlings are prone to include damping-off disease, rot disease and powdery mildew; the main insect pests that easily occur include Chinese pine caterpillar and pine shoot borer.
5.1 Diseases
5.1.1 Damping-off Disease
5.1.1.1 Damage characteristics: Shortly after Chinese pine emerges, brown elongated streaks can be seen. As time goes on, the elongated streaks gradually expand, the seedling roots turn red-brown, the root cortex begins to rot, and then the plants dry up and die. In severely affected plots, Chinese pine seedlings die in large patches.
5.1.1.2 Control methods: First, select a good nursery site and avoid raising seedlings where plants susceptible to this disease have grown. At the same time, when fertilizing and plowing, 70% dexon can be spread at 4-6 g/m3, or a 2%-3% ferrous sulfate aqueous solution can be used to irrigate the seedling raising land at a rate of 9 L/m3. Second, when sowing, fertilize reasonably, and farmyard organic fertilizer must be fully decomposed when applied. After emergence, for plants in the early stage of disease, spray 72.2% propamocarb aqueous solution at 400 times dilution, or 20% tolclofos-methyl emulsifiable concentrate at 1,200 times dilution, or 75% chlorothalonil wettable powder at 600 times dilution, or 50% wettable thiram at 800-1,000 times dilution, or spray the seedlings with Bordeaux mixture at 1:1:100.
5.1.2 Rot Disease
5.1.2.1 Damage characteristics: It mainly damages the central trunk and the lower cortex of main branches. The diseased area initially appears red-brown, slightly raised, water-soaked, and later the cortex rots, often exuding yellow-brown sap, wet-rot in appearance, with a distillers' grain smell. The lesions are round or oval, with unclear edges, sometimes showing alternating light and dark concentric rings.
5.1.2.2 Control methods: Strengthen cultivation management, prune and thin in a timely manner, cut out diseased plants and burn them, and choose local tree species with strong stress resistance. In addition, the diseased bark can be scraped clean and 1-2 applications of fungicide applied. Fungicides can include 40% asomate, thiram, lime sulfur mixture, 843 rehabilitation agent, rot spirit and others.
5.1.3 Powdery Mildew
5.1.3.1 Damage characteristics: It mainly damages new shoots and tender leaves. After new shoots are affected, the internodes shorten, the leaves become slender, the leaf margins curl upward, and the texture becomes hard and brittle. The damaged parts are covered with a layer of white powder, which later turns yellow-brown. In severe cases, the entire shoot dies.
5.1.3.2 Control methods: Remove the pathogen; strengthen cultivation management; chemical control mainly includes thiophanate-methyl, carbendazim, benomyl, asomate and others.
5.2 Insect Pests
5.2.1 Chinese Pine Caterpillar. The Chinese pine caterpillar generally occurs mostly around the Spring Festival, with the initial occurrence period in late March, when overwintering larvae begin to climb the tree crowns to cause damage. The requirements for the living environment are also increasingly high, and a beautiful landscape environment has become a major factor people consider. The growing material and cultural needs have stimulated the development of the leisure tourism and wellness industries, and the development of the leisure tourism and wellness industries cannot be separated from the support of the landscape industry. The development of the landscape industry in turn has driven the recovery of the seedling market.
The above are all the key points of the Chinese pine seedling raising stage. Fellow seedling growers, be sure to learn and prepare in advance!
Redbud Cultivation and Management Techniques
Redbud is a deciduous tree of the genus Cercis in the Fabaceae family and is widely used in landscaping. Its cultivation and management techniques are introduced below.I. Morphological Characteristics and Ecological Habits
Redbud can reach 15 m in height with a diameter at breast height of 50 cm, and is mostly used in landscaping in shrub form. The flowers are purple-red, borne in clusters of 4 to 10 on old branches. The flowering period is April, with flowers appearing before the leaves, and the fruit matures in mid-to-late September. White redbud is a common form, with pure white flowers.
Redbud likes light and grows vigorously in places with sufficient sunlight. It has a certain degree of cold resistance; in North China, adult seedlings can overwinter safely without cold protection measures. Redbud prefers fertile, well-drained sandy loam, and generally grows poorly in clay soil. It has a certain degree of salt-alkali tolerance and grows robustly in saline-alkali soil with a pH of 8.8 and a salt content of 0.2%. Redbud does not tolerate flooding, and planting it in low-lying areas very easily leads to death from root rot.
II. Water and Fertilizer Management
Redbud likes a moist environment. After planting, water immediately with the first watering, water a second time on the third day, and water a third time after the sixth day. After the third watering, water according to weather conditions, keeping the soil moist but not waterlogged. Water promptly in summer and spray the leaves as well. Drain promptly after rain to prevent root rot from excess water. After autumn begins, if temperatures are not high, control watering to prevent autumn growth. Before winter begins, water thoroughly for freeze protection. In early March of the following year, water for greening-up. Except in July and August, when watering depends on rainfall, water thoroughly once each month from April to October, and water for freeze protection before winter. Use the same method in the third year. In the fourth year, enter normal management, but the freeze-protection water and greening-up water should be watered sufficiently and thoroughly. If conditions permit, water thoroughly once in mid-to-late April and once in late September; in other seasons, it can rely on natural growth. Some people believe redbud is drought-tolerant and afraid of flooding; in fact, redbud likes a moist environment, but it simply cannot grow in waterlogged conditions.
Redbud likes fertilizer. With sufficient fertilizer, its branches are lush and its flowers are numerous and brightly colored; with insufficient fertilizer, its branches are sparse, its leaves are few, and its flowers are few and pale. Sufficient base fertilizer should be applied at planting time, preferably leaf mold, barnyard manure or dried chicken manure, and it should be thoroughly mixed with the planting soil before use, otherwise the root system will be burned. After normal management begins, apply nitrogen fertilizer once each year after flowering to promote vigorous growth, and apply a phosphorus-potassium compound fertilizer once in early autumn to benefit flower bud differentiation and safe overwintering after the new branches lignify. In early winter, combine with the freeze-protection watering and apply cow or horse manure. If the plants grow poorly, spray the leaves with a 0.2% potassium dihydrogen phosphate solution and a 0.5% urea solution.
III. Shaping and Pruning
Redbud is often used in landscaping as a shrub, so pruning should be strengthened from the beginning of seedling cultivation to help form a good plant shape.
After transplanting, the seedlings can be lightly headed back to encourage more branching, expand the nutritional area, accumulate nutrients and develop the root system. In the following spring, they can be heavily headed back to induce new shoots; select 3 branches with better growth to keep and prune out all the rest. During the growing season, strengthen water and fertilizer management and pinch back the retained branches. After planting, promptly remove excess suckers and strengthen the tending of branches retained from the previous year, doing more pinching to encourage more secondary branches. During cultivation, strengthen the renewal of flowering branches. Practice has shown that old branches over 5 years old bear fewer flowers, and the flower buds move upward, affecting ornamental value, so they should be renewed in a timely manner.
IV. Pest and Disease Control
1. Insect pests include the brown-margined coreid, cotton aphid, Canephora bagworm, Parasa consocia, Latoia lepida and Orthocraspeda trima. If they occur, during the nymph stage of the brown-margined coreid, spray 48% chlorpyrifos emulsifiable concentrate at 3,500 times dilution or 25% chlorfenapyr suspension concentrate at 1,000 times dilution for control; if cotton aphid occurs, spray lime sulfur mixture in early spring; if Canephora bagworm occurs, before its newly hatched larvae form protective cases, spray 20% diflubenzuron suspension concentrate at 7,000 times dilution for control; if Parasa consocia, Latoia lepida or Orthocraspeda trima occur, during their larval stage use Bt emulsion at 500 times dilution, or 25% fenoxycarb wettable granules at 300 times dilution, or 1.2% nicotine-matrine emulsifiable concentrate at 1,000 times dilution for control.
2. The main diseases are redbud angular leaf spot, redbud dieback and redbud sooty mold.
Redbud angular leaf spot infects redbud leaves. In the early stage of disease, brown spots appear on the leaves. As the disease develops, the spots gradually expand to form irregular polygonal patches, and in the late stage dark green powdery granules form on the lesions.
This disease is caused by infection by the deuteromycete fungus Cercospora cercidicola. The pathogen overwinters as mycelium on diseased branches and fallen leaves. In the following spring, conidia spread through wind and rain and invade through stomata or wounds. The rainy season is the peak period of disease occurrence. When it occurs on a large scale, it often causes leaves to wither and fall early.
Control methods require reasonable pruning and attention to ventilation and light penetration; strengthen water and fertilizer management and pay attention to nutritional balance, avoiding excessive application of nitrogen fertilizer; spray 75% daconil wettable granules at 800 times dilution for control, once every seven days, for three to four consecutive sprays.
Redbud dieback mainly damages redbud branches. In the early stage of disease, small cankers appear on the branches, then the cankers expand, the diseased area becomes sunken, the center of the lesion is black, the edges crack, and the xylem of the lesion turns brown-black. When the lesion expands around the branch stem in a full circle, the branches and leaves above the diseased area wither.
This disease is caused by infection by the deuteromycete fungus Botryosphaeria. The pathogen overwinters as mycelium on branch cankers and begins infecting in spring when humidity and temperature are suitable.
Control methods include promptly pruning out diseased branches and burning them; for cankers on large branch stems, scrape off the lesion and apply a sulfur powder paste or a mixture of 50 g of 50% thiram plus 250 g of 50% sulfur suspension concentrate to the wound; during the disease season, spray 75% chlorothalonil wettable granules at 700 times dilution, once every 10 days, for three to four consecutive sprays.
Redbud sooty mold mainly damages leaves. In the early stage of disease, dotted and patchy sooty layers appear on the leaves. The dots and patches gradually enlarge and thicken and connect with each other; in severe cases, they can cover the entire leaf.
This disease is caused by infection by sooty mold fungi of the Deuteromycotina subdivision. The pathogen overwinters as mycelium on diseased leaves and branches and is spread by aphids, scale insects, wind and rain. When scale insects and aphids occur in large numbers in June, their excrement and plant exudates serve as nutrients, inducing massive reproduction of the pathogen.
For control, promptly kill aphids and scale insects; strengthen pruning and maintain ventilation and light penetration; for minor occurrences, wipe clean with a clean cloth.
V. Propagation Methods
It can be propagated by sowing, division, cuttings and layering, but sowing is more commonly used.
The fruit matures in October. Remove the pods, clean the seeds and store them dry. Choose fertile, loose sandy loam that is easy to drain and irrigate for seedling raising, and apply 400 kg of organic fertilizer per mu. In April of the following spring, soak the seeds in 45°C warm water for 24 hours and then sow in furrows. After sowing, press the soil firm with the feet and irrigate; sprouts can emerge in 25 days. After emergence, the seedlings grow slowly and do not root deeply. In addition to timely watering to keep the soil moist, proper shading should also be provided in the hot summer to prevent the seedlings from being scorched. Routine care should include loosening the soil, weeding, and preventing and controlling diseases and pests. After watering for freeze protection in late autumn, the seedlings should also be covered with soil for cold protection.