Cultivation Techniques and Pest and Disease Control Methods for Loropetalum chinense var. rubrum
Loropetalum chinense var. rubrum, also known as red loropetalum, belongs to the genus Loropetalum in the family Hamamelidaceae. This tree species has a graceful form, with both flowers and foliage being outstanding, brilliantly colorful and uniquely distinctive. It can bloom multiple times within a year and is a highly prized landscaping and bonsai plant. The promotion of this tree species can not only enrich species diversity but also enhance the color of beautified environments. In today's wave of image economy driven by urban landscaping and urban forestation, it has broad development prospects.
1. Morphological Characteristics
Evergreen or semi-evergreen shrub or small tree, with gray-purple branches and slender twigs densely covered with rust-colored stellate hairs. Leaves alternate, elliptic-ovate, 2-5 cm long, dark purple on the surface, purplish-red on the underside, with stellate hairs on both sides. Capitulum inflorescence, flowers pale red to purplish-red, petals linear. The flowering period is long, but spring is the peak blooming season. Varieties of the same genus include golden-leaf red loropetalum, whose leaves are golden yellow year-round.
2. Ecological Habits
Red loropetalum is a variety of white loropetalum. Wild red loropetalum grows in semi-shaded environments and is a neutral sunlight plant. It has strong adaptability, prefers warm and humid climates, and is also quite cold-tolerant and tolerant of drought and barren soil. It grows best in slightly acidic soil. Although it can tolerate shade, in environments with sufficient sunlight, the leaf color is more vivid and the flower quantity is greater, while in shaded areas the ornamental value decreases. It grows relatively quickly. Loropetalum is distributed in the Dabie Mountains, Tongbai Mountains, and the southern Funiu Mountains. Red loropetalum is extensively cultivated in Shangqiu, Pingdingshan, Xuchang, Xinyang, and other areas of Henan.
3. Propagation and Cultivation
Softwood cuttings are preferable. Cutting bed preparation: Select a plot with loose soil, level ground, a pH value of around 6, and convenient drainage and irrigation to build the cutting bed. After selecting the plot, carefully prepare the soil, apply sufficient base fertilizer, and then build the cutting bed with a width of 1-1.20 m and a height of 15-20 cm. About 2 m above the cutting bed, erect a shade shelter using black shade netting (light transmittance 20%-30%). Cuttings: Select semi-lignified softwood twigs as cuttings, with a length of 6-8 cm. Remove the lower leaves, keeping 2-3 upper leaves and axillary buds. After disinfection treatment, set aside for planting. Cutting selection and trimming should be done in a cool place to strictly prevent water loss. Cutting can generally be done from May to September, but cuttings taken in late August and September need to be treated with rooting powder and watered after insertion. Build a plastic mini-tunnel 50 cm high over the seedbed to maintain humidity. Seedbed management: Water timely to maintain moisture in the seedbed. When the temperature inside the tunnel is too high, open the plastic film at both ends of the cutting bed for ventilation and cooling. Generally, about 120 d after cutting, the film at both ends of the seedbed can be opened to allow rooted seedlings to adapt to temperature changes outside the bed. After 5-7 d, remove all film. At 140-150 d, dismantle the shade shelter and carry out full-light hardening for 25-30 d. During this period, apply topdressing 2-3 times using a 0.20% compound fertilizer aqueous solution, or a mixed aqueous solution of 0.10% urea and 0.20% phosphate fertilizer, applied as a liquid drench. The production cycle for cutting seedlings is 6 months, after which they can be lifted for transplanting or sale.
If growing large seedlings for over a year, they can be transplanted to deep, fertile field soil. Generally, plant spacing is 35 cm and row spacing is 45 cm. For two-year-old large seedlings, plant spacing is 50 cm and row spacing is 60 cm. Large seedlings must be transplanted with a soil ball. After planting, pay attention to cultivating and weeding. Seedlings over two years old should be shaped and pruned. The principle is to prune more from the upper part and less from the lower part of the seedling. After pruning, the crown takes on a flattened spherical shape. Diseases to watch for include mosaic disease, damping-off, leaf rot, and black spot. Pests include cutworms and scarab beetles.
4. Pest and Disease Control - Diseases
The main diseases include mosaic disease, damping-off, leaf rot, and black spot. The main pests include star longhorn beetles, cutworms, and scarab beetles.
4.1 Mosaic Disease
It first manifests as chlorosis of leaf veins, followed by slight mottling on the leaves, which later becomes mottled with dark and light red patches. Symptoms are more pronounced on new leaves. This viral disease is mostly spread by aphids. In addition, red loropetalum is mostly propagated by cuttings. If the cutting material carries the virus, it is also a direct cause of the disease. Aphid control has a certain controlling effect on red loropetalum mosaic disease. Additionally, since red loropetalum is mostly propagated by cuttings, the accumulation of virus eventually manifests to a certain degree. Therefore, selecting healthy branches for cuttings is also key to disease prevention.
In any case, paying attention to field sanitation management, eradicating diseased plants, and removing other hosts of CMV to reduce sources of infection are the most important control methods.
4.2 Black Spot
This disease is prone to occur when 1-4 leaves have grown after seedling emergence. It can harm leaves, petioles, young twigs, and pedicels, but mainly damages leaves. In the early stage of the disease, brown radial lesions appear with distinct edges, 5-10 mm in diameter, with small black dots on the lesions. In severe cases, leaves wither and fall prematurely, affecting growth.
Control methods: (1) In autumn and winter, prune diseased branches and leaves, remove fallen leaves and residual plants from the ground, and burn them in a centralized manner to reduce sources of infectious bacteria. (2) Select disease-resistant and disease-tolerant varieties. (3) Strengthen cultivation management, enhance tree vigor, and improve disease resistance. Pay attention to shaping and pruning, ensure light penetration and ventilation, attend to drainage, reduce irrigation, and lower humidity. (4) During the leaf expansion period, spray 50% carbendazim wettable powder at 500-1,000 times dilution, or 70% thiophanate-methyl at 1,000 times dilution, or 75% chlorothalonil at 1,000 times dilution, or 80% zineb at 500 times dilution, once every 7-10 d, for a total of 2-3 times.
4.3 Star Longhorn Beetle
The larvae girdle the bark at the base of the tree in a ring pattern, and finally bore into the xylem. Because the phloem of the seedling is destroyed, the transport of water and nutrients is obstructed, gradually causing partial death, and ultimately resulting in the death of the entire plant. Capture adults in May-June. During the adult activity period, wrap the tree base with plastic sheets to prevent egg-laying. Mix 80% dichlorvos emulsion or 40% dimethoate emulsifiable concentrate with water and yellow clay into a paste and brush it onto the tree base. To hook and kill larvae, insert medicated cotton and seal it with mud.
4.4 Cutworms and Scarab Beetles
They mainly bore into and feed on the root system as larvae. Cutworms mainly harm cutting seedlings and small seedlings, while scarab beetles harm seedlings of all sizes. Use black lights to trap and kill adults; take advantage of the adults' death-feigning behavior to manually capture and kill them at dusk; spray 40% omethoate emulsifiable concentrate at 1,000 times dilution, or 90% trichlorfon original solution at 800 times dilution.
Cultivation and Management Techniques for Loropetalum chinense var. rubrum -- Seedling Transplanting Techniques for Loropetalum chinense var. rubrum -- Pest and Disease Control for Loropetalum chinense var. rubrum
Loropetalum chinense var. rubrumCultivation and Management Techniques--Seedling Transplanting Techniques for Loropetalum chinense var. rubrum--Pest and Disease Control for Loropetalum chinense var. rubrum--Loropetalum chinense var. rubrum, also known as red zhimu and red loropetalum flower. It is an evergreen shrub or small tree of the family Hamamelidaceae. Young twigs are covered with dark red stellate hairs. Leaves alternate, leathery, ovate, entire margins, young twigs pale red, overwintering old leaves dark red. Flowers in clusters of 4-8 on racemose peduncles, forming terminal capitate or short spike-like inflorescences, with 4 petals, pale purplish-red, ribbon-like linear. Capsule woody, obovate; seeds long-ovate, black, glossy. Flowering period April-May, fruiting period September-October. Loropetalum chinense var. rubrum has luxuriant branches and leaves, a graceful tree form, and flexible wood that tolerates pruning and wiring, making it an excellent material for creating stump bonsai. The flowers, roots, and leaves can be used medicinally.Land Preparation and Bed Forming for Loropetalum chinense var. rubrum
Plow the subsoil to a depth of 20 to 30 cm, break up soil clods, and remove stones, tiles, residual roots, and weeds. Apply 400 to 800 kg of calcium-magnesium-phosphorus-potassium fertilizer per mu. Small seedlings of red loropetalum are cultivated in raised beds. The bed surface is 20 cm above ground level, bed width is 1.2 m, and length depends on the terrain. Between every two beds, set a 40 cm wide walking path. On the outer side of each bed, set a 20x20 cm drainage and irrigation ditch. Around the entire plot, set 40x30 cm drainage and irrigation ditches.
Transplanting Loropetalum chinense var. rubrum Seedlings
Seedling lifting should be carried out when the soil is moist. Water thoroughly 3 hours before lifting seedlings so that moist soil adheres to the root mass and avoids root damage. When lifting seedlings, plant them as you lift them, and do not expose them to strong light for extended periods. If long-distance transport is required, the seedling roots should be coated with thin mud slurry and tightly wrapped in plastic bags. After the entire plot is planted, irrigate promptly. The best planting seasons are from early October to mid-December and from early February to late March. From late December to late January, frost damage is likely to occur. Planting after April may affect survival due to strong light and high temperatures. Planting can be done in furrows or holes, with 10,000 to 15,000 plants per mu. For bare-root transplanting, spread the root system in the hole without curling, cover with fine soil, gently lift the seedling to spread the roots, then press down lightly, water thoroughly to settle the roots, and cover with a layer of topsoil to conserve moisture. Autumn planting should avoid freezing in winter. When the temperature drops below 0°C, cold protection measures should be taken, generally by spreading dry grass and fallen leaves over the seedbed, or arch-covering with plastic film.
Cultivating and Weeding for Loropetalum chinense var. rubrum
Cultivating and weeding can promote the absorption of nutrients by seedling roots. The depth of cultivation depends on the depth of the seedling root system and the growth stage. For young seedlings and small seedlings, cultivate shallowly; for medium and large seedlings, cultivate deeply. Near the plant base, cultivate shallowly; between plants and rows, cultivate deeply, generally 3 to 5 cm. Cultivating and weeding is often carried out from May to June. After July, when the seedling root system has expanded into the inter-row spaces, cultivation should be stopped; otherwise, the root mass will be cut and the seedlings damaged.
Timely Topdressing - For 2-3 year old seedlings ready for saleLoropetalum chinense var. rubrum balltypes, the purpose of topdressing is to promote branch and leaf growth. More nitrogen fertilizer can be applied, but in the late growth stage in autumn, phosphorus and potassium fertilizers should be increased. In addition to dried manure and human waste, decomposed pig manure and urine can also be applied as topdressing, which has a color-enhancing effect on red loropetalum. For large-scale cultivation, chemical fertilizers can also be applied in combination. For seedlings ready for sale at 2-3 years, apply 1.2 kg ammonium nitrate, 1.5 kg superphosphate, and 0.5 kg potassium chloride per 100 sq m.
Pest and Disease Control for Loropetalum chinense var. rubrum
Damping-off: Damping-off mainly occurs in spring when there is abundant rain, and both seedlings and mature plants are affected. Dark brown lesions appear at the affected areas, and in severe cases, plants die in patches. Control methods: Transplant with disease-free new soil. Fertilizers used must be thoroughly decomposed; never use fresh farmyard manure. Promptly remove diseased plants. Before transplanting, disinfect the soil with 50 mL of 40% formaldehyde diluted in 6 kg of water per sq m, or mix 70% pentachloronitrobenzene with fine soil at a ratio of 1:30 and spread it on the seedbed soil. For spring-planted small seedlings, spray 70% thiophanate-methyl at 1,000 times dilution or 75% chlorothalonil at 1,000 times dilution one week later, spraying once every 10 days, alternating between the two.
Pests of Loropetalum chinense var. rubrum
The main pests include aphids, geometrid moths, yellow noctuid moths, dòupàn noctuid moths, large and small cutworms, and scarab beetles. Aphids affect plant growth and induce sooty mold. Geometrid moths and noctuid moths harm plants by their larvae feeding on leaves. In severe cases, they can consume all tender shoots in 2 to 3 days. Cutworms and scarab beetles bore into and feed on the root system as larvae. Cutworms mainly harm cutting seedlings and young seedlings, while scarab beetles harm large, medium, and small seedlings alike. To control aphids, spray 5% diesel emulsion or 3-5 degree Baumé lime sulfur mixture before sprouting to kill overwintering adults and eggs. Spray a second application after flower fall, and a third application in October in autumn. To control geometrid and noctuid larvae, spray 50% methamidophos at 1,500 times dilution. Control early and when pests are small. Cutworm and scarab beetle larvae are underground pests. Control methods include strengthening nursery management and not applying undecomposed organic fertilizer. Plow in winter to turn overwintering larvae to the surface to freeze to death. Apply 3% carbofuran granules at 2 kg per mu, placed in furrows 10 to 20 cm deep in the soil.
Pest and Disease Control Techniques for Loropetalum chinense var. rubrum
Loropetalum chinense var. rubrum (Latin scientific name: Loropetalum chinense var. rubrum), also known as: red loropetalum, red zhimu, red zhimu, red loropetalum flower, red zhimu flower, red zhimu flower, red loropetalum, is a variety of Loropetalum chinense in the genus Loropetalum of the family Hamamelidaceae. It is an evergreen shrub or small tree. The bark is dark gray or light gray-brown, with many branches. Young twigs are red-brown, densely covered with stellate hairs. Leaves leathery, alternate, ovate or elliptic, 2-5 cm long, apex short-acuminate, base rounded and oblique, asymmetrical, with stellate hairs on both sides, entire margins, dark red. Petals 4, purplish-red, linear, 1-2 cm long. Flowers in clusters of 3-8 at the tips of branchlets. Capsule brown, nearly ovoid. Flowering period April-May, long flowering period of about 30-40 days, and can bloom again during National Day. Flowers in clusters of 3-8 on a common peduncle forming terminal capitate inflorescences, purplish-red. Fruiting period August. It is mainly distributed in the middle and lower reaches of the Yangtze River and areas to the south, and northern India. The flowers, roots, and leaves can be used medicinally. Planting flowers is important, but maintaining them is even more important. With the continuous development of urban greening, red loropetalum, as a colorful tree species, occupies an increasingly important position in urban greening.However, due to some weak links in greening maintenance and management, we often see entire red loropetalum plants with a crown diameter of over 1 meter dying, seriously affecting the landscape effect of green spaces. Last November, we studied the causes of red loropetalum death and corrected the incorrect treatment methods previously adopted.
1. Pests: After digging up the roots of large-sized red loropetalum on the verge of death in the nursery and carefully observing them, it was found that the damage was mainly caused by the trunk-boring pest, the star longhorn beetle.
1. Damage pattern: The larvae girdle the bark at the base of the tree in a ring pattern, and finally bore into the xylem. Because the phloem of the seedling is destroyed, the transport of water and nutrients is obstructed, gradually causing partial death, and ultimately resulting in the death of the entire plant.
2. Larval morphological characteristics: There is a "convex" shaped mark at the posterior end of the prothorax, and in front of it there is also a pair of flying-bird-shaped marks.
3. Control methods: 1. Capture adults in May-June. 2. During the adult activity period, wrap the tree base with plastic sheets to prevent egg-laying. 3. Mix 80% dichlorvos emulsion or 40% dimethoate emulsifiable concentrate with water and yellow clay into a paste and brush it onto the tree base. 4. To hook and kill larvae, insert medicated cotton and seal it with mud.
2. Loropetalum chinense var. rubrum Mosaic Disease
1. Damage symptoms: It first manifests as chlorosis of leaf veins, followed by slight mottling on the leaves, which later becomes mottled with dark and light red patches. Symptoms are more pronounced on new leaves.
2. Disease pattern: This viral disease is mostly spread by aphids. In addition, red loropetalum is mostly propagated by cuttings. If the cutting material carries the virus, it is also a direct cause of the disease.
3. Control methods: Aphid control has a certain controlling effect on red loropetalum mosaic disease. Additionally, since red loropetalum is mostly propagated by cuttings, the accumulation of virus eventually manifests to a certain degree. Therefore, selecting healthy branches for cuttings is also key to disease prevention. In any case, paying attention to field sanitation management, eradicating diseased plants, and removing other hosts of CMV to reduce sources of infection are the most important control methods.