A Detailed Guide to Myrica rubra (Chinese Bayberry) Tree Planting Techniques and Cultivation Management
The Myrica rubra tree is a fruit tree native to China, and its fruit has a unique flavor and is rich in nutrients, making it highly favored by consumers. In today's world, where dietary therapy and health are valued, Myrica rubra has attracted even more attention due to its good medicinal value. Every part of the Myrica rubra tree is useful; its roots, trunk, branches, leaves, fruit, and seeds all have high utilization value. The seeds contain 40% oil and can be refined into high-grade vegetable oil. The leaves can be used to extract essence for making high-grade perfume. The bark of the roots and branches is rich in tannins and can be used as dye, while the wood is dense in texture and can be used for fine woodworking.
Growth Habits of Myrica rubra
Myrica rubra prefers acidic soil. It originated in the temperate and subtropical humid climate of China, on hillsides or in valley forests at altitudes of 125-1500 m. It is mainly distributed south of the Yangtze River basin and north of Hainan Island, that is, between 20 degrees and 31 degrees north latitude, with a distribution similar to that of citrus, loquat, tea trees, and moso bamboo, but its cold resistance is stronger than that of citrus and loquat.
The Influence of Terrain on Myrica rubra
Different types of mountainous terrain have different effects on the growth of Myrica rubra.
1. Foothill slope zones: In the main production areas, Myrica rubra is most abundant in foothill zones. Because the terrain is relatively low and the soil moisture content is high, the fruit flavor of Myrica rubra is slightly bland.
2. Mountain valleys: This type has deep soil and is fertile, and the Myrica rubra fruit is large in size and excellent in quality.
3. Steep hillside zones: This type has relatively thin soil and can achieve large, delicious fruit, but the yield is relatively low.
Introduction to Myrica rubra Varieties
1. Dongkui: Dongkui Myrica rubra originated in Huangyan, Zhejiang, and is famous for its exceptionally large fruit. Its main characteristics: the fruit is irregularly round, with a single fruit weight of 20-25 grams, purple-red in color, and relatively thick flesh columns. The soluble solids content is 13.5%, the sugar content is 10.5%, the juice content is 74%, and the acid content is only 1.35%, far superior to other Myrica rubra varieties.
2. Wando Myrica rubra: Because its ripening period is 15—20 days later than other varieties, it is called Wando Myrica rubra. Wando Myrica rubra originated in Zhoushan City, Zhejiang, and is one of the excellent varieties of Zhejiang Myrica rubra. Its main characteristics: the fruit is spherical, with an average single fruit weight of 11.2 grams, purple-black in color, fine in texture, sweet and sour and tasty, juicy and fragrant, and the flesh columns and pit separate easily; the edible rate is 94%-96%, and the soluble solids content is 12.6%. The fruit ripens at the end of June. Wando Myrica rubra does not show obvious alternate bearing, has excellent quality, and can be planted in appropriate amounts.
3. Daye Xidi Myrica rubra: Produced in Wu County, Jiangsu. Its main characteristics: the fruit is round, with an average single fruit weight of 15 grams, the flesh is purple-red, soft, and juicy, and the soluble solids content is 10%. The fruit ripens in late June. After ripening, this variety does not drop fruit easily, has relatively good storage tolerance, and is high-yielding but shows alternate bearing, so it can be planted in small amounts.
4. Xiaoye Xidi Myrica rubra: Xiaoye Xidi originated in Dongshan, Dongting, Wu County, Jiangsu, as well as Liyang, Changshu, Wuxi, and other places. The tree crown is tall and upright, the branches are slender, and there are many branchlets. The leaves are lanceolate, with entire margins or slightly fine serrations at the tip, slightly recurved at the tip, and narrowly cuneate at the base. The fruit is medium to large, oblate, with an average single fruit weight of 10.5 grams. The flesh columns are round and tightly arranged, and the fruit surface is relatively smooth. When fully ripe, the fruit surface is dark purple-red; the flesh is relatively thick, relatively firm in texture, rich and sweet in flavor, and of superior quality, containing 12.1% soluble solids. It ripens from late June to early July. The tree vigor is relatively strong, the fruit-setting rate is high, and it is high-yielding and high-quality. It does not drop fruit easily before harvest, has relatively good storage and transport tolerance, and shows alternate bearing.
5. Zaoji Mimei: This is an early-maturing seedling variety selected from Biqi Myrica rubra by the Horticulture Institute of the Zhejiang Academy of Agricultural Sciences and other institutions. It ripens in early to mid-June, more than 10 days earlier than ordinary Biqi. The tree vigor is moderate, the leaves are relatively small, and both sides are slightly upturned. The fruit is oblate, and when fully ripe the fruit surface is dark purple-red and glossy. The single fruit weight is about 9 grams, the soluble solids content is 12.4%, and the edible rate is 93.1%. It tastes sweet and sour and has excellent quality. This variety enters the fruiting stage relatively early and has strong stress resistance. Its flowering period is about 20 days earlier than usual, avoiding the harm of "yellow sand fall," which is one of the reasons for its high fruit-setting rate and stable yield.
6. Wanji Mimei: Wanji Mimei is a new high-quality late-maturing Myrica rubra variety selected from the main cultivated variety Biqi by the Horticulture Research Institute of the Zhejiang Academy of Agricultural Sciences. This variety matures more than 5 days later than Biqi, has excellent quality for both fresh eating and processing, good high-yield performance, and stable traits. In January 2003, it passed the achievement appraisal organized by the Science and Technology Department of Zhejiang Province. In Yuyao, Zhejiang, this variety flowers from April 4-15 and its fruit matures from July 5-10. It has good high-yield performance: the yield per 4-year-old plant can reach 5.7 kg, and the yield per 6-year-old plant can reach 36 kg, increasing yield by more than 15% compared with Biqi. The fruit is dark purple-red, and the fruit surface is glossy and beautiful with no Myrica rubra flower markings. It has a strong sweet taste, good mouthfeel, dense flesh, and good storage and transport tolerance. The average single fruit reaches more than 12.5 grams, and the quality for both fresh eating and processing is excellent; the edible rate of the fruit reaches 95.6%, and the soluble solids content reaches 13.7%, with a maximum of 15.7%. Every year, 30-40% of spring shoots and summer shoots do not bear fruit and become reserve fruiting branches for the next year, so the yield is stable and alternate bearing is not obvious.
7. Crystal Myrica rubra: Also called “Baisha Myrica rubra,” its color is crystal-clear like jade, and the fruit is round and large, with a fresh, mellow, and sweet taste. However, this kind of Myrica rubra tree is not easy to cultivate; from seedling raising and forest establishment to large-scale fruiting, it takes 20 years.
8. Datanmei: Datanmei originated in Hangzhou, Yuyao, and other places. The tree vigor is medium, the tree crown is not very neat, and the branches are slender. The leaves are thick and large but sparse, long-elliptic or broadly obovate-lanceolate, with slightly wavy margins. The fruit is large, round or oblate, with a flat or slightly concave base, weighing about 14 grams. The fruit stalk is extremely short, the flesh columns vary in length, with pointed tips or blunt tips bearing points, and the fruit surface is rough and uneven, deep red with black. The flesh is soft, juicy, contains 9.9% soluble solids, has a rich flavor, is appropriately sweet and sour, and is of excellent quality. It ripens in early July. The fruit has relatively poor storage tolerance, and its disease resistance and drought resistance are relatively weak.
Planting Techniques for Myrica rubra
1. Land preparation: When establishing a Myrica rubra orchard, land preparation should be carried out. Generally, land preparation uses the methods of building contour terraces, contour ridge ditches, and fish-scale pits.
① Contour terraces: On slopes of 10°-25°, terraces are suitable for construction. On the slope, contour lines should first be measured according to contour intervals or row spacing, with a gradient of 0.2%-0.3%. Generally, when setting out contour lines, construction should proceed from bottom to top, first carrying out foundation clearing along the lowest contour line. The depth of foundation clearing should be determined according to the thickness of the soil layer. For stone-walled terraces, the general depth is 0.5-1.0 m. The width of foundation clearing should increase as the terrace wall is raised, generally 0.3-1.5 m. When building the terrace wall, soil must be turned and banked at the same time, moving soil from the upper slope to the lower slope, so that the terrace inclines inward by about 3°-5°, and then deep plowing is carried out to loosen the soil of the entire terrace.
② Contour ridge ditches: Contour ridge ditching is a soil and water conservation measure that changes long slopes into short slopes in sloping orchards. It is suitable for slopes of 6°-10° with deep soil. On the slope surface, ditches are dug along contour lines, and the excavated soil is piled beside the ditch on the hillside to build ridges (mounds). Myrica rubra trees are planted in 1 row along the contour line of the outer slope of the ridge ditch. Generally, the ridge ditch width is 50-70 cm, the ditch depth is 30 cm, and within the ditch, a slow-water berm is built every 5-10 m, forming a bamboo-joint shape. The height of the ridge ditch and the depth of the ditch are roughly the same. The outer slope of the ridge ditch should be slightly longer than the inner slope, and the ridge width should be slightly greater than the ditch width.
③ Building fish-scale pits: If the terrain is complex and unsuitable for building level terraces and ridge ditches, fish-scale pits can be built to conserve soil and water. The specific method is to determine the planting points on contour lines, take the planting point as the center, dig soil from the upper part, and build a half-moon-shaped small platform field that is higher outside and lower inside. The outer edge of the platform field is built with stones or earth mounds. The row and plant spacing specifications commonly used for planting Myrica rubra are 4 m×5 m, 6 m×4 m, and 5 m×4 m. The diameter of a fish-scale pit is 2 m, of which the planting hole diameter is 1 m and the depth is 80 cm.
2. Planting
① Digging planting holes: Planting holes should be set at 1/3 of the distance from the outer edge of the terrace or fish-scale pit. According to the requirements of row and plant spacing, measure the positions of the planting holes, then take the planting point as the center and dig the planting holes. The specifications of the planting holes are 1 m in length and width and 0.8 m in depth. Generally, planting holes are dug in autumn and winter. When digging the planting holes, the topsoil should be placed on one side and the subsoil on another side. The topsoil should be mixed well with decomposed farmyard manure and superphosphate. When planting in spring, first place a certain amount of topsoil, then place the mixed fertilizer soil, and finally place the subsoil, then plant the seedlings. There are 4 combinations for the base fertilizer and superphosphate: ① 50 kg of garbage or compost, 0.5-1 kg of superphosphate; ② 25-30 kg of poultry manure, 0.5-1 kg of superphosphate; ③ 5 kg of rapeseed cake or soybean cake, 0.5-1 kg of superphosphate; ④ 25-30 kg of mountain weeds or burnt mud and grass turf after burning the mountain.
② Planting density: This should be determined according to the orchard's climatic conditions, soil fertility, varietal characteristics, and crown management techniques. Generally, where the climate is hot, the soil is fertile, the soil layer is deep, and more fertilizer is applied, planting can be sparser; where the soil is poor, the soil layer is relatively shallow, and the slope is relatively steep, planting can be denser. Generally, 15-40 Myrica rubra trees are planted per 667 sq m. Row and plant spacings include 5 m×7 m, 4 m×6 m, 5 m×4 m, and several other specifications.
③ Planting time: In places with winter frost damage such as Zhejiang, Jiangsu, Hunan, and Jiangxi, spring planting is suitable, that is, planting from late February to mid-March. In warm areas without severe cold in winter, autumn planting or spring planting can be used, that is, planting from early October to early December, or from mid-February to mid-March of the following year. Planting should be carried out on cloudy days or light rainy days. Special attention should be paid not to plant in weather with northwest winds.
④ Planting method: Generally, strong seedlings with pure variety, well-healed rootstock and scion, well-developed roots, fresh and robust seedlings, and no pests or diseases should be selected for planting. Large seedlings transplanted or planted over short distances must be kept with soil. Seedlings transported over long distances must be carefully packaged. After arriving at the orchard site, the roots need to be soaked before planting, and then the packaging should be loosened and planting carried out.
Tree Management of Myrica rubra
1. Training of Myrica rubra: The tree shape of Myrica rubra mostly adopts the natural curved-head form. Because the terminal bud of Myrica rubra and the nearby 1-4 buds can sprout shoots to become scaffold branches or lateral branches, the growth vigor of the shoots sprouting at the tip is very strong, and the lower parts are mostly latent buds, so the crown branching is very regular. When training young trees, only light pruning is needed, and the shape can be formed in 5-6 years. After the shape is formed, in spring (April) and autumn (August-September) each year, remove dead branches, diseased and insect-damaged branches, injured and disabled branches, useless root and trunk sprouts, and crossing and messy branches; no special pruning is otherwise done. For aging trees, renewal of large branches should be carried out together with fertilization.
2. Shortening fruiting branches and thinning flowers: Generally from February to mid-March, for heavy-crop trees with excessive flower bud differentiation, uniformly shorten 1/5-2/5 of the fruiting branches throughout the tree, and thin out slender and densely growing fruiting branches. At the same time, apply 0.5-1.0 kg of quick-acting nitrogen such as urea per tree to promote vegetative shoots.
3. Chemical flower thinning: For heavy-crop trees or plants bearing too much fruit, use “Shu 6” at 100 mg/kg solution at full bloom. The flower thinning rate can reach 50%, and it can also enlarge fruit shape, advance ripening, and increase the rate of high-quality fruit, significantly increasing the number of new shoots and the yield of the following year (Miao Songlin et al., 1999). In addition, for weak trees and trees with excessive flower buds, gibberellin at 200-300 mg/kg can be sprayed after fruit harvest, once every 10 days, for 2-3 consecutive sprays, to increase the number of autumn shoots and inhibit the rate of flower bud formation.
4. Manual fruit thinning: Fruit thinning is one of the most effective and simplest means of overcoming alternate bearing. In Chaoshan, Yuhang, Zhejiang, manual fruit thinning has been carried out in late May for many years on Datanmei, Xiaotanmei, and others. Of 6 fruiting branches, 3 are kept to bear fruit and 3 are thinned out. Generally, 2 fruits are kept per fruiting branch. For the large-fruited Datanmei, 1-3 fruits are kept per fruiting branch depending on the specific situation, while for the small-fruited Xiaotanmei, 4-6 fruits are kept. In addition, fewer are kept on the upper part of the crown and more on the middle and lower parts, to promote summer shoots and the formation of fruiting branches. In recent years, Huangyan, Zhejiang, and Dongguan, Guangdong, have begun to promote manual fruit thinning for Dongkui Myrica rubra, with fruit thinning carried out in 2-3 stages. The first time is about 20 days after full bloom, when the fruit has reached the size of a peanut. The main purpose is to thin out densely growing fruit, small fruit, and inferior fruit, leaving about 4-6 fruits per fruiting branch; the second time is 30-35 days after flower fall, when the fruit transverse diameter is 1 cm, again thinning out small fruit and inferior fruit, leaving about 2-4 fruits per fruiting branch; in Huangyan, by 40-45 days after full bloom, that is, before the fruit water-filling stage in early June, the fruit set is finalized, leaving an average of 1.8-2.0 fruits per fruiting branch, 3-4 fruits on long fruiting branches longer than 15 cm, 2-3 fruits on medium fruiting branches 5.0-15.0 cm long, 1 fruit on short fruiting branches less than 5 cm long, and no fruit on slender weak branches. Achieve “thin more in heavy-crop years and less in light-crop years.” Heavy-crop trees have few spring shoots, so more fruit should be thinned on the upper part of the crown; light-crop trees have many and vigorous spring shoots, so more fruit should be kept on the upper part of the crown to suppress shoots with fruit. While thinning fruit, combine with selective spraying of Lüwang No. 1, nutritional-type nucleotides, Penschibao 7000-fold solution 2-3 times, or “Tianda 2116” 750-fold solution. Especially in rainy weather, nucleotides can enhance the leaves' utilization of diffuse weak light and improve photosynthetic capacity, thereby enlarging fruit shape, reducing acid content, and making the ripening period more uniform.
Promoting Flowering and Fruiting in Myrica rubra
1. Paclobutrazol for crown control and flower promotion: Suitable for non-bearing trees over 5 years old with especially vigorous growth, and vigorous but non-bearing or vigorous and low-yielding trees. It cannot be used on young trees under 5 years old or on trees with weak vigor. In addition, to produce pollution-free fruit, adult fruiting trees also cannot use it. Methods of use include soil application and foliar spraying. For soil application, the period from October to March of the following year is effective. The method is to scrape away the surface soil under the crown, spread it evenly in the tree disk, and then cover with soil. The dosage used should vary according to variety, tree vigor, and tree disk size. For foliar spraying, on non-fruiting vigorous trees, apply when spring shoots or summer shoots are about 5 cm long; on adult fruiting trees, spray when spring shoots or summer shoots are about to stop growing, that is, before flower bud differentiation. The dosage is 500-1000 mg/kg water. Paclobutrazol has obvious shoot-inhibiting and flower-promoting effects, but it should be used carefully, and several precautions must be noted.
2. Gibberellin: Spray the crown once with gibberellin at 15-30 mg/kg at full bloom or flower-fall stage, which generally can increase the fruit-setting rate by 20-30%.
3. Vigorous trees: Do not apply nitrogen or apply little nitrogen in the current year, and appropriately apply potassium fertilizer and phosphate fertilizer; in late summer and early autumn, open ditches near the drip line of the crown, 30-40 cm deep, to cut roots; perform spiral girdling on large branch groups.
4. Top-grafting flowering branches: When pollinator trees are lacking, top-graft flowering branches.
5. Preventing and reducing pre-harvest fruit drop: For some Myrica rubra varieties with severe pre-harvest fruit drop, such as the Shuimei group, the fruit drop rate can reach 1/5-1/4 of the total fruit on the tree. Spraying the “L-type” anti-drop agent developed by the Horticulture Department of Zhejiang University once 15-20 days before harvest can significantly reduce fruit drop.
Control of Myrica rubra Pests and Diseases
1. Diseases
① Myrica rubra cancer disease: Also known as Myrica rubra sore and canker disease, it is a bacterial disease. It mainly damages branches and trunks. In the early stage, milky white small protrusions appear, with a smooth surface, which gradually enlarge into tumors. The surface becomes rough or uneven, suberized, and hard in texture. The tumors are spherical, and the largest diameter can reach more than 10 cm. On a branch, there may be as few as 1-2 tumors or as many as more than 5, generally occurring more often at branch nodes, causing serious effects on branch growth. The pathogen overwinters in the tumors on the tree or in residual branches. In mid-to-late April of the following year, bacteria overflow from the tumors and spread through rain, air, scions, and insects. They can invade only through wounds, with the most occurrences from June to August. For control, measures can include pruning out diseased branches, avoiding bark abrasions on branches and trunks, and not collecting scions from diseased branches. After harvesting Myrica rubra, promptly spray 1:2:200 Bordeaux mixture, 80% Bibei wettable powder 400-600-fold solution, 70% Thiophanate-methyl wettable powder 800-fold solution, 77% Kocide 2000 1000-fold solution, or 10% agricultural streptomycin 600-800-fold solution. It is also necessary to scrape the diseased spots clean, then apply sulfur suspension plus 402 antibacterial agent (843 Kangfuji) 100-200-fold solution to the wound; lime sulfur mixture can also be applied to the wound.
② Myrica rubra brown spot disease: Also known as anthracnose, commonly called Myrica rubra red spot. It is a fungal disease. It mainly damages leaves. In the early stage, needle-sized purplish-red spots appear on the leaf surface, then expand into round or irregular lesions. In the later stage, black dots grow in the center of the lesions, namely the fungal ascocarps. When there are many lesions, the leaves dry up and fall off, and in severe cases the whole plant loses all leaves or the tree dies. The pathogen overwinters in the leaves. From late April to early May of the following year, the pathogen spreads with rain and invades through stomata or wounds. The incubation period is relatively long, and lesions appear only in mid-to-late August. The disease occurs once a year and has no secondary infection. Control methods: prune out diseased leaves and dead branches, apply more organic fertilizer and potassium fertilizer, and ensure good drainage. Spray 80% Daconil M-45 or 70% mancozeb 600-fold solution, 80% Bibei wettable powder 500-fold solution, 1:2:200 Bordeaux mixture, 75% chlorothalonil wettable powder 600-800-fold solution, 25% metalaxyl aqueous solution 500-fold solution, 70% Thiophanate-methyl or 50% carbendazim 800-1000-fold solution, etc.
③ Myrica rubra branch blight: It mainly damages branches and trunks. The affected parts lose water and form sunken band-shaped streaks. When the diseased part encircles the branch or trunk completely, the branch or trunk dies. The pathogen is a broad-spectrum weak parasite, generally invading through wounds. Trees with poor vigor are susceptible. The main approach is to enhance tree vigor. For control, prune out dead branches, burn them, cut away diseased spots, and apply 50-fold 402 antibacterial agent to wounds for protection. Spray the crown with 0.5-2 degrees Baumé lime sulfur mixture.
④ Myrica rubra branch rot: It damages the cortex of branches and trunks. In the early stage, the diseased tissue is soft and loose, with dense, fine black granules growing on it, and slender bristles growing on those. After onset, the branches and trunks rot and die, and leaves and fruit also die. This pathogen is a weak parasite, and old trees are prone to the disease. To control it, apply more organic fertilizer and potassium fertilizer, prune out diseased branches, and burn them promptly. After scraping off the diseased spots, apply 50-100-fold 402 antibacterial agent to the wounds, or mix 2000 g fresh cow dung, 100 g Thiophanate-methyl, and 50 g zineb with an appropriate amount of water evenly, apply to the wounds, and wrap firmly with plastic film on the outside. Spray the crown with 0.5-2 degrees Baumé lime sulfur mixture.
⑤ Myrica rubra red coat disease: It is a fungal disease. It mainly damages branches and trunks, and severely diseased trees die within a few years. This disease mostly occurs at branch and trunk forks. The affected area is covered with a thin layer of pink mold. In the first year, extremely thin silvery-white or pink pustule-like substances appear on the bark on the shaded side of the branches and trunks. The disease begins in mid-March of the following year, then small pox-like blisters appear and connect into long strip-shaped lesions. Soon afterward, a pink mold layer covers the lesions. The peak periods of occurrence are May-June and October each year. It is prone to occur in rainy conditions, and old trees are more severely affected. For control, apply more organic fertilizer and potassium fertilizer, prune out diseased branches, and burn them. Scrape off the lesions on diseased branches, then apply 843 Kangfuji or Bordeaux paste. Spray the crown with 65% zineb 600-fold solution, 70% Antaison 600-fold solution, or 4%-5% ferrous sulfate solution, etc.
⑥ Myrica rubra white rot: It infects fruit. If rainy weather occurs during the ripening period, the disease is severe, the fruit becomes soft and rots, and many white mist-like substances grow on the fruit surface. To prevent this disease, film rain-shelter facility cultivation is especially best, or spray potassium sorbate 600-fold solution and Cuikang Gaibao nutrient solution to improve fruit firmness and enhance disease resistance.
⑦ Myrica rubra root rot: It damages the root system, first invading fine roots, then spreading to lateral roots, the root crown, and the main trunk, causing the vascular bundles to turn brown and necrotic. It manifests as rapid wilting of aboveground branches and leaves and moldy rot of the underground root system. To control this disease, first apply sulfur suspension and 402 antibacterial agent to large wounds; dig out and burn severely diseased plants. Spray chemicals in stages: in the early bud stage, spray 80% mancozeb 600-fold solution, 80% Bibei 400-600-fold solution, 0.5:1:100 Bordeaux mixture, or 80% Daconil M-45 600-fold solution; after leaf expansion, spray 75% chlorothalonil 500-800-fold solution, 50% carbendazim or 70% Thiophanate-methyl 600-800-fold solution, or 25% Ridomil 500-fold solution.
⑧ Myrica rubra little leaf disease: It is a physiological disease, also called nutrient deficiency disorder. It shows symptoms such as earlier cessation of growth in various types of shoots, shortened internodes at the top shoots, or scorched and dead tips, with shortened clustered branches growing from the sides, leaves relatively small, thickened, rough, hard and brittle in texture, veins protruding, suberized, or longitudinally cracked, leaves unable to turn green and mature, early death, terminal bud shrinkage, and no fruiting or few fruit. To prevent this disease, phosphate fertilizer should not be applied, more organic fertilizer should be applied, and clustered branches should be pruned out. Apply zinc sulfate and borax to the soil (for a tree crown 3 m in diameter, apply 50-100 g + urea 100-200 g, then water to dissolve). Spray the crown with 0.2% borax + 0.4% urea mixed solution, 0.2% zinc sulfate, or liquid boron fertilizer or zinc fertilizer 600-1000-fold solution, for 2-3 consecutive sprays.
⑨ Myrica rubra shoot blight: This disease is a physiological disease caused by a lack of available boron in the soil. It appears as small leaves, dead shoots, clustered branches, and no fruiting or little fruiting. It may occur on half a plant, several branches, or the whole plant, and may also occur at the top of the crown while the surrounding parts are normal. Spray 0.2% borax solution plus urea at 2 times the weight of borax; or apply 50-100 g borax per plant to the soil, mixed with 100-300 g urea, by opening a ditch near the drip line around the outer edge of the crown and applying it.
2. Insect pests
① Scale insects: There are many kinds of scale insects, mainly including Cypress oyster scale, Elm oyster scale, and Camphor armored scale. Female adults and nymphs gather on branches or leaves to cause damage. After being damaged, leaves fall, and in severe cases branches die and the tree dies. It occurs 2 generations a year, overwintering as female adults on treetops and leaves. Eggs are laid in April and hatch in May, and can then damage branches and leaves. To control scale insects, first prune out insect-infested branches and dead branches and burn them promptly; clear weeds inside and outside the orchard; strengthen fertilizer and cultivation management. Second, protect and utilize natural enemies. Finally, spray chemicals. Optional agents include 40% Supracide (methidathion) emulsifiable concentrate 1000-1500-fold solution, 25% Buprofezin 1500-fold solution, 99.1% Disichong 200-fold solution, machine oil emulsion 120-fold solution, or 25% Applaud 1000-1500-fold solution.
② Moths: These include bagworms, small leaf miners, inchworms, tussock moths, pseudo-small yellow tortrix, and fruit-sucking noctuid moths. Most damage leaves and feed on tender leaves. Moth control should focus on integrated management. In winter, clean the orchard, sweep up fallen leaves, remove weeds at the orchard edges, and burn them centrally; remove insect bags, prune insect-infested leaves, and destroy egg masses; protect and utilize beneficial natural enemies such as mantises, ladybugs, lacewings, and spiders; use light or sugar-wine-vinegar traps to kill adults and larvae; spray chemicals: use 5% Regent 1500-fold solution or 10% imidacloprid 2000-3000-fold solution to control moths, tussock moths, and inchworms; use 50% malathion or 50% phoxim 800-1000-fold solution, or 20% fenvalerate 2000-fold solution, 90% trichlorfon 1000-fold solution, 5% Nomolt 1000-fold solution, or 25% chlorbenzuron No. 3 1500-fold solution to spray and kill tortrix moths and small leaf miners. Bacillus thuringiensis, Beauveria bassiana, or Bacillus thuringiensis can also control many pests. Spraying 5.7% Baythroid 1000-1500-fold solution on the crown is relatively good for controlling fruit-sucking noctuid moths.
③ Fruit flies: During the fruit ripening period of Myrica rubra, many fruit flies feed on the fruit among the flesh columns and lay eggs or give birth to maggots among the flesh columns, affecting the fruit. To control fruit flies, no chemicals can be sprayed during the ripening period. Only 90% trichlorfon or 80% dichlorvos 800-1000-fold solution can be sprayed on the ground, or a trapping agent can be made from trichlorfon, banana, honey, and vinegar in a ratio of 10:10:6:3 and placed in the orchard to trap and kill fruit flies.
④ Termites: There are 3 types: Coptotermes formosanus, yellow-winged termite, and black-winged subterranean termite. They gnaw on the main trunk and roots of Myrica rubra trees and build mud tubes, damaging the phloem and xylem, causing yellow leaves, dead branches, and tree death. For control, use grass piles for trapping and killing. That is, dig holes in termite-infested areas, about 10 holes per 667 sq m, place ferns or tender grass in the holes, spray with 48% Lorsban emulsifiable concentrate 1000-fold solution or 5% Regent emulsifiable concentrate 2000-fold solution, preferably with 1% brown sugar added, then cover with soil. Alternatively, rake away the surface soil under the crown, spray with 2.5% Uranus emulsifiable concentrate 1000-fold solution plus 1% brown sugar, then cover with soil. The trapped termites gnaw and die from poisoning, or after carrying poison back to the nest, they transmit it to each other and cause other termites to die.
Harvesting of Myrica rubra
Myrica rubra fruit generally matures from early June to early July. After ripening, the fruit rots and drops very easily, so it must be picked in time. When harvesting, it is best to harvest in stages and batches, picking the red ones and leaving the rest. Before harvesting, trim the fingernails, and pay attention to picking and placing gently to avoid injuring the fruit and causing rot. The best harvesting times are early morning and evening, when the temperature is low and losses are relatively small. It is not suitable to harvest on rainy days or just after rain has cleared, otherwise the fruit has high moisture content and rots easily.
Planting Techniques and Cultivation Management Points for the Chinese Medicinal Herb Epimedium
Epimedium is a perennial herbaceous plant of the genus Epimedium in the family Berberidaceae. It grows under forests, in thickets by ditches, or in shady and moist places on hillsides. It is cultivated in Shaanxi, Gansu, Shanxi, Henan, Qinghai, Hubei, Sichuan, and other regions of China. The whole plant is used medicinally and has extremely high medicinal value and cultivation value. Let us now take a look at Epimedium planting techniques!
Growth Habits of Epimedium
Epimedium prefers shade and moisture. The soil moisture should be 25-30%, and the relative air humidity is preferably 70-80%. It is relatively sensitive to light and avoids direct sunlight, requiring about 80% shading. It has relatively strict soil requirements and prefers neutral acidic or slightly alkaline, loose, humus-containing, organic-rich soil, preferably loamy sand. It is suitable for growth in thickets, sparse forests, or semi-shady forest edges in low and medium mountain areas at altitudes of 450-1200 m.
Propagation Techniques for Epimedium
1. Rhizome propagation
① Rhizome selection: When digging wild Epimedium rhizomes as propagation material, select those with well-developed and thick roots, sufficient sap, many fibrous roots, root diameter of more than 0.3-0.5 cm, plump overwintering buds, and no pest or disease infection.
② Harvest and storage: The withering period of Epimedium is from late September to mid-October, and the rhizome harvest period is during this time. Cut the dug rhizomes into small sections 10-15 cm long, each section with more than 2 overwintering buds, and tie them in bundles for later use.
2. Seed propagation
① Seed harvest: The seed maturity period of Epimedium is from late May to early June. When the fruit skin is about to open and the seeds are exposed and brown, pick the fruit promptly, harvesting as they mature. After bringing them back, thresh them, winnow out impurities, and keep them fresh for storage in time. The selected seeds should be fully mature, plump and intact in appearance, free of pathogenic microorganisms, with a seed purity of 80%, a thousand-seed weight of 4.5-4.7 grams, no mildew, and a germination rate of more than 90%.
② Seed storage: Epimedium seeds have a short lifespan and should be sown immediately after harvest. If special circumstances require it, after the seeds are selected, store them mixed with fine river sand, or fine river sand mixed with humus soil, or humus soil and seeds. First disinfect the substrate with carbendazim at 1% of the substrate weight, then thoroughly mix the substrate and seeds at a ratio of 3:1, put them into a wooden box, and store in a cool, dry place. There should be a rain shelter, and during this period they should be checked frequently to prevent heating, insufficient moisture, mildew, etc. The storage period is about 2 months.
Seedling Raising Techniques for Epimedium
1. Site selection and bed preparation: Choose natural conditions on shady slopes or half-shady half-sunny slopes, with a slope below 35℃, and soil that is slightly acidic leaf humus soil, black loam soil, or black sandy loam soil. Cultivation can be carried out under broadleaf forests, mixed coniferous and broadleaf forests, or fruit tree economic forests. Remove the turf from the forest floor, make strip beds 120-140 cm wide and 12-15 cm high along the slope, and plant seedlings in horizontal strip trenches with a trench depth of 6-10 cm.
2. Sowing time: Epimedium seeds have a short lifespan and should be sown immediately after seed collection in mid-June. Under special circumstances, stored seeds should also be sown before freezing in the same year. Under special circumstances, they can be sown after thawing in the following spring.
3. Broadcast seedling raising: For broadcast sowing of Epimedium, dig shallow grooves 3-5 cm deep in the bed, level the bottom of the grooves with sieved fine humus soil, and then sow. After sowing, cover with sieved fine humus soil 0.5-1 cm, then cover with a layer of fallen leaves or similar materials to maintain soil moisture. Water thoroughly once before sowing or after covering with soil. The sowing rate is 10-15 g/sq m.
4. Drill seedling raising: For drill sowing of Epimedium, open trenches across the bed, with a row spacing of 10-15 cm and a trench depth of 3-4 cm. After opening the trenches, press the bottom firmly, then sow in the trenches, cover with soil 0.5-1 cm thick, and cover with fallen leaves or similar materials. The sowing rate is 10 g/cu m.
5. Seedling raising under forest: For seed seedling raising under mountain forest, choose relatively flat gentle slope land, clear shrubs and weeds under the forest, and appropriately thin out overly dense trees and branches so that the canopy density is about 0.5-0.7. Then make beds 1.2 m wide and 20-25 cm high along the diagonal line of the hillside, apply sufficient base fertilizer, and sow according to the flatland seedling raising method. For rhizome seedling raising under mountain forest, remove shrubs and weeds under the forest, make planting belts along contour lines, loosen the soil according to a belt width of 30-50 cm, and pick out stem roots before planting.
Transplanting Techniques for Epimedium
1. Seed seedling raising: The transplanting time is early to mid-October, when one-year-old seedlings are dug out and transplanted. Divide the selected seedlings into three grades: large, medium, and small, and plant them separately. When planting, open trenches across the bed with a row spacing of 15-20 cm and a trench depth of 9-10 cm. Place seedlings in the trenches at a plant spacing of 8-10 cm, making sure the fibrous roots spread out, cover with soil 6-8 cm thick, and press lightly.
2. Rhizome seedling raising: Divide the prepared rhizomes into three grades according to thickness and plumpness of overwintering buds. Soak quickly in No. 5 rooting powder solution at a concentration of 50-100 mg/kg for 5 seconds, then plant separately. When planting, open trenches across the bed with a row spacing of 20-25 cm and a trench depth of 9-10 cm. Plant seedlings in the trenches at a plant spacing of 10-15 cm, cover with soil 6-8 cm, and press lightly. After planting, disinfect the bed surface with Eduling 3000-fold solution or carbendazim 600-fold solution, then cover the bed surface with leaves. They can also be planted on arranged planting belts under the forest for semi-wild management.
3. Wild seedling transplanting: Cut the dug wild seedling rhizomes into small sections 10-15 cm long, each section must retain more than two overwintering buds, soak the roots in No. 5 rooting powder solution at a concentration of 50-100 mg/kg for 5 seconds, and plant according to the above method.
Field Management of Epimedium
1. Replanting: After Epimedium emerges in February-March of the following spring, promptly remove dead seedlings, weak seedlings, and diseased seedlings, and replant on cloudy days to ensure the basic number of plants.
2. Weeding: In Epimedium cultivation, weeding should be combined with intertillage, with the goal of having few weeds on the bed surface. During the peak growth season, weed once every 10 days; in autumn and winter, weed about once every 30 days.
3. Irrigation: Epimedium prefers a moist soil environment, and drought can cause growth stagnation or seedling death. If there are 5-6 consecutive sunny days in summer, artificial watering must be carried out in the morning and evening.
4. Fertilization: Epimedium is a perennial plant. After transplanting, topdressing should be carried out in different ways each year. In the first year after transplanting, foliar topdressing can be carried out, generally after leaf expansion and during the green fruit stage. After the second year of transplanting, in addition to foliar spraying, side-root topdressing should also be carried out. The time for topdressing is mainly autumn, that is, after the plants wither and before the soil freezes, and cake fertilizer, superphosphate, or decomposed pig manure is preferable.
5. Harvest: The harvest time for Epimedium is from late June to late July. When harvesting, use a sickle to cut the aboveground stems and leaves, remove thick stems, tie them into small bundles while cutting, and transport them back to the drying yard the same day. When cutting stems and leaves, do not cut the knife into the soil, to prevent damaging the rhizomes and overwintering buds, and do not pull them up by the roots, so as not to affect growth in the following year.
6. Processing: Freshly harvested Epimedium stems and leaves cannot be washed with water. Hold the base of the stems with your hands, shake off or remove weeds, foreign matter, and diseased and residual plants. Then, hang the small bundles in a pre-built shade shed to dry in the shade. The shade shed should be set up in a high, dry, and ventilated place, with rainproof facilities. Never expose them to direct sunlight or let dew form on them, so as not to affect the appearance quality of the product. A far-infrared tobacco curing barn can also be used for artificial drying. The drying standard is a moisture content reduced to below 14%.
Pest and Disease Control of Epimedium
1. Leaf brown spot and blight disease
[Symptoms] Leaf brown spot and blight disease damages leaves. On diseased leaves, the lesions are initially brown spots surrounded by yellow halos. After expansion, the lesions become irregular, with red-brown to brown edges and gray-brown centers. In the later stage, the lesions are gray-brown, shrunken, and black granular substances appear, which are the fungal pycnidia. The pathogen occurs in both the seedling stage and adult plant stage of Epimedium, with more occurrence and severe damage in the seedling stage.
[Control] ① Promptly remove and destroy diseased residues to reduce sources of infection. ② In the early stage of disease, chemicals can be applied for control. Common agents include 50% zineb wettable powder 600-fold, 50% Tuzet wettable powder 800-fold solution, 1:1:160 Bordeaux mixture, 30% copper oxychloride 600-800-fold solution, 50% carbendazim wettable powder 500-600-fold solution, 70% Thiophanate-methyl wettable powder 800-1000-fold solution, and 75% chlorothalonil wettable powder 500-600-fold solution. The above agents should be used alternately to avoid resistance.
2. Crinkle virus disease
[Symptoms] In the seedling stage in the seedbed. Infected leaves often appear as leaf tissue crinkled, uneven, thickened, deformed, and recurved. In the adult seedling stage, there are often 2 types of symptoms in the field: mosaic mottling type: diseased leaves are distorted, deformed, crinkled, uneven, and thickened, showing mottled mosaic with uneven shades of green. Yellow mottled mosaic type: infected leaf tissue is chlorotic, showing yellow mosaic mottling.
[Control] ① Select virus-free seedlings for seed production. ② During the growth period of Dipsacus asper, promptly kill virus-transmitting insect vectors. ③ When disease symptoms appear, if chemical control is needed, spray potassium dihydrogen phosphate or 20% Dukexing wettable powder 500-fold solution, or 0.5% antitoxin No. 1 aqueous solution 250-300-fold solution, or 20% Bingduning water-soluble powder 500-fold solution, etc., once every 7 days, for 3 consecutive times. Promote leaves to turn green and spread out, and reduce damage. Stop using chemicals 20 days before harvest.
3. Epimedium rust disease
[Symptoms] The pathogen damages Epimedium leaves, fruit, and so on. On diseased leaves, inconspicuous small spots first appear on the leaves, and later the underside of the leaves becomes orange-yellow slightly protruding small blister spots, which are uredinia. After the lesions rupture, they release rust-yellow urediniospores. In severe cases, leaves wither and die, and diseased fruit develops orange-yellow slightly protruding small blister spots, and in severe cases the diseased fruit becomes mummified fruit.
[Control] ① Clean the field and strengthen management. ② Remove alternate hosts. ③ During the disease period, 15% triadimefon wettable powder 1000-1500-fold solution can be selected,
4. Epimedium powdery mildew
[Symptoms] It damages Epimedium leaves. In the early stage of disease, small nearly round white powder spots appear on the front or back of the leaves, gradually expanding into large white powder areas with indistinct edges, covering the leaf surface as if sprinkled with a layer of white powder. After wiping off the white powder, the leaf surface can be seen to be chlorotic, withered yellow, and brittle. In severe cases, the leaf surface is covered with white powder and turns gray-white, until the entire leaf withers and dies. There is no foul odor after onset, and the white powder is its obvious disease sign.
[Control] ① Clean the field and strengthen management. ② During the disease period, spray 50% carbendazim 500-fold solution or 75% thiophanate-methyl 1000-fold solution. When the disease is at its peak, spray 15% triadimefon 1000-fold solution and other agents for control.
5. Physiological red leaf disease
[Symptoms] This disease usually appears in exposed places without shade. The leaves become chlorotic and red, and plant growth is inhibited and stunted. In the seedbed stage, severely affected plants may die early. In the adult seedling stage, although affected plants generally do not die after discoloration, there are fewer new buds, affecting biomass yield and causing significant yield reduction.
[Control] ① Raise seedlings under shade. ② For base planting, choose to plant under shade trees such as Myrica rubra trees and pine trees.
What fertilizer should be applied to Myrica rubra trees after fruit harvest? Key Fertilization Points for Myrica rubra Trees After Fruit Harvest
Myrica rubra trees have the characteristics of strong growth and easy cultivation, with low cultivation cost and high planting value, and are therefore praised by people as a “green enterprise” and a “money tree.” In the process of planting Myrica rubra trees, doing a good job of fertilization after fruit harvest is very important, and has important significance for restoring tree vigor, increasing nutrient accumulation, and promoting the formation of more flower buds. So, what fertilizer should be applied to Myrica rubra trees after fruit harvest? The key fertilization points for Myrica rubra trees after fruit harvest are introduced as follows.
Figure: Myrica rubra
I. What fertilizer should be applied to Myrica rubra trees after fruit harvest?
The summer shoots that sprout in the current year are the main fruiting mother branches for the following year, and their sprouting amount should account for more than 70% of the total shoots for the year, requiring a relatively large supply of nutrients. After fruit harvest, fertilizer should be supplemented in time to quickly restore tree vigor, promote active leaf function, increase nutrient accumulation, promote a sufficient number of summer shoots, and promote the formation of more flower buds. The amount of fertilizer applied should depend on tree vigor and yield. Generally, for a tree yielding more than 50 kg, apply 40-50 kg of burnt mud ash, 20-40 kg of plant ash, plus 1-2 kg of cake fertilizer. After the cake fertilizer is decomposed, mix it evenly with the ash fertilizer and apply it in a ring-shaped ditch 30-40 cm deep at the drip line of the crown. After fruit harvest of Myrica rubra, because the soil under the crown has become compacted by rain, foot traffic, and so on, opening holes for fertilization can enhance the soil's water storage and fertilizer retention capacity, improve the tree's resistance to drought in July-August, and is very favorable for flower bud differentiation.
Figure: Myrica rubra
II. Key Fertilization Points for Myrica rubra Trees After Fruit Harvest
1. Apply the post-harvest “tonic” fertilizer well:Because Myrica rubra consumes a large amount of nutrients during fruiting, applying the “tonic” fertilizer well after fruit harvest is very important for promoting the recovery of tree vigor, promoting summer shoots, and improving and promoting flower bud differentiation. It can be said that this fertilization is the most important fertilization of the year and also the basic fertilizer of the year, generally required within one month after fruit harvest. The fertilizer used in this fertilization is preferably quick-acting fertilizer combined with organic fertilizer such as cake fertilizer and manure. Reference fertilization method: taking an adult tree yielding 30-50 kg of Myrica rubra as an example, apply 1.5 kg of potassium sulfate compound fertilizer, 0.5 kg of superphosphate or lime, and 3.5-4 kg of cake fertilizer or manure per tree.
2. Apply the shoot-promoting fertilizer well:When Chinese bayberry (Myrica rubra) produces new shoots in the eighth and ninth lunar months, flower buds also emerge at the leaf axils at the same time, which means the bayberry fruit matures along with the growth of the new shoots. Therefore, in the sixth and seventh lunar months, a shoot-promoting fertilizer must be applied to the bayberry; this application is mainly a quick-acting chemical fertilizer used as a top dressing. Reference fertilization method: taking a mature tree with an annual yield of 30-50 kg of bayberry as an example, apply 0.5 kg of urea and about 0.5 kg of potassium sulfate per tree.
Image: Chinese bayberry
3. Bearing trees should avoid excessive phosphorus fertilizer:Because phosphorus promotes cell division, excessive application of phosphorus fertilizer can cause problems such as too many fruits, hard stones, little juice and a dry, astringent taste, seriously affecting the quality and edible value of the fresh fruit. Of course, phosphorus fertilizer cannot be omitted either, otherwise too few flower buds will form and the next year's yield will suffer. Generally, the ratio of nitrogen, phosphorus and potassium should be 6:3:1 or 1:0.3:4. Since chloride ions harm the bayberry root system, fertilizers containing chlorine such as potassium chloride and ammonium chloride should not be applied heavily; it is best to use potassium sulfate instead of potassium chloride.
4. Apply lime as a top dressing to regulate pH:This is a problem that fruit growers often overlook. Because the red soil of the southern mountains is fairly acidic and the soil pH is relatively low, it affects both the growth of bayberry roots and the uptake of water-soluble phosphorus. Applying lime can reduce soil acidity and raise soil pH, and it can also supply a large amount of calcium to promote the development of the bayberry root system and accelerate the growth of bayberry mycorrhizae, increasing the nitrogen-fixing activity of the mycorrhizae, thereby making the bayberry tree more vigorous and improving fruit quality. Lime as a top dressing can be applied together with other fertilizers at the first fertilization after harvest, or scattered within the canopy in winter, which also helps prevent insects and diseases. The amount of lime applied depends on the soil type, and generally should not exceed 0.5 kg per tree.
[Editor's Closing Words]Doing a good job of fertilizing Chinese bayberry trees after harvest is the key to achieving high quality and high yield. The article above has introduced the key points of fertilizing Chinese bayberry trees after harvest, and we hope it will be helpful to you!