When to Plant Peanuts? Detailed Explanation of Cultivation and Management Key Points

The peanut is a nut with abundant yield and widespread consumption in China, also known as groundnut, longevity fruit, mud bean, foreign bean, ground bean, etc. It is an annual herbaceous plant of the genus Arachis in the Fabaceae family under the order Rosales, with production areas mainly distributed in Brazil, China, Egypt and other places, and is suitable for planting in sandy soil areas with a warm climate and moderate rainfall. Its growing season is relatively long. Let us take a look at the planting time of peanuts!

Peanut Planting Time

In the southern spring-autumn double-cropping peanut region, the suitable sowing period is from February to mid-March. In the Yangtze River basin spring-summer peanut rotation region, the suitable sowing period is from March to late April. In the northern large peanut region and peanut production areas, the suitable sowing period is mostly from late April to early May. When sowing peanuts, if the soil temperature at a depth of 10 cm remains stable above 15 degrees for 5 consecutive days, sowing can begin. Remember, never sow when the temperature is below 11 degrees, to prevent seed rot and seedling death. Even if the peanuts can emerge, the peanut seedlings will not be robust and yields will be affected. Summer peanut growing areas can choose relay intercropping and sow early to increase yields.

Peanut Sowing Methods

1. Sowing methods: Peanut sowing methods are divided by cultivation method into open-field sowing and film-mulch sowing, and by operation method into manual dibbling and mechanical sowing.

2. Sowing density: The planting density of peanuts is determined by plant height, fruiting range and leaf area size. The suitable planting density depends on climate characteristics, soil fertility, selected varieties and cultivation conditions.

3. Sowing depth: Generally, peanut sowing depth of about 5 cm is appropriate. The principles of "do not sow deep when dry, do not sow shallow when wet" and "shallow for clay soil, deep for sandy soil or plots with high sand content" should be mastered. For open-field cultivation, the deepest should not exceed 7 cm, and the shallowest should not be less than 3 cm.

4. Post-sowing compaction: Post-sowing compaction is a successful experience for drought-resistant peanut sowing to ensure full stands. After compaction, it not only reduces soil moisture evaporation, but also brings the seeds into close contact with the soil, promotes the rise of moisture from lower soil layers, prevents seeds from drying out, and facilitates seed germination and emergence.

Peanut Cultivation Techniques

1. Land leveling: The peanut is an economic crop that flowers above ground and, after forming gynophores, burrows into the ground to set fruit. It is suitable for planting in loose sandy soil and oil-sand soil. Peanut plots should be deep-plowed, and during plowing, 30-40 tons of high-quality farmyard manure per hectare should be applied, followed by 1-2 passes of compaction after plowing. Where conditions permit, irrigation can be done first, then farmyard manure and chemical fertilizer mixed and applied into the furrows, followed by ridging and compaction, in preparation for timely sowing.

2. Cultivated varieties: For high peanut yields, good seed is the foundation. Peanut varieties suitable for planting mainly include the Fuhua series and the Jifu series (commonly known as Silihong), with a growth period of about 110-120 days. Select pods that are large, plump, uniform in shape and unbroken as seed. Before shelling, sun-dry for 1-3 days. After shelling, further select seeds, choosing kernels with pure color and uniform shape as seed.

3. Scientific fertilization: Peanuts are relatively tolerant of poor soil. Fertilization should be mainly basal fertilizer, with 30 tons of farmyard manure per hectare. Chemical fertilizer should be mainly phosphorus fertilizer, with 300-400 jin of diammonium phosphate per hectare. For peanuts grown on poor soil, apply an additional 200-300 jin of urea per hectare.

4. Replanting and thinning: From late May to early June, peanut seedling surveys should be carried out as early as possible. For fields with obvious gaps, replant as early as possible. Replanting can use the method of pre-germination and water-dibbling, and complete the thinning and final spacing work.

5. Clearing around seedlings and root exposure: After peanut seedlings have all emerged, use a small hoe to dig a ring of soil around each seedling at a distance of 2 cm, then gently expose the two cotyledons above the ground by hand. Clearing around seedlings and root exposure is generally carried out three days after the first hoeing and ridging.

6. Timely hoeing and ridging: Begin hoeing after peanut seedlings emerge. Three days after hoeing, do the first ridging. After 15-20 days, do the second hoeing and ridging. Be careful not to bury seedlings when earthing up. After the peak flowering period, complete the third hoeing and ridging. When closing the rows, ridge in four directions to facilitate gynophore penetration into the soil, and also pay attention to pulling out large weeds.

7. Reasonable topdressing: During the pod-filling and full-pod stage, peanuts can be topdressed according to growth conditions with targeted foliar spraying of fertilizers such as potassium dihydrogen phosphate (suitable concentration 0.3%) and plant growth regulators such as Lufeng 95, to promote kernel formation.

8. Timely harvest: When peanut leaves turn yellow and some stems and leaves dry up, harvest can begin, generally in mid-September. After harvest, sun-dry to reduce moisture, promote after-ripening, and improve seed maturity. Peanuts kept for seed must be harvested and sun-dried before frost.

Alright, that concludes our introduction to peanut planting time and cultivation techniques. Now let us take a look at peanut pest and disease control techniques!

Stem Rot

[Symptoms] At the seedling stage, the cotyledons become dark brown and dry-rotted, then the disease spreads along the petiole to the stem base, forming yellow-brown water-soaked lesions, and finally black-brown rot. In later stages, water-soaked lesions first appear at the stem base or main and lateral branches, turning yellow-brown and then black-brown, with the above-ground parts wilting and dying. Peanut stem rot occurs severely, with about 80% of the area affected. The general incidence rate is 60-70%, and in severely affected bacterial blocks it reaches as high as 80-90%. Some severely diseased plants have died entirely.

[Control] Before sowing, treat seeds with 50% carbendazim wettable powder (dosage 0.3-0.5% of seed weight), or use 0.5 kg of 50% carbendazim wettable powder mixed with 50-60 kg of water to cold-soak 100 kg of seeds for 24 hours before sowing, with remarkable control effects. In the early stage of disease, use 50% carbendazim wettable powder or 65% zineb wettable powder at 500-600 times dilution, or 70% thiophanate-methyl wettable powder at 800 times dilution for spraying, once every 7 days, for 2-3 consecutive sprays.

Root Rot

[Symptoms] This disease can occur throughout the entire growth period of peanuts. Infected plants are stunted, with leaves turning yellow from bottom to top, drying and falling off, and the outer skin of the main root turning black and rotting until the entire plant dies. This disease mainly spreads through rainwater and within the field. Waterlogging at the seedling stage, low soil temperature, or sowing too early or too deep can all easily trigger this disease.

[Control] (1) Prepare land and improve soil, apply increased decomposed organic fertilizer, prevent waterlogging and drain water, and strengthen field management. (2) Treat seeds with 50% carbendazim wettable powder at 0.3% of seed weight. In the early stage of disease, spray the entire field with 50% carbendazim at 1000 times dilution.

Leaf Spot

[Symptoms] Brown spot disease lesions are circular, dark brown, relatively large, with a yellow halo around the lesion edge, and grayish mold appears in later stages. Black spot disease lesions are circular, black-brown, without a yellow halo around the lesion, and smaller than brown spot lesions.

[Control] In the early stage of disease, when the diseased leaf rate in the field reaches 10-15%, begin the first spraying. Chemical options include 50% carbendazim wettable powder at 1500 times dilution, or 50% thiophanate-methyl wettable powder at 2000 times dilution, or 80% zineb wettable powder at 400 times dilution, or 80% mancozeb at 400 times dilution, 75% chlorothalonil wettable powder at 600-800 times dilution, or Kangku Ning at 700 times dilution, or 0.3-0.5 degrees Baume lime-sulfur mixture, etc. Afterward, spray once every 10-15 days, for 2-3 consecutive sprays, with 50-75 kg of spray solution per mu each time.

Peanut Rust

[Symptoms] The bottom leaves are affected first, with yellow blister spots appearing on the leaves, small in size, surrounded by a very narrow yellow halo. After the epidermis cracks open, rust-colored powder is released. In severe cases, leaves turn yellow, dry up and fall off.

[Control] When the diseased plant rate in the field reaches 10-20%, choose 50% colloidal sulfur at 150 times dilution, or sodium rust-resistant at 600-800 times dilution, or 75% chlorothalonil at 800 times dilution, or Bordeaux mixture at 1:2:200 (copper sulfate:quicklime:water), or 25% triadimefon wettable powder at 3000-5000 times dilution, spraying once every 10 days or so, for 3-4 consecutive sprays. Sodium rust-resistant should not be used continuously and should be alternated with other chemicals. Spray 60-75 kg of solution per mu each time.

Peanut Web Blotch

[Symptoms] Natural infection in the field generally starts from the bottom leaves of the plant. Initially, needle-head-sized small brown spots appear on the upper surface of the leaves, gradually becoming brown starburst-shaped spots, then expanding into a net-like pattern with gray-green edges. As the lesions gradually expand, they finally form circular, oval or irregular brown to chestnut-brown large spots, with the lesion edges light green-brown and the boundaries indistinct, causing premature leaf drop. The underside of the leaves shows no symptoms initially, but later presents light brown lesions with indistinct edges.

[Control] In addition to the pathogen surviving on diseased and residual peanut leaves falling into the field, carrying out crop rotation, and selecting disease-resistant varieties, when the diseased plant rate in the field reaches above 5%, choose Kangku Ning at 700 times dilution, 80% mancozeb at 400 times dilution, "Nongkang 120" (0.5 kg per mu) at 200 times dilution. Use 75-100 kg of solution per mu each time, spraying once every 10-15 days, for 2-4 consecutive sprays.

Peanut Bacterial Wilt

[Symptoms] Peanuts are most susceptible to this disease generally at the early flowering stage. In the initial stage of diseased plants, the first and second leaves at the top of the main stem first lose water and wilt, with leaf opening delayed in the morning and leaf closing advanced in the afternoon. After 1-2 days, the entire plant or one side of the leaves wilts rapidly from top to bottom, with a dull color, appearing greenish dirty-green. In later stages, diseased leaves turn brown and scorched. Diseased plants are easily pulled up, and the tip of the main root, fruit stalks and pods appear black-brown wet-rot, with root nodules dark green. The vascular bundles in the longitudinally cut diseased stem are black-brown, and white sticky liquid can be seen oozing out from the cross-section under moisture with slight squeezing.

[Control] Before sowing, soak seeds in 1000 times diluted 32% Kexin solution for 8-12 hours for disinfection and sterilization. In the early stage of disease, spray 2500-3000 times diluted agricultural streptomycin or Xinzhi mycin, or 1500-2000 times diluted 32% Kexin solution, once every 7-10 days, for 3-4 consecutive sprays. In addition, spraying Baode biological foliar fertilizer at the early flowering stage can promote beneficial microbial activity in the root system and also plays a certain role in inhibiting the development of the pathogen.

Black Mold

[Symptoms] Black mold mainly occurs in the early growth stage of peanuts. The pathogen first infects the cotyledons, causing them to turn black and rot, then infects the root and stem base of seedlings. In moist conditions, abundant mold grows on the diseased parts, covering the stem base, and the stems and leaves lose water, wilt and die.

[Control] Prepare land and improve soil, apply increased decomposed organic fertilizer, prevent waterlogging and drain water, and strengthen field management. Treat seeds with 50% carbendazim wettable powder at 0.3% of seed weight.

Southern Blight

[Symptoms] After peanut roots, pods and stem bases are infected, they initially show brown soft rot. White silky mycelium (hence called southern blight) appears at the root-stem junction of the above-ground parts, along with rapeseed-shaped sclerotia. Stems and leaves turn yellow and gradually die, and peanut pods rot. The pathogen begins to germinate under high temperature and high humidity conditions, infecting peanuts. It occurs more severely in sandy soil, continuous cropping, excessive density with poor ventilation, and on rainy days.

[Control] At the peanut sowing stage, apply 1 kg of quintozene per mu mixed with 20 kg of fine moist soil, placed in the sowing furrow to cover the seed. Also pay attention to using chemicals such as Shennongdan and fenamiphos to prevent underground pests. At the early pod-setting stage, spray 20% triadimefon emulsifiable concentrate at 1000 times dilution or iprodione at 1000 times dilution for control. During the disease period, triadimefon, Genfuling, thiophanate and other chemicals can also be used for root irrigation, with very obvious control effects.

Peanut Pest Control

1. Reasonable crop rotation: Good preceding crops for peanuts are corn, millet and other grass-family crops. Avoid continuous cropping.

2. Autumn deep plowing: Autumn deep plowing can turn pests up to the surface, exposing them to death by sun or predation by birds, reducing pest sources.

3. Seed coating: Coat seeds with seed coating agent before sowing. This method can also effectively prevent rodent damage.

4. Soil treatment: When preparing land before sowing, evenly broadcast 22.5-30 kg of 3% carbofuran granules or 22.5-30 kg of 3% phorate granules per hectare on the field surface, then shallow-plow into the soil. Alternatively, broadcast carbofuran or phorate granules into the sowing furrow before sowing, or mix insecticides into organic fertilizer as basal fertilizer.

6. Larva control: In late June and late July, during the peak hatching and young larval stages of scarab beetles, apply 35-45 kg of phoxim granules per hectare plus 250-300 kg of fine soil and broadcast at the peanut root zone, then shallow-hoe into the soil. Alternatively, irrigate roots with 50% phoxim or 90% trichlorfon at 1000 times dilution.

Camellia Oleifera Planting Techniques and Cultivation Management Key Points

China is the place of origin of oil-tea camellia. Oil-tea camellia, belonging to the Theaceae family, is the main and unique woody oil tree species in China. The oil-tea camellia tree has a long lifespan and strong adaptability, and can grow on hills, mountains, ditch edges and roadsides, without competing with grain and cotton for land. Oil-tea camellia can not only green barren hills and conserve soil and water, but is also an evergreen broadleaf tree with thick leathery leaves and smooth trunks that can serve a fire-prevention function, making it an excellent tree species for firebreak belts.

Distribution and Cultivation

The suitable cultivation area for oil-tea camellia refers to the suitable growing area for oil-tea camellia with oil production as the management goal. The distribution boundary of oil-tea camellia in China is: 23°30'N-31°00'N, 104°30''E-121°25'E, with the main cultivation distribution area at 23°-30°N. Within the distribution area, it belongs to the mid-subtropical humid monsoon climate, with abundant water and heat conditions.

Characteristics and Traits

1. Morphological characteristics: Oil-tea camellia is an evergreen small tree, up to 4-6 m tall, with shorter ones 2-3 m. Flowers are bisexual, sessile, blooming in mid-to-late October. After flowering, the fruit only matures by October of the following year. Therefore, flowers and fruits are present simultaneously on the oil-tea camellia tree.

2. Suitable growing conditions: Oil-tea camellia prefers a warm and humid climate, requiring an annual average temperature of 14-21°C, with the lowest monthly average temperature not below 0°C and the highest monthly average temperature of 31°C, relative humidity between 74-85%, annual average rainfall above 1,000 mm with even distribution across the four seasons, and sunshine of 1,800-2,200 hours. It has low requirements for soil and strong adaptability, tolerating relatively poor soil. Generally, acidic yellow soil with a pH of 5-6 is most suitable. However, loose, deep, well-drained and relatively fertile sandy soil is particularly beneficial for the growth and development of oil-tea camellia. Oil-tea camellia growing on south-facing, southeast-facing or southwest-facing sunny mountain slopes has thick trunks, oval crowns, abundant fruiting and high yields. Oil-tea camellia is a deep-rooted tree species with well-developed main roots that extend downward more than 1.5 m. Oil-tea camellia has sprouting ability and strong regeneration capacity. This characteristic can be used for renewal and transformation of old and residual forests, where new branches sprout after cutting and are tended into forests.

3. Growth and development process

(1) New shoots: Oil-tea camellia has spring shoots, summer shoots and autumn shoots. The vast majority of flower buds differentiate on spring shoots, and spring shoots account for over 98% of new shoots. Before the full fruiting stage, spring shoots grow vigorously; after the full fruiting stage, spring shoots grow relatively slowly.

(2) Flowers: Flower bud differentiation begins on the current year's spring shoots in April. Early flowering stage is in early-to-mid October, full flowering stage begins in late October, and late flowering stage is from late November to December. Each flower takes about 5-6 days from opening to withering. On the 1st-2nd day of flowering, the stigma is normal; on the 3rd-4th day it begins to wither. Pollen on the stigma has the highest germination rate and strongest vitality on the 1st-2nd day, and is most easily fertilized. Oil-tea camellia is generally insect-pollinated, with cross-pollination, especially between different plants, giving good results. During the full flowering stage, if it is warm and sunny with active insects, the fruit-setting rate of flowers is high. Self-pollination and pollination at the beginning and end of flowering have low fruit-setting rates. Therefore, ground bees should be protected and introduced into the forest to increase pollination rate and seed-setting quantity.

(3) Root system: The root system begins activity in mid-February, with the most rapid growth period from late March to mid-April. Growth is also fast in June-July and lasts relatively long. From late December to early February of the following year, root growth is very slow.

Seedling Cultivation

1. Seedling raising by seed: Drill sowing is preferable. Sowing can be done in winter or spring. Winter sowing in November, spring sowing in February-March. For winter sowing, furrow width 10-12 cm, furrow spacing 18-21 cm, depth 4-5 cm, sowing rate 100-125 kg per mu. Before sowing, seeds should be water-selected and disinfected. After sowing, cover with soil 3-4 cm, then thinly cover with a layer of rice straw, and remove the straw in late April. When seedlings are about 10 cm tall, apply quick-acting nitrogen fertilizer; when 3-5 true leaves appear, apply compound fertilizer. In the container seedling method, seeds are germinated and then directly sown into the nutrient soil in container bags. Afforestation is not restricted by season, with high survival rate and fast growth and development, making it an efficient seedling-raising method. For direct propagation of seedlings from oil-tea camellia seeds, due to disadvantages of seedling variation such as large progeny differentiation, serious variety degradation, uneven forest appearance, inconsistent fruit maturity, late fruiting time and delayed full fruiting stage, seedlings should not be used for afforestation.

2. Vegetative propagation

(1) Cutting propagation: The soil of the nursery for cuttings is divided into two layers. The surface layer is a mixture of yellow subsoil and sand at 1:1 or 2:1 (ratio depending on the viscosity of the yellow subsoil), 6-10 cm thick; the lower layer is fertile soil with a loose layer of about 10 cm. The pH of the cutting soil should not exceed 6. Cuttings should be taken from individual plants of superior varieties or superior clones, requiring robust, straight, one-year-old lignified spring shoots with healthy axillary buds and intact leaves. Cut branches should be placed in a cool place, sprayed with water to maintain moisture, and protected from compression and heating. Depending on the internode length of the branches, cut into long cuttings or short cuttings, with short cuttings being preferable. Each short cutting carries 1-2 leaves and is 3-5 cm long. After cutting (trimming), bundle every 20 cuttings into one bundle, and soak the cut ends in 200-400 mg/kg naphthalene acetic acid solution for 12-16 hours. After cutting, a shade shed is needed. The temperature inside the shed must not exceed 30°C. When too high, open the shed for ventilation and cooling. Water frequently. The survival rate is generally above 80%. Where conditions are good, using closed or automatic misting devices gives better cutting results. However, oil-tea camellia seedlings propagated by cuttings have underdeveloped root systems and poor drought resistance, leading to low afforestation survival rates. They should be used with caution, and cutting propagation is not recommended.

(2) Grafting propagation: Mainly based on bud seedling rootstock grafting, using ordinary oil-tea camellia seedling buds as rootstock. Soak seeds 35-45 days before grafting, then sow on sand beds or nutrient soil at a depth of about 3 cm. After covering with sand, press slightly. Sand thickness about 10 cm. If the sand is too thin, the seedling stem emerges early, becomes thin and aged, which is unfavorable for grafting. Graft when seedlings emerge from the sand (soil) and have 2-3 leaves. Bud seedling rootstock grafting generally uses the cleft grafting method. The procedure is as follows: First, take out the bare-root seedlings from the sand bed, wash them clean, cover with a wet cloth and place on an indoor operating table (desk) for later use. Second, use a blade (single-edge blade) to cut off the seedling above the bud at 1-1.5 cm, then split open from the center of the rootstock pith, with an opening of about 1 cm, keeping the radicle at 5-6 cm and removing the excess part. Third, fit the rootstock, using a thin aluminum sheet (or toothpaste tube skin) with a diameter slightly larger than the rootstock diameter to cover the rootstock. First, make a cylinder from a thin aluminum sheet cut to about 3 cm long and about 1 cm wide (the diameter can be larger or smaller) for easy rootstock fitting. Fourth, cut the scion. On both sides of the scion's lower end, 1-2 cm from the petiole, cut one 15-degree, about 1 cm long double-slanted wedge shape each, then cut off from 2-3 mm above the petiole to form a scion with 1 bud and 1 leaf. Place in clean water for later use. Finally, insert the cut scion into the rootstock incision, aligning the cortex on the petiole side, and gently lift and pinch the sleeve tube to make the rootstock and scion fit tightly. The planting depth should be such that the base seed shell just enters the soil. Plant firmly and press tightly without leaving air pockets around the roots. Water after planting to maintain moisture, and immediately plant in a moisture-retaining shed shaded with 80% shading net and 20% light transmission. The sealing material is generally plastic film, which is both light-transmitting and moisture- and heat-retaining. The humidity inside the cover is 85%-90%, temperature 25-28°C, must not exceed 33°C. When too high, appropriately open the film for ventilation and cooling, and water to maintain moisture. When most scions sprout and open leaves (about one and a half months), the moisture-retaining cover can be removed, with shading until autumn. Afterward, carry out timely management such as sprout removal, fertilization and weeding according to conditions.

Land Preparation and Afforestation

1. Land preparation

Oil-tea camellia has low requirements for afforestation land, but for high and stable yields, afforestation land should be selected with deep soil (soil thickness above 60 cm, at least exceeding 40 cm), good drainage, relatively good fertility, moist, good aeration, slightly acidic (pH range: 5.5-6.5) sandy loam or light clay loam (limestone mountain areas cannot be planted). However, try to avoid planting on mountaintops with high sand content and poor water retention sandy soil and poorly drained land. Land preparation should be carried out in autumn and winter of the year before afforestation.

(1) Full reclamation land preparation: On flat or gently sloping land, full reclamation land preparation can be used (slope within 15°). Around September, carry out land preparation at a depth of 20-25 cm in mountainous areas and 25-30 cm in hilly areas. Remove rocks, tree roots and other debris, let the soil be exposed and aged. By November, rake level and then set points around the mountain to dig planting holes, with holes 60×60×60 cm.

(2) Strip land preparation: For slopes exceeding 15°, horizontal strip land preparation should be used. Open contour horizontal strips by row spacing, with the outer side higher and inner side lower. Strip width depends on slope: narrow slope, wide strip; steep slope, narrow strip. Set points on the strips by plant spacing to dig holes, with specifications same as full reclamation.

(3) Block land preparation: For land types with slopes greater than 20° but less than 25° and relatively large slopes, or for mountain ponds, reservoirs and areas along transportation routes with high soil and water conservation requirements, block hole reclamation should be used. Set points in a contour horizontal "pin" shape arrangement to dig holes. Hole size is generally 50×50×50 cm, and add soil and water conservation measures.

2. Afforestation

Initial planting density: For pure forests, initial planting density of 2.5 m×2.5 m, 2.5 m×3 m, 3 m×3 m row and plant spacing is relatively suitable. Planting density should be determined according to site conditions, variety characteristics and management objectives. For fertile soil at mountain feet and relatively flat land types, use 2.5-3×3 m, i.e., 74-89 plants per mu; for land types with poor soil fertility and relatively large slopes, use row and plant spacing of 2-2.5×3 m, i.e., 89-111 plants per mu. In short, reasonable close planting should be determined according to local conditions. It is required that the coverage density of oil-tea camellia entering the full fruiting stage is not less than 0.6 and not more than 0.8.

Oil-tea camellia afforestation has two methods: seedling planting and direct sowing. Seedling planting afforestation is carried out in winter and spring, with spring being preferable. The key points are: put topsoil into the hole, make the hole soil fine and crumbly, and where conditions permit, apply a certain amount of organic fertilizer or farmyard manure in the hole before planting. Keep the seedling stem upright, plant slightly deep, spread the root system, tread firmly in layers to make the roots and soil closely contact, and cover with loose soil on top. For one-year-old seedlings, the planting depth is best when the upper end of the graft union is 1 cm above.

The root collar should be 2-3 cm below the ground. To ensure survival, do not plant overnight seedlings. Before planting, the roots of tea seedlings should be evenly coated with slurry, preferably with relatively fertile field mud from paddy fields or pond mud from ponds. Afforestation seedlings should be first-grade seedlings or two-year-old seedlings to facilitate survival and forest formation. When afforesting oil-tea camellia, attention should be paid to variety configuration. For areas above 15 mu, there should be more than 2 varieties; for areas above 75 mu, there should be more than 5 varieties of seedling configuration for afforestation. The flowering period and maturity period of varieties must match. The most suitable afforestation period is from early to late February, and it must be completed by mid-March at the latest. Container seedlings can also be planted during the plum rain season or in autumn and winter.

Direct sowing afforestation is carried out in winter and spring. Winter sowing in November-December, spring sowing in February-March, with winter sowing being preferable. Winter sowing has the advantages of early root development, fast sprouting, robust seedlings and strong drought resistance, and also saves seed storage. For winter sowing, sow 3 seeds per hole in a triangular arrangement, then cover with soil 4-5 cm thick; for spring sowing, cover with soil about 3 cm.

Planting Management

1. Management of young oil-tea camellia plantations

The tending period for young plantations is before oil-tea camellia is 4 years old. Tending content includes intertillage and weeding, supporting seedlings and earthing up, thinning and replanting, pest and disease control, shaping and pruning, and fertilization and other technical measures.

(1) Loosening soil and weeding: In the year of afforestation, weed and loosen soil once, then 2 times per year thereafter. The first time is in May-June, the second in late August to September, varying by region. During the dog days, the surface is scorching hot and not suitable for loosening soil and weeding. Loosening depth is generally 3-5 cm. In the year of afforestation, it should be shallow, then gradually deepen each year; near the base of young trees it should be shallow, gradually deepening outward; loam should be shallow, clay should be deep.

(2) Fertilization of young plantations: For forest land with sufficient basal fertilizer, do not fertilize again in the first year. Fertilize twice a year: apply slow-release fertilizer in winter, such as wood ash or other decomposed organic fertilizer; apply quick-acting fertilizer in spring, such as urea. Early spring is better than summer and autumn. The annual fertilization amount per plant should not exceed 25 grams, preferably applied multiple times, with no more than 10 grams per plant per application. Methods include broadcast application and ring ditch application. Broadcast application means evenly spreading fertilizer around the crown and turning it into the soil with intertillage; ring ditch application means digging a circular or semi-circular ditch 20-30 cm wide and deep along the outer edge of the crown and applying into it.

(3) Shaping of young trees: The shaping method for young oil-tea camellia trees is divided into two steps: First, train the trunk. Within 1-2 years after afforestation, all spring shoots sprouting from the terminal bud should be retained to rapidly form the main trunk; the second step is shaping. When the main trunk is 60 cm high, select and retain 3-4 strong main branches around the trunk. The number of secondary main branches on each main branch depends on tree size and the distance between the two main branches. The most suitable pruning period is early spring. Remove sprouts promptly after pruning. Pruning of young trees should be light rather than heavy.

(4) Intercropping in forest land: Intercrop short-harvest crops, medicinal herbs, green manure, etc. in young forest land to replace tending with cultivation, which benefits oil-tea camellia growth and provides short-term harvests, improving economic benefits. The selection of intercrop species should follow the principle of not competing with oil-tea camellia for light, fertilizer or water. Intercropping requires leaving 1 sq m of area for the oil-tea camellia tree. Oil-tea camellia forest land is suitable for intercropping peanuts, beans and other crops and some green manure plants, but not tall-stemmed, vine and high water-consuming crops in the dry season.

2. Management of mature oil-tea camellia plantations

(1) Reclamation: After oil-tea camellia enters the full fruiting stage, according to site conditions and variety types, shallow hoe at least once a year and deep dig once every 3 years. Generally carried out after the rainy season each year and before the dry season arrives. Depth about 10 cm. Deep digging should be done after fruit harvest until before sap flow the following year, at a depth of 15-20 cm. Reclamation must pay attention to soil and water conservation in forest land. For oil-tea camellia forest land with gentle terrain and slope below 15°, full reclamation can be used, but depending on the length of the slope, leave water conservation strips at the mountaintop, mid-slope and foot of the mountain. For slopes above 15°, especially soil developed from sandstone and granite, strip reclamation should be used, digging one strip and leaving one strip, alternating every other year.

(2) Fertilization: According to soil nutrient content, oil-tea camellia growth status and different growth periods, apply different types of fertilizer. In bumper years, mainly phosphorus and potassium fertilizer and organic fertilizer; in lean years, mainly phosphorus and nitrogen fertilizer. Apply compound fertilizer at 15 kg or more per mu per year, and apply it with equal importance to organic fertilizer.

(3) Pruning: Oil-tea camellia mainly uses thinning pruning, heavy pruning in bumper years and light pruning in lean years. From fruit harvest each year until before sap flow the following year, cut off dead branches, disease and pest branches, crossing branches, thin and weak inner branches, foot branches, water sprouts, etc.

(4) Density adjustment: In densely planted forest land, generally at 10-12 years when branches and leaves mutually cover. At this time, depending on forest land conditions, carry out density adjustment in 1-2 operations within 2-3 years, replanting sparse forests and replacing varieties in inferior forests.

(5) Top grafting to replace crowns: For some inferior plants in mature forests, after two years of observation and marking, use superior tree scion branches and adopt the bark grafting method. Specific operations: cut the rootstock, select rootstock with trunk diameter 3-4 cm and saw off at a trunk height of 40-80 cm. When cutting the rootstock, prevent tearing of the rootstock cortex. Keep 2-3 main branches per plant as nutrient branches and shade, and remove all the rest; wash the rootstock cut with clean water and wipe dry, use a grafting knife to smooth the saw cut, with the cut surface higher inside and lower outside, slightly sloped; cut the rootstock and peel bark, use a single-edge blade to cut open the dry bark deep to the xylem, tear the bark in one direction to facilitate wrapping after grafting; cut the scion, use a single-edge blade on the opposite side of the scion leaf bud from slightly below the bud base, cut straight downward at a slant, about 2 cm long, with the cut surface slightly showing xylem and the base showing pith. Cut a short incision obliquely below the leaf bud, then cut off from 2-3 mm above the petiole to form a scion with 1 bud and 1 leaf. Place in clean water for later use. Insert the scion with the long cut surface facing inward, inserted tightly against one side. The scion cut surface should be slightly higher than the rootstock cut to facilitate healing between scion and rootstock. When wrapping, leave a little torn bark below, because large trees have vigorous nutrition, facilitating the discharge of excess nutrients; use a water-soaked plastic bag for moisture retention. When bagging, turn the outside of the bag inward, keep the moisture inside the bag for moisture retention, and leave the supporting bamboo strips outside the bag to facilitate the outflow of excess water from the bag. Use newspaper (bamboo shoot sheath) tied in an east-west direction on the outer layer of the plastic bag for shading. Remove the moisture-retaining bag after 40 days but still need shading. Grafting time: in our city, mid-to-late May to mid-June is preferable. The same forest land must complete this within 1-2 years.

Pest and Disease Control

The main diseases of oil-tea camellia include anthracnose, soft rot, sooty mold, etc. The main pests include stem borers, tea shoot moths, longhorn beetles, weevils, ants, tea caterpillars, scarab beetles, sawflies, etc.

1. Anthracnose: For winter prevention, use 50% carbendazim wettable powder at 500 times dilution. For summer prevention, use 50% Tuzet wettable powder at 300 times dilution or 50% carbendazim at 500 times dilution.

2. Soft rot: 50% carbendazim at 300-500 times dilution, 75% thiophanate-methyl at 300-500 times dilution, 50% Tuzet at 1000-1500 times dilution, 1/100 Bordeaux mixture.

3. Root rot: 1% copper sulfate or Dexon, etc., to disinfect diseased seedlings.

4. Blue-winged longhorn beetle: At the peak emergence period of adults, spray 20% fruit emulsifiable concentrate at 500 times dilution, 90% trichlorfon at 1000 times dilution. At the larval stage, spray 90% trichlorfon at 500 times dilution.

5. Weevils: 90% trichlorfon crystals at 1000 times dilution, 80% dichlorvos emulsifiable concentrate at 1:1 diluted with water at 1000 times.

The control of oil-tea camellia pests and diseases must implement the comprehensive control measures of "prevention is more important than treatment," based on silvicultural techniques, combined with biological and chemical control. When carrying out reclamation, intercropping and fertilization, pay attention to deeply burying diseased branches, diseased leaves and diseased fruits, killing eggs and pupae, and cutting down historically diseased plants. Also protect and utilize natural enemies, such as protecting and cultivating black-edged ladybugs, large red ladybugs and other natural enemies, as well as parasitic wasps, parasitic flies, fungi, etc., for biological control.

Harvest and Processing

1. Maturity indicators: Fruit skin smooth, color becoming bright. For red-skin types, when fruit matures the skin is red with yellow; for green-skin types, green with white. Seed shell is deep black or yellow-brown, glossy. Kernel is white with yellow, showing oil luster. Harvesting fully mature seeds not only increases oil yield but is also the original guarantee for reducing the acid value of tea oil. The suitable harvest period starts 3 days before the fruit maturity period and is completed within 7 days after. Cold Dew seeds are harvested in mid-October. Frost's Descent type seeds are harvested at the end of October, and Start of Winter seeds in early November. Early harvesting is strictly prohibited.

2. Harvesting method: When harvesting fruits, it is exactly the period when oil-tea camellia is in bud. Breaking branches to pick fruits is strictly prohibited.

3. Fruit processing: After fruits are brought back, stacking time must not exceed 5-6 days. Spread out to sun-dry, turning several times a day to promote fruit cracking. Remove all debris, collect seeds and store in the warehouse for oil pressing.

Traditional Chinese Medicinal Plant Evodia rutaecarpa Planting Techniques and Cultivation Management Key Points

Evodia rutaecarpa is a bitter stomachic and analgesic, also known as Wuyu, Chala, Qilazi, Choulazi tree, Milazi, etc. It is a small tree or shrub of the genus Evodia in the Rutaceae family. It is planted in small or large amounts in various places south of the Qinling Mountains, growing in open forests or shrub thickets from flat land to mountain areas at an altitude of 1500 m, mostly on sunny slopes. Let us take a look at the planting techniques of Evodia rutaecarpa!

Growth Habits of Evodia rutaecarpa

Evodia rutaecarpa is produced in various places south of the Qinling Mountains, but no natural distribution has been seen in Hainan. It was once introduced and cultivated but grew poorly. It has low requirements for soil and can generally be planted on mountain slopes, plains, in front of and behind houses, and roadsides. It can grow in neutral, slightly alkaline or slightly acidic soil, but for seedbeds, loam or sandy loam with deep soil layers, relatively fertile and good drainage is best. Low-lying waterlogged land is not suitable for planting.

Propagation Methods of Evodia rutaecarpa

1. Root cutting propagation: Select 4-6 year old individual plants with well-developed root systems, vigorous growth and robust and superior quality as mother plants. In early February, dig out the soil around the mother plant's root zone, cut lateral roots the thickness of chopsticks into 15 cm segments. On prepared beds, open furrows at 15 cm row spacing, and at 10 cm plant spacing, insert the roots obliquely into the soil with the upper end slightly exposed above the soil surface. Cover with soil and press slightly, water with diluted manure, then cover with straw. New shoots grow in about 2 months, and they can be lifted from the nursery and planted in the following spring or winter.

2. Stem cutting propagation: Select 1-2 year old healthy, pest-free branches, take the middle section and cut into 20 cm cuttings in February. Cuttings must retain 3 buds, and the lower end near the node is cut into a slanted surface. Insert the lower end of the cutting into a 1 ml/L indolebutyric acid solution, soak for half an hour, then remove and insert into the seedbed. The insertion depth should preferably be 2/3 of the cutting length. Cover with soil and press firmly, water and shade. Generally roots form after 1-2 months, and they can be transplanted the following year.

3. Tillering propagation: Evodia rutaecarpa easily propagates by tillering. Every winter, at 50 cm from the mother plant, dig out lateral roots, wound the cortex every 10 cm, cover with soil, fertilize and cover with straw. In the following spring, many root-tiller seedlings will emerge. Remove the straw, and when seedlings are about 30 cm tall, separate and transplant.

Planting Techniques of Evodia rutaecarpa

1. Site selection and land preparation: Evodia rutaecarpa has low requirements for soil and can generally be planted on mountain slopes, plains, in front of and behind houses, and roadsides. Apply 2000-3000 kg of farmyard manure per mu as basal fertilizer, deep-plow and sun-expose for several days, break up the soil and rake level, and make high beds 1-13 m wide.

2. Timely transplanting: Transplant in winter and spring, with winter transplanting being preferable (around December). In spring (March-April), dig holes at 330-400 cm row and plant spacing, with a diameter of 50-60 cm. Hole depth depends on root length. First apply decomposed stable manure or river mud as basal fertilizer, then plant seedlings and cover with soil and press firmly. Newly planted seedlings are small and can be intercropped with peanuts, beans, sweet potato, etc.

3. Field management: Carry out timely intertillage and weeding and keep the soil moist. Apply decomposed human manure once before spring sprouting. Fertilization amount depends on tree age. For three-year-old trees, apply 10-25 kg of human manure per plant, in a ring-shaped shallow ditch about 48 cm from the plant, then cover with soil. Before flowering and fruiting in July, apply phosphorus and potassium fertilizer once. In winter, apply compost (or river mud, human manure), wood ash, etc., and earth up to prevent freezing.

4. Pruning and shaping: For young trees, when 80-100 cm tall, cut off the top of the main trunk to promote sprouting. Among the lateral branches growing in all directions, select and retain 3-4 robust branches and cultivate them as main branches. In the second summer, select and retain 3-4 well-developed branches in the leaf axils of the main branches and cultivate them as secondary main branches. Later, allow lateral branches to grow from the main branches. After several years of shaping and pruning, form a high-yield tree shape of natural open-center type with rounded outside and hollow inside, open crown, ventilation and light transmission, and short trunk and low crown. After 3-4 years, it can enter the full fruiting stage.

Pest and Disease Control of Evodia rutaecarpa

1. Sooty mold

[Symptoms] Sooty mold, also known as black mildew, is induced by aphids and scale insects damaging Evodia rutaecarpa, causing irregular dark brown sooty spots. In later stages, leaves and branches are covered with a thick sooty layer. Diseased trees bloom and fruit poorly.

[Control] During the occurrence period of aphids and scale insects, spray 40% dimethoate emulsifiable concentrate at 2000-3000 times dilution, or 25% phosmet at 800-1000 times dilution, once every 7 days, for 2-3 consecutive sprays. During the disease period, spray Bordeaux mixture at 1:0.5:150-200, once every 10-14 days, for 2-3 consecutive sprays.

2. Rust disease

[Symptoms] Rust disease mainly affects the leaves of Euodia rutaecarpa (Wu Zhuyu). In the early stage of the disease, nearly round, inconspicuous small yellow-green spots and small orange-yellow blister-like spots form on the leaves, causing the leaves to wither and die.

[Control] Spray with 0.3 degree Baume lime sulfur mixture or 65% zineb wettable powder at 500 times dilution, once every 7 to 10 days.

3. Old wood borer

[Symptoms] The larvae bore and feed inside the trunk, causing the stem to become hollow and die. From July to October, on the main trunk below 30 cm from the ground, thread-like gummy secretions, wood shavings and insect frass appear.

[Control] Use a small knife to scrape off the egg masses and newly hatched insects. When larvae have bored into the wood, pour wettable benzene hexachloride powder at 50 times dilution into the bore hole, or soak cotton with 80% dichlorvos original liquid and insert it into the bore hole, then seal the opening to kill the larvae.