To strengthen the management of Tea gardens during summer and autumn and ensure production of teas during these seasons as well as the following spring, the Department of Plant Industry Management of the Ministry of Agriculture and Rural Affairs, together with the National Agricultural Technology Extension Service Center, the Expert Advisory Group on Tea of the Ministry of Agriculture and Rural Affairs, and the National Tea Industry Technology System, have proposed technical guidelines for tea production in summer and autumn 2024.
Strengthen Fertilization Management of Tea Gardens
1. Top-Dressing Fertilization in Tea Gardens
(a) Root Fertilization: Top-dressing fertilization for summer tea should be carried out after the spring tea harvest, and for autumn tea after the summer tea harvest. For tea gardens in production, about 15-20 kg of urea or 20-30 kg of specialized compound fertilizer for tea (with a formula of 18:8:12 N:P2O5:K2O) is generally applied per mu, with higher-yielding gardens receiving slightly more.
Image Source: Anji White Tea Website
Fertilizer should be applied in trenches dug vertically below the edge of the tree canopy, with a depth of about 10-15 cm. Broadcasting of fertilizer is prohibited.
In young tea gardens (1-2 years old), fertilizer should be applied 5-10 cm away from the root collar; in 3-4-year-old tea gardens, it should be applied 10-15 cm away from the root collar.
In flat tea gardens, fertilizer can be applied on one side or both sides of the tea rows.
In sloped (terraced) tea gardens, fertilizer should be applied on the upper side of the tea row to prevent loss of nutrients.
(b) Foliar Fertilization:
When root fertilization is not effective, foliar fertilization can be performed as needed. It is typically applied after each tea season and before the emergence of new shoots in the next cycle. Foliar fertilizers should be sprayed in the morning before 10 am or after 4 pm, or on overcast days, avoiding rain. Electrostatic sprayers should be used to evenly spray the leaves, or agricultural drones can be used at a flight height of 1.5 meters.
Image Source: FastTech
Foliar fertilizers suitable for use include water-soluble urea, amino acid-based water-soluble fertilizers, humic acid foliar fertilizers, and biogas slurry. Water-soluble urea can be used at a concentration of 5%; amino acid-based foliar fertilizers are recommended at 50 mg of active ingredients per mu; humic acid foliar fertilizers can be applied at a concentration of 2%, using 15 kg per mu; biogas slurry is effective at a nitrogen concentration of approximately 2%.
2. Base Fertilization
Base fertilization should be completed by October, with organic fertilizers such as cake meal, compost, and manure being the preferred choices. Organic fertilizers can also be combined with chemical fertilizers. The base fertilization (in terms of pure nitrogen) should account for 30-40% of the annual fertilization amount. Typically, 1-2 tons of livestock manure or 200-300 kg of cake meal per mu is applied, along with 25 kg of Calcium-Magnesium phosphate and 5-10 kg of potassium sulfate per mu, which should be mixed and then applied in trenches 15-20 cm deep or incorporated during deep plowing. In young tea gardens, care should be taken to avoid direct contact between the fertilizer and the roots of the tea plants.
3. Green Manure Cultivation
In young tea gardens and mature tea gardens with wide spacing between rows and exposed soil, green manures such as foxtail millet can be planted between the rows to increase soil organic matter, improve soil aeration, and suppress weed growth.
Planting Foxtail Millet in Tea Gardens
Foxtail millet can be sown in rows or broadcast in September, with a seeding rate of 1-2 kg per mu, ensuring a distance of more than 30 cm from the tea plants. Before sowing, the seeds can be mixed with fine sand in a ratio of 1:10. After sowing, cover lightly with soil to prevent the seeds from Drying out. Sowing should ideally be done before the rainy season, and if there is prolonged drought afterward, irrigation should be provided. In February of the following year, apply 8-12 kg of nitrogen fertilizer (in terms of pure nitrogen) per mu to promote growth. Foxtail millet will naturally die off and fall in June when its seeds ripen, and in the following year, a small amount of reseeding can be done based on the germination situation.
4. Appropriate Intercropping
After the summer tea harvest, shallow cultivation should be conducted in the tea garden to a depth of 5-10 cm. For tea gardens that harvest autumn tea, shallow cultivation should be repeated after the autumn tea harvest. Avoid cultivating under continuous high temperatures and drought conditions.
Pest and Weed Control
1. Pest Control Techniques for Summer and Autumn
During summer and autumn, pests such as the gray tea looper, tea looper, tea hairy caterpillar, and tea green leafhopper are prevalent. Integrated pest control measures should be implemented to reduce the population density of these pests and prevent severe infestations. When necessary, efficient and safe pesticides can be used for emergency control. In tea gardens that meet the standards for harvesting, the tea should be picked frequently in batches to disrupt the egg-laying sites of pests and remove some eggs and young nymphs along with the tea shoots. For lepidopteran pests, narrow-band LED insect traps and pheromone lures can be used during the adult emergence period to accurately target them and reduce their egg-laying in the field. Parasitic wasps can be released during the adult emergence period to control the tea hairy caterpillar. Yellow-red double-sided sticky boards can be hung to trap adult tea green leafhoppers before the rainy season in autumn.
Comparison of Larval Stages of the Tea Looper and Gray Tea Looper (a, c, e represent the third, fourth, and fifth instar larvae of the tea looper, respectively; b, d, f represent the third, fourth, and fifth instar larvae of the gray tea looper, respectively)
Tea Green Leafhopper
