To strengthen the management of Tea gardens during summer and autumn, ensuring production of summer and autumn teas as well as Spring Tea the following year, 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 formulated technical guidelines for tea production in summer and autumn 2024.

Strengthen Fertilization Management in Tea Gardens

(I) Top-dressing in Tea Gardens

1. Root top-dressing. For summer tea, top-dressing should be done after the spring tea harvest; for Autumn Tea, it should be done after the summer tea harvest. For productive tea gardens, apply 15-20 kg of urea or 20-30 kg of a specialized compound fertilizer (18-8-12 N-P2O5-K2O formula) per mu. For high-yielding tea gardens, slightly increase the amount. For mature tea gardens, fertilize by digging trenches along the edges of the canopy, 10-15 cm deep, avoiding broadcast spreading. For young tea gardens (1-2 years old), fertilize 5-10 cm away from the root collar; for those 3-4 years old, fertilize 10-15 cm away from the root collar. In flat land tea gardens, fertilize on one or both sides of the row; in sloped (terraced) tea gardens, fertilize on the upper side of the row to prevent nutrient loss.

2. Foliar top-dressing. When root fertilization is not effective, foliar top-dressing can be applied as needed. Generally, apply foliar fertilizers after each tea season ends and before new shoots sprout in the next cycle. Apply in the morning before 10 AM, after 4 PM, or on cloudy days, avoiding rain. Use an electrostatic sprayer to evenly spray the underside or both sides of the leaves, or use agricultural drones at a flight height of 1.5 meters.

Foliar fertilizers may include water-soluble urea, amino acid water-soluble fertilizers, humic acid foliar fertilizers, and biogas liquid fertilizers. Water-soluble urea can be used at a concentration of 5%; amino acid foliar fertilizers can be used at 50 mg of active ingredients per mu; humic acid foliar fertilizers can be applied at 2% concentration at 15 liters per mu; biogas liquid fertilizers can be used at an effective nitrogen concentration of about 2%.

(II) Base Fertilizer Application

Base fertilizer application should be completed by October, using organic fertilizers such as cake meal, compost, and manure, or a combination of organic and chemical fertilizers. The base fertilizer (calculated in pure nitrogen) should account for 30-40% of the annual fertilizer application, typically 1-2 tons of livestock manure organic fertilizer or 200-300 kg of cake meal per mu. Add 25 kg of calcium magnesium phosphate and 5-10 kg of potassium sulfate per mu, mix thoroughly, and apply in trenches 15-20 cm deep or combine with deep plowing. For young tea gardens, avoid direct contact between the fertilizer and the roots when applying base fertilizers.

(III) Green Manure Planting

In young tea gardens or mature tea gardens with wide row spacing and high soil exposure, sow green manure plants like foxtail millet between rows to increase soil organic matter, improve soil permeability, and suppress weed growth. Foxtail millet is typically sown in rows or broadcast in September at 1-2 kg per mu, keeping the seeds more than 30 cm away from the tea plants. Before sowing, mix the seeds with fine sand at a ratio of 1:10. Cover lightly with soil after sowing to prevent the seeds from drying out. Sow before the rainy season, and if there is prolonged drought after sowing, irrigate appropriately. Apply 8-12 kg of nitrogen (in pure nitrogen) per mu in February of the following year to promote growth. After foxtail millet seeds in June, the plants will die back and can be re-sown the next year based on seedling emergence.

(IV) Proper Tillage

After the summer tea harvest, shallow tillage should be conducted in the tea garden at a depth of 5-10 cm. For tea gardens that harvest autumn tea, shallow tillage should be performed again after the autumn tea harvest. Avoid tilling under continuous high temperatures and drought conditions.

Strengthen Pest and Weed Control

(I) Pest Control Techniques for High Incidence Pests in Summer and Autumn

In summer and autumn, pests such as the gray tea looper, tea looper, tea hairy caterpillar, and tea green leafhopper occur severely. Comprehensive measures should be taken to control these pests, reducing their population density in the field and preventing severe infestations. If necessary, use efficient and safe pesticides for emergency control. For tea gardens that meet harvesting standards, pick the tea leaves frequently to disrupt the egg-laying sites of pests and remove some eggs and young nymphs with the harvested leaves. For lepidopteran pests, use narrow-band LED insect traps and pheromone lures during the peak adult emergence period for precise trapping to reduce the number of eggs laid in the field. Release parasitic wasps to control the tea hairy caterpillar during the peak adult emergence period. For the tea green leafhopper, hang yellow-red double-colored sticky traps before the autumn rainy season to trap adults.

For tea gardens with particularly severe pest outbreaks, select non-water-soluble pesticides for emergency control based on the specific pest situation. For the gray tea looper, tea looper, and tea hairy caterpillar before the third instar, use highly effective biological pesticides (such as Paenibacillus polymyxa) or safe chemical pesticides (such as lambda-cyhalothrin, abamectin, or emamectin benzoate). For the tea green leafhopper, use neem oil, eucalyptus oil, or chemical pesticides like chlorfenapyr, flonicamid, cyantraniliprole, or indoxacarb. When applying pesticides in tea gardens intended for picking, follow the safety intervals indicated on the pesticide labels.

(II) Pest Control Techniques for Spring Outbreaks in Autumn

In some tea regions, the green stink bug and tea lace bug have high incidence in spring, severely affecting spring tea production. Therefore, preventive measures should be implemented in autumn.

1. Green Stink Bug Control. From September to October, monitor the entry time of the green stink bug into the tea garden using pheromone lures and color boards. After the green stink bugs enter the tea garden, timely spray 10% bifenthrin on the tea plants and surrounding weeds to control them, repeating every 7-10 days for 2-3 times, in conjunction with the control of the tea green leafhopper.

2. Tea Lace Bug Control. Use botanical pesticides such as matrine alkaloids or neem oil for biological control. For severe outbreaks, combine the application of bifenthrin or lambda-cyhalothrin with the control of other pests. Prune the side branches of tea plants before spraying to enhance the penetration of the pesticide solution, ensuring even coverage of the tea leaves.

(III) Weed Control Techniques in Tea Gardens

Weed control can be achieved through manual or mechanical means in conjunction with tea garden tillage, burying the removed weeds deeply in the soil. Typically, weed control is carried out once a month from June to August. For productive tea gardens, tillage and weeding should be done before the vegetation flowers in autumn to reduce weed occurrence the following year. For young tea gardens, increase the frequency of tillage and weeding. For young tea gardens and mature tea gardens with low canopy coverage, use mulching mats or intercrop with green manure plants like foxtail millet or white clover to control weeds.