Key Technical Points for Tea Production in Summer and Autumn

1. Strengthen Tea Garden Fertilization Management

(1) Fertilization for Tea Trees

1. Root fertilization. Summer tea fertilization should be done after the spring tea harvest, and autumn tea fertilization should be done after the summer tea harvest. For productive tea gardens, apply 15-20 kg of urea or 20-30 kg of tea-specific compound fertilizer (18-8-12 N-P2O5-K2O) per acre. High-yield tea gardens can increase the amount appropriately. For mature tea gardens, fertilize by digging a trench 10–15 cm deep directly below the canopy edge. Avoid broadcasting fertilizers. For young tea gardens (1-2 years old), apply fertilizers 5-10 cm from the root collar, and for 3-4-year-old tea trees, apply fertilizers 10-15 cm from the root collar. For flatland tea gardens, fertilizers can be applied to one or both sides of the tea rows. For sloped (terraced) tea gardens, apply fertilizers on the upper side of the tea rows to prevent nutrient runoff.

2. Foliar fertilization. If root fertilization is ineffective, foliar fertilization may be done as needed. This should be applied after each tea season ends and before the next round of new shoots begins. It is best to spray in the morning before 10 AM or in the afternoon after 4 PM, or on overcast days. Avoid spraying before rain. Use an electrostatic sprayer to spray evenly on the back or both sides of the leaves, or use agricultural drones at a flight height of 1.5 meters.

Water-soluble urea, amino acid water-soluble fertilizers, humic acid foliar fertilizers, and biogas slurry fertilizers are recommended for foliar feeding. Water-soluble urea can be applied at a 5% concentration, amino acid foliar fertilizers at 50 mg of effective ingredients per acre, humic acid foliar fertilizers at 2% concentration (15 kg per acre), and biogas slurry fertilizers with an effective nitrogen concentration of around 2%.

(2) Application of Base Fertilizer

Base fertilizers should be applied by October, with priority given to organic fertilizers such as cake fertilizer, compost, and manure, which may be mixed with chemical fertilizers. The base fertilizer (based on pure nitrogen) should account for 30–40% of the total annual fertilization amount. Apply 1-2 tons of livestock manure or 200-300 kg of cake fertilizer per acre, and mix with 25 kg of calcium-magnesium phosphate and 5-10 kg of potassium sulfate per acre. Apply this mixture by digging a trench 15-20 cm deep or combining with deep plowing. For young tea gardens, avoid direct contact of the fertilizer with the tea tree roots.

(3) Green Manure Planting

In young tea gardens and mature tea gardens with large row spacing and exposed soil, plant green manure such as millet to increase soil organic matter, improve soil permeability, and suppress weed growth. Millet should be sowed between tea rows in September, with a seeding rate of 1-2 kg per acre. The distance between the seeds and tea trees should be greater than 30 cm. Before sowing, mix the seeds with fine sand in a 1:10 ratio and lightly cover the seeds with soil to prevent drying out. Plant before the rainy season, and irrigate if drought occurs after sowing. In February of the following year, apply 8-12 kg of nitrogen fertilizer per acre (based on pure nitrogen) to promote growth. After millet seeds mature in June, they should be allowed to wither, and a small amount of re-sowing may be done the following year.

(4) Proper Cultivation

After the summer tea harvest, shallow tillage should be done in the tea garden at a depth of 5–10 cm. For gardens that will harvest autumn tea, shallow tillage should be repeated after the autumn tea harvest. Avoid tilling during prolonged high temperatures and dry weather.

2. Strengthen Pest and Weed Control

(1) Pest Control Techniques for the Summer and Autumn Seasons

Pests such as the gray tea caterpillar, tea caterpillar, tea weevil, and small green leafhopper are prevalent in summer and autumn, requiring integrated pest management measures to reduce pest density and prevent severe outbreaks. If necessary, use effective, safe pesticides for emergency control. For tea gardens that are ready for harvest, regular and careful picking should be done to destroy pest egg-laying sites and remove some eggs and young larvae along with the leaves. For lepidopteran pests, use narrow-wave LED insecticidal lamps and pheromone traps during the peak adult period to reduce egg-laying in the field. For tea moths, release parasitic wasps during the peak adult period for control. Small green leafhoppers should be controlled before the rainy season arrives by hanging yellow-red color traps to attract and kill them.

In gardens with particularly severe pest outbreaks, choose non-water-soluble pesticides for emergency control based on the specific pest issues. For larvae of the gray tea caterpillar, tea caterpillar, and tea moth before the third instar, use effective biological pesticides (such as Bacillus thuringiensis) or high-efficiency chemical pesticides (such as cypermethrin, abamectin, or imidacloprid) for emergency treatment. For the small green leafhopper, use neem oil, eucalyptus oil, or high-efficiency chemical pesticides like spirotetramat and acetamiprid. Always follow the safety interval recommendations for pesticide use when applying to tea gardens.

(2) Pest Control Techniques for Spring Pests in the Autumn Season

Some tea areas experience high occurrences of green blind bugs and tea thrips in spring, which severely affect spring tea production. Control measures should be implemented in the autumn.

1. Green Blind Bug Control. From September to October, use pheromone traps and color boards to monitor the entry of green blind bugs into the tea garden. After the bugs enter, spray 10% bifenthrin on tea trees and surrounding weeds, with a 7-10 day interval, spraying 2-3 times.

2. Tea Thrips Control. Use natural biocontrol agents like sophora alkaloids and neem oil. For severe outbreaks, combine the use of bifenthrin and high-efficiency cypermethrin with other pest control efforts. Before applying pesticides, trim the side branches of tea trees to enhance the penetration of the pesticide and ensure even coverage on the leaves.

(3) Weed Control Techniques in Tea Gardens

Weed control can be combined with tea garden tillage, using manual or mechanical methods to remove weeds and bury them deep in the soil. Typically, weeding is done 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 the occurrence of weeds 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, control weeds by laying weed cloth or interplanting green manure plants like millet or white clover between rows.