Summer and autumn are crucial periods for Tea garden management. Strengthening summer and autumn production management is the foundation for ensuring high-quality and high-yield tea in both seasons as well as the following spring. Considering the recent drought and heavy rainfall in our city, we provide the following guidance on summer and Autumn Tea garden production management and disaster prevention and mitigation.

I. Pruning of Tea Plants

Light pruning should be carried out after the Spring Tea harvest, trimming off the top 5-10 cm of shoots. During the summer tea harvest, it is advisable to leave some leaves and use a topping method to maintain an appropriate leaf layer thickness. It is recommended to cease harvesting earlier in autumn to avoid affecting the yield and quality of the next year's spring tea. The second light pruning should be completed by mid-July, with the cutting height raised 5-10 cm above the previous cut. In case of high temperatures and drought, pruning should be postponed. For tea gardens requiring renovation, severe or deep pruning should be conducted after the spring tea harvest.

II. Fertilization of Tea Gardens

1. Top-dressing in Tea Gardens

(1) Root Application of Fertilizer

Summer tea top-dressing should be done after the spring tea harvest, while autumn tea top-dressing should be done after the summer tea harvest. Established tea gardens typically receive 15-20 kg of urea or 20-30 kg of specialized compound fertilizer (18:8:12 N:P?O? :K?O) per mu, with higher yields allowing for more. High-nitrogen, low-phosphorus, medium-potassium compound fertilizers are recommended, avoiding excessive phosphorus application. Trenches about 10-15 cm deep should be dug along the edges of the canopy for fertilizer application, and broadcast spreading is prohibited.

(2) Foliar Application of Fertilizer

Foliar fertilization can be used when root fertilization is insufficient. Foliar fertilizer should generally be applied after each tea season and before the emergence of new shoots in the next round. Spraying should ideally be done on clear days before 10 a.m. or after 4 p.m., or on cloudy days, avoiding rain. Electrostatic sprayers can be used to apply fertilizer evenly to the underside or both sides of the tea leaves, or agricultural drones can be used at a flight height of 1.5 meters.

For foliar fertilization, water-soluble urea, amino acid water-soluble fertilizers, humic acid foliar fertilizers, and biogas liquid fertilizers are recommended. Water-soluble urea foliar fertilizers can be used at a concentration of 5% urea; amino acid foliar fertilizers should contain about 50 mg of active ingredients per mu; humic acid foliar fertilizers should be applied at a concentration of 2%, using 15 kg per mu; biogas liquid fertilizers should have an effective nitrogen concentration of about 2%.

2. Base Fertilizer Application

Base fertilizer should be applied by October, with preferred options being cake manure, compost, and stable manure. Organic fertilizers can also be combined with chemical fertilizers. The base fertilizer (calculated as pure nitrogen) should account for 30%-40% of the annual fertilization volume. Typically, 1-2 tons of livestock manure organic fertilizer or 200-300 kg of cake manure per mu is applied, along with 25 kg of calcium magnesium phosphate and 5-10 kg of potassium sulfate per mu, mixed and applied in trenches 15-20 cm deep or incorporated during deep plowing. In young tea gardens, direct contact between fertilizer and the roots of tea plants should be avoided during base fertilizer application.

3. Green Manure Cultivation

In young tea gardens and mature tea gardens with wide row spacing and high soil exposure, green manure such as foxtail millet can be planted between rows to increase soil organic matter, improve soil aeration, and suppress weed growth.

4. Shallow Tillage After Fertilization

After each fertilization and irrigation, shallow tillage (5-10 cm deep) should be performed promptly. Tea gardens that harvest autumn tea should undergo another shallow tillage after the autumn tea harvest. Avoid tilling during prolonged high temperatures and drought.

III. Weed Control

Weeds can be controlled through manual or mechanical means, with the removed weeds buried deeply in the soil. This should typically be done once a month from June to August. In established tea gardens, cultivation and weed control should be done before the fall vegetation flowers to reduce weed growth the following year; young tea gardens may require more frequent cultivation and weed control. In young tea gardens and mature tea gardens with low canopy coverage, weed control can be achieved by laying mulch fabric or intercropping with green manure plants like foxtail millet or white clover.

IV. Pest Control

The occurrence of pests such as the tea green leafhopper, green plant bug, and tea mites is severe during the summer and autumn. Integrated measures should be employed to strengthen pest control, reduce pest populations, and prevent outbreaks. If necessary, highly efficient and safe pesticides can be used for emergency control.

1. Tea Green Leafhopper

In the Rizhao tea region, the tea green leafhopper has only one peak annually. Damage begins to occur in tea gardens in mid-to-late July, with the peak occurring in mid-September (or late August to mid-September). The control threshold is 8-10 insects per hundred leaves. For non-polluted tea gardens, pesticides such as bifenthrin, indoxacarb, abamectin, and triflumizole can be used. For organic tea gardens, pesticides such as platycodin, sophoridine, and pyrethrum can be used.

2. Green Plant Bug

There are two periods for controlling the green plant bug: spring and autumn. Spring control: during the peak hatching period of overwintered eggs (3-5 days after brown spots caused by green plant bugs are first observed on the new shoots of tea plants in spring). Autumn control: from mid-September to mid-October, when the green plant bugs return to the tea garden. The specific time of return can be determined using pheromone traps. One spray should be applied at the beginning of their return, followed by another spray seven days later, for a total of three sprays, to reduce the number of overwintering eggs in the tea garden. For non-polluted tea gardens, pesticides such as bifenthrin, indoxacarb, and abamectin can be used. For organic tea gardens, pesticides such as platycodin, sophoridine, and pyrethrum can be used.

3. Tea Mites

Winter control: after frost, spraying a solution of 0.5Be sulfur suspension in the tea garden can effectively control the overwintering population of tea orange spider mites, reducing their incidence in the spring. During the production season: the tea orange spider mite has multiple generations per year with overlapping generations. Chemical control should be carried out before the peak of insect populations (in late May and late August to early September), when the rate of infested leaves reaches 50% or there are an average of 2 mites per leaf. For non-polluted tea gardens, pesticides such as abamectin and fenbutatin can be used. For organic tea gardens, pesticides such as platycodin, sophoridine, and pyrethrum can be used.

Contributed by: Agricultural Technology Center of the City's Agriculture and Rural Affairs Bureau