The golden autumn season sees lush Tea mountains, as tea gardens enter the autumn harvest period. In the fragrant tea gardens, tea farmers are seizing good weather to pick tea leaves. As autumn gives way to winter, while busy with harvesting, it is also important to focus on winter management of tea gardens to help the tea trees comfortably “survive the winter.”
Due to the compounded effects of drought and the pandemic, winter management has started earlier this year, with higher technical requirements and more meticulous fertilization management. Local areas should conduct targeted pruning of tea Tree canopies, fertilization management, and pest control based on the impact of drought in their respective tea gardens. They should also prepare the necessary materials for winter management. Good tea comes from good cultivation and good management. Winter management of tea gardens is a crucial technical measure for increasing the yield and quality of tea next year, reducing pest and weed damage to tea trees, and enhancing the overall efficiency of tea gardens.
To implement scientific tea cultivation, one must understand the growth characteristics of tea trees. The cessation of sprouting in tea trees marks a key timepoint for winter management of tea gardens. This is when the root system of tea trees is at its most vigorous stage of growth and also the peak period for root nutrient absorption. This period is the optimal time for tilling and fertilizing tea gardens. If fertilization is done too early, the tea trees may sprout again, affecting their ability to survive the winter. If fertilization is done too late, it will not meet the nutrient absorption needs, nor achieve the purpose of increasing root storage nutrients, which could affect the quality and yield of spring tea next year.
Winter management of tea gardens primarily involves soil and Fertilizer management, canopy management, pest control, and frost prevention.
1. Soil and Fertilizer Management
Tilling:
Deep tilling of the inter-row soil in tea gardens can improve the physical and chemical properties of the soil, enhance soil permeability, and promote the growth and development of tea tree roots. Deep tilling is usually carried out between early November and mid-December. For young tea gardens planted in trenches, it is advisable to fill the trenches with soil to a depth of 15-20 cm. For mature tea gardens, a depth of 20-30 cm is recommended.
Applying Base Fertilizer:
The amount of winter fertilizer applied to tea gardens should be determined based on a comprehensive analysis of factors such as soil fertility, the age of the tea trees, tea yield, and the growth vigor of the tea trees. Organic fertilizers should be used extensively but must be composted and fermented before application. Generally, each mu (about 0.067 hectares) of tea garden should receive 200-400 kg of commercial organic fertilizer or 1000-2000 kg of farmyard manure applied in trenches. Young tea gardens may use less fertilizer. The timing of fertilizer application depends on when above-ground growth stops, and it is advisable to apply it early rather than late, typically between mid-October and mid-November. In regions with higher altitudes and lower temperatures, where tea tree growth stops earlier, the application period should also be advanced accordingly.
Fertilizer Selection:
Tea-specific organic-inorganic compound fertilizers or organic fertilizers, composted and fermented farmyard manure, rapeseed cake fertilizer, etc., can be used.
Precautions:
Commercial fertilizers must be produced by reputable manufacturers to ensure fertilizer quality and efficacy. Farmyard manure and rapeseed cake fertilizer must be strictly controlled from the source to ensure that they do not exceed heavy metal or pesticide residue limits and are not contaminated. Tea companies and tea-growing regions with conditions should conduct quality tests on fertilizers and enforce strict controls.
Soil and Fertilizer Management for Winter in Tea Gardens
2. Canopy Management
Light pruning is mainly used to level the picking surface of the tea garden. Light pruning is best conducted between late October and mid-November.
Pruning Method:
Generally, the top 3-5 cm of the canopy is trimmed using a pruning machine. For vigorously growing tea trees, only the protruding parts of the canopy are trimmed to make the canopy surface flat. For tea gardens with many weak branches and chicken-claw branches, deep pruning is performed, cutting off 10-12 cm of the green leaf layer, removing all chicken-claw branches, promoting the comprehensive renewal of the tea tree canopy, and quickly restoring productivity. In regions with higher altitudes and lower temperatures, pruning should be done earlier.
Deep Pruning and Heavy Pruning of Mature Tea Trees for Harvesting
3. Pest and Weed Control
Agricultural Measures for Prevention:
First, perform winter pruning of tea tree canopies, then combine this with fertilization and deep tilling of the inter-row soil in tea gardens. This buries and covers dead branches, fallen leaves, weeds, and other places where pests overwinter. Parts of the pupae can be exposed on the soil surface. Legumes like white clover, perilla, and lemongrass can also be intercropped to prevent diseases, pests, and weeds.
Spraying Mineral-Based Pesticides:
This should be completed before December and can prevent mite infestations and effectively control mealybugs, scale insects, and leaf diseases. Mineral-based pesticides such as crystalline Sulfur-lime mixture, mineral oil, and their mixtures can be used.
Dosage:
For a 45% crystalline sulfur-lime mixture, use a 150-fold dilution (200-300 grams per mu) for spraying. Mineral oil can be used at a 150-200-fold dilution.
Requirements:
The tea plants, both above and below, and the upper and lower surfaces of the leaves, as well as weeds on the ground, should be thoroughly sprayed to enhance control effectiveness. Sulfur-lime mixture is a strongly alkaline pesticide and should not be mixed with acidic pesticides. Strictly control the concentration of the solution to avoid phytotoxicity.
Pest and Weed Control in Winter for Tea Gardens
4. Frost Prevention
Prevention:
1. Strengthen predictions and forecasts for disastrous weather and take preventive measures in advance.
2. The timing of leaf retention in high-altitude tea gardens is closely related to frost damage to tea trees. Retaining leaves during the later stages of Autumn Tea results in tender leaves that are susceptible to frost damage. Leaf retention should occur at the end of spring tea or the beginning of summer tea.
3. The formation of frost damage on tea trees is closely related to the presence of ice-nucleating bacteria on the leaf surface. Spraying fungicides or antibiotic solutions can reduce and inhibit bacterial activity, playing a role in preventing frost damage.
4. Strengthening fertilization management during the growing season and accumulating more organic matter can improve resistance to low temperatures. Applying substantial amounts of base fertilizer (organic fertilizer) in autumn and winter can raise soil temperature.
5. Establishing windbreaks in the direction of prevailing winds can reduce wind speed within the area and effectively resist cold waves.
6. Mulching tea gardens with straw can raise soil temperature by 1-2°C, mitigating the severity of frozen soil and