Summer and autumn are critical periods for tea garden management. Strengthening tea garden production management in summer and autumn is the fundamental work for ensuring the quality and high yield of summer-autumn tea and the following year’s spring tea.
On June 21, the Planting Industry Management Department of the Ministry of Agriculture and Rural Affairs, together with the National Agricultural Technology Extension Service Center, the Tea Expert Guidance Group of the Ministry of Agriculture and Rural Affairs, and the National Tea Industry Technology System, issued the “Technical Guiding Opinions on Summer-Autumn Tea Garden Production Management and Disaster Prevention and Mitigation.” Let’s take a look together.
Strengthening Tea Garden Production Management
(1) Tea Tree Pruning. For tea gardens picked year-round, the first light pruning should be carried out promptly after spring tea picking ends, cutting off the upper 5cm~10cm of shoots on the canopy. During summer tea picking, adequate foliage should be retained, using leaf-retaining picking and top-picking methods to maintain a suitable leaf layer thickness.
In autumn, picking should be stopped appropriately early so as not to affect the yield and quality of the following year’s spring tea. To cultivate a good picking canopy, the second light pruning should be completed before mid-to-late July, with the pruning height raised about 10cm above the previous cut.
Pruning should be postponed in the event of high-temperature drought weather. Tea gardens requiring renovation should undergo heavy pruning or deep pruning after spring tea picking ends.
(2) Tea Garden Fertilization. Topdressing is usually based on fast-acting chemical nitrogen fertilizer, supplemented with phosphorus and potassium fertilizers. The amount should comprehensively consider factors such as tree age, growth vigor, target yield, and soil nutrient content.
1. Soil fertilization. General production tea gardens can be topdressed before summer tea growth begins, applying 15kg~20kg of urea per mu or 30kg~40kg of tea-specific compound fertilizer per mu, with high-yield gardens receiving appropriately more. A high-nitrogen, low-phosphorus, medium-potassium compound fertilizer should be selected to avoid applying excessive phosphorus fertilizer. Fertilizer is usually applied in trenches dug vertically downward at the edge of the tea tree canopy, with a trench depth of more than 10cm. Row-planted gardens should be band-fertilized; cluster-planted gardens should be fertilized in rings around the clusters.
2. Foliar fertilization. During the summer-autumn tea growing period, foliar topdressing can be applied appropriately, spraying after each round of the tea season ends and before the next round of new shoots emerges, once every week, before 10 a.m. or after 4 p.m. on sunny days, or on cloudy days. Use an electrostatic sprayer or an agricultural plant-protection drone for application, with the drone flying at a height of 1.5m and a foliar fertilizer application rate of 1.0L per mu. Water-soluble urea, amino acid water-soluble fertilizer, humic acid foliar fertilizer, and biogas slurry fertilizer can be selected, prepared at appropriate concentrations. Among them, water-soluble urea foliar fertilizer should be at a urea concentration of 1%~2%; amino acid foliar fertilizer at about 50mg per mu; humic acid foliar fertilizer should be sprayed at a 2% concentration of humic acid active ingredient, at 15kg per mu, with commercial products generally requiring 600-800 times dilution; biogas slurry fertilizer should be diluted according to its actual concentration.
(3) Weeding and Weed Control
1. Mechanical weeding. Choose common portable power weeders or walk-behind multi-function hoes on the market. When weeding, keep the blade or trimming line at a certain angle so that the cut weeds fall as close to the tea trees as possible. Use a medium throttle and move at a steady speed through the garden; if the grass is too dense, reduce the weeding speed; if the grass is sparse, the speed can be appropriately increased. During use, the blade or trimming line should avoid hitting hard objects such as stones as much as possible, and internal grass debris or weeds tangled around the motor should be cleaned regularly to ensure safe operation.
2. Manual weeding. Usually carried out once a month from June to August. Summer shallow-tillage weeding should be treated differently according to the age of the tea trees. For mature and aging tea gardens, tillage weeding should be done before the vegetation flowers in autumn to reduce weed occurrence in the following year; young tea gardens should appropriately increase the frequency of tillage weeding.
3. Mulching for weed suppression. Young tea gardens and production tea gardens with low canopy coverage can lay weed-control fabric between the tea rows, divided into full coverage and partial coverage. Full coverage means completely covering the soil of the tea rows with weed-control fabric; this method requires the fabric width to be 10cm greater than the row spacing, laid flat, kept as close to the base of the tea seedling stems as possible, and secured with ground pegs every 2m. Partial coverage usually takes the tea planting row as the center line, with 40cm~50cm of weed-control fabric covering each side, leaving 40cm~50cm of soil exposed in the middle of the row. It is mostly used in young tea gardens and can be combined with the “using grass to control grass” technique.
4. Using grass to control grass. In young tea gardens or production tea gardens with low canopy coverage, white clover, Chinese milk vetch, ryegrass, and the like can be intercropped between rows, generally sown between rows in mid-to-late October at 1kg~1.5kg per mu, with a strip width of 40cm~50cm, keeping a distance of more than 20cm between the grass seed and the tea tree roots. After sowing, topdress with 5kg of nitrogen fertilizer per mu in early-to-mid March of the following year to promote growth.
(4) Shallow Tillage of Tea Gardens. Shallow tillage should be carried out after summer tea harvesting ends, to a depth of 5cm~10cm. For regions that pick large quantities of autumn tea, another round of shallow tillage should be carried out in August-September. Mountain tea gardens can use small rotary tillers or mini-tillers; flatland tea gardens can use ride-on multi-function cultivators, crawler self-propelled multi-function cultivators, and similar equipment. Shallow tillage should be avoided during sustained high-temperature drought weather.
(5) Pest and Disease Control
1. Hemipteran pests. In summer, the tea green leafhopper and the citrus spiny whitefly occur severely. Red-and-yellow dual-color sticky traps can be used for trapping, hung 20cm above the tea canopy at 23~25 boards per mu, left in place for 2 to 3 weeks, and are best used after tea garden pruning. When pest density is high, biopesticides can be sprayed.
2. Lepidopteran pests. June to September is the peak damage period for the tea geometrid and the grey tea geometrid; late June to July is the peak damage period for the tea caterpillar, with adult emergence peaks in early June and August. Use insecticidal lamps to continuously trap adults, with the light source 40-60cm above the tea canopy, working 3 hours after sunset each day; use sex pheromones to trap male moths at 2-4 sets per mu, hung 25cm above the tea canopy, replacing the lure cores every 3 months. When pest density is high, biopesticides can be sprayed.
3. Thysanopteran pests. In summer, the tea stick thrips and the tea yellow thrips cause severe damage, with the peak occurrence period in June. Use sticky traps for trapping, hung 20cm above the tea canopy at 23-25 boards per mu, replaced promptly when fully loaded, and best used after tea garden pruning.
4. Acarine pests. In summer, the orange tea rust mite, the tea short-whiskered mite, and the tea tarsonemid mite cause severe damage. The orange tea rust mite has two occurrence peaks in summer; the tea short-whiskered mite population grows rapidly in June, with peak occurrence from July to September; the tea tarsonemid mite peaks from July to August. At the early stage of mite occurrence, fungus-carrying Amblyseius cucumeris can be released in the tea garden at 40,000~60,000 individuals per mu.
Preparing for Disastrous Weather
(1) Flood and Waterlogging Disasters in Tea Gardens
1. Flood and waterlogging prevention. Pay close attention to weather forecasts, and inspect and clear the tea garden’s drainage and irrigation ditches before heavy rain to ensure normal drainage. Tea gardens lacking drainage ditches should have drainage ditches urgently dug inside and around the garden; low-lying gardens or those with excessively high groundwater levels need drainage ditches more than 1m deep. Gardens ready for picking should organize emergency harvesting and processing to reduce losses.
2. Emergency repair and remediation of waterlogged tea gardens
(1) Drain surface water as soon as possible. After a tea garden suffers flooding or waterlogging, organize the removal of surface water as soon as possible to reduce the effects of waterlogging damage. Flatland tea gardens should have perimeter ditches dug around them and central or furrow ditches dug in the middle for drainage, lowering the groundwater level to below 1m. Nurseries and young tea gardens should use water pumps to pump out water directly.
(2) Repair infrastructure as soon as possible. Promptly repair damaged roads, ditches, pumping stations, and other infrastructure; clear ditches to keep water and roads flowing and prevent secondary disasters. Collapsed tea gardens must be quickly repaired and rebuilt to restore the garden’s appearance as soon as possible.
(3) Clean the tea garden in a timely manner. For tea gardens soaked by floodwater, promptly remove mud and debris from the canopy to keep it clean and hygienic. Dig out the mud and silt accumulated beneath the tea trees. Right the fallen trees, mound soil to cover the root systems, and protect the tea seedlings so they survive upright.
(4) Prune in a timely manner. For tea trees that have been submerged for too long, have severely damaged roots, or show obvious wilting symptoms in their leaves, heavy pruning or deep pruning should be carried out after the topsoil dries, to reduce water evaporation and nutrient consumption and prevent the whole plant from dying. Tea trees with exposed or injured roots should be earthed up promptly, and ground-dragging branches carrying mud and sand, as well as broken branches, should be cut off. Disaster-affected tea gardens should be pruned in time to cultivate high-yield canopies and promote the even sprouting of new buds.
(5) Replenish nutrients in a timely manner. Disaster-affected tea gardens should be inter-tilled and weeded, with fertilizer applied in trenches about 15cm deep and covered with soil promptly after application. Well-rotted organic fertilizer and compound fertilizer can be applied: production tea gardens generally receive 500kg of organic fertilizer and 20kg~30kg of compound fertilizer per mu (which can be applied in 2 splits), while young tea gardens generally receive 100kg of organic fertilizer and 10kg~20kg of compound fertilizer per mu (which can be applied in 2 splits); foliar fertilizer can also be sprayed appropriately.
(2) Water Conservation and Drought Resistance in Tea Gardens
1. Implement drought prevention measures
(1) Build channels and ponds, and irrigate promptly against drought. Tea gardens in hilly and mountainous areas should take advantage of favorable terrain to build ditches, channels, reservoirs, and mountain ponds to improve drainage and water storage capacity; tea gardens with the means should build irrigation systems. When the relative moisture content of the tea garden’s plow layer falls to about 70%, or when the daily average temperature reaches above 28 degrees Celsius with no rain for 7 to 10 days, use sprinkler irrigation or surface furrow irrigation to replenish water promptly. Mulch the tea garden after irrigation to improve moisture retention.
(2) Tea garden shading. Where conditions permit, use scaffolding and other methods to install shade net coverage, reducing light intensity and alleviating drought. The shade net should be more than 50cm above the tea trees to avoid clinging to the trees and causing scorching.
(3) Shallow tillage, hoeing, and grass mulching. Before the dry season arrives, carry out shallow tillage and hoeing, and spread grass mulch between rows. Use about 1 ton of dry grass per mu, laid 5cm~10cm thick; mountain grass and weeds can be cut, or rice straw, wheat stalks, bean stalks, bagasse, wood chips, and pruned tea garden branches and leaves can be used as mulch sources.
2. Post-drought management
(1) Prune in a timely manner. Severely drought-affected tea trees should be pruned promptly after the drought passes. Depending on the degree of withering of branches and leaves, use light pruning, deep pruning, or even collar cutting to remove dead branches and re-cultivate a good canopy.
(2) Replant seedlings in good time. Young tea gardens are prone to tea tree death; after the drought, replant seedlings promptly to avoid missing plants and broken rows.
(3) Fertilize rationally to restore tree vigor. Young tea gardens can be given extra-root topdressing with a 0.5% potassium dihydrogen phosphate aqueous solution during the dry season. Production tea gardens can be trench-fertilized with compound fertilizer or organic fertilizer after the drought, with the amount determined by planting density, growth vigor, and other factors. Generally, 20kg~30kg of compound fertilizer and more than 500kg of organic fertilizer can be applied per mu; foliar fertilizer can also be sprayed appropriately.
(4) Plant fill-in crops. Depending on the length of the fallow period of the shed or greenhouse, corn, wheat and beans, heat-tolerant amaranth, and the like can be planted to improve the soil ecological environment, reduce disease, and promote the growth of the next crop of vegetables.
Produced by: China Co-op Times · Tea Weekly All-Media
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Author: Lam Sam (LamSam), the Old Tea Head
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