The tea regions of Guiyang City have been frequently impacted by extreme spring weather in recent years. According to meteorological forecasts, the city is expected to experience another Cold wave soon. To cope with the upcoming temperature drops, thunderstorms, and late spring cold snaps, this document, “Preventive and Remedial Measures for Low-Temperature Freeze Damage (Late Spring Cold Snap) in Guiyang and Guian Tea Gardens,” has been specially formulated for your reference.
I. Preventive Measures
(1) Pay Attention to Cold Wave Forecasts
Strengthen forecasting and early warning systems for disastrous weather conditions, promptly issue cold wave information, and prepare in advance. After a cold wave forecast is released, tea gardens that are already open should mobilize manpower to harvest as much as possible to minimize losses from frost damage.
(2) Cover Tea Gardens for Frost Protection
Straw, bamboo leaves, and rice husks can be spread between rows of tea plants to keep them warm, ideally at a thickness of about 10 centimeters, which can generally increase temperatures by 1-2°C. In tea gardens on windward slopes prone to frost damage, cover the canopy with straw, weeds, or shade nets, not too tightly so that the tea plants are still visible. This will help reduce the magnitude of temperature drops and excessive Water evaporation from the leaves. After the cold wave, remove the covering materials promptly.
(3) Clear Accumulated Snow Timely
Remove accumulated snow from the Tree crowns to prevent damage from the weight of heavy snow or prolonged freezing, which can harm new buds on the tea plants.
II. Remedial Measures
(1) Moderate Pruning
Prune frozen branches immediately when the temperature rises and there is no risk of further severe frost damage. The extent of pruning should vary according to the degree of damage. For lightly affected plants, perform light pruning, keeping cuts shallow—ideally 1-2 cm deeper than the frozen area. For plants with only edge-damaged leaves, pruning may not be necessary. Heavily affected plants require more severe pruning or stump cutting to promote the growth of new shoots.
(2) Shallow Tilling and Fertilization
After a low-temperature freeze, carry out shallow tilling and fertilization to raise Soil temperatures, strengthen the trees, and stimulate bud emergence and Shoot growth. Use specialized tea plant fertilizers.
(3) Cultivate the Canopy
After light pruning, the spring shoots should be partially harvested to leave some leaves behind to restore the tree's strength. Summer and autumn teas can be harvested as usual. For trees that have undergone shaping or stump cutting, avoid or delay harvesting that year, focusing instead on cultivating the canopy. Implement harvesting measures to remove damaged shoots promptly to prevent excessive nutrient depletion and hinder new shoot growth, leading to greater yield losses.
(4) Tea Seedling Replacement
For young tea plants in newly planted tea gardens that have died due to freezing, replace them with new seedlings as soon as possible. Arrange for the purchase and transportation of seedlings to ensure timely replacement.
(5) Pest and Disease Prevention
The late spring cold snap can freeze and kill most first-generation green leafhoppers and tea thrips, reducing their population and decreasing the potential harm to tea plants. After the weather warms up, install wind-suction LED insect traps to control adult pests. Tea plants damaged by the cold snap will have reduced immunity, especially in high-altitude gardens, where the occurrence of tea white spot disease should be monitored. Strengthen nutrient management and adopt leaf retention harvesting methods to restore tree vigor and enhance resistance in tea plants.