According to the Zhejiang Meteorological Bureau, starting from July 4th, the subtropical high will shift northward and control Zhejiang Province, marking the end of the Plum rains season and the arrival of scorching summer days!
The forecast for the next seven days in Zhejiang Province shows no widespread heavy rainfall. Most areas will experience sunny and hot weather with daily maximum temperatures reaching 36-39°C, and some regions may exceed 40°C. Afternoons will often see scattered thunderstorms.
Since entering the plum rains period on June 9th, many areas in Zhejiang have experienced heavy precipitation. Prior to June 18th, the heavy rainfall was concentrated in central and southern Zhejiang, but it shifted to northern Zhejiang thereafter. Statistics show that by June 28th, the total rainfall over 18 days approached the average amount for the entire 30-day plum rains period, exceeding nearly twice the total rainfall for 2023.
Multiple Tea-producing areas in Zhejiang have suffered varying degrees of damage due to continuous widespread heavy rainstorms.
Heavy rain can wash away soil in tea gardens, which can lead to exposed root systems, making tea plants susceptible to toppling in strong winds. Additionally, mud and debris can flow into tea gardens, potentially carrying pathogens and covering leaves, leading to reduced yields.
Tea plants thrive in moist conditions but are vulnerable to waterlogging. Excessive moisture in the soil due to heavy rain can cause tea plants to suffer from wet stress, manifesting as yellowing of young leaves, stunted growth, and even cessation of growth.
Tea gardens located on hills and mountains can also experience landslides or mudslides, resulting in severe damage.
Post-Flood Management Measures for Tea Gardens
1. Repair Damaged Infrastructure: Timely repair damaged roads, ditches, terraces, and other infrastructure in the tea garden to ensure road access. Clear and repair only when geological conditions are stable. Clear mud, stones, and other debris from the garden, wash off the mud on the tea plants to ensure clean leaves, aiding recovery.
2. Drainage: If there is standing Water in the tea garden after heavy rain, promptly dig drainage trenches. Excavate temporary drainage ditches and improve existing channels. For severely waterlogged gardens, use a pump to remove water quickly.
3. Shallow Cultivation: After the soil dries, perform shallow cultivation to restore its permeability, encouraging new root growth and recovery of plant vigor.
4. Restoring Plant Vigor: Promptly support fallen tea plants and cover exposed roots to help them recover quickly.
5. Pruning and Maintenance: For plants with exposed or injured roots, cover them with soil and prune branches dragging on the ground or broken branches covered in mud.
6. Fertilization: Quickly take advantage of clear weather to cultivate and fertilize, using mature organic Fertilizer and compound fertilizer. Dig trenches about 15 cm deep, apply fertilizer, and cover with soil to promote growth and enhance heat tolerance.
7. Disease Control: Tea gardens are prone to infection by foreign pathogens after heavy rain, so disinfect the gardens post-disaster and conduct regular inspections for early detection and treatment.
8. Garden Disinfection and Pest Management: This period coincides with the peak season for tea pests and diseases, so closely monitor the garden's condition, strengthen pest and disease forecasting, and focus on green pest control techniques. Pay particular attention to monitoring for tea looper outbreaks.
For more information, refer to technical measures for mitigating and recovering production in tea gardens after extreme flood disasters.
Measures to Combat Heatwaves and Drought in Tea Gardens
1. Irrigation System Preparation: Check and maintain the irrigation system to ensure it functions properly during heatwaves and drought. For gardens without irrigation facilities, consider building simple irrigation systems or using drip, sprinkler, or furrow irrigation methods. Water the garden in the early morning or late evening to reduce evaporation. Ensure sufficient water is applied to meet the needs of the tea plants.
2. Shade Measures: Install shade nets or use natural vegetation to provide shade in the tea garden. Keep the shade net at least 40-50 cm above the canopy to prevent direct contact and scorching. Younger gardens are more vulnerable to heat and drought and may benefit from shading during summer.
3. Mulching: Apply straw or other organic material between rows in the tea garden, maintaining a thickness of 10-15 cm to retain moisture, regulate soil temperature, and suppress weed growth. Regularly check and replenish mulch to ensure effectiveness.
4. Drought Resistant Sprays: During persistent heatwaves and drought, spray methyl salicylate or brassinolide on the canopy before 9 AM or after 4 PM to improve heat tolerance, especially effective for younger gardens.
5. Pest and Disease Control: Continue to monitor and manage pests and diseases.
For more information, refer to technical measures for mitigating and recovering production in tea gardens during extreme heatwaves and drought.
Other Measures
1. Weather Monitoring: Closely follow weather forecasts and meteorological changes, adjusting management practices accordingly.
2. Growth Monitoring: Regularly observe the growth status of tea plants, including leaf color and branch growth, addressing any abnormalities promptly.
3. Flexible Management: Adjust management strategies flexibly based on the actual situation and weather changes. For example, increase irrigation frequency and volume during heatwaves and drought, and intensify pest and disease control during peak seasons.
Given the recent flooding and the onset of high temperatures in Zhejiang's tea gardens, tea farmers should adopt scientific and reasonable measures according to their specific circumstances to minimize losses and ensure the normal growth and stable production of tea plants.
(Reviewed by: Dr. Han Wenyan, Researcher at the Tea Research Institute, Chinese Academy of Agricultural Sciences)