What are the key technical points for harvesting asparagus while retaining the mother stalks?
Asparagus stem blight is a devastating disease known as "asparagus cancer." Once stem blight occurs, it causes reduced yields in mild cases and total crop loss in severe cases, bringing huge losses to asparagus growers. Affected by the 2003 SARS outbreak, asparagus prices were low, many growers abandoned management, stem blight outbreaks were relatively severe, and asparagus fields...
This technique adopts different harvesting methods according to different field growth conditions. For fields where the above-ground nutrient growth of the harvested portion is weak in the first year, the method of retaining stalks first and then harvesting must be adopted; for fields with good growth in the first year and those harvested for many years, the method of harvesting first and then retaining stalks is used.1. Selecting and retaining mother stalks: When the young stalks grow to 15-20 cm, select young stalks about 1 cm in diameter, without bending or damage, and evenly distributed around the crown as mother stalks. The number of mother stalks per hole can be 3-8 plants depending on the growing years, allowing them to grow healthily.
2. Coating stalks to prevent disease: When the young stalks grow to 20-40 cm, use 1:20 diluted Fangkuling or asparagus fungicide to coat the stalks upward from the plant base. When small tillers appear on the plants, use asparagus cleaner or Fangkuling at 400-500 times dilution, spraying every 7-10 days for prevention, to protect the mother stalks and prevent asparagus stem blight.
3. Driving stakes and pulling ropes to prevent lodging: When the mother stalks grow to 1.2-1.3 m, stakes should be driven and ropes pulled to secure the mother stalks, and pinching off the tips and topping should be done to prevent lodging.
4. Skillful fertilization for more asparagus harvesting: When branches produce cladodes, apply 15-20 kg of urea and 20 kg of compound fertilizer per mu by trenching. Thereafter, fertilize once every 15 days during the harvest period, applying 20 kg of urea per mu each time, and stop fertilizing half a month before the harvest ends.
5. Clearing plants, tending plants, and soil disinfection: According to the growth condition of the mother stalks, promptly remove diseased plants and mechanically damaged plants. Generally, change the stalks once around July, and clean up the mother stalks after harvest ends before October. Also, before retaining mother stalks, during the stalk-changing period, and after the harvest while retaining mother stalks ends, use 2 bottles of asparagus cleaner per mu each time for soil disinfection.