Aster Pest and Disease Control Methods and Processing Techniques Explained in Detail
Pest and Disease Control and Processing of Aster
Aster Pest and Disease Control 1. Diseases Mainly include black spot, damping-off, leaf spot, and powdery mildew. Aster disease control: (1) Disease-resistant varieties should be selected. (2) Ensure ventilation, control temperature, and prevent dew on leaf surfaces. (3) Chemical control: Before disease onset, spray 1:1:100 Bordeaux mixture, once every 7-10 days; 75% chlorothalonil 500-800 times dilution spray may be used. Aster powdery mildew control: Select disease-resistant varieties, enhance field ventilation, reduce humidity and temperature, and use "Nongkang 120" at 200 times dilution. 2. Pests Mainly include the perilla red pink pyralid, the purple-striped geometrid moth, the small cutworm, the yellow cutworm, the large black chafer, the black velvet chafer, and the red spider mite. The perilla red pink pyralid and the purple-striped geometrid moth mainly damage leaves and branch tips as larvae. (1) Manually remove branch tips. (2) Clean the garden by disposing of dead branches and fallen leaves, and plow the land after harvest to reduce overwintering pest sources. (3) Spray trichlorfon at 800 times dilution. Control of the small cutworm, yellow cutworm, large black chafer, black velvet chafer, and red spider mite: (1) Clear weeds from the field and field edges. (2) Trap and kill adults: During the adult activity period, use a sugar-vinegar liquid (1 part brown sugar, 0.5 part liquor, 2 parts vinegar) in basins placed at a height of 1 m in the field in the evening to trap and kill adults. (3) Manually capture larvae: Inspect seedlings every morning; if broken seedlings are found, dig open the surface soil nearby to capture the larvae. Chemical control: Use lycoris bulbs plus baibu powder at 7-8 jin per mu combined with fertilization and watering. For larvae under the 3rd instar, spray 90% trichlorfon at 1000 times dilution. Red spider mite: Spray 0.3% Sophora flavescens botanical insecticide at 1000 times dilution for prevention, and spray sulfur suspending agent during the outbreak period from June to August. V. Harvesting and Processing Around Frost's Descent is the best harvest time for aster; if there is no time to harvest in autumn, dig before sprouting in February of spring. When digging, first cut off the withered aboveground stems, water slightly to moisten the soil so that the soil is slightly loosened, then carefully dig out the underground roots and rhizomes; be careful not to break the fibrous roots. After digging out, shake off the soil, and select some robust rhizomes to cut off as planting material. Slit the dug aster rhizomes lengthwise several times, place them in a dry place to dry until half-dry, braid them into plaits, and then dry until fully dry; this is the "braided aster" medicinal material. Generally, the yield is about 300 kg of dried product per mu, with a drying ratio of 25%. The processing site environment and tools should meet hygiene requirements. The drying yard should be cleaned in advance, kept away from highways to prevent dust pollution, and equipped with rainproof and poultry-proof facilities. Aster medicinal material is irregularly block-shaped, with stem bases and petiole remnants at the top, occasionally with unremoved mother roots at the bottom, grayish-yellow, fibrous, slightly hard in texture, with many fine roots clustered below the rhizome, 3-15 cm long and 1-3 mm in diameter, grayish-red on the surface or with longitudinal striations, flexible in texture, grayish-white in cross-section, with a purple edge, slight fragrance, sweet and slightly bitter taste.