Pollution-free control methods and techniques for sclerotinia disease of coriander
1. Agricultural control (1) Practice crop rotation or high-temperature control. In diseased fields, practice a 2-3 year rotation with grain crops, or a 1-year rotation with rice or with aquatic vegetables. Where protected cultivation land cannot be rotated, high-temperature control may be adopted, as follows: during the high temperatures of the three summer months, first clean the field, remove diseased leaves and stems and weeds, carry them out of the field and bury them deep or burn them; apply 50-100 kg of lime per 666.7 sq m, add 500 kg of chopped rice straw or wheat straw, spread evenly on the surface, immediately turn into the soil, form high ridges about 30 cm tall, and fill the furrows with water until saturated; to keep water in the furrows at all times, irrigate every day; cover with plastic film, seal the edges tightly with soil, and keep the greenhouse or room closed for 15-20 days. This method can not only kill the lower sclerotia, but also kill pathogens such as Fusarium and root-knot nematodes.
1. Agricultural control
(1) Practice crop rotation or high-temperature control. In diseased fields, practice a 2-3 year rotation with grain crops, or a 1-year rotation with rice or with aquatic vegetables. Where protected cultivation land cannot be rotated, high-temperature control may be adopted, as follows: during the high temperatures of the three summer months, first clean the field, remove diseased leaves and stems and weeds, carry them out of the field and bury them deep or burn them; apply 50-100 kg of lime per 666.7 sq m, add 500 kg of chopped rice straw or wheat straw, spread evenly on the surface, immediately turn into the soil, form high ridges about 30 cm tall, and fill the furrows with water until saturated; to keep water in the furrows at all times, irrigate every day; cover with plastic film, seal the edges tightly with soil, and keep the greenhouse or room closed for 15-20 days. This method can not only kill the lower sclerotia, but also kill pathogens such as Fusarium and root-knot nematodes.
(2) Raise seedlings in disease-free soil. Field soil or peat soil should be selected for raising seedlings, and management should be strengthened to produce disease-free strong seedlings. Where conditions permit, for seedbeds that have previously grown vegetables, heating cables can be used to raise seedlings; before sowing, adjust the seedbed temperature to 55-56 degrees C and treat for 2 hours, which can kill the sclerotia in the seedbed soil. Then lower the temperature, sow, and raise seedlings normally.
(3) Use disease-free seed. Save seed from disease-free plants. For seed mixed with sclerotia, rinse the seed with 10% salt water to wash out the sclerotia. Then rinse the seed repeatedly with clean water, dry it, and sow. Seed may also be soaked in warm water at 50 degrees C for 10 minutes (maintaining the temperature), which can kill the sclerotia mixed in with the seed.
(4) Strengthen ventilation. For protected cultivation, ventilation should be strengthened to reduce humidity and create environmental conditions unfavorable to the occurrence and development of sclerotinia disease.
(5) Cover with plastic film. Plastic film can block the emergence of apothecia from the soil; if ultraviolet-blocking film is used to cover the ground, the effect is even better, because this film can inhibit the germination of sclerotia.
(6) Clean the field. If diseased plants are found in the field, they should be pulled out promptly, which can reduce the spread of the pathogen in the field.
2. Pollution-free pesticide control. For protected cultivation, before disease onset use 3.3% thiabendazole smoke agent, 250 g each time per 666.7 sq m, divided into 4-5 points, applied in the evening, with closed fumigation, once every 7 days, for 5-6 consecutive times. In the early stage of disease, 42% thiabendazole suspension concentrate at 1000 times dilution may also be sprayed, once every 7 days, for 3-4 consecutive sprays.