About author:Ji Genlin, senior agronomist, vice president of Xi'an Meteorological Association, chairman of Genlin Vegetable Cooperative. Mr. Ji has been engaged in vegetable planting and pest control for more than 20 years, has rich practical experience, and has been awarded the honorary title of "Agricultural Doctor" by the China Plant Protection Association for many times.
Cucumber virus disease is a systemic disease caused by virus infection, and the degree of occurrence varies from year to year, and can occur in both spring protected and autumn open-field cultivation of cucumbers. There are four main types of manifestations, often mixed disease, the harm is more extensive, infestation mainly relies on insect transmission, prevention and control is more difficult.
<h1>One or four types of presentation</h1>
(1) Mosaic virus disease: susceptible to disease at the seedling stage, the cotyledons become yellow and wilted, the young leaves are dark and light green flowers and leaves, and the plants are short. The new leaves are yellow and green flowers, the diseased leaves are small, wrinkled, and in severe cases, the leaves are rewinded and hardened and brittle, and there are often angular necrotic spots and clustered leaflets. Dark and light green mosaic spots appear on the surface of the diseased fruit, uneven or deformed, stop growing, and in severe cases, the internodes of the diseased plant are shortened, do not bear melons, shrink and die.
(2) Wrinkled virus disease: the new leaves appear thick green bulging wrinkles along the leaf veins, the leaves are small, and fern leaves and lobes appear; sometimes necrosis occurs along the leaf veins. The fruit surface produces mottled or uneven nodules, the fruit is deformed, and the severely diseased plant causes death.
(3) Green spot virus disease: the new leaves produce small yellow spots, which later become pale yellow spots, and the green part is raised and nodular. The fruit has thick green spots and bulging nodules, mostly deformed melons.
(4) Yellowing virus disease: the middle and upper leaves appear faded green spots between the leaf veins, and then develop into a pale yellow, or the whole leaf becomes bright yellow, the leaves harden, curl to the back, and the leaf veins remain green.
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2. Transmission Routes </h1>
1. Seeds, seedlings, or soil with poison, mostly whitefly, gray whitefly; aphids as a disease transmission vector, field agricultural operations and sap contact can also transmit poison.
2. Field farming operations and sap contact transmission: a single-stranded cyclic RNA pathogen consisting of about 350 nucleotides without a protein shell. Infection of higher plants is usually transmitted through seeds or pollen. Virus-like RNA can be used as its own template, using the enzymes of host cells for replication, the product is a multi-linked of the daughter chain, after self-cutting to form a new virus-like RNA genome.
<h1>Third, the law of occurrence</h1>
Cucumber virus disease is mainly caused by infection with cucumber mosaic virus, tobacco mosaic virus and pumpkin mosaic virus. The virus overwinters in the field with perennial root plants and residual tissues of diseased plants, and can also overwinter with seeds with poisoning. The virus is mainly transmitted to host plants through seed, sap friction, poisoning vector insects and field agricultural operations, and is re-infected multiple times.
The virus prefers high temperature and drought environment, the most suitable environmental temperature is 22 ~ 26 °C, the relative humidity is about 85%, the most suitable disease manifestation period is the adult fruit stage, and the incubation period is 15 to 25 days. The peak period of viral disease in Xi'an facilities is from March to June. During the year, there is little high temperature and little rain, and the incidence of insects such as aphids, greenhouse whiteflies, thrips and other poison vectors is heavy in the year. Pest control is not timely, fertilizer is insufficient, and the field is extensively managed.
<h1>Fourth, prevention and control methods</h1>
1. Physical prevention and control
(1) Selection of disease-resistant varieties There are differences in the resistance of different varieties to viral diseases, and it is necessary to select and use disease-resistant and disease-resistant varieties according to local conditions in production practice. Tsuyu 35, Tsuyu 38 or Tsusai 3, etc.
(2) After the dead branches and leaves of the front stubble in the shed are taken out of the shed for incineration or deep burial, the seeds are soaked with 10% trisodium phosphate for 10 minutes before sowing; the seeds can also be soaked in 60 °C warm soup for 30 minutes.
(3) Deep turning of the soil. After harvesting in the winter greenhouse, it is necessary to turn over early and deep in time to accept rain and snow to freeze to death and loosen the soil of diseases and insects. Deep ploughing should be more than 40 cm to the ground no later than 20 days before colonization. Reasonable crop rotation: more than 2 years of rotation with solanaceous, legumes, etc.
(4) Apply plantar fertilizer. 3000kg of farmyard fertilizer or 40kg of two-plus-one organic fertilizer and 75kg of high-phosphorus and high-potassium compound fertilizer plus 2kg of non-deep ploughing are applied per mu.
(5) Greenhouse disinfection After the dead branches and leaves of the former stubble in the shed are taken out of the shed for incineration or deep burial, before the cucumber colonization, each acre of greenhouse greenhouse with 2 to 3 kg of sulfur powder mixed with sawdust 5 to 6 kg of ignition fumigation, but also per mu with 45% bacterium clearing agent 1 kg fumigation, fumigation, greenhouse needs to be sealed.
(6) High furrow planting: combined with soil ridge ridge general non-stick hand for the ridge when the ridge is suitable for the ridge spacing of 1m, the ridge ditch width of 0.3m, depth of 0.15m.
(7) Reasonable dense planting; balanced growth. Create reasonable ventilation and light transmission conditions, mu 3000 nests. Spray 3g + Bio 30g at the seedling stage. Spray again every 20 days to prevent the growth of the disciple.
(8) Control the temperature and humidity in the shed. At 32 ° C, let the air out, reduce to 22 ° C and close the air outlet, so that the room temperature at night is maintained at 15-17 ° C. Cloudy days should be appropriate and timely ventilation according to the facts.
(9) Reasonable irrigation. Listen to the weather forecast before watering on at least sunny or rainy and cloudy days before watering. Fertilizer water management Fruit During the expansion period, cucumber fruit grows to 3-5 cm in size, mainly phosphorus and potassium fertilizers. 3KG of high-purity potassium dihydrogen phosphate and 8-10kg of 1S13 per acre of land were applied. Under normal circumstances, watering and fertilization are 10-15 days apart.
(10) Supplement carbon dioxide. The application of CO2 after colonization of slow seedlings is beneficial to the formation of a robust assimilator tube, and the increase in CO2 production is generally increased by 10% to 20%, which can also enhance the resistance of cucumbers to viral diseases, find diseased leaves, spray and remove them in time, and take them to the shed for deep burial or incineration.
(11) Physical anti-whitefly, thrips and other sucking pests - upper and lower vents cover 50 mesh insect nets or, or yellow board aphids (hanging yellow wooden boards or cardboard in the shed, applying oil to it, absorbing aphids and sticking them).
2. Pharmacy therapy
Viral diseases should be supplemented by the principle of prevention as the main treatment.
(1) Prevention for the entire reproductive period. The interval period is 10-15 days at a time; during the disease period, 20% viramine 50g-75g plus 75% imidacloprid 10-15g mixed with water 45-60kg even spray; 6.5% bacterial toxin clear water 40-60g, plus 20% acetamiprid 2-4g with water 45-60kg uniform spray; 83 anti-antibody agent 200-350g plus 505 anti-aphid 30-40g mixed with water 45-60kg uniform spray, the above formulas are used alternately, the interval is 10-15 days. Prevention for the entire reproductive period.
(2) Treatment: 8% niyramycin 75-100 grams plus 75% zinc sulfate 15-20g plus 3g of bigu with water 45-60kg of uniform spray, and then spray every 7-10 days can effectively control viral diseases.
(3) When the drug is used for the first time or the condition is serious, the dosage can be appropriately increased.