Bad seedling disease
The pathogen is caused by Fusarium beads and belongs to the subphylum Semi-Epiphylum Fungi. There are two types of conidia, small conidia ovate or oblate-oval, colorless monocell, chain-like, large conidia are mostly spindle or sickle-shaped, the top is blunt or uniform in thickness, with 3 5 septa, most of the spores are light red when they are gathered, and they are pink or white when dry.
Rice seedling disease is also known as the disease of longevity, the diseased grains often do not germinate or can not be unearthed after sowing, the diseased seedlings at the seedling stage are slender and taller than the healthy seedlings, the leaf sheath is slender, the leaf color is light yellow, the root system is poorly developed, and some diseased seedlings die before transplanting.
The typical symptom of rice seedling disease is obvious elongation of internodes, which is significantly higher than that of normal plants1 3 control technology.
Rice seedling disease is mainly diseased seeds as the source of primary infection, so comprehensive control measures should be taken based on the selection of disease-free seeds and pre-sowing seed treatment.
1) Select and retain disease-free seeds.
Do not leave seeds from diseased fields and nearby paddy fields, and establish disease-free farmlands. Choose disease-resistant varieties and avoid planting susceptible varieties. Leave the planting field and the nearby general production field, and the diseased plants should be uprooted in time to prevent the spread of the disease. Reserved farming should be singled, singled, and stored.
b) Seed treatment.
1.Soak seeds in warm soup with 52 55 warm water for 30min.
2.Soaking seeds with 1% lime water clarifier, soaking for 3d at 15 20 hours, 25 soaking for 2 d, the water layer should be 10 15cm higher than the seeds, avoiding direct light; Or soak seeds with 200 250 times of 35% mold suspension, and the ratio of seed amount to liquid medicine is 1:15 2, temperature 16 18 under the condition of soaking for 3 5 days, stirring once in the morning and evening, after soaking with medicine live broadcast or germination.
3) Cultivation management.
The germination time before sowing should not be too long, so as not to be injured during planting; Do sparse sowing and cultivate strong seedlings. When pulling seedlings and transplanting, root damage should be minimized, and transplanting seedlings should be avoided in the middle of the day. In production practice, some people put forward the "first planting", that is, not planting overnight seedlings, not planting old seedlings, not planting deep mud seedlings, not planting scorching sun seedlings, and not planting cold water soaked seedlings.
4) Eliminate the source of bacteria.
Timely uprooting of diseased seedlings and diseased plants and treatment of diseased straw, concentrated burning or fertilizer making; Diseased straw is not exposed and stacked; Avoid covering seedlings and plugging water outlets with diseased straw and its weaving to reduce the probability of returning diseased grass to the field.
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