(1) Symptoms mainly harm stem bases and leaves. At the beginning of the victim’s part, there were irregular, light-colored hazel-like irregular spots on the edge. The latter disease was softly rotted, giving birth to white or grey cotton flocculent mycelium, and the formation of black murine fecal sclerotia. One week after the disease stem ring stems caused the whole plant to die. The seed-cultivation strains are often victimized at the final flowering stage. In addition to infesting leaves and pods, the stems can also be rotted and hollowed, or flocculent mycelia and black sclerotia can be produced on the surface and pith, and the stems can be folded in the late stages. The pedicel infected the diseased part with a white or wet rot, causing the seed to lose weight, endogenous hyphae or sclerotia, and the disease can easily become premature or burst. 4 chemical control. At the beginning of the disease, apply 5% chloramphetamine powder 2-2.5 kg/mu, add 15 kg of fine soil and mix well and spread it in the rows, or spray 50% chloramphetamine wettable powder 800 times, or 20% methyl bromide. Phosphorus Emulsion 900-1000 times, or 40% more than Sulfur Suspension 500 times, or 70% thiophanate-methyl WP 500-600 times, or 50% Propionine WP 1000-1500 times Liquid, or 50% Scrokton WP 2000x, or 40% Sclerot® Net WP 500x. About 1 time every 10 days, continuous control 2-3 times. 3Ply Face Mask, Disposable 3ply Face Mask,Non-Woven 3ply Face Mask,3ply Face Mask with Ear Loop Ningbo Jiashang textile co., LTD., , https://www.wellwayopto.com
(2) The onset condition is a fungal disease. It is mainly due to sclerotia remaining in the soil or contaminating the seed during summer or winter. In the southern vegetable area, sclerotia mostly germinated in 2-4 months and in October-December; northern vegetable areas mostly germinated in winter and spring. The germinating sclerotia produce a sub-disc disk, and the spores in the plate are ejected after being matured and transmitted through the air flow. First infect on weak leaves and petals. After gaining nutrition, they have the ability to infect the health department through mycelium. The optimal temperature for pathogenic bacteria development was 20°C, the highest temperature was 30°C, and the lowest was 0°C. The optimum temperature for spore germination was 5-10°C, the highest temperature was 35°C, and the lowest was 0°C. The hyphae are not dry, and the relative humidity is higher than 85% and well developed. Less than 70% of the diseases are obviously blocked. Sclerotia can survive for more than 3 years in dry soils and only 1 year in wet soils. In water, it rots after 1 month. Sclerotia were killed at 50°C for 5 minutes. Cultivation conditions have a greater impact on the disease, generally the incidence of poor drainage, poor permeability, partial application of nitrogen fertilizer or frost, frost damage or fertilizer damage.
(3) Control methods
1 Discard the sclerotia mixed in the seeds with 10% saline and reduce the primary infestation source.
2 Where there are conditions in areas where paddy-upland rotations are used, sorghum planting is used to avoid partial nitrogen fertilization. Drain the plants in time after the rain, and remove the diseased bodies after harvest to perform deep plowing.
3 Spent sclerotia can be killed by increasing the bed temperature to 55°C for 2 hours before sowing.