Brinell hardness tester is a precision measuring instrument for measuring brinell hardness of metals . Brinell Hardness Tester,Portable Brinell Hardness Tester,Brinell Hardness Test Unit,Portable Hardness Tester Brinell TROJAN (Suzhou) Technology Co., Ltd. , https://www.trojanmaterial.com
First, the symptoms
After the leaves and calyx of the leek are susceptible, dark brown water-stained lesions begin to appear from the lower part and gradually extend upward to half of the leaves and calyx. After the diseased part loses water, it collapses, and the leaves and calyx above the contracture sag. When the air is humid, the site of the disease grows sparse white mold. The pseudo-stem is damaged by water-stained pale brown soft rot, which grows white mold and the leaf sheath is easy to fall off. The bulbs are mostly damaged by light brown or dark brown rot in the root plate, and the internal tissues become pale brown. The roots are brown and rot, with few root hairs.
Second, the law of incidence
1. Pathogen: Amaranth disease is a fungal disease caused by Phytophthora nicotianae infection. The pathogens overwinter in the soil with the oospores and the diseased plant residues, becoming the first source of infection in the second year.
2. Mode of transmission: The pathogen is firstly infested by sporangia and oospore germination. The diseased part produces sporangia under humid conditions, and spreads repeatedly through wind and rain, causing disease prevalence.
3. Incidence conditions: The optimum temperature for field disease is 25 ° C ~ 32 ° C, high humidity, heavy onset. Generally, the rainy season is long, the rainfall is large, the temperature is high, the terrain is low, and the rain is affected. The ventilation of the protected area is not timely or the time is not enough. Excessive dense planting or partial application of nitrogen fertilizer is easy to occur.
Third, prevention and treatment methods
1. Strengthen cultivation management: arrange 3 to 4 years of squatting, avoid perennial continuous cropping; concentrate on removing and destroying diseased bodies after harvest to prevent the spread of pathogens; keep leeks and sputum, refurbish irrigation and drainage system, facilitate drainage and flood control, avoid excessive application of excessive nitrogen fertilizer, and diligently cultivate; The protective ground adopts measures such as timely release of air and moisture, so that the sporangia is not easy to germinate, thereby reducing the accumulation of pathogens and reducing the incidence.
2. Chemical control: Before the onset, 70% mancozeb 500 times solution was used to prevent disease. In the early stage of the disease, the following agents were sprayed: 64% imported anti-virus cockroach (produced by Swiss Syngenta) WP 500 times, 72.2 %Pulke water agent (produced by Bayer, Germany) 800 times solution, 69% decanoylmorpholine-manganese zinc wettable powder 800 times solution, 75% chlorothalonil WP 600 times solution, 58% metalaxyl Manganese clock wettable powder 500 times liquid, 50% nail cream copper wettable powder 600 times liquid and the like. Spray once every 7 to 10 days, even spray 2 to 3 times.
Brinell hardness tester is mainly used for cast iron, steel, non-ferrous metals and the degree of hardness measurement of the soft material such as alloy, brinell hardness test is one of the largest dimple all Hardness Testing method, it can reflect the comprehensive performance of materials, from the sample organization microsegregation and composition is not uniform, so it is a kind of hardness test method with higher accuracy.
Pay attention to the prevention of leek disease in the rainy season
Amaranth disease is an important disease in the current production of amaranth. The disease has occurred all over the country, especially in the rainy season, which can directly reduce production by 30% to 40%. In addition, the disease can also harm vegetables such as onions, onions, and garlic.
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