The causes and prevention methods of sugar beet brown spot disease: Beet brown spot symptoms Beet brown spot disease mainly occurs on the leaves and petioles, and the pedicels and bulbs of the remaining plants can also be infected. The lesions on the leaves initially have small brown spots, which gradually enlarge to 3-4 mm, with brown or reddish brown edges, grayish white mold layers in the center, and finally the central dry and shed perforations. When the environment is suitable, the number of lesions per leaf is as high as 400-1000, and it is connected into pieces, which eventually causes the leaves to die. The lesion on the middle handle is fusiform. The leaves of the whole plant of the diseased beet have different physiological maturity and the damage is different. The outer leaves first develop, causing the drooping to die, the middle leaves are covered with lesions, and the young leaves of the heart layer are still healthy. The occurrence of sugar beet brown spot Seed-borne bacteria cause the incidence of cotyledons or cotyledons. The diseased tissue remains as the primary source of infection, causing the onset of true leaves. Pathogen spores are spread by airflow, irrigation water, insects, and wind and rain. But more important is the spread of raindrops from the ground to the leaves. The daytime temperature is 27-32 °C, and the nighttime temperature is above 16 °C, which is conducive to spore growth and infection. Conidia sprouting with a relative humidity of 90% or more is best. Beet brown spot prevention and control method (1) Plant disease-resistant varieties and carry out seed cleaning. It is planted with Jizhi series and sweet research series. Before planting, it can be used for seed dressing with phenanthrene powder (“201â€) equivalent to 0.3%~0.5% of seed weight. (2) contiguous planting, regional rotation. Beet brown spot disease mainly lives on the diseased leaves or soil in the mycelium group. Therefore, the disease is serious and the disease is serious. The rotation of the sugar beet is carried out for more than 4 years. When the crop is rotated, the sugar beet must be separated from the beet land of the previous year by 500 meters. Last year, the beet land was on the limelight to prevent spores from spreading by wind and rain. (3) Strengthening cultivation management, clearing the residual diseased leaves in the field and the weed species that can infect brown spot disease, such as sorrel, leeks, plantain, dandelion, etc., reducing the source of re-dyeing, and deepening the loose soil, which can reduce the second The degree of annual damage. (4) Strengthen disease prediction and forecast, and apply drugs in time. To control beet brown spot disease, when the first batch of brown spots appeared on the beet leaves in late July, use a fungicide 25% prochloraz aqueous emulsion 80 ml, add 25 liters of water to spray once, spray again every 10 days, a total of 2 sprays -3 times. If the rain occurs within 6 hours after spraying, it should be sprayed as appropriate. If the above-ground pests such as cabbage moths occur, they can be mixed with pesticides. Avoid long-term use of a single agent to produce drug resistance, should be used interchangeably with a variety of agents, such as chlorothalonil, carbendazim, triphenylacetate and other effects. Regulating Flow Sphere For Ball Valve Regulating Flow Sphere For Ball Valve,Three Way Ball,Three Way Sphere,Control Ball Valve Antong Valve Co.,Ltd , https://www.atvalveball.com