First, the identification of viral diseases. Due to the different types of rapeseed, the symptoms vary greatly. Cabbage-type, mustard-type rapeseed: The typical symptom is "flower mosaic." When the seedlings develop, they start from the veins and stems of the heart, and turn green along the sides of the veins to show the translucent "Mingmai", and some become net-like. At the end of the veins, the green retreat expands and the leaves appear. The onset of convulsions, stem shortening, twisting, flowers and pods intensive, mild disease often mature in advance, the sick can be dead with the whole plant. Brassica napus: A systemic type of spot appeared on the virus-infected strains. The old leaves had an early onset and symptoms were evident and spread to new leaves. At the time of initial onset, the leaves developed transparent patches of needle-point size, which later expanded into a circular macula of 2-4 mm in diameter. The center was dark brown withered and dead spots, the necrotic spot was in the form of a greasy stain, and purple-black shuttle-shaped to strip-shaped disease appeared on the dish. Spots spread from the lower part to the branches and fruit stems, with multiple longitudinal or horizontal cracks on the stem, and flowers and pods tend to shrink or die. Black dead spots appear on the pods and are often malformed.
Second, prevention and control methods. 1. Use resistant varieties. Cabbage-type rape is precocious, susceptible to viral disease, and low yield, while B. napus is significantly more resistant than B. campestris and has high yield. 2. Appropriate early sowing. Early rapeseed rape is more severe than virus rape, especially cabbage rapeseed. Therefore, the appropriate sowing date should be determined based on the local climate, the characteristics of rapeseed varieties, and the occurrence of aphids. Generally, rapeseed will be sown in mid-late September. 3. Strengthen seedling management. Rape seedbeds should be kept away from cruciferous vegetable fields, fertile soil, and convenient drainage and irrigation. If the weather is dry and the soil is dry, timely irrigation can reduce the virus disease. 4. Cure annihilation. Using the characteristics of silver-gray and white wings, the silver-gray plastic film can be used to avoid maggots, and locusts tend to have yellow color. Six to eight pieces of yellow traps can be inserted into each rapeseed field to kill the locusts. In the 3-6 leaf stage of rapeseed, 40% dimethoate, 50% malathion, 50% chlorbenazide, kung fu and other pesticides were used to control aphids. In the early stage of virus disease, 0.5% anti-virus mushroom protein hydrolysate is used 300 times, or 10% virus king WP 500 times, 1.5% plant disease emulsion 1000 times, 83 resistance agent 100 times. Sprays such as pharmaceuticals, spray once every 10 days, even spray 2-3 times.
Welding manipulator also called as Welding column boom, which always combine with Welding Rotator and Welding Positioner to become the dedicated automatic welding device for welding structure parts` internal and external circular seam, fillet weld, inside and outside longitudinal seam and has different structure forms such as fixed type, rotary type, versatile position type, etc.And according to user`s requirements, we also can choose structure or equipped with different kinds of welding machines and adding tracking, swing, monitoring, solder recycling& conveying functions. The welding manipulator is widely used for many kinds of industries such as pressure vessel, cooling device, power plant construction, metallurgical construction, engineering machinery, shipbuilding, roll surfacing welding, petrochemical construction, etc.
Welding Manipulator,Tank Welding Manipulator,Automatic Robot Welding Manipulator,Boom Welding Manipulator
Zhengzhou Yueda Technology Equipment Co., Ltd. , https://www.yuedawelding.com