Chinese cabbage root disease is a soil-borne disease, which is common in all planting areas of our city and is seriously harmful. In addition to Chinese cabbage, it also infects cruciferous vegetables such as cabbage, cabbage, radish and rape. The suitable environment for the disease is that the soil is acidic and the soil has a large water content. Based on years of work experience, several suggestions for the prevention and treatment of this disease are made:
First, the implementation of rotation: diseased fields and non-crown vegetables for 4-5 years or more rotation.
Second, increase the application of lime: 60-80 kg per mu (or grass ash) to increase the soil pH.
Third, sorghum drainage.
Fourth, the chemical control: carbendazim and other pesticide soil disinfection, 4 kg per mu.
Spade bits are used for rough boring in wood. They tend to cause splintering when they emerge from the workpiece. Woodworkers avoid splintering by finishing the hole from the opposite side of the work. Spade bits are flat, with a centering point and two cutters. The cutters are often equipped with spurs in an attempt to ensure a cleaner hole. With their small shank diameters relative to their boring diameters, spade bit shanks often have flats forged or ground into them to prevent slipping in drill chucks.
Some bits are equipped with long shanks and have a small hole drilled through the flat part, allowing them to be used much like a bell-hanger bit. Intended for high speed use, they are used with electric hand drills. Spade bits are also sometimes referred to as "paddle bits".
Spade drill bits are ordinarily available in diameters from 6 to 36 mm, or ¼ to 1½ inches.
Wood Spade Drill Bit,Fat Drill Bit,Paddle Drill Bit,Wood Drill Bit
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