Controlling tomato blight with cockroach

Use 40% pentachloronitrobenzene 9-10g per square meter, add 4.0~4.5kg of fine soil and mix well. Pour the bottom water once before sowing. After the water seeps, take 1/3 of the soil on the surface. Seed the seed that is germinated, and then cover the remaining 2/3 of the soil---