Herbicide injury prevention: see growth of the seedlings, grass conditions, weather, soil. Or thin seedlings to take root not easy administration: depending on the type of medication and growth of weeds; application rates at lower temperatures in the upper limit of medication; high dosage of heavy clay soil more, Lactofen, sandy soil treatment some less; the soil is dry without medication. Herbicides prevent: first herbicide injury and environmental conditions are closely related. Typically, soil texture, Zhejiang Lactofen, organic matter content is relatively constant, and humidity, light, precipitation, soil moisture is changed greatly from year to year, so the impact of environmental factors on the injury more complicated. Most herbicides conditions at higher temperatures better efficacy, crop is safe.