Matters needing attention of soil fumigation in greenhouse in six links

Greenhouse vegetables

Soil chemical fumigation is an effective method to control root-knot nematodes and soil-borne diseases. However, there are also individual vegetable farmers in the soil chemical fumigation due to improper methods, resulting in the greenhouse diseases and insect pests can not be effectively controlled. Therefore, we should pay attention to the following points when fumigating soil chemicals:

1. The fumigation time should be timely. Soil fumigation should be carried out immediately after the harvest of the previous crop. At this time, most of the root-knot nematodes gather on the soil surface, which is easier to kill. Otherwise, the effect of soil disinfection will be reduced after the diseases and insect pests migrate to the deep layer of the soil, resulting in some bacteria getting away with it and happening again in the coming year.

2. The medicament should be chosen properly. The main soil fumigants on the market are: methyl bromide, cotton, chloropicrin, 1,3-dichloropropene, thioyl fluoride, Weibai mu and so on. These agents all have certain control effects on fungi, bacteria and nematodes, but many of them are highly toxic and highly toxic products, which are not safe to human and livestock, so it is recommended to choose high-efficient, low-toxic and environmentally friendly compound liquid soil fumigant pesticides, such as Deler, Abassa and so on.

3. The environmental conditions should be suitable. Disinfection with soil fumigant, sterilization (insect) mechanism is mostly: the chemical agent is applied into the soil from the original liquid or solid into gas, and the gas spreads among the soil particles, killing pathogens and pests that can cause plant disease in the soil, so as to play the effect of disease prevention, so it is required that the permeability of ① soil should be good. Before soil fumigation, the plot to be treated will be turned over 20 cm to 30 cm. The soil moisture of ② is suitable. In general, the soil fumigation effect is best when the soil water content is 40%-70%. ③ soil temperature is reasonable. The ideal temperature can make the pest in a "living" state, so that the fumigant can play a better role. Usually the ideal soil temperature is 15 cm, 15 ℃, 20 cm.

4. Prevent re-infection after fumigation. Fumigants only eliminate the existing diseases and insect pests in the soil, there is no lasting period, and there is nothing they can do about the re-introduced diseases and insect pests. The land where nematodes and other diseases and insect pests are found soon after fumigation may not be smoked well, but caused by the re-infection of diseases and insect pests, such as seedlings with diseases and insect pests. Some are after smoking Rain Water rushed into the soil with diseases and insects, diseases and insects outside the shed with shoes, and so on, these should be paid attention to, as far as possible to cut off the nematode re-transmission channels.

5. do not turn the soil too deep after fumigation: if the soil is much deeper after fumigation than before, or even before fumigation, it will turn up diseases and insect pests such as deep nematodes that have not been smoked.

6. Add organic fertilizer after fumigation: soil disinfection fumigant will kill not only pests but also beneficial organisms, so the sterilized soil should apply more bio-organic fertilizer to supplement the number of beneficial organisms.