Title: Chemical control of nematodes: efficiency and side-effects
Headings: Chemical control of nematodes: efficiency and side-effects
Chemical control of nematodes: efficiency and side-effects
S.R. Gowen
Introduction
Chemical control of nematodes
The demand
Efficacy
TABLE 1
Nematicides currently available on world markets
TABLE 2
Examples of recommended nematicidal dosages and treatments for some important crops1
Side-effects
Future developments
References

Content: Persistence of soil-applied nematicides depends on the soil characteristics. In warm countries, relatively high soil temperatures may accelerate the natural degradation of nematicides, and in protected crops where even higher soil temperatures than out-of-doors may occur, the effective life of a nematicide might be as short as one to three weeks (Bromilow, 1980). The repeated use of products of similar structure can lead to the selection of a soil microflora that metabolizes these compounds and decreases their persistence. Side-effects
All nematicides are eventually degraded if they remain in the topsoil where there is greatest microbial activity. Once nematicides or their degradation products are flushed through the upper soil layers their persistence may be extended. It is the problem of toxic products in groundwater that has led to the prohibition of fumigant and non-fumigant nematicides in some countries. The permitted level of pesticide residues in