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: Chemical control of nematodes: efficiency and side-effects
Chemical control of nematodes: efficiency and side-effects
S.R. Gowen
Introduction
Chemical control of nematodes
References
Introduction
Plant-parasitic nematodes are at their most vulnerable during their active phase in soil when searching for the roots of host plants. Once endoparasitic species have penetrated a root, control with chemicals is more difficult as nematicidal compounds have to be non-phytotoxic and preferably systemic. A nematicide that can be safely applied to growing plants and is translocated to the roots in sufficiently large amounts to kill endoparasitic or ectoparasitic nematodes has not been discovered. Oxamyl, a systemic compound that is translocated basipetally, is the only commercial product that is used as a foliar treatment, but its use as a liquid formulation is restricted in many countries for toxicological reasons. There are several nematicides that can be used effectively for nematode pests of annual crops (van Berkum and Hoestra,1979), but there appears to be little prospect for management of nematodes in many susceptible perennial crops without repeated application of nematicides (Tables 1 and 2). Only in certain cases will such treatments be justified economically. Since the discovery and wide-scale use of fumigant nematicides 50 to 60 years ago, a number of products and formulations (Table 1) have been developed for use against several nematode pests, and these are available in most regions of the world (Hague and Gowen, 1987). Only in comparatively recent times have the dangers associated with the manufacture and use of these products become apparent.