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: This has resulted in restrictions on use and sometimes withdrawal from the market. It seems that the age of the traditional fumigants and nematicides has passed, and the opportunity for managing nematodes with synthetic chemicals with broad biocidal activity is declining. The development of new classes of nematicides with novel activity, that are effective when used in soil or applied directly to crops and are environmentally benign and specific to target pests, is perhaps an idealistic hope. Such compounds will, by definition, require considerable research effort, and if they are specific only to certain nematodes are unlikely to be considered an economic proposition for the traditional agrochemical company. Chemical control of nematodes
The demand
The elimination of nematodes from some crops is essential for certain export requirements, particularly of high-value horticultural products. Chemical treatment with fumigants or nematicides may be the only technique available, and from the plant quarantine standpoint it is important that their use is retained. The use of chemicals in protected cropping may still be preferable to other techniques such as steam treatment for economic and practical reasons. The use of soil-less growing media in some north European countries has resulted in a decreased demand for chemical treatments. In southern Europe, the Mediterranean region and North Africa, many horticultural and salad crops are grown in soil under polythene and soil treatment with methyl bromide, dazomet or non-fumigant nematicides is widely practised. The cost of such treatments may be as much as US$500 per hectare per year and can only be justified if the crops are of high market value.