Worldwide, the crop damage caused by parasitic nematodes is a major problem with highly toxic chemicals commonly used to try and control these pests. Unfortunately the use of such chemicals increases pressure on the environment, the more so as even larger quantities are often needed in subsequent years. Fallowing the soil for a year may be effective, but depends on keeping the ground weed free during this period and re-infection can easily occur by soil blowing over from adjacent infected areas.
Fysicon Research, a company based in the Netherlands, carried out an analysis of existing data concerning non-chemical control methods and established that certain Tagetes varieties had a nematocidal effect.

Tagetes Polynema

Using this knowledge to guide an extensive breeding program, Fysicon Research was able to breed a new variety, Tagetes Polynema, which has the following desirable features.

a) In trials, the root system killed up to 97% of free-living nematodes in the soil (e.g. Pratylenchus penetrans)
b) The plants are tall enough (more than 2m height) to help prevent soil blowing in from adjacent areas.
c) Tagetes Polynema roots deeply enough to ensure that the nematocidal effect extends into the lower layers of the soil.
d) The plants develop quickly giving a fast covering of the soil.
e) The huge quantity of biomass created builds up the organic material in the soil.

Using Polynema will result in an increase in both the quality and quantity of the following crop through the suppression of diseases and the enhancement of the humus levels.

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