Nematode management starts with knowledge

Some species of nematodes, or roundworms, can become a serious problem, says Dr Driekie Fourie, technical product lead for Syngenta Seedcare in Africa and the Middle East. 

- Magda du Toit

Nematodes are far more prevalent and a more serious problem than many farmers think. This was the important message conveyed by Dr Driekie Fourie, technical product lead for Syngenta Seedcare in Africa and the Middle East during a panel discussion with Yolandi Furniss, marketing lead, Syngenta Seedcare South Africa, at the International Seed Federation’s World Seed Congress. The conference was hosted by the South African National Seed Organisation and held recently in Cape Town.

Nematodes are commonly referred to as roundworms. Microscopically small and mostly transparent, they can usually not be observed with the naked eye: a microscope is needed to identify many of the nematode species.

VARIOUS GROUPS

The biggest plant-parasitic nematode is about 11mm long but very thin, only a few micrometres in diameter, and it can be seen as a little thread in a petri dish when extracted in water, Fourie pointed out.

There are different groups of nematodes. Some, the plant-parasitic nematodes, are seen as pest organisms while others are as seen as beneficial as they play an important role in nutrient recycling in soils, and feed on other organisms.

Mature adult females in some species, such as the root-knot nematode, change to a swollen, pearlike shape, whereas the females of other species such as lesion nematodes remain slender worms.

According to Fourie, three of the most important nematode species that have a major impact on agriculture in South Africa and that farmers should be aware of, include rootknot nematodes (