5 December 1997

Know your nematode

POTATO growers need to be more aware of the nematode threats to production on their own land, according to Pat Haycock of Harper Adams.

Although most growers test their soils for potato cyst nematode (PCN), too few know which species is prevalent, claims Dr Haycock. "Species testing is almost as important as knowing how many nematodes you have."

Such knowledge is vital whether growers are using varietal resistance or rotation as a control method, he says. "Plants have different resistance levels to each species, and G pallida can decline more slowly in non-potato ground than G rostochiensis."

Only 48% of respondents to a recent DowElanco survey pinpointed pallida as the species likely to cause most problems.

"The general feeling among experts is that pallidas longer hatching period may lower the efficacy of traditional in-crop granular nematicides, meaning that significantly more growers could be affected by this species in future."