24 July 2002

Nematode light test

MONITORING light levels reflected from the canopy of potato crops could help signal the severity of potato cyst nematode infestation, but a commercially viable test is still some way off.

Researchers at the Nematology and Entomology Research Group at HAUC have recorded light levels reflected from both healthy and diseased crops using ground level, aeroplane and satellite-mounted spectrometers to assess PCN damage, says PCN specialist Pat Haydock.

Analysis of light readings taken last year by researcher Bill Heath will help differentiate between PCN and other pathogen damage. The aim is to compile an index that could be used as a commercially viable test in future.

Other methods of PCN control are being trialled. Trap cropping is looking the most viable solution, says Dr Haydock.

"This method is particularly suitable for heavily infested sites with up to 500 PCN eggs per gram of soil. But the key is when to destroy trap crops? Reducing population densities at 42 days or 500 day degrees over 4C can have an impact." &#42