Latest results from NIAB’s Labtest service suggest that while Potato Leaf Roll Virus (PLRV) is largely absent this year, a quarter of farm-saved seed potatoes destined for the 2009 crop have been infected at some level with Potato Virus Y (PVY), one of the most serious potato viruses affecting crop yields and tuber quality.
To date, one in ten tuber samples analysed by NIAB have shown PVY infection levels of 20%, high enough to cause serious damage in some varieties. PVA and PVS have also been present, although not at the same levels as PVY.
Although overall virus levels are lower than in some years, NIAB is advising potato growers to get farm-saved seed virus-tested to avoid costly disease problems. As time to planting gets shorter, January is a critical month to get virus tests started on further samples.
ELISA tests take between 4 to 6 weeks to complete, although NIAB also offers the faster PCR-based method, which can report on the PLRV and PVY status of a sample within 5 working days. Tests are conducted on 100 tuber samples.
When conditions allow, NIAB is also advising growers to take soil samples for free-living nematode tests as soon as possible. Analysis of soil samples to date have revealed high populations of Pratylenchus, which can cause damage by direct feeding on root crops such as potatoes and carrots, leading to reduced growth, yellowing and smaller tubers, and lesions on both roots and tubers.
For further information about NIAB’s testing services, please contact Helen Appleyard on 01223 342248 or helen.appleyard [at] niab.com ()