ADAS/BASF Sclerotinia free monitoring service starts for the 2011 season

ADAS and BASF’s web-based Sclerotinia monitoring service has gone live for the 2011 season, in what is predicted to be a potentially “high risk” year. The service, which is free to all, can be accessed from 18th March at www.totaloilseedcare.co.uk and will run for a twelve week period.

Jon Williams, Agronomy Manager for BASF, explains that Sclerotinia is a widespread, damaging disease which can substantially erode yields. "Sclerotinia has become a common disease of oilseed rape and, with closer rotations, its risk is increasing. There are some very severe attacks each year, and as yields of affected plants can be halved as a consequence of premature ripening, control is worthwhile. This is especially so this year when prices of rape are so high.”

"Rape crops are at highest risk when sclerotia germination is synchronised with early flowering. Extended flowering, high levels of sclerotia in the soil, plus spores travelling over 100 metres from adjacent crops all add up to high risk in most crops. With most farms growing rape one in three or four years, many oilseed rape crops will be coming back onto land that will have significant levels of viable sclerotia in the soil. You only need 2 sclerotia /m² to start an epidemic,” he says.

Published on the 18th March, the first of twelve ADAS/BASF Sclerotinia monitoring report shows no sclerotia germination recorded in depots so far. Sclerotia germinate when soil temperatures reach 10˚C, so soils are currently too cold for active germination as yet.
"Crops are at early stem extension stage, so are more advanced than last year. With flowering expected in the second half of April and the disease threat starting when the crop is at early flowering, growers and advisors will need to review the Sclerotinia monitoring reports every week from now on, points out Jon.

The service monitors the germination of the pathogen’s sclerotia at six sites in Cambridgeshire, Yorkshire, Herefordshire, Lincolnshire, Kent and Devon. Germination assessments are made each week for 12 weeks and results are updated every Friday, starting on the 18th March this year. Each site will also be further supported by petal tests at first flower, early flower and mid-flower, which will help establish disease pressure from air-borne spores.

"Because fungicides are mainly protectant, it is important to understand disease risk and when the disease is likely to come into the crop. By knowing this information you will be in a better position to time fungicide applications correctly, in advance of disease and before any significant petal fall, hence the need for disease monitoring. BASF advise growers to apply a well-timed early to mid-flower fungicide treatment of either Filan (boscalid) or Compass (thiophanate-methyl and iprodione), especially where crops have suffered in the last three years,” says Jon Williams.