Prediction of Sclerotinia stem rot on oilseed rape in Switzerland

• Published in: Revue suisse d'agriculture Vol. 35; no. 5
• Main Authors: Gindrat, D, Frei, P, Vullioud, P, Pellet, D. (Station federale de recherches en production vegetale de Changins (RAC), Nyon (Switzerland))
• Format: Journal Article
• Language: French
• Published: 01.08.2003
• Subjects: BRASSICA NAPUS; CONDICIONES ATMOSFÉRICAS; CONDITIONS MÉTÉOROLOGIQUES; CROP YIELD; DISEASE RESISTANCE; DISEASE SURVEYS; ENCUESTAS SANITARIAS; ENQUÊTE PATHOLOGIQUE; EXPERIMENTACIÓN EN CAMPO; EXPÉRIMENTATION AU CHAMP; FIELD EXPERIMENTATION; FORECASTING; METEOROLOGICAL FACTORS; RENDEMENT DES CULTURES; RENDIMIENTO DE CULTIVOS; RESISTENCIA A LA ENFERMEDAD; RÉSISTANCE AUX MALADIES; SCLEROTINIA SCLEROTIORUM; SUISSE; SUIZA; SWITZERLAND; TECHNIQUE DE PRÉVISION; TÉCNICAS DE PREDICCIÓN; VARIEDADES; VARIETIES; VARIÉTÉ
• ISSN: 0375-1325

Surveys of sclerotia deposits and isolations from oilseed rape petals showed that apothecia of Sclerotinia sclerotiorum were formed and petals contaminated every year in various regions of Switzerland from 1991 to 2002. However, severe stem rot was observed only in years where air temperature averaged or was beyond 12 °C between early and full blooming (growth stages BBCH 61 to 65). This temperature threshold accounts for the poor relation between the contamination of petals and the severity of the disease. In the field, all oilseed rape cultivars cultivated in Switzerland were susceptible to Sclerotinia stem rot to some extent, except cv. Capitol. A relation was obtained between disease severity and yield. A simple method for predicting at growth stage 65 a risk of severe stem rot is proposed. The role of moisture (rainfall, dew) should be defined more precisely in order to refine the prediction method.