First Report of Fusarium Head Blight on Winter Wheat in the Grand Duchy of Luxembourg

Following a comparatively mild winter (1.9°C above average [2000–2007]), Fusarium head blight (FHB) on winter wheat was observed during the 2007 season in 17 sites representing all three districts of Diekirch, Grevenmacher, and Luxembourg. The cultivars encountered were diverse and included Achat, Akteur, Aron, Bussard, Cubus, Enorm, Exclusiv, Flair, Rosario, Tommi, and Urban. The preceding crops were maize (six sites), rapeseed (three sites), and one site each of pea, triticale, winter barley, and winter wheat. Rainfalls recorded during the flowering period (June 1–23, mean June 12 for GS 65) ranged from 13 to 62 (mean 38) mm. An overall prevalence of FHB (percentage of infected spikes) of 8.9 ± 15.5% (mean ± SD) and a severity (percentage of infected grains per spike) of 21.0 ± 17.8% were recorded. A significant difference in FHB severity was observed between the cantons north and south of Luxembourg City, 13.4 ± 13.1% (range 0.01 to 46.4) and 35.1 ± 18.1% (range 6.2 to 61.9), respectively (Man-Whitney, P = 0.027), indicating the importance to take regional specificities such as topoclimatological aspects into account. Maize as a preceding crop resulted in significant higher prevalence of FHB as opposed to the other crops (5.9 ± 1.6% versus 3.3 ± 2.2%, Man-Whitney, P = 0.022).