Profitability of fungicides on winter wheat Gindrat, D; Frei, P; Pellet, D.,Agroscope RAC Changins, Station federale de recherches agronomiques, Nyon (Switzerland)
Revue suisse d'agriculture,
May-Jun 2004, Letnik:
36, Številka:
3
Journal Article
Data from field experiments with winter wheat cv. Arina in four areas of Western Switzerland from 1987 to 2002 have been examinated. In individual trials, a close relation was found between the total ...intensity of foot, leaf and ear diseases at growth stages 69-75 and yield. In the whole of all trials, the probability of a significant yield increase after a fungicide spray in the presence or in the absence of a disease threshold was about the same. However, following a disease threshold ' except for eyespot ' increased probability of a gain in yield in the Plaine de l'Orbe area (peat soils) and in an altitude area (Gros-de-Vaud, Jorat). In Changins and Chablais vaudois the interest of fungicides on winter wheat (cv. Arina) was questionable. The probability of financial gain after a fungicide spray depended on a yield increase of 1.2 to 2.1 dt/ha according to the cost of the product (at 2003 prices).
Fungi were isolated from lesions on the stem base of winter wheat between BBCH 30 and 79 during several years in four regions of Western Switzerland. Pseudocercosporella herpotrichoides (eyespot) was ...scarcely isolated before BBCH 32. The uselessness of an early visual diagnose to predict eyespot was confirmed. P. herpotrichoides occurred mainly in an altitude region and in Changins and was almost absent in peat soils and in areas exposed to cold air lakes. P. herpotrichoides was less frequently isolated these last years than during the 1989-1995 period. Rhizoctonia cerealis was common at all wheat growth stages from 1989 on, but its occurrence also decreased later. Other dominant fungi in 1996-2002 were: Microdochium (= Fusarium) nivale, Stagonospora (= Septoria) nodorum, Bipolaris sorokiniana and Fusarium spp. (mostly F. graminearum and F. culmorum).
