Conception and method of a future-oriented, targeted control of foliar and head diseases of cereals
1988
Hoffmann, G.M. (Technische Univ. Muenchen (Germany, F.R.). Lehrstuhl fuer Phytopathologie) | Verreet, J.A. | Kremer, F.W.
The practice of chemical plant protection in the form of "integrated pest management" is contingent upon the availability of active ingredients suitable for purposive application and requires the use of scientifically founded decision aids making it possible to justify the need for the control measure on biological criteria. As practised at present, growth stage based routine measures too rarely intervene specifically in the actual infection process of the pathogens on cereals. A crucial factor in ensuring the targeted use of fungicides is a reliable diagnosis, especially of foliar pathogens which induce symptoms appearing as unspecific necroses whose fungal structures are not visually recognizable (parasites: Septoria sp., Drechslera sp., saprophytes: Ascochyta sp., Didymella sp.). To ensure a reliable diagnosis of fungal structures, thereby allowing the development of the pathogen in different leaf levels to be quantified and decisions concerning control measures and the assessment of their results to be optimised, a diagnostic instrument has been developed which is both easy to use and meets practical requirements. The "Bayer Cereal Diagnosis System" according to Verrett/Hoffmann consists of two transparent sheets of plastic connected with hinges and provided with guide strips for monocular lens systems (30- to 100-fold), between which selected leaf material (lesions) can be placed on graduated scales and can be diagnosed after wetting with water, utilizing natural or artificial light sources (field, laboratory) and allowing work to be performed at a constant level
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