Improved methods for detecting and estimating the number of cystsori of Polymyxa betae from infested soil, and for separating the cystsori from infected rootlets of sugar beet [Beta vulgaris]

analyse microbiologique beta vulgaris esporas infestation letargo microbiological analysis polymyxa racine repos rest roots soil sol spore spores suelo vecteur de maladie vectores vectors virose viroses virosis