Survival of Polymyxa betae during processing of vegetables and sugarbeet

Samples of effluent were taken at various stages in a range of waste-water treatment systems from seven sugarbeet factories and 14 vegetable processors and tested by a seedling-baiting method. None of the systems examined appeared completely to remove Polymyxa betae , the fungal vector of beet necrotic yellow vein furovirus, the cause of rhizomania disease of sugarbeet. In laboratory experiments, neither anaerobic conditions, raising the pH to 12 nor treating with peracetic acid had any discernible effect on P. betae viability. It is concluded that there is a risk that rhizomania disease could be spread by waste water from processing infected sugarbeet or vegetables from infested land, although there is some evidence that this risk is reduced where systems involving extensive settlement are used.