Each 250g (8.8oz) pack of NOGALL product contains a pure culture of a minimum of 250 billion viable cells of the non-pathogenic soil bacterium Rhizobium rhizogenes (formerly Agrobacterium radiobacter), strain K1026, contained in a pre-sterilised, microfine peat medium. Strain K1026 cells can colonise wounded plant tissue and block infections by the predominant crown gall-causing pathogenic agrobacteria that infect nut trees (almonds, walnuts, etc), stone fruit trees (peach, plum, apricot, cherry, etc), roses, euonymus, several caneberries and many other horticultural crops.