Figure 4

Schematic representation of the important steps for spot-inoculation. A. Imbibed seeds placed in vermiculite. B. Seedling radicle placed in trough of trimmed pouch. C. Pea cotyledons and epicotyls protruding from tightly-closed pouches. D. Pots, with pouches inside, filled with vermiculite to prevent light exposure. E. Inoculation 5 days later with R. leguminosarum bv. vicieae placed as a minute drop (seen as a black dot drawn with a marker on plastic) at the most susceptible zone of infection of several lateral roots. F. Pouches later returned to pots. G. Healthy plants allowed to grow until inspection.