ABSTRACT
The establishment of a plant disease consists of: inoculation transfer of inoculum from its source to an infection court, incubation penetration and colonization of host tissue by the pathogen, and symptom inducement development of visible signs or symptoms of the disease. To determine resistance in a population of plants, inoculation method is used to assess qualititative and quantitative differences in susceptibility. Stem inoculation is used generally for screening for resistance to vascular wilt pathogens, but pathogens causing cankers, collar rot, damping-off, root rot, or stalk rot may be inoculated into stems. Injection avoids transplanting shock to plants inoculated by the root-dip method, and permits differentiation of high, moderate and low resistance as opposed to just high and low resistance by the root-dip method. Inoculating stems using a reservoir collar for the inoculum is useful for testing resistance of woody plants to wilt and foot-rot pathogens. Resistance of some crops to certain pathogens can be tested by seed inoculation.
