Asexual Reproduction
V. inaequalis reproduces asexually by spores called conidia. Conidia are single-celled, uninucleate, and narrower at one end than the other (Figure 11). In mass, conidia appear brown or olive, but they are lighter when viewed individually under a microscope.  Conidia measure between 6 and 12 µm wide and 12 and 22 µm long and are produced by specialized short hyphae called conidiophores. Conidiophores are formed on a dense mat of mycelia that pushes up through and ruptures the leaf cuticle (Figure 12). It is this mass of conidia and conidiophores that causes the velvety appearance of young scab lesions.

Conidia are produced nine to thirty days after initial leaf infection, depending upon temperature. They are disseminated by wind and by wind-driven rain. Both ascospores and conidia require a period of wetness in order to germinate. The germination hypha penetrates the cuticle and establishes a new infection. There can be many cycles of conidial production and infection within a single growing season