Several fungal and bacterial diseases are prevalent
in radish seed production areas in the Pacific
Northwest, particularly those that are favored by
the wet conditions west of the Cascades
Mountains. Due to the commercial demand for
clean, pathogen-free seed, growers must pay
particular attention to management of seedborne
diseases. In organic production, the lack of
approved pesticides and fungicides necessitates
preventative management and non-chemical
control measures. Routinely eliminating any
exceptionally diseased plants in the field is
important, not only for reducing incidence of
infection, but for maintaining or improving the
overall horizontal (or non-race specific) resistance
to particular pathogens. Although it may take a
number of cycles of selection to significantly
increase the level of resistance in a variety, this
slow, methodical approach can lead to improved
resistance over time.