Dose curves of disinfestants applied to plant production surfaces to control Botrytis cinerea.
W. E. Copes, USDA/ARS Small Fruit Experiment Station, Poplarville, MS 39470. Plant Dis. D-2004-0223-01R, 2004 (online). Accepted for publication 22 December 2003.

Percent spore mortality of the gray mold fungus (Botrytis cinerea) was compared in response to multiple concentrations of six disinfestants on various materials (pine lumber [natural, pressure-treated, exterior latex-painted], polyethylene [ground fabric, pot plastic], and metal [galvanized, stainless steel]). The spore mortality responses were used to calculate predictive lethal dose ranges. The predictive lethal doses of three commercially available disinfestants (hydrogen dioxide, quaternary ammonium chloride, sodium hypochlorite) were additionally compared with concentrations that resulted in zero growth of B. cinerea for the same substrates. Results show that the material being disinfested affects the concentration of a disinfestant needed to rid the surface of B. cinerea spores. In general, higher rates were required on natural and pressure-treated pine lumber, and lower rates were required on latex-painted pine lumber and stainless steel. The rates presented are to disinfest only clean surfaces of the specific fungus tested. This research increases our knowledge about the selectivity of disinfestant rates.

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