Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 22, 2003
Publication Date: May 1, 2004
Citation: Copes, W.E. 2004. Dose curves of disinfestants applied to plant production surfaces for control of Botrytis cinerea. Plant Disease. 88:509-515 Interpretive Summary: The study compares percent spore germination of the gray mold fungus (Botryis cinerea) in response to increasing doses of commercially-available disinfectants and how that response varies depending on the material [polyethylene (ground fabric, solid disc), metal (galvanized, stainless steel), and pine (natural, pressure-treated, latex-painted)] being treated. This research provides detailed response information. Rates of all six disinfestants were affected by the substrate being treated, with rate differences that ranged from a half to up to 17 times the recommended rates. This knowledge will improve our understanding of how to effectively achieve sanitation and provide data for commercial companies to evaluate label statements about rates. This research will be beneficial to other scientists, extension agents, ornamental plant producers, and any plant commodity group that uses disinfectants.
Technical Abstract: Rates of the disinfectants, chloramine-T, hydrogen dioxide, hydrogen peroxide, iodine, quaternary ammonium (dimethyl benzyl and dimethyl ethylbenzyl ammonium chlorides), and sodium hypochlorite, were sprayed on 2.25 to 4 cm2 pieces of polyethylene (ground fabric, solid disc), metal (galvanized, stainless steel), and pine (natural, pressure-treated, latex-painted) that had been inoculated 18 hrs earlier with a suspension of Botrytis cinerea conidia. Several hours after the disinfestants had dried, substrates were inverted and rubbed across 50% potato dextrose agar to dislodge conidia. The next day percent germination was counted for greater than 100 conidia. Lethal dose of the disinfestant resulting in 50 percent mortality (LD50) and slope of the dose curve were calculated by Probit analysis. Substrate affected disinfestant activity (LD50's). In general, LD50's were highest on natural and pressure-treated pine and lowest on latex-painted pine and stainless steel. Results show that the material being disinfested affects the rate of a disinfestant.