At the IR-4 Ornamental Horticulture Program Workshop in 2011, Botrytis Efficacy was selected as a high priority project to expand the knowledge and list of fungicides available to growers for these diseases. In addition to research collected through the IR-4 Program, this summary includes a review of experiments conducted from 1998 to 2015 on ornamental horticulture crops. During this time period, numerous products representing 42 active ingredients were tested as foliar applications against several Botrytis species causing blight and gray mold on ornamentals. Most products are registered and commercially used. Almost all trials were conducted on Botrytis cinerea; other species tested were B. elliptica, B. paeoniae and B. tulipae. Although there were insufficient IR-4 data for definitive conclusions, four relatively new products that are included in this research project project, Orkestra Intrinsic, Mural, NUP 09092, and S2200 looked effective, while Proud 3 and SP2770 looked ineffective. Data on other relatively new products (F9110, MBI-110, Regalia, SP2773, Torque, Tourney, Trinity, ZeroTol) were limited to provide some conclusions. Of the registered products, Daconil, Decree, Heritage, Insignia, Pageant and Palladium generally provided excellent efficacy; Chipco 26019 and Veranda O provided good efficacy and Disarm provided mediocre efficacy. ZeroTol, and the copper products (Badge X2, Camelot, Phyton 27, STBX-304) generally performed poorly.
