Research Summary Abstract
From 2003 to 2020, numerous products representing 35 active ingredients were evaluated in greenhouse experiments as soil drenches against Thielaviopsis basicola causing black root rot on environmental horticulture crops. Although there were insufficient data for definitive conclusions, two experimentals (Aveylo – mefentrifluconazole) and A20808C showed promising efficacy comparable to the standards. Several products that are not yet labeled for Thielaviopsis basicola also showed promising efficacy in single trials. These include Empress Intrinsic (pyraclostrobin), Endorse/Veranda O (polyoxin D), Mural (azoxystrobin + benzovindiflupyr), Stargus (Bacillus amyloliquefaciens strain F727). Tourney (metconazole) and Vital (potassium phosphite). A newly registered fungicide Picatina Flora (pydiflumetofen + fludioxonil) provided excellent efficacy in a single experiment; however, it is not yet available commercially. The established standards 3336 and Terraguard generally provided excellent efficacy.