Dinoseb (2-sec-butyl-4,6-dinitrophenol) and certain dinitroaniline herbicides suppressed root rot caused by Aphanomyces euteiches Drechs. and other fungal pathogens in peas (Pisum sativum L.). Dinoseb was the most effective. At 6.72 kg/ha pre-plant incorporated (PPI) it reduced the disease severity index (DSI) in glasshouse bioassays to the level considered safe for general use by commercial growers. In fields tests disease severity was reduced and yield of peas was increased with dinoseb. Dinitroaniline herbicides reduced DSI values to the level considered safe for early crop peas. A simplified DSI method of measuring root rot based on mid-season root symptoms was found to be effective. Weed control was superior with the dinitroanilines and propachlor (2-chloro-N-isoproylacetanilide). Dinoseb significantly reduced weed populations relative to untreated plots. Several dinitroaniline treatments caused stunting and stand reduction.