This research was conducted to evaluate (1) rice tolerance to saflufenacil applied preemergence (PRE) and postemergence (POST) and (2) the combination of saflufenacil and clomazone in light-textured soils. No injury from PRE application of saflufenacil was observed in 2009, and minimal injury for saflufenacil alone was observed in 2010. Injury as high as 68% was observed with combinations of 505？g？ha？1 of clomazone applied PRE and 50？g？ha？1 of saflufenacil applied POST in 2009 early evaluations. No interaction between clomazone and POST saflufenacil rates was observed in 2010. Rice injury intensified with increasing rates of saflufenacil applied POST. However, rice recovered with time for herbicide treatments applied PRE and POST in both years. Consequently, rice yield was not affected by any of the saflufenacil rates applied either PRE or POST in a clomazone weed control program. 1. Introduction Rice is a staple food in numerous countries around the world. Rice consumption provides more calories than any other single food [1], serving daily as a source of carbohydrate, proteins, lipids, vitamins, and minerals [2, 3]. Rice yield is on an upward path to achieve higher worldwide production as indicated by data compiled in the last ten years by the Food and Agriculture Organization (FAO). Production increased from 599 million tons in 2000 to 685 million tons in 2009 [4]. However, current supply trends are considered insufficient to track projected demand as the world population continues to rise [5]. Crop management will be even more important in production areas in order to maintain and/or expand rice production. In the United States, 1.07 million hectares were harvested resulting in the production of 8.5 million tons of rice in the crop season of 2011 [6]. The southern states of Arkansas, California, Louisiana, Mississippi, Texas, and Missouri primarily contributed to this production. As weeds are one of the most important biological factors limiting rice production [7], weed management is crucial to maximize rice yield potential. Several annual grasses and broadleaf species are considered troublesome weeds in United States rice regions [8]. In Arkansas, the largest-producing state, barnyardgrass (Echinochloa crus-galli) was reported to be the most problematic grassy weed [9]. In the same survey, clomazone was described to be the most regularly recommended preemergence (PRE) herbicide. Clomazone is a relatively recent herbicide in rice, with commercialization occurring at the beginning of the century [10, 11]. This herbicide is metabolized to the 5-keto
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