Oxathiapiprolin is a new fungicide active ingredient (a.i.) that provides excellent control of important Oomycete diseases including black shank (Phytophthora nicotianae) on tobacco. The mode of action is novel and mediated via interaction with an oxysterol binding protein with an essential, but as yet uncharacterized, function. Oxathiapiprolin has been assigned FRAC Code U15. With high potency and a single site mode of action, there is the potential for development of resistance to the fungicide. In order to mitigate this possibility, label directions will incorporate strict stewardship guidelines that include a limitation on the number of applications containing oxathiapiprolin to one third of the total sprays in a program. Field trials over the last three years have focused on evaluation of different rates of oxathiapiprolin (35-140 gai/ha) applied solo or in mixture with Ridomil Gold^® SL (RGSL), in transplant water or at first cultivation or at layby. In programs with two or three applications overall, the remaining sprays were RGSL solo. Programs that included oxathiapiprolin provided black shank control as good or better than competitor treatments (RGSL; Presidio^®) and with good crop selectivity. Federal registration of oxathiapiprolin is anticipated during the third quarter of 2015, with full launch early in 2016. A family of products based on oxathiapiprolin and under the tradename ORONDIS™ will be available to growers. Tobacco is included in the first wave of crops. In addition to black shank, oxathiapiprolin will also be labeled on tobacco blue mold (Peronospora tabacina). (Reprinted with permission)