A diffuser adapted to dissipate air from seed conveyed in a stream of air at a planter to an opener arm and seed boot. The diffuser provides a housing that pivotally supports a counter-weighted valve piece and a resilient valve piece. Admitted seeds are resiliently deflected between the valve pieces. Repeated deflections between the dual valve pieces and simultaneous venting of the conveying air through an associated fulcrum screen and relief ports at the housing dissipate the conveying air. Spent seed momentarily collects on a surface inside the housing and gravitationally falls from the housing and through a lower lying seed boot at a relatively uniform, singulated rate without scatter and damage to the seed.