A bioperformance enhancing adjuvant of Formula (I) R1O[BO]n[AO]m R2 where BO is butylene oxide; and each AO is independently propylene oxide or ethylene oxide; n is from 1 to 12; m is from 0 to 20; R1 is optionally substituted C4-20 alkyl or optionally substituted C4-20 alkenyl; and R2 is hydrogen or optionally substituted C1-3alky.