Abstract
Abstract Pressure-induced flow (PIF) and transpiration-induced flow (TIF) methods were used to obtain estimates of root hydraulic resistance (R root ), stem hydraulic resistance (R stem ), and total hydraulic resistance (R total = R root + R stem ) of ‘Lovell’, ‘Nemaguard’‚and ‘Siberian C’ peach [ Prunus persica (L.) Batsch] rootstocks. Estimates of R total did not differ significantly between the PIF and TIF methods, and R root differed between methods for ‘Siberian C only. However, R stem was about three times lower and velocity of flow was greater in the PIF than in the TIF method for all three rootstocks. Lower R stem in the PIF than the TIF method was not due to water moving in non-xylem pathways (i.e., pith, cortex) of stems in PIF determinations. R root and R total were highly correlated in all cases, except TIF determinations with ‘Nemaguard’. R root accounted for 64% to 73% of R total in TIF determinations, but significantly more (90% to 91%) of R total in PIF determinations.