摘要：Root damage to seedlings is inherent in a bareroot lifting operation. Full-bed lifters lift all seedling drills across a nursery bed at one time, whereas two-row lifters selectively lift any two seedling drills across a nursery bed but require multiple passes to lift all the seedlings. To determine the extent of root damage among lifting methods, we compared roots of seedlings lifted with a two-row or a full-bed lifter, each operated at the normal calibrated speed and a faster noncalibrated speed, to hand-lifted seedlings at three nurseries in the Southern United States. When root growth potential (RGP) and root morphology were used to evaluate lifter speed for the full-bed lifter, two of the three nurseries had greater RGP or root morph- ology measurements at a faster tractor speed. The use of two-row seedling lifters, which travel four to six times faster than full-bed lifters, resulted in significantly more root injury than hand-lifted seedlings. No difference existed in root biomass or root weight ratio measurements with nursery treatments. If nursery staff use ocular comparisons of seedling roots to evalu- ate lifter efficiency, careful attention needs to be given to the presence of fine root tips, mycorrhizae, and damage to root cortex on lateral roots that could cause a reduction in RGP.
