Table 1 Average number of new lateral roots per treated root of bareroot trees (250-300 cm tall).
SpeciesDigging seasonTreatment
ControlIBA (3000 ppm)
Red oakfall3.912.8**
Sugar maplefall15.413.0**
spring12.7*15.9   
Green ashfall8.87.9 
spring 3.1*3.2*
European birchspring6.25.6  
Littleleaf lindenspring7.510.7   
  • 1 Fall dug trees were held in cold storage until spring. Mean separation by t-test; * .05 level, ** .01 level.