Effects of Growing Location on Fruit Tree Root Suckers

Abstract

Root suckers are vegetative shoots that develop from root buds and are generally considered a negative trait of a rootstock. Root sucker production for a given rootstock often varies with site. Published data from three peach and five apple multi-location NC-140 rootstock trials were used to determine if some sites are more prone to root sucker development than other sites. For each trial, the number of root suckers per site were ranked in ascending order and the correlations of the ranks for pairwise combinations of trials were evaluated with Spearman’s rank correlation coefficient. Although the associations were usually not significant at the 5% level, certain sites consistently had higher rankings. Sites with high rankings for peach root suckers also tended to have high rankings for apple root suckers. Sites with consistently high rankings included Utah, Pennsylvania, Kentucky and South Carolina. British Columbia and Ontario had consistently low rankings. Sites with high rankings in some trials and low rankings in other trials included North Carolina, New York, and Maryland. Although root sucker production is ultimately controlled by genetics, these analyses suggest that factors related to the site, such as soil conditions, environmental factors or orchard practices also influence the development of root suckers.