Overview of Current Apple Rootstock Technologies from the Geneva® Breeding Program
Since its inception in 1968-69 the apple rootstock breeding program conducted in Geneva, New York, USA has had a focus on disease resistance as part of its regimen of selection and evaluation procedures. In addition to disease resistance, the program aimed to develop yield efficient dwarfing rootstocks. The program accomplished several of the original objectives by releasing a series of apple rootstocks that possess resistance to fire blight and root rots that are also tolerant to replant disease and that have similar or better yield efficiency than M.9 clones.
This accomplishment was aided by the incremental testing that was performed in coordinated trials like the NC-140 system or more recently in EUFRIN which has generated many decades of multi-site performance data. In the process of these tests we have discovered additional properties that may be influenced by the choice of apple rootstock such as nutrition and hormonal profiles, insect resistance, biennial bearing, chilling hour requirement, fruit size and maturity.
The main effect of these new technologies that are packaged in a diverse set of apple rootstocks is the provision of valuable and valid alternatives to the M.9 monoculture that has characterized the past 30 years. This diversity of rootstocks is setting the stage to improve precision orchard management and customize solutions for different types of scions, soils, climates and orchard systems that maximize the production of high quality fruit.