Lessons Learned From Rootstock Field Trials

Tacy CalliesResearch, Rootstocks

Rootstocks can affect tree height, as seen by these 24-year-old Valencia trees. In front, the small tree is on Flying Dragon trifoliate orange, the left rear tree is on Volkamer lemon, and the right rear tree is on Carrizo citrange.

By Bill Castle

“The notion that field trial data are of little value in the early years and trials must run for 15 years is outdated.”  [Lesson 7]

“Our new website provides the grower community with user-friendly access to our collective decades of rootstock trial data…” [Lesson 9]

Those are two of many lessons shared in a recent article authored by the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Research and Education Center Plant Improvement Team. Fred Gmitter, Jude Grosser and I have long been engaged in field research to evaluate new scions and rootstocks.

Research efforts continue and have involved trials on public and private property. While public sites are valuable, they are limited in number. Thus, most of our trials are conducted cooperatively with citrus growers. When public and private sites are viewed together, it is clear that a broad range of circumstances are encountered that call for flexibility in designing and managing those trials.

Our opinions and experiences cover various topics in the rootstock evaluation process from planning to trial design, nursery and field operations, data collection and handling to how and when it is decided to release a candidate rootstock. See the full story on nine lessons we have learned from our field work with rootstocks.

Bill Castle is a UF/IFAS emeritus professor in Lake Alfred, Florida.