crec.ifas.ufl.edu/extension/citr...trus_rootstock/
The 4th edition has updated literature review articles, 3 new rootstocks(US Super Sours 1, 2 and 3), updated info about the UFR Series in the Rootstock Data Table, additional authors and contributors, and a new section with the History of the FLCRSG.
The revised FLCRSG is also available as an Interactive Web version called Expert System. This system emulates a human expert by systematically sorting information you provide, then determining the best possible recommendation for the given rootstock. The FLCRSG system will use the traits about the rootstocks, and utilize data that can provide facts that you tell it to deduce the best recommendations for your circumstance. The Expert System will ask you a series of questions about your location, horticultural needs and pest management requirements. It will compare across all the rootstocks for those that rate highest on the most traits, then provide you a list of its top five recommendations.