The 3rd edition of the Florida Citrus Rootstock Selection Guide is now available. The updated guide features 20 characteristics of 45 rootstocks and highlights 21 recently released rootstocks, some of which show reduced citrus greening incidence in early field trials.
Of the 45 rootstocks, 12 are time-honored commercial ones, 12 are minor commercial ones that are less frequently used but may have been prominent once. The third group is the most recently released rootstocks for which there is limited commercial experience, but are increasingly being used in the Florida citrus industry.
The revised guide is important because rootstocks provide the root system of a citrus tree and influence many traits of the whole plant and when a Valencia orange or Marsh grapefruit is grafted to the rootstock seedling, such things as tree size, fruit quantity and quality are usually improved by the rootstock.
The ability of a citrus tree to resist pests and diseases is also determined by the rootstock.
“A revised guide was sorely needed to make sure growers had the best information to make rootstock choices,” said Bill Castle, a UF professor emeritus in horticultural sciences at the UF/IFAS Citrus Research and Education Center in Lake Alfred.
With the discovery and spread of huanglongbing (HLB), commonly called “citrus greening”, rootstocks initially were not part of the discussion in managing the disease. ”
“That’s changed, especially given that some evidence shows trees on various rootstocks may differ in their incidence or tolerance of the disease,” said Stephen Futch, a multi-county Extension agent, based at the Citrus REC.
“These new rootstocks offer improvements of many meaningful traits that appear essential to the future of our citrus industry – among them, tree-size control, high yield and juice quality, and possible HLB tolerance,” according to the guide’s authors.
The revised Florida Citrus Rootstock Selection Guide is available on the UF/IFAS Electronic Data Information Source (EDIS), and an interactive version will soon be available on the UF/IFAS Citrus Research and Education Center website.
The Citrus Rootstock Selection Guide was co-authored by Castle; Futch; Kim Bowman, a research geneticist at the Agricultural Research Service of the U.S. Department of Agriculture in Fort Pierce; Jude Grosser, a UF/IFAS professor of plant cell genetics at the Citrus REC; and Jim Graham, a UF/IFAS professor of soil microbiology, also at the Citrus REC.