|Faulkner, Marjory - Lynn|
|KESINGER, MIKE - Florida Department Of Agriculture And Consumer Services|
Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/18/2016
Publication Date: 10/15/2016
Citation: Bowman, K.D., Faulkner, M.L., Kesinger, M. 2016. New citrus rootstocks released by USDA 2001-2010: field performance and nursery characteristics. HortScience. 51(10):1208-1214.
Interpretive Summary: Rootstock is of critical importance to the success of commercial production everywhere citrus is grown. Four new citrus rootstocks released by USDA between 2001 and 2010 have become widely used in Florida, and are becoming favored over most other rootstocks for many new commercial citrus plantings. The results from multiple field trials indicate outstanding performance for each of these four rootstocks for some situations, including superior tolerance to Huanglongbing (HLB) disease under some conditions. The rootstock US-942 has appeared to provide the most consistent superior performance in field plantings, including those affected by HLB. Information is also presented on nursery traits and performance of the rootstocks to facilitate continued and expanding nursery propagation.
Technical Abstract: Four new citrus rootstocks developed by USDA, ARS and released between 2001 and 2010 have gained considerable commercial popularity in Florida and have been used for propagation of more than 2 million trees over the last two years. Trends in commercial use of these rootstocks are discussed. Results from three new field trials are presented comparing these rootstocks with other important rootstocks, and discussion is presented to summarize field performance in these trials and from numerous other sources. The rootstocks vary widely in their effect on tree vigor. When used as a rootstock for sweet orange, US-802 typically supports strong vigor and development of a large tree, US-812 and US-942 provide moderate vigor, and US-897 induces a relatively dwarf tree. Other characteristics and attributes of the four rootstocks are also discussed, including effects on cropping, fruit quality, disease and pest resistance and tolerance of abiotic factors. Of special relevance, relative tolerance of these rootstocks to huanglongbing disease can now be surmised from a combination of data from several sources, with US-942, US-802, or US-897 typically providing the best yields per tree in trials containing many rootstocks and affected by huanglongbing. To facilitate continuing expansion of commercial use, information on seed production, and the relative ease of nursery propagation is also presented.