Author
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Bowman, Kim |
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McCollum, Thomas |
Submitted to: HortScience
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 9/30/2015 Publication Date: 11/1/2015 Citation: Bowman, K.D., Mccollum, T.G. 2015. Five new citrus rootstocks with improved tolerance to huanglongbing. HortScience. 50:1731-1734. Interpretive Summary: New citrus rootstocks tolerant to huanglongbing disease and highly productive of good quality fruit are urgently needed in Florida. Five new citrus rootstock developed and released by USDA were observed to have much higher fruit yield and good fruit quality under disease pressure from huanglongbing in some Florida locations than the most common commercial rootstock used in Florida. These rootstocks are expected to allow Florida citrus growers in the East coast area to produce fruit more successfully despite rapid spread of huanglongbing to newly planted trees. Technical Abstract: Five new citrus rootstocks, US-1279, US-1281, US-1282, US-1283, and US-1284 were released by the Agricultural Research Service in September 2014 for commercial use in areas threatened by huanglongbing disease. These rootstock selections originated from 1995 crosses of mandarins × Trifoliate Orange. Rootstock performance was described at two trial locations over multiple years. All five rootstocks produced sweet orange trees that have fruit yields significantly higher than the most common Florida rootstock, Swingle, in the Florida East coast area over several years following tree infection with the believed causal pathogen of huanglongbing disease, Candidatus Liberibacter asiaticus. Sweet orange fruit quality was also good on these rootstocks, with better total soluble solids, and a significantly higher fruit weight, as compared to trees on Swingle rootstock after they became infected by huanglongbing. Evaluation of trees in the field trials suggests that the improved performance of trees grafted on this rootstock was due to tolerance of the rootstocks to Candidatus Liberibacter asiaticus. |