Submitted to: Scientia Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/12/2016
Publication Date: 1/19/2016
Citation: Bowman, K.D., McCollum, T.G., Albrecht, U. 2016. Performance of 'Valencia' orange (Citrus sinensis [L.] Osbeck) on 17 rootstocks in a trial severely affected by huanglongbing. Scientia Horticulturae. 201:355-361.
Interpretive Summary: Choice of rootstock is of critical importance to the success of commercial production everywhere citrus is grown. This article describes in detail the performance of 17 different rootstocks with sweet orange in a central Florida field site affected by the serious disease huanglongbing. Results from the trial indicate large differences between rootstocks in effects on fruit productivity, fruit quality, tree size, and disease symptom development. Three rootstocks were identified that appear promising to improve productivity in central Florida sweet orange plantings affected by huanglongbing.
Technical Abstract: Valencia orange (Citrus sinensis L. Osbeck) was grown on 17 rootstocks through seven years of age and the first four harvest seasons in a central Florida field trial severely affected by huanglongbing (HLB) disease. All trees in the trial had huanglongbing symptoms and were shown by Polymerase chain reaction (PCR) to be infected with Candidatus Liberibacter asiaticus (Las) by seven years of age. Large differences were noted between rootstocks for many metrics examined, including yield, fruit quality, and tree size. Highest yields in the trial were on US-942 rootstock and two other rootstocks not yet released, US-896 and US-1516. A comparison of tree performance in this trial with a similar trial conducted prior to the huanglongbing epidemic, demonstrated the disease resulted in a 22-49 percent reduction in yield and 2-34 percent reduction in tree growth, depending on rootstock, through seven years of age. Use of a tolerant rootstock is suggested as an effective means of ameliorating crop losses to huanglongbing.