Rootstock influences on health and growth following Candidatus Liberibacter asiaticus infection in young sweet orange trees

Authors: Bowman, Kim; ALBRECHT, UTE - UNIVERSITY OF FLORIDA

Submitted to: Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/30/2020
Publication Date: 12/2/2020
Citation: Bowman, K.D., Albrecht, U. 2020. Rootstock influences on health and growth following Candidatus Liberibacter asiaticus infection in young sweet orange trees. Agronomy. 10(12):1907. https://doi.org/10.3390/agronomy10121907.
DOI: https://doi.org/10.3390/agronomy10121907

Interpretive Summary: Health and fruit production of citrus crops is severely affected by tree infection with Candidatus Liberibacter asiaticus (CLas) and subsequent development of the disease huanglongbing (HLB). Sweet orange trees in areas affected by HLB usually all become infected by the disease within a few years, but trees on some rootstocks appear to suffer less canopy damage and less reduction of marketable crop than other rootstocks during multiyear field trials. Although the long-term rootstock effect is clear, such field trials take many years for establishment and evaluation, and this long time period is very limiting to expeditiously evaluate new rootstocks for HLB-tolerance. In this study, we describe greenhouse methods that were used to evaluate sweet orange trees infected with CLas on a group of rootstocks over a one year period. In the greenhouse study, sweet orange trees on some rootstocks exhibited much better tolerance to CLas infection, and those results corresponded well with multiyear field performance of sweet orange infected by the disease on those same rootstocks. The greenhouse methods described can be useful for more rapid evaluation of HLB-tolerance of new rootstocks, and evaluation of other new HLB management techniques.

Technical Abstract: Health and fruit production of citrus crops is severely affected by tree infection with Candidatus Liberibacter asiaticus (CLas) and subsequent development of the disease huanglongbing (HLB). Sweet orange trees in areas affected by HLB usually all become infected by the disease within a few years, but trees on some rootstocks appear to suffer less canopy damage and less reduction of marketable crop than other rootstocks during multiyear field trials. Although the long-term rootstock effect is clear, such field trials take many years for establishment and evaluation, and this long time period is very limiting to expeditiously evaluate new rootstocks for HLB-tolerance. In this study, we describe greenhouse methods that were used to evaluate sweet orange trees infected with CLas on a group of rootstocks over a one year period. In the greenhouse study, sweet orange trees on some rootstocks exhibited much better tolerance to CLas infection, and those results corresponded well with multiyear field performance of sweet orange infected by the disease on those same rootstocks. The greenhouse methods described can be useful for more rapid evaluation of HLB-tolerance of new rootstocks, and evaluation of other new HLB management techniques.