Vol. 121 (2008): Proceedings of the Florida State Horticultural Society
Citrus

Citrus greening effects on fruit size distribution and yield in citrus trees

Timothy M. Spann
UF/IFAS
W. Chris Oswalt
Polk County Extension

Published 2008-12-01

Abstract

Citrus greening disease or huanglongbing (HLB) is a bacterial disease caused by the phloem-limited bacteria Candidatus Liberibacter spp. The disease causes phloem collapse, which leads to a number of symptoms expressed in leaves and fruit of infected trees. Fruit symptoms include small fruit size, misshapen and lopsided fruit, an inverted color change and off-flavors in the fruit. It is important to keep off-flavored greening-affected fruit from entering the processing plant where they could taint large volumes of juice, as they would be unacceptable to consumers. We hypothesized that there is a significant difference in the fruit size distribution, more heavily weighted to smaller fruit, in greening-infected trees than healthy trees. This change in size distribution caused by greening would reduce yield and might be used to grade out affected fruit at harvest from a potentially infected area. Additionally, a load of fruit with a disproportionately high number of small fruit could be an indicator of possible greening infection, thus helping to direct scouting efforts.