SÍNTOMAS DEL HUANGLONGBING (HLB) EN ÁRBOLES DE LIMÓN MEXICANO [Citrus aurantifolia (Christm) Swingle] Y SU DISPERSIÓN EN EL ESTADO DE COLIMA, MÉXICO

Abstract

This work was carried out in orchards of Mexican lime [Citrus aurantifolia (Christm) Swingle] affected by Huanglongbing (HLB) disease and located in the state of Colima, Mexico. The objectives of this work were to characterize the symptoms of the disease in the trees, to evaluate the effect of HLB on the yield and other physical characteristics of the fruit, to determine its dispersion within an orchard andquantify the total orchards affected by HLB. Results showed that in this citrus species, the new vegetative shoots grow strong and healthy looking despite having emerged from symptomatic branches. The symptoms start as small yellowish spots on the leaves when the shoots are 45 to 60 days old. And they show the asymmetric diffuse mottling characteristic of HLB disease when they are 60 to 70 days old. This damage was observed in trees located inside of a structure covered with anti-aphid mesh and also in unprotected trees in the field. There was a significant yield reduction proportional to the percentage of canopy affected by the disease. In HLB symptomatic branches of diseased trees, the fruit was smaller but no misshapen fruits, inverted ripeness or an increase in the number of aborted seeds were detected. In an orchard without HLB vector control, the disease was detected in 53 % of the trees in only one year. HLB is widely spread throughout Colima state. This is the first report on HLB disease symptoms in Mexican lime and their effects on yield and fruit quality.