2012 Annual Report
Greenhouse experiments were conducted to show that the level of Citrus Greening associated bacterium within diseased citrus trees could be reduced by basal bark applications of a mixture of antibiotics and specific phloem penetrants. Residue analysis in leaves of bark treated plants showed that the antibiotics activity was lost eight days following application, thus requiring frequent repeated applications. This result led to ongoing experiments designed to identify a time-release strategy to prolong the exposure of citrus to the antibiotics and thereby reduce the application costs. Similar greenhouse experiments were conducted to determine if foliar uptake of antibiotics by citrus could be improved. In these experiments foliar uptake was greatly improved by the addition of glycerol to the spray mixture. Field experiments using healthy citrus trees were continued from previous year resulting in a two year study that identified basal bark application treatments that reduced the occurrence of citrus greening disease in treated plants.