Which commercial adjuvants achieve systemic delivery of antimicrobials?

Which commercial adjuvants achieve systemic delivery of antimicrobials?

Report Date: 09/15/2020
Project: 19-023   Year: 2020
Category: CLas Bacteria
Author: Christopher Vincent
Sponsor: Citrus Research and Development Foundation

We completed implementation of the field study of delivery of oxytetracycline (OTC). OTC in the leaves to which the foliar sprays were applied have been quantified. OTC quantification in the leaves that were protected from direct contact with the sprays is in process. Results to-date indicate that no commercial adjuvant delivered significant quantities of OTC.  Of all adjuvants, only Flotek 1, an experimental adjuvant, had significantly more OTC than the treatment with water and no OTC.  All others were statistically similar to no OTC (Water – AB).  Based on the MIC developed by Li et al. (2019), no adjuvant achieved this minimum threshold.  Injection, however exceeded 4x the MIC.  In all cases, the same amount of was applied to each plant.  When considering this, we considered injection to represent the foliar concentration when 100% of the treatment entered the plant, and the Water – AB treatment to be the quantity when nothing was delivered.  Using this standardization we calculated the efficiency of delivery of each treatment.  The most efficient treatment, Flotek 1, had a mean of less than 5%. We completed the field study of streptomycin and samples are being processed. We have requested an NCE because COVID-19-related delays have prevented us from acquiring materials for streptomycin quantification.  We also intend to repeate OTC and streptomycin applications with select adjuvants to confirm results.  We have presented results to the Citrus Expo audience, and have submitted a manuscript for publication in a peer-reviewed journal. 


Your browser does not support pdfs, click here to download the file.