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ARS Home » Southeast Area » Fort Pierce, Florida » U.S. Horticultural Research Laboratory » Subtropical Plant Pathology Research » Research » Publications at this Location » Publication #321076

Title: Field trials of the integrated approach to control citrus huanglongbing in Florida

item ZHANG, MUQING - University Of Florida
item YANG, CHUANYU - University Of Florida
item Duan, Ping
item POWELL, CHARLES - University Of Florida

Submitted to: International Research Conference on Huanglongbing
Publication Type: Abstract Only
Publication Acceptance Date: 10/15/2014
Publication Date: 3/30/2015
Citation: Zhang, M., Yang, C., Duan, Y., Powell, C.A. 2015. Field trials of the integrated approach to control citrus huanglongbing in Florida. J Cit Pathol. 2(1):48. iocv_journalcitruspathology_30222

Interpretive Summary:

Technical Abstract: Developing strategies/approaches for managing HLB-affected trees in the field is the most urgent need facing Florida citrus industry. Based on our screened compounds and optimized nano-emulsion formulations, Three independent field trails were conducted on the integrated approach to combat citrus HLB, including i) Exp-1: Four compounds of SDX, AMP, ZS and VA were prepared and loaded in the W/O and O/W nano-formulations for trunk-injection using injectable bag and bark-application; ii) Exp-2: Antibiotics of SDX and AMP were prepared and loaded into the O/W nano-formulation coupled with insecticide and fertilizer by trunk-injection; Exp. 3: Carv and PCY were prepared and loaded into W/O nano-formulation for foliar spray. Before application, all HLB-affected citrus were trimmed and pruned, and then fertilized in Dec. 2013. All compounds were applied once every two month. Following initial treatments, all trees were tested for Ca. L. asiaticus using qPCR once every two months. Citrus effects of the combined treatments will be investigated. The preliminary results showed that trunk-injection using injectable bag was good for water-soluble antibiotics. One liter of solution could be uptakes in 24 h by improving the injection technology. Compared to other compounds, Pen was one of the most effective to eliminate the Las bacterium. Bark application was good for SDX loaded into O/W nanoemulsion. Pen and SDX promoted the growth and emergence of new flushes or leaves with longer and more new branches. Foliar spray of Carv and PCY in W/O nanoemulsion were not effective to suppress the Las bacterium in the HLB-affected citrus. The results also indicated that supplemental insecticide or fertilizer in the injectable bag caused temporal phyototoxicity, thereby it was better to be applied by foliar spray.