The traditional fungicide TBZ is the best chemical option to reduce Stem End Rot in citrus fruits

Stem-end-rot (SER), caused by Lasiodiplodia theobromae?and Phomopsis citri, is an important postharvest disease in humid and warm citrus growing areas, such as the?Northwestern region of Argentina. Its commercial control?was conducted with benomyl systemic fungicide. However,?alternative chemicals and integrated management program?must be developed due to the increase of restriction regulations?in Argentina and the oversea market requirements.The aim of this report was to describe the in vitro inhibition?of both pathogens by several fungicides and evaluate?the effectiveness of three copper sources and ten postharvest?fungicides to control SER, using an optimized artificial?inoculation method. The in vitro growth of L. theobromae?was more difficult to inhibit than that of P. citri. In in vivo trials,?Imazalil and Thiabendazole (TBZ), in combination with?agronomic field practices, were the most effective chemicals?used to reduce SER. Besides, the addition of potasio?sorbate to the fungicide solutions did not improve Lasiodiplodia-SER control. The TBZ treatment was improved with?the immersion time, but not with changes in pH and temperature.TBZ-residue loading was between 2.0 and 3.0 mg?L?1, optimal values without exceeding the maximum residue?levels. The traditional fungicide TBZ included in commercial?treatment is the best chemical option to reduce SER.Financial support: PICT 2012-2838 and PIUNT 26D-530. Source?CITRUS STEM END ROT: AN OLD DISEASE WITHOUT NEW?SOLUTIONSCerioni L1, Bennasar PB2, Lazarte D2, Sepulveda M2,?Rapisarda VA1 & Ramallo J21Inst Qca Biol Dr B Bloj (UNT) and INSIBIO (CONICET-UNT),?Argentina; 2S.A. San Miguel, Argentinae-mail: lucerioni@hotmail.comInternational Citrus Congress 2016 Picture, stem end rot by Phomopsis citri,?Postharvest Technology Center - UC Davis