Review of Plant Studies 2412-365X 2410-2970 10.18488/journal.69.2020.71.16.26 Review of Plant Studies Chemical Control of Alternaria Brown Spot on Mandarins Cultivars in Tunisia Review of Plant Studies Review of Plant Studies 12-2020 2020 12-2020 12-2020 7 1 16 26 30 Sep 2020 01 Dec 2020 Three field experiments were conducted to evaluate the efficiency of seven active ingredients (Tryfloxystrobin, Iprodione, Procymidone, Mancozebe, Propinebe, Tebuconazole and Coppersulfate), against Alternaria brown spot (ABS) caused by Alternaria alternata on Minneola, Fortune, Nova and Tangerine mandarins citrus cultivars in Tunisia. Over the three trials, citrus trees received 6, 10 and 16 fungicides sprays. The results of the present investigation demonstrated the prevention ability of Mancozebe, Iprodione and Copper sulfate according to disease incidence, fruit infection and losses caused by ABS. Furthermore, the applications of those three fungicides used in mixture reduce the ABS development. In fact, disease incidence was reduced better after an application of a mixture of Mancozebe and Iprodione compared to application of Mancozebe or Iprodione alone and after an application of an alternation of Mancozebe and Iprodione with copper sulfate. From this study, it revealed that the incidence of ABS, an emerging fungi disease on Citrus in Tunisia, could be reduced by using chemical products.