Abstract
The alternaria brown spot (ABS) is the main fungal disease of tangerines. It has as causal agent the fungus Alternaria alternata, whose asexual spores (conidia) germinate on susceptible tissue: fruits, branches and new leaves, causing lesions of dark brown coloration. The penetration of the fungus on the leaf surface can be direct, in the epidermis or through the stomata and wounds. The t…