Effects of gamma and UV-C irradiation on the postharvest control of papaya anthracnose

Anthracnose is the main postharvest disease in papaya fruit. Today, there is considerable interest on alternative methods of control to promote resistance against pathogens and supplement or replace the use of fungicides. The goal of this work was to evaluate the effects of gamma and UV-C irradiation on Colletotrichum gloeosporioides, the causal agent of anthracnose. Mycelial growth, sporulation, and conidial germination were evaluated in vitro after fungal exposition to different irradiation doses. In the in vivo assays, _eGolden_f papaya fruit were inoculated through subcuticular injections of a conidial suspension or mycelium discs. Next, fruit were submitted to different irradiation doses (0, 0.12, 0.25, 0.5, 0.75, and 1 kGy), using Co60 as source, or UV-C (0, 0.2, 0.4, 0.84, 1.3, and 2.4 kJm.2). To check the possibility of resistance induction by irradiation, papayas were also inoculated 24, 48, or 72 h after the treatments. The fruit were stored at 25 .C/80