Chemical control of the olive rot caused by Glomerella cingulata1

The effect of various fungicides on Glomerella cingulata, the causal agent of a serious rot of olive fruits, was evaluated both in vitro and in the field. The following fungicides were tested: copper oxychloride, Bordeaux mixture, ziram, myclobutanil, hexaconazole, metiram, bitertanol and benomyl. Field trials were carried out in Calabria (southern Italy) for 2 years on two olive cultivars, Ottobratica (susceptible) and Sinopolese (resistant). The minimum effective concentrations of bitertanol, hexaconazole, myclobutanil, benomyl, metiram, ziram, and copper oxychloride on mycelial growth in vitro were < 5, < 50, < 50, < 1000, < 1000, < 1000, < 1000 μg ml−1, respectively. The ED90 values for conidial germination were 0.01, 0.02, 50, 50, 1000, 1000, and 1000 μg ml−1 of benomyl, ziram, myclobutanil, copper oxychloride, bitertanol, hexaconazole and metiram, respectively. In field trials, Bordeaux mixture and copper oxychloride proved to be the most effective products; however ziram, myclobutanil, bitertanol, metiram, and hexaconazole reduced the incidence of fruit rot significantly.