[Identification and control of the main fungi causing postharvest rots in sweet pepino (Solanum muricatum Ait.)]

In order to determine the main fungi causing post-harvest rots in sweet pepino (Solanum muricatum Ait.), the affected areas of the fruit with rot symptoms were isolated, using Petri dishes with APD and incubated for 10 days at 22 deg C. Botrytis cinerea, Alternaria alternata and Fusarium oxysporum were isolated and identified. To confirm their pathogenicity, sound sweet pepinos were inoculated and incubated at 20 deg C in a moist chamber until developing the symptoms; the pathogen was reisolated to verify if it corresponded to the initially inoculated organism. To evaluate possible alternatives of chemical control, the fungicides Imazalil, Benomyl, Iprodione and Vinclozolin were applied to fruits inoculated with the three identified pathogens. Pathogens conidia were introduced into small wounds made in the fruit and these were subsequently incubated for 18 hours at 20 deg C after which the fungicides were applied. The rates used were as follows: Imazalil, 37.5 cc a.i./100 lt water; Iprodione and Vinclozolin, 60 gr a.i./100 lt water and Benomyl, 30 gr a.i./100 lt water. The in vivo B. cinerea was not controlled by Imazalil. Iprodione showed the best control even though no significant differences were found among this fungicide and Vinclozolin and Benomyl. Imazalil proved the most effective in controlling A. alternata, Iprodione was not so effective, and Vinclozolin and Benomyl did not control this pathogen. With respect to F. oxysporum, the four fungicides tested showed an acceptable control with no significant differences among them. In the in vitro tests, B. cinerea was completely controlled by the four fungicides. Imazalil and Iprodione had a total control of A. alternata. Vinclozolin controlled it in a lesser degree, whereas Benomyl virtually did not control it. F. oxysporum was totally controlled by Benomyl but not as effectively by Benomyl; Vinclozolin and Iprodione obtained a minimum control of this pathogen