The potential for anti-oxidant chemicals to control Colletotrichum musae on banana fruit.
Khan, S. H.; Aked, J.; Magan, N.;
Mededelingen - Faculteit Landbouwkundige en Toegepaste Biologische Wetenschappen, Universiteit Gent Year: 1999 Vol: 64 Issue: 3b Pages: 531-537 Ref: 10 ref.
1999
บทคัดย่อ
The fruit disease, crown rot is a major cause of fruit losses in export bananas. Infection leads to blackening of the crown, weakened fruit pedicels and subsequent finger drop. Crown rot is caused by a complex of fungal pathogens of which C. musae is one of the most prevalent. This pathogen also causes unsightly blemishes on the peel of the ripe fruit called anthracnose disease. With intensive use of fungicides pre-harvest, many fruit pathogens such as C. musae are becoming tolerant of the same fungicides when applied postharvest to control fruit disease. Alternative postharvest chemicals will be needed in the future. In this study, 4 isolates of C. musae cultured from anthracnose lesions on imported banana fruit were screened against the fungicides thiabendazole (TBZ) and imazalil. Two of the isolates showed some tolerance of TBZ even at 250 ppm, whereas all 4 isolates were very sensitive to imazalil at concentrations of more than or equal to 5 ppm. One susceptible and 1 tolerant isolate (of TB
Z) was selected, and 9 antioxidants were evaluated over a range of concentrations for their effectiveness in inhibiting the germination and growth of these isolates in vitro. These chemicals were ascorbic acid, propionic acid, benzoic acid, butylated hydroxyanisole (BHA), butylated hydroxytoluene, propyl paraben (PP), propyl gallate (PG), dimethyl sulphoxide and thiourea. BHA, benzoic acid, PP and PG showed the most promise as control agents in vitro at 1 mM. These 4 chemicals were evaluated for their effectiveness alone and in combination in retarding the growth of C. musae on banana fruit both on the fruit peel and the cut crown. Different concentrations of antioxidant compounds or thiabendazole or imazalil were applied either before inoculation or 24 hours after inoculation to test their protectant and eradicant potential, respectively. BHA showed the most promise as a control agent in vivo with low concentrations causing strong suppression of anthracnose lesions and crown rot development in combination w
ith low concentrations of imazalil, benzoic acid and PP.