earticle

영어

This work aimed to investigate the anti-microbial activity of a fermented papaya extract, mainly composed of alpha-hydroxy acids (AHAs) as the active ingredients, against the disease-causing micro-organisms in agricultural fruits and crops such as Mycosphaerella fijensis causing black sigatoka disease and Ralstonia solanacearum causing Moko disease in Cavendish (banana) and Colletotrichum gloeosporioides causing anthracnose, amongst others. During bioassay tests, the extract significantly inhibited the growth of the fungal pathogen M. fijiensis causing black sigatoka on Cavendish banana. The efficacy is comparable to a standard fungicide check after 48 and 72 hours of incubation. The degree of control exhibited by the extract against the fungal pathogen ranged from 64.65% to 100% inhibition at various dosages. Results of the single-leaf test against Sigatoka disease also showed that the lowest dosage rate at 0.187 li/ha is the most effective and comparable with the standard, Dithane M-45 at 2.0 kg/ha. The extract was also tested in vitro against R. solanacearum, a bacterial pathogen causing moko wilt disease of Cavendish banana. No growth of the bacterium was observed three days and seven days after incubation during bioassay tests.
The extract was effective against the pathogen beginning at 50 ml per 16 liters of water, and significantly superior when compared to the bactericidal antibiotic check streptomycin. Furthermore, results also show that the extract exhibits a consistently strong inhibition against C. gloeosporioides, which causes anthracnose. Its zone of inhibition reaches an average of 24.19 mm during the five-day incubation period, and is well-sustained during an extended period of ten incubation days. A concentrated sample of the extract shows total inhibition against C. gloeosporioides as no growth of the microorganism was observed during the extended 10-day incubation period.