Evaluation of the fungicidal potential of two natural occurring compounds to reduce anthracnose of papaya during storage
S. Bautista-Banos , M. Hernandez-Lopez, L. Bravo-Luna and E. Bosquez-Molina
Proceedings of 26th International Horticultural Congress. Volume of Abstract . Toronto, Canada, 11-17 August, 2002. Abstract S09-P-190. pp. 268.
2002
บทคัดย่อ
One of the limitations of extending papaya fruit shelf life is the incidence of postharvst rots. In previous in vitro studies, the efficacy of chitosan and papaya seed extracts to reduce Colletotrichum gloeosporioides development and other fungi of this fruit was demonstrated. The objectives of this work were to evaluate the effect of chitosan and papaya seed aqueous extract on C. gloeosporioides development on papaya after five days ambient storaage and to determine fruit quality. Fruit were dipped the following treatments for 20 min: 1- chitosan 0.5%, 2-chitosan 1.5%, 3.-papaya seed extract (2:10w/v), 4-chitosan 0.5% + papaya seed extract, 5.- chitosan 1.5% + papaya seed extract and 6-control. Three experiments were carried out: 1- treatment were carried out: 1-treatment were applied before artificial inoculation by C. gloeosporioides, 2-treatments were applied after inoculation and 3-treatments were applied without previous artificial inoculation. Percentage infection was evaluated at the end of the five-day storage period. Physiological parameters such as solid solubles content (SSC), firmness and mass loss were evaluated at the end of the storage period. Results indicated significant (P<0.001) less fruit infection with chitosan (1.5%) or chitosan combined with papaya seed extract (infection of 40% and 47%, respectively) and when treatments were applied before inoculation. The highest infection was observed when fruit was treated after inoculation for all treatments (range infection of 95%-100%). In the noninculated experiment, percentage infection for all treatment was not significantly different from that of the control fruit (range infection of 60%-75%). The main fungus isolated was Phomopsis. No differences were observed between treatments and the frequency of the fungi isolated. There was a tendency of higher firmness in fruit treated with the chitosan solutions and seed exrract. No significant differences were observed between SSC and mass loss.