- Monday, January 1, 2001
- Effect of Fungicides and Antagonistic Microorganisms on the Black Fruit Spot Disease on Persimmon
- Published at:Agricultural Sciences , Dirasat Journal, Volume: 28, Issue: 2, 2001, 165 - 171
Alternaria alternata is the causative agent of black fruit spot disease on Persimmon. This disease infects fruits in the field near the harvesting time, but develops during the postharvest period causing fruit rot. In this study, suspensions of different strains of antagonistic microorganisms such as Trichoderma harzianum and Bacillus amyloliquefaciens were tested against the disease, in addition to applying fungicidal treatments with new, non-residual fungicides against the disease. Artificial infections with the disease were made on harvested fruits and subsequently fungicides or antagonistic microorganisms were applied in the different experiments. Preventive and curative effects of tested fungicides or antagonistic strains were evaluated according to the extent of supression of disease lesion diameter. Results showed that significant differences between tested fungicides or antagonistic strains were obtained. Consequently, Difenoconazole, and Cyprodinil + Flodioxonil proved to be the most effective preventive fungicides against the disease. This significant prevention was also provided by the antagonistic strain Trichoderma-Th1 of Trichoderma harzianum urn. In addition, the tested formulations of Metalaxyl + Mancozeb, Captan, and Cyprodinil + Flodioxonil had a significant curative effect against the disease. This curative effect was also shown by the strains Trichoderma-Th1 and Bacillus-GA1. A control program of the disease based on the above results comprising chemical and biological means is discussed. Such program should replace the current traditional fungicidal treatment since it is more effective and has no side-effects on the consumers or the local environment.