Control of post-harvest anthracnose infection in guava (Psidium guajava) fruits with phosphites, calcium chloride, acetyl salicylic acid, hot water, and 1-MCP

The control of anthracnose (Colletotrichum simmondsii) during the post-harvest stage in guava fruits (Psidium guajava L.) was performed by the application of phosphites [phosphite-K (40% P2O5 and 30% K2O) and phosphite-Ca (10.7% P2O5, 3.89% Ca, and 0.5% B)] including the Carbendazim as reference, calcium chloride (CaCl2), acetyl salicylic acid (ASA), hot water (HW), and 1-methylcyclopropene (1-MCP). These treatments were applied individually or in combination each other with two or three compounds. The evaluated parameters were diameter of anthracnose lesion (DL), number of lesions (NL), and fruit quality (fresh weight loss, pH, total soluble solids, and titrable acidity]. The fruits were disinfested, inoculated, and maintained in an incubator containing fluorescent lights at 75 µmol·m-2·s-1 (25°C, 12h photoperiod) for 5 days and were then analyzed. The results showed that the DL and the NL were reduced following treatments, and that the HW (47°C for 20 min) was the strongest and the 1-MCP treatment was the least effective. The physico-chemical characteristics of fruits were affected by some treatments without compromising fruit quality. The combination of treatments was also able to alleviate the anthracnose effect on fruits compared to individual treatments and the control without affect the fruit quality. The combinations which included the HW treatment showed the best performance to control this disease, particularly when combined with the 1-MCP and phosphite.