Improved the Shelf Life of Guava Fruits by Salicylic Acid against Postharvest Black Spot Disease

Abstract

Guava fruit (Psidium guajava L.) is one of the most important popular fruits in the tropical and subtropical zones. It is a perishable and has a short postharvest shelf life at environment temperature due to climacteric ripening with changes in physicochemical properties; However, the most serious microorganisms attacked guava fruits are the fungi. Guava black spot (GBS) is a latent infection disease caused by the ascomycete fungal Phyllosticta capitalensis, that infect immature guava in the field. This postharvest decay can lead to significant economic losses. Since the commercial application of fungicides to control postharvest diseases found harmful to human and the ecosystems. Therefore, the search of finding alternative fungicides, safety and environmentally friendly strategy is a major aim of the researchers worldwide. Salicylic acid (SA) is one of the safe, natural compounds applied in the postharvest treatment of fruit. The present investigation aimed to evaluate the effect of different concentrations of SA on fungal growth in vitro and postharvest treatment of infected fruit to improve the shelf life of guava fruits. Guava fruit collected from local supermarket and measurement of disease incidence and severity (DI & DS%) carried out in the three seasons (2015-2017). SA at different concentrations assessed on mycelial linear growth inhibition (MLGI%) of P. capitalensis in vitro. Exogenous postharvest treatment of guava fruit with SA tested at five concentrations, three times of immersion and kept for three periods time of shelf life. DS% evaluated after three period time. Total soluble solids (TSS) and weight loss (WL) evaluated after three period time. SA concentrations at 6 mmol/L significant on MLGI of P. capitalensis in vitro. Postharvest treatment with SA at 3 mmol/L significantly reduced DS% on guava fruit, at three immersion time and after three periods of shelf life, compared to control. SA with a concentration at 4 mmol/L decreased TSS and WL after three periods of shelf life. Postharvest treatment with SA solutions had an overall positive effect on fruit quality of guava during shelf life. A decay incidence decreased, TSS and weight loss noticed in treated guava fruit compared to control. The present study demonstrated the efficacy and potential of SA solutions in preserving the shelf life of a highly perishable like guava fruits.

Reducing Fruit Quality Losses in Peach Fruits and Increasing Profitability during postharvest Storage Using Salicylic Acid and Aspirin

“…Similarly, Razavi et al (2018) concluded that treating peaches with SA during storage at 1 °C for 4 weeks delayed fruit postharvest decay due to the rising of antioxidant enzymes (APX, SOD, and CAT) content. Similar findings were reported on treating fruit (tomato, apricot, mandarin and guava) with SA during storage, resulted in delayed ripening, decreased decay percentage, extended fruit storage and enhanced fruit quality and storability (El-Abbasy et al, 2018, Orabi et al, 2018, Arafat, 2019. That could be attributed to SA inhibits the action of ethylene receptors, which enhances fruit decay (Heydari et al, 2020).…”

“…Salicylic acid is one of the safe natural chemicals used for postharvest quality maintenance of horticultural and ornamental produces, regulates plant growth and development, and affects postharvest physiological and metabolism of perishable crops (Davies, 2010 andArafat, 2019). Aspirin (AS), a trading name for acetylsalicylic acid, undergoes spontaneous hydrolysis to SA, in an aqueous solution.…”