Control of Postharvest Diseases of Fruit by Heat and Fungicides: Efficacy, Residue Levels, and Residue Persistence. A Review

Abstract

Extensive research has been done in recent years to reduce the heavy dependence on chemical fungicides to control postharvest diseases and disorders of horticultural crops. Alternative strategies were based on improved cultural practices, biological control, plant-defense promoters, and physical treatments such as UV illumination, radiofrequency treatment, heat therapy, and storage technologies. Among these, postharvest heat treatments such as hot water dips, short hot water rinsing and brushing, and hot air conditioning have reduced rot development and enhanced fruit resistance to chilling injury in sensitive cultivars while retaining fruit quality during cold storage and shelf life. Additive or synergistic increases in effectiveness were observed by integrating heat therapy with various chemical compounds, thus leading to significant reductions in the application of active ingredients to protect produce from decay. This paper highlights the knowledge on this topic with emphasis on heat therapy effects and factors affecting the uptake, persistence, and performance of fungicide residues when they are applied in combination with hot water.

Effects of Combined Heat and Preservative Treatment on Storability of Ponkan Fruit (Citrus reticulataBlanco cv. Ponkan) during Postharvest Storage

“…This may be because the heat treatment was effective in enhancing the efficacy of preservative [14] and was an effective measure to decrease the preservative content while still controlling fruit decay, which was similar with the effect of heat treatment combined with preservative on other fresh produce [19][20][21]. Also, the heat treatment may promote resistance to microorganisms in Ponkan fruit during storage, which has been reported in other fruits [22][23][24].…”

“…Previous reports also showed that heat treatment enhanced the efficacy of preservative and decreased the amount of chemicals used for decay control in fruits [13,14]. However, the effects of HT combined with iminoctadine tris (albesilate), 2,4-dichlorophenoxyacetic acid, and imazalil mixture on storability and quality in Ponkan fruit have rarely been studied.…”

Evaluation of alternatives to synthetic fungicides to control citrus postharvest diseases.

“…As demonstrated by results from this thesis and has also been pointed out by other workers (Schirra et al, 2011;Valencia-Chamorro et al, 2011;, and in contrast to what typically happens with synthetic fungicides, the effectiveness of many physical, chemical or biological alternative nonpolluting treatments is greatly dependent on citrus species and cultivar. Because of their mode of action, the effectiveness of these treatments usually varies with the natural susceptibility of treated fruit to penicillium decay.…”

Degradation of imazalil, orthophenylphenol and pyrimethanil in Clementine mandarins under conventional postharvest industrial conditions at 4°C

“…Since then, it has been continuously employed as an antifungal postharvest agent (Siegel & Ragsdale, 1978). IMZ is effective for the control of citrus green mold caused by Penicillium digitatum (Pérez et al, 2011), one of the most important postharvest pathogens in the citrus industry worldwide (Altieri, Di Renzo, Genovese, Calandra, & Strano, 2013;Lado et al, 2010;Schirra, D'Aquino, & Cabras, 2011 application has become routine for all Uruguayan packinghouses (Pérez et al, 2011). It can be applied through different technologies, such as dip tank, spray, drencher, cascade, or mixed with wax (Erasmus et al, 2011).…”