Assessment of a Postharvest Treatment with Pyrimethanil via Thermo-Nebulization in Controlling Storage Rots of Apples

Apples are very susceptible to infections from various fungal pathogens during the growing season due to prolonged exposure to environmental influences in the field. Therefore, a strict and targeted fungicide strategy is essential to protect fruit and trees. Increased environmental and health concerns and pathogen resistance have resulted in a rising demand to reduce fungicide usage and residues on marketed fruit. Thus, producers must develop new plant protection strategies to conform to the legal and social demands while still offering high-quality apples. This study assessed the efficacy of a post-harvest fungicide treatment with pyrimethanil via thermo-nebulization for controlling storage rots and compared the results to those of standard pre-harvest fungicide strategies. The results showed that a single post-harvest application of pyrimethanil successfully controlled storage rots and is comparable to strategies using multiple pre-harvest fungicide applications. The control of fungal rot was sustained even after 5 months of storage and 2 weeks of shelf life. Thermo-nebulization into the storage facility allowed for a lower dosage of fungicide to be used compared to pre-harvest applications, while still maintaining optimal rot control. Residue analyses showed that the post-harvest fungicide treatment did not exceed legal or retailer’s standards.

Influence of Solution Combination for Postharvest Treatment Stage on Vase Life of Cut Hydrangea Flowers (Hydrangea macrophylla cv. ‘Verena’)

Vase life is one of the most important factors that determines the marketability of cut flowers and is greatly affected by the water balance. The vase life of cut hydrangea flowers varies greatly depending on the postharvest solution management. Therefore, this study investigated the vase life of freshly harvested hydrangea (Hydrangea macrophylla ‘Verena’) according to the three types of preservative solutions (tap water (TW), 1% Chrysal Professional Ⅲ (CPⅢ), 2% sucrose + 250 mg/L 8-hydroxquinoline + 100 mg/L citric acid (SHQC)) and the combination solutions (pretreatment; TW, 0.1% Chrysal RVB (RVB), Floralife Quick Dip (FQ), transport; TW, CPⅢ, Floralife Clear (FC), preservative; CPⅢ, FC) for each distribution stage (pretreatment–transport–consumer). In the preservative comparison experiment, compared with the control, SHQC and CPⅢ significantly increased the vase life in 2019 (0.7 days, 3.4 days) and 2020 (1.4 days, 3.1 days), respectively. In the comparative experiment, by solution combination, the group (RVB, FQ) using the pretreatment significantly extended the vase life by 5.9 days and 4.6 days compared with the TW. These results confirm the importance of preservative solutions and pretreatment, suggesting that appropriate pretreatment and preservatives should be used to improve the marketability of cut hydrangea flowers.

A COMBINED METHOD OF POST-HARVEST HANDLING OF SWEET CHERRY FRUIT VERSUS FRUIT STORABILITY

The objective of the research was to determine an optimum method of postharvest handling of sweet cherry fruits which may contribute to prolonged shelf-life. The following physical factors were examined – storage temperature: 2–4°C, 6–8°C, 18–20°C; postharvest fruit packaging and treatment: Xtend® CH-49 bags + no exposure to UV-C, Xtend® + exposure to UV-C for 120 s or 600 s, no bagging + no exposure to UV-C, no bagging + UV-C for 120 s or 600 s. UV-C irradiation, regardless of the duration and storage conditions, prolonged the storage life of sweet cherry fruit. During the 14-day period of storage, the smallest weight loss as well as the highest number of fruits suitable for consumption were found after exposure to UV-C for 600 s in both Xtend® bags and flat, exposed polyethylene containers. After 28 days, higher amount of fruits suitable for consumption were found after storage at 2–4°C than at 6–8ºC. The most advantageous postharvest treatment method was placing fruits in containers and irradiating them with UV-C for 600 s. However, statistically similar results were obtained also after packing the fruits in Xtend® bags and irradiating them with UV-C for 600 s as well as placing them in containers and irradiation with UV-C for 120 s. In addition, UV-C irradiated fruits for 120 s and 600 s contained significantly more reducing sugars than non-irradiated fruits after 14 days of storage. UV-C irradiated fruits for 600 s also contained the greatest amount of flavonoids. After 28 days of storage, the highest content of flavonoids and phenols was determined in UV-C exposed fruits stored in containers. In addition, it emerged that storing sweet cherry fruit at 2–4°C without bagging contributed to increased total phenolic content compared with fruit stored in Xtend® bags. Packaging cherry fruit in Xtend® bags is the most reasonable when it stored at 6–8°C and at room temperature.

Development of a Quarantine Postharvest Treatment against Guatemalan Potato Moth (Tecia solanivora Povolny)

Tecia solanivora is a quarantine organism regarded as one of the insect pests causing major economic losses during potato cultivation and storage in Central America. The potatoes trade between countries, the interest in introducing new potato varieties, the great adaptability of the insect to different agro-ecological conditions, and the globalization world are serious risks in other potato growing countries. This pest was first recorded in Europe in the Canary Islands, Spain, in 1999, later in Galicia (2015) and then in Asturias (2016). Unfortunately, there are no effective chemical treatments for field control, and their integrated management has variable efficacy. Therefore, the implementation of a postharvest treatment to eradicate the insect, at any stage, during storage and marketing of potato becomes essential to achieve a product free of the insect that prevents its dissemination while maintaining the quality during its commercialization. This article presents the development of a new postharvest treatment of potatoes to eliminate all developmental stages of the Guatemalan moth by the application of a control atmosphere enriched in carbon dioxide. Infested potatoes were exposed to different control atmospheres combination (10, 20, 30, 40, or 50% CO2, 20% O2, and rest of N2). These treatments were applied for 4, 7, and 10 days at 18 ± 2 °C. The 10 days duration treatment (30 ± 2% CO2, 20 ± 2% O2 and 50 ± 2% N2) killed the insect in the semi and commercial trials performed without affecting potatoes quality and postharvest life, giving the possibility of its consideration as a quarantine postharvest treatment against T. solanivora.