Search Results (10)

Drosophila suzukii, classified as a quarantine pest in some countries, poses a serious threat to global trade due to its ability to damage berries and cherries. Recent studies indicate that low-temperature phosphine (PH₃) fumigation effectively controls this pest without compromising fresh produce quality. However, the specific protocol for managing D. suzukii larvae in cherries using this method remains underexplored. This study evaluates the efficacy of low-temperature PH₃ fumigation in controlling D. suzukii larvae across three cherry varieties at 3 °C and investigates potential effects on key quality metrics. Tolerance assessments revealed that 3rd instar larvae exhibit the highest resistance to PH₃ among all developmental stages. A concentration of 800 mL/m³ PH₃ for 84 h at 3 °C achieved phytosanitary efficacy for 0.99997 with no negative effect on the quality attributes of the tested cherry varieties. These results support low-temperature PH₃ fumigation as a viable postharvest treatment for D. suzukii management in sweet cherries. Full article

Fungi can degrade grain quality, produce harmful mycotoxins, and hinder germination in the post-harvest stage, resulting in significant economic losses. Ethyl formate (EF) is an efficient and eco-friendly fumigant for controlling pest insects in grains, horticulture, and quarantine treatments. However, there is a lack of research on the antifungal activity of EF and its degradation products on barley seeds. In this study, fifteen fungal species, predominantly Alternaria infectoria, were isolated and identified from seven Australian barley samples. Efficacy results indicated that EF significantly inhibited fungal growth at a commercial concentration of 2.4 mmol/L, except for Penicillium sp. 2, Fusarium chlamydosporum, and Rhizopus arrhizus. To control these EF-tolerant fungal species, the EF concentration was increased to 5 mmol/L, which achieved a 100% inhibition rate. The degradation product of EF, formic acid, effectively inhibited all EF-tolerant fungi, requiring only 0.08 mmol/L in the in vitro study. There were no significant differences in vigor and germination rates in barley treated with EF at concentrations of 2.5, 3.7, and 5 mmol/L. Additionally, EF treatments led to a significant increase in the barley root length from an average of 9.1 cm in the control group to 13.2, 13. 6, and 12.3 cm at 2.5, 3.7, and 5 mmol/L. The findings suggest that EF could be a suitable alternative fumigant to safeguard grain from fungal infestation, particularly in the context of advancing agricultural practices and improving seed germination quality. The degradation compound, formic acid, may contribute significantly to the overall antifungal function of ethyl formate fumigation, particularly in high-humidity environments. Full article

The fumigation of apples using methyl bromide (MeBr) can cause severe deterioration in fruit quality. Moreover, maintaining the quality of apples during postharvest storage and eradicating pests, especially those involved in quarantine issues, are important for facilitating the export of apples, including the “Fuji” apple (Malus pumila var. “Fuji”) in South Korea. In the present study, phosphine (PH₃) fumigation as an alternative to MeBr was found to be more effective for the control of peach fruit moth larvae (Carposina sasakii), which had naturally infested Fuji apples, at a high temperature (25 °C) rather than at a low temperature (5 °C). To achieve the industry requirement of better-quality perishable commodities and meet quarantine guidelines for export, PH₃ fumigation at the low temperature (5 °C) was followed by cold treatments at 3 ± 2 °C for 2 and 4 weeks, which led to higher efficacy than was achieved using PH₃ at 5 °C alone. Given that chemical treatments, such as treatment with 1-methylcyclopropene, can inhibit ethylene synthesis, low-temperature PH₃ fumigation for 72 h followed by 4 weeks of cold treatment could also extend the shelf life of apples and resolve known quarantine issues when used as an alternative to MeBr treatment. Full article

Drosophila suzukii is a quarantine pest that is rapidly spreading in berries. This study evaluated the synergistic effect of combination treatment with ethyl formate (EF) and cold temperature for D. suzukii control on imported grapes. A higher insecticidal effect was observed at 1 °C than at 5 °C at all developmental stages, and the pupal stage showed the strongest tolerance to cold temperature. After EF fumigation alone, eggs showed the highest tolerance at 216.67 mg·h/L (LCT₉₉ value), and adults showed the highest susceptibility at <27.24 mg·h/L. Among the combination treatment methods, cold temperature after fumigation resulted in the best synergistic effect. The effect of this combination was significant, with 23.3% higher mortality for eggs, 22.4% for larvae, and 23.4% for pupae than observed with EF fumigation alone. Furthermore, the period of complete D. suzukii control in the 12 L desiccator was shorter in the combination treatment group at the LCT₈₀ value than at the LCT₅₀ value of the egg stage. EF showed a very high sorption rate (24%) after 4 h of exposure at a grape loading ratio of 15% in a 0.65 m³ fumigation chamber. As the grape loading ratio for combination treatment decreased, D. suzukii mortality increased, but when EF was administered at the LCT₈₀ value, there was little difference in the mortalities of the eggs and larvae but not the pupae. All D. suzukii developmental stages were completely controlled within 7 days after combination treatment, and phytotoxicity was not observed in grapes. These results suggest that the combination of cold-temperature treatment and EF fumigation could be used for D. suzukii control. Full article

The present study investigates the comparative effect of pre- and post-storage quarantine heat treatments (hot water treatment (HWT) and vapor heat treatment (VHT)) on the post-harvest performance of the mango fruit cv. ‘Chenab Gold’. The results indicate that the application of HWT at 48 °C for 60 min or VHT at 47 °C for 25 min after 21 days under cold storage enhanced the ethylene production and fruit weight loss, while decreasing fruit firmness and vitamin C content. Noticeably, the post-storage heat treatments ruptured the fruit and destroyed their market value. However, fruit treated with HWT or VHT at harvest exhibited slow weight loss, better skin color, and maintained biochemical attributes as compared to the control when kept under ambient storage conditions. Taken together, the application of hot water before storage has a positive influence on mango fruit quality, while post-storage heat treatment has a devastating impact upon fruit quality and shelf life, cancelling its potential commercial application. Full article

Mango production and trade in sub-Saharan Africa is hampered by direct damage and the high quarantine status of B. dorsalis and the paucity of effective post-harvest phytosanitary treatments. The current study reports the development of a quarantine treatment protocol using hot water to disinfest B. dorsalis and assess its effect on cv. Tommy Atkins mango quality. We first determined the development of the eggs and all larval stages of B. dorsalis in cv. Tommy Atkins mango and used the information to establish a time–mortality relationship of the immature stages after subjecting infested fruits to a regimen of eight, time instances of hot water at 46.1 °C. Using probit analysis, we estimated the minimum time required to achieve 99.9968% mortality of each stage. Our results indicate that the egg was the least heat tolerant, followed by the first, second, and third instar. The time required to achieve 99.9968% control of the third instar in cv. Tommy Atkins mango (400–600 g) was determined to be 72.63 min (95% Cl: 70.32–74.95). In the confirmatory trials, the hot water treatment schedule of 46.1 °C/72.63 min was validated, and none of the 59,120 most heat-tolerant individuals treated survived. Further, there were no significant differences between hot water-treated and untreated mangoes recorded in weight loss, fruit firmness, pH, total soluble solids, moisture content, and titratable acidity eleven days post-treatment. These findings demonstrate an effectively optimum post-harvest disinfestation treatment against B. dorsalis in cv. Tommy Atkins mango that should be adopted commercially to facilitate access to profitable but strict export markets globally. Full article

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. Full article

Citrus black spot (CBS) is caused by Phyllosticta citricarpa, which is classified as a quarantine organism in certain countries whose concerns are that CBS-infected fruit may be a pathway for introduction of the pathogen. This study evaluated the reproductive capability and viability of P. citricarpa under simulated conditions in which the whole fruit, peel segments, or citrus pulp with CBS lesions were discarded. Naturally infected ‘Midknight’ Valencia orange and ‘Eureka’ lemon fruit, either treated using standard postharvest sanitation, fungicide, and wax coating treatments or untreated, were placed into cold storage for 5 weeks (oranges at 4 °C and lemons at 7 °C). Thereafter, treated and untreated fruit were incubated for a further 2 weeks at conditions conducive for CBS symptom expression and formation of pycnidia. The ability of pycnidia to secrete viable pycnidiospores after whole fruit and peel segments or peel pieces from citrus pulp were exposed to sunlight at warm temperatures (±28 °C) and ±75% relative humidity levels was then investigated. The combination of postharvest treatments and cold storage effectively controlled CBS latent infections (>83.6% control) and pycnidium formation (<1.4% of lesions formed pycnidia), and the wax coating completely inhibited pycnidiospore release in fruit and peel segments. Pycnidiospores were secreted only from lesions on untreated fruit and peel segments and at low levels (4.3–8.6%) from peel pieces from pulped treated fruit. However, spore release rapidly declined when exposed to sunlight conditions (1.4% and 0% after 2 and 3 days, respectively). The generally poor reproductive ability and viability of CBS fruit lesions on harvested fruit, particularly when exposed to sunlight conditions, supports the conclusion that citrus fruit without leaves is not an epidemiologically significant pathway for the entry, establishment, and spread of P. citricarpa. Full article

Nitric oxide (NO) fumigation under ultralow oxygen (ULO) conditions was studied for its efficacy in controlling codling moth and effects on postharvest quality of apples. NO fumigation was effective against eggs and larvae of different sizes on artificial diet in 48 h treatments. Small larvae were more susceptible to nitric oxide than other stages at 0.5% NO concentration. There were no significant differences among life stages at 1.0% to 2.0% NO concentrations. In 24 h treatments of eggs, 3.0% NO fumigation at 2 °C achieved 100% egg mortality. Two 24 h fumigation treatments of infested apples containing medium and large larvae with 3.0% and 5.0% NO resulted in 98% and 100% mortalities respectively. Sound apples were also fumigated with 5.0% NO for 24 h at 2 °C to determine effects on apple quality. The fumigation treatment was terminated by flushing with nitrogen and had no negative impact on postharvest quality of apples as measured by firmness and color at 2 and 4 weeks after fumigation. This study demonstrated that NO fumigation was effective against codling moth and safe to apple quality, and therefore has potential to become a practical alternative to methyl bromide fumigation for control of codling moth in apples. Full article

According to their origin, major postharvest losses of citrus fruit are caused by weight loss, fungal diseases, physiological disorders, and quarantine pests. Cold storage and postharvest treatments with conventional chemical fungicides, synthetic waxes, or combinations of them are commonly used to minimize postharvest losses. However, the repeated application of these treatments has led to important problems such as health and environmental issues associated with fungicide residues or waxes containing ammoniacal compounds, or the proliferation of resistant pathogenic fungal strains. There is, therefore, an increasing need to find non-polluting alternatives to be used as part of integrated disease management (IDM) programs for preservation of fresh citrus fruit. Among them, the development of novel natural edible films and coatings with antimicrobial properties is a technological challenge for the industry and a very active research field worldwide. Chitosan and other edible coatings formulated by adding antifungal agents to composite emulsions based on polysaccharides or proteins and lipids are reviewed in this article. The most important antifungal ingredients are selected for their ability to control major citrus postharvest diseases like green and blue molds, caused by Penicillium digitatum and Penicillium italicum, respectively, and include low-toxicity or natural chemicals such as food additives, generally recognized as safe (GRAS) compounds, plant extracts, or essential oils, and biological control agents such as some antagonistic strains of yeasts or bacteria. Full article