Control Of Postharvest Decay Research Articles

Orchard calcium and fungicide treatments mitigate effects of delayed postharvest fungicide applications for control of postharvest decay of pear fruit

Postharvest decay of pear fruit is commonly initiated at wounds that occur during harvest and handling, yet pears may be held in cold storage for considerable lengths of time before fungicides are applied to prevent postharvest decay. The efficacy of postharvest fungicide treatments declines as the time between harvest and fungicide treatment increases. Foliar sprays of calcium chloride applied to ‘Bosc’ pear trees beginning in mid-July and repeated every two weeks for a total of three applications slowed the increase in decay incidence observed when thiabendazole or fludioxonil treatments were delayed up to eight weeks after harvest. Increased decay incidence due to delayed postharvest fungicide application was also reduced by application of either pyraclostrobin + boscalid, thiophanate-methyl, or trifloxystrobin one week before harvest. Calcium chloride treatments followed by either of the pre-harvest fungicides provided the greatest decay suppression when postharvest fungicide treatments were delayed. Decay control by fludioxonil treatment was superior to that provided by thiabendazole when the fungicides were applied to fruit promptly after harvest, but differences between these two fungicides decreased as the delay in application approached eight weeks after harvest. A program of orchard calcium chloride followed by pre-harvest fungicide treatments can reduce overall decay incidence and mitigate the consequences of delays in postharvest fungicide treatment.

Thymus kotschyanus and Carum copticum essential oils as botanical preservatives for table grape.

In the present study, essential oils extracted from Thymus kotschyanus and Carum copticumhas been evaluated for efficacy in the control of postharvest fungal decay in Thompson seedless table grape. Results showed that the tested oils exhibited good inhibitory activity against fungal decay in oil-treated grapes. In addition, the essential did not show a negative impact on the sensory quality of the grape. The profile of the oil components showed that carvacrol (28.54%) and thymol (63.18%) were the main compounds available in T. kotschyanusand C. copticum respectively. Results of this research showed that the evaluated essential oils may be used as a preservative for reduction of postharvest losses. Key words: Essential oil, table grape, Thymus kotschyanus, Carum copticum, antifungal.

The use of essential oils for postharvest decay control. A review.

AbstractFood safety is one of the major issues related to fresh fruit and vegetables. The preservation of the ‘freshness’ quality of these products is relevant due to their economical impact. This chapter is a comprehensive review of the use of essential oils from different sources and their constituents on the control of postharvest decay and overall quality preservation of fresh fruit and vegetables. An overview on the most significant postharvest diseases and their impact, as well as on the mainly used synthetic chemicals and their side‐effects has been included. Emphasis has been on the sources of essential oils and their constituents studied up to now, and their effects on controlling postharvest diseases, either in vitro or in vivo, and their effect on overall quality and storage life of fresh commodities. Issues regarding their impact on human health and the environment have also been analysed.

Improved control of postharvest decay in Chinese bayberries by a combination treatment of ethanol vapor with hot air

The effect of ethanol vapor treatment (EVT, 250 or 500 μL L −1 for 3 h) alone or in combination with hot air treatment (HAT, 48 °C for 3 h) on postharvest decay and microbial loads in Chinese bayberries was investigated. Treatment with ethanol vapor or hot air alone both resulted in significantly lower decay incidence caused by Verticicladiella abietina, Penicillium citrinum or Trichoderma viride compared with the control. The combined treatment of 500 μL L −1 ethanol vapor with hot air showed the lowest incidence of fruit decay caused by these pathogens. This treatment also significantly inhibited spore germination and germ tube elongation of the pathogens in vitro than EVT or HAT alone. Meanwhile, the combined treatment exhibited the lowest natural decay incidence and microbial loads on Chinese bayberries without impairing fruit quality. These results suggest the usefulness of the combined treatment for reducing fruit decay in Chinese bayberries.

Yeasts associated with nectarines and their potential for biological control of brown rot

Resident fruit microflora has been the source of biocontrol agents for the control of postharvest decay of fruits and the active ingredient in commercialized biocontrol products. With the exception of grapes and apples, information on the resident microflora of other fruits is only fragmentary, but greater knowledge in this area can be very helpful in developing biocontrol strategies. We characterized the yeast microflora of nectarines ('Croce del Sud') from the early stages of fruit development until harvest. The fruit samples were collected from trees in an unmanaged orchard. The resident fruit microflora was separated from the occasionally deposited microorganisms by discarding initial fruit washings before the final wash, followed by sonication and plating on NYDA medium. The isolated yeasts were identified by BIOLOG and by sequencing the D1/D2 domain of a large subunit of the rRNA gene and, where available, the ITS sequence. BIOLOG identified 19 and the genetic analysis 23 species of yeasts. Although the identification by these two systems was not always the same, the predominant yeasts were Rhodotorula spp., Sporodiobolus spp., Cryptococcus spp., Pichia spp., Candida spp. and yeast-like Aureobasidium pullulans. Several of the taxa appear to represent new species. The preliminary biocontrol tests against brown rot of nectarine fruit caused by Monilinia fructicola indicates significant decay control potential of some of the identified yeast species, namely Cryptococcus magnus, Cryptococcus sp. nov., Sporidiobolus pararoseus, A. pullulans and Rhodotorula sp. nov.

STRATEGIES FOR THE USE AND ENHANCEMENT OF BIOLOGICAL CONTROL OF POSTHARVEST FRUIT DECAYS

Biological control of postharvest decays (BCPD) has been used commercially on pome and citrus fruits since 1996 in the United States, and its use were later expanded to include cherries and seed potatoes. The spectrum of activity of these biocontrol products differs with respect to fruit type and maturity, stage of pathogen infection, and specific pathogen causing decay, and is not as broad as fungicides. Thus, commercial use of BCPD has been targeted for certain commodities and may even be limited to certain postharvest applications within a commodity. Unlike fungicides, currently registered biocontrol products are exempt from residue tolerance by the U.S. Environmental Protection Agency and can be used well into storage even to the point of packing fruit for shipment. Recent research has focused on improving biocontrol itself and/or combining BCPD with other alternative methods to synthetic fungicides. The efficacy of BCPD has been improved by developing antagonist mixtures, and manipulation of growth and formulations of antagonists. Manipulation of biocontrol mechanisms have not yet resulted in improved biocontrol. The potential of foreign antimicrobial genes introduced into antagonists is also being explored. Greater efficacy and broader spectrum of postharvest decay control on fruit was achieved by combining BCPD with heat treatment, GRAS substances, lytic enzymes, or the induction of resistance in fruit by physical or chemical means.

Use of Ozone in the Citrus Industry

The use of ozone for postharvest sanitation and decay control of fruits, vegetables and their products during handling, processing and storage has been investigated for commercial applications. Due to their significant contribution to world trade and human nutrition, citrus fruits are thought to be important commodities. Decay can be observed in these products because of microbial activity and ethylene accumulation throughout storage. Residues of pesticides and other compounds in citrus fruit and food-borne illness outbreaks caused by consumption of contaminated citrus juice are important health issues. In this study, the possible uses of ozone in citrus industry for all these problems, and efficacy, benefits and/or detrimental effects of these applications are discussed.

Control of Colletotrichum gloeosporioides (penz.) Sacc. In yellow passion fruit using Cymbopogon citratus essential oil

The use of antibiotics in agriculture is limited when compared to their applications in human and veterinary medicine. On the other hand, the use of antimicrobials in agriculture contributes to the drug resistance of human pathogens and has stimulated the search for new antibiotics from natural products. Essential oils have been shown to exert several biological activities including antibacterial and antifungal actions. The aim of this study was to determine the activity of 28 essential oils from medicinal plants cultivated at CPMA (Medicinal and Aromatic Plants Collection), CPQBA/UNICAMP, against Colletotrichum gloeosporioides (Penz.) Sacc., the anthracnose agent in yellow passion fruit (Passiflora edulis Sims f. flavicarpa Deg), as well as evaluating their effect in the control of post-harvest decay. The oils were obtained by water-distillation using a Clevenger-type system and their minimal inhibitory concentrations (MIC) determined by the micro-dilution method. According to the results, 15 of the 28 essential oils presented activity against Colletotrichum gloeosporioides, and the following four oils presented MIC values between 0.25 and 0.3 mg/mL: Coriandrum sativum, Cymbopogon citratus, Cymbopogon flexuosus and Lippia alba. The evaluation of Cymbopogon citratus essential oil in the control of post-harvest decay in yellow passion fruit showed that the disease index of the samples treated with the essential oil did not differ (P < 0.05) from that of the samples treated with fungicide. The present study shows the potential of Cymbopogon citratus essential oil in the control of the anthracnose agent in yellow passion fruit.

Control of postharvest decay on cherry tomatoes by marine yeast Rhodosporidium paludigenum and calcium chloride

In this study, the potential of calcium chloride (CaCl(2)) application to improve the efficacy of the marine antagonist Rhodosporidium paludigenum in controlling postharvest diseases of cherry tomatoes was assessed. CaCl(2) alone was found not to have any direct influence on the population growth of R. paludigenum in NYDB cultures or in cherry tomato wounds. However, the combined treatments with 1 x 10(8) cells ml(-1)R. paludigenum and CaCl(2) at the concentration from 0.5 to 2% showed high activities to reduce black rot caused by Alternaria alternata in cherry tomato wounds, significantly higher than those of R. paludigenum or CaCl(2) alone. Meanwhile, 0.5% CaCl(2) in combination with 1 x 10(8) cells ml(-1)R. paludigenum greatly inhibited the natural decay of cherry tomatoes in 21 days' storage at 25 degrees C. The combination of R. paludigenum and CaCl(2) enhances the inhibition of black rot and natural decay of postharvest cherry tomatoes. The results from this study provide a new way to improve the efficiency of R. paludigenum in maintaining the quality of postharvest fruits and vegetables. The marine yeast R. paludigenum combined with CaCl(2) has greatly potential use as an alternative to chemical fungicides in inhibiting postharvest decay on cherry tomatoes.

Control of Colletotrichum gloeosporioides (penz.) Sacc. In yellow passion fruit using Cymbopogon citratus essential oil.

The use of antibiotics in agriculture is limited when compared to their applications in human and veterinary medicine. On the other hand, the use of antimicrobials in agriculture contributes to the drug resistance of human pathogens and has stimulated the search for new antibiotics from natural products. Essential oils have been shown to exert several biological activities including antibacterial and antifungal actions. The aim of this study was to determine the activity of 28 essential oils from medicinal plants cultivated at CPMA (Medicinal and Aromatic Plants Collection), CPQBA/UNICAMP, against Colletotrichum gloeosporioides (Penz.) Sacc., the anthracnose agent in yellow passion fruit (Passiflora edulis Sims f. flavicarpa Deg), as well as evaluating their effect in the control of post-harvest decay. The oils were obtained by water-distillation using a Clevenger-type system and their minimal inhibitory concentrations (MIC) determined by the micro-dilution method. According to the results, 15 of the 28 essential oils presented activity against Colletotrichum gloeosporioides, and the following four oils presented MIC values between 0.25 and 0.3 mg/mL: Coriandrum sativum, Cymbopogon citratus, Cymbopogon flexuosus and Lippia alba. The evaluation of Cymbopogon citratus essential oil in the control of post-harvest decay in yellow passion fruit showed that the disease index of the samples treated with the essential oil did not differ (P ≤ 0.05) from that of the samples treated with fungicide. The present study shows the potential of Cymbopogon citratus essential oil in the control of the anthracnose agent in yellow passion fruit.

Natural products for postharvest decay control in horticultural produce: a review

Purpose of review: This review offers a perusal of reports on the use of natural products for postharvest decay control in fresh horticultural produce. In light of research findings, it considers the use of natural products for postharvest decay control in horticultural produce. Main findings: Important wastage of produce occurs in the postharvest chain, of which decay, caused by various postharvest pathogens, dictates a considerable part. The use of synthetic fungicides has faced limitations and restrictions owing to their teratogenicity, acute residual toxicity, long degradation period, and other effects on human health and the environment. Biodegradable and ecofriendly natural compounds such as flavour compounds, acetic acid, jasmonates, glucosinolates, chitosan, essential oils and active principles of some plants have gained importance and attention for their use as decay-control agents and safer alternatives to synthetic chemicals. Encouraging results on the use of natural products to control postharvest decay indicate the possibility of developing natural fungicides that would be as effective as synthetic fungicides, and yet are safe for man and environment. Directions for future research: Coordinated and continuous search for natural products may yield safer alternatives for postharvest decay control. Research efforts need to be directed towards establishing the mode of action of the products so as to provide important guidance for their application. Natural products that are found efficacious during in vitro and in vivo studies should be considered for commercial application. Emphasis should be placed on developing these products which can be used easily by the end users.

Control of Table Grapes Postharvest Decay by Ozone Treatment and Resveratrol Induction

Continued and intermittent (12 h per day) ozone treatments (2 ppm) to control postharvest decay have been assayed during the storage of ‘Superior Seedless’, ‘Cardinal CL80,’ and ‘Regina Victoria’ table grapes (Vitis vinifera L.) at 5 °C for 72 days. The effects of these treatments on the main fruit quality parameters, including resveratrol content, were monitored. Both ozone treatments considerably reduced decay of cold stored grapes compared to those kept in air, continuous ozone treatment being the most effective for controlling postharvest losses. Intermittent ozone treatment induced the highest resveratrol content in stored grapes. On the contrary, ozone-treated grapes got lower scores in the sensory evaluation tests and also showed significantly higher weight losses than the fruits kept in air.

Combined effect of curing followed by acetic acid vapour treatments improves postharvest control of Penicillium digitatum on mandarins

In recent years several alternatives to the chemical control of postharvest decay have been examined but satisfactory levels of control, with a single system, have not been achieved yet. In the present study the results of an integrated postharvest approach are reported. Early and late harvested hybrid mandarin fruit “Fremont” and “Fairchild”, inoculated with Penicillium digitatum (Pers.:Fr.) Saccardo, were cured at 36 °C for 36 h with 95% RH and then fumigated with 0, 5, 15, 25, 50, 75 and 100 μL/L of acetic acid (AAC) vapours for 15 min. Following the treatments, fruit was stored at 20 °C and 80% RH to simulate a marketing period, and after 2 weeks the decay incidence and the visual appearance were evaluated. Curing or fumigations performed alone reduced decay with respect to untreated fruit, but the best control was achieved with combined treatments. For early harvested fruit the lowest decay percentage was obtained by using 75 μL/L with 8.3% and 2.1% of rots for “Fremont” and “Fairchild”, respectively, whereas for late harvested fruit the highest efficacy was observed using 50 μL/L (1.4% and 6.6%). Rind damage as pitting was observed only if fruit was treated with AAC alone at 100 μL/L.

Harvesting and handling effects on postharvest decay

Purpose of review: The aims of this review are: (1) to highlight the most significant results over the last few years in harvesting methods and pre- and postharvest handling of horticultural products; and (2) to provide insights in terms of technological aspects, with special reference to the control of postharvest decay. New system approaches that should be considered as components of an integrated decay control strategy and overall good agricultural practices are also described. Main findings: Harvest and handling practices have major effects on postharvest decay. Mechanical harvesting systems and time of harvest have a prominent effect on postharvest decay and mycotoxin contamination. Fruit maturity at harvest, which directly affects bruising, is a major factor affecting infection by postharvest pathogens. Harvest of fruits from the ground and contact of harvest containers with soil contaminate fruits with postharvest propagules and result in increased decay. Climatic conditions affect sources of contamination and infection of fruits: under dry, hot subtropical climates latent and quiescent infections preharvest play a significant role while under warm, humid tropical climates contamination of fruit wounds during harvest can be of great importance, affecting levels of postharvest decay. Packing directly in the field reduces production costs but increases chances for postharvest decay. Electronic noses have been constructed that can “smell” and separate decayed fruits in packinghouses and predict mycotoxin contamination. Regression models have been developed to detect the impact of mechanical damage on postharvest decay. In addition, new packaging systems have been created to minimise mechanical injuries and decrease susceptibility to decay and bruising. Postharvest treatments, such as application of reduced-risk fungicide, biological agents and natural products, heat treatment and edible coating formulations, alone or in combination, can be successfully applied in a range of commodities in order to prevent decay. Directions for future research: The mode of action of antagonistic yeast in postharvest fruit disease control may be an important tool in postharvest biocontrol strategies, thus providing important guidance for their future application. In addition, mixtures of low-risk fungicides with biological agents should be carried out to identify the best postharvest treatments with the lowest environmental impact and the greatest consumer safety. Comparative studies for a range of fleshy products harvested from organic, integrated and conventional production systems should be also carried out.

Effects of microwave treatment on postharvest decay of fruits: a review

Purpose of review: Postharvest decay causes considerable losses to harvested fruits during transportation and storage. Synthetic fungicides are primarily used to control postharvest decay loss. However, the recent trend is shifting toward safer and more eco-friendly alternatives for the control of postharvest decay. Microwave power as a potential alternative to synthetic fungicides is increasingly used in controlling postharvest decay of fruits. This review aims at understanding microwave power fully and laying a good foundation for further research and application of this technology to controlling postharvest decay. Main findings: In this review, we mainly introduce the control effect of microwave power on postharvest decay in different fruits, discuss the possible mode of action in this process and the method of enhancing the control efficacy. These results are important for further use of microwave power on postharvest decay. Directions for future research: Future studies should focus on the mechanisms of action of microwaves in systemic resistance of fruits, finding more effective methods to enhance the control efficacy of microwave power on postharvest decay of fruits, and developing the technology to be used under large-scale operations.

Influence of post-harvest treatments with fludioxonil and soy lecithin co-application in controlling blue and grey mould and fludioxonil residues in Coscia pears

The residue levels of fludioxonil (FLU) were determined in Coscia pear following a 1-, 2- or 4-min dip in an aqueous mixture of FLU containing 300 or 100 mg l−1 (active ingredient, a.i.) at 20 and 50°C, respectively, with or without 2% soy lecithin. The efficacy of heat treatment with water and FLU mixtures was investigated on artificially inoculated pears for the control of post-harvest decay caused by blue (Penicillium expansum Link) and grey (Botrytis cinerea Pers. ex Fr.) mould. Treatment with 300 mg l−1 FLU at 20°C increased residues significantly when treatment time rose from 1 to 2 min; no further increase was recorded when dip time raised from 2 to 4 min. FLU residue rates were unaffected by treatment time when 300 mg l−1 a.i. was applied in combination with lecithin at 20°C. While treatment with 100 mg l−1 a.i. at 50°C for 1 and 2 min resulted in similar residue levels, significantly higher residues were detected when dip time increased from 1 to 4 min. Co-application of lecithin significantly decreased FLU residues with respect to fruit treated with FLU alone. Treatments with FLU at 20 or 50°C effectively controlled decay over 10 days of incubation. While co-application of lecithin did not affect the efficacy of FLU at 300 mg l−1and 20°C, treatment efficacy decreased when lecithin was applied in combination with 100 mg l−1 FLU and 50°C for 4 min and to a greater extent when dip time was 1–2 min.

Bell Pepper Plant Growth, Gas Exchange, Mineral Nutrition, Phytophtora Blight, Fruit Yield, and Postharvest Fruit Decay as Affected by Harpin Protein

Harpin protein is an elicitor of hypersensitive response in plants. When applied exogenously, harpin is claimed to control plant diseases, increase plant growth and yield, and reduce postharvest fruit decay. The plant responses to harpin application have been inconsistent. This study was intended to determine the effects of harpin on plant growth, gas exchange, control of Phytophtora blight, fruit yield, and control of postharvest fruit decay in bell pepper (Capsicum annum L.). When applied only before planting, harpin increased marketable yield of bell pepper, but when applied both before and after planting, it reduced marketable and total yields. Harpin had no beneficial effect on plant growth, leaf mineral nutrient content, leaf gas exchange, incidence of Phytophtora blight in the field, and incidence of softrot of fruit after harvest. Harpin had little or no positive effect on most plant attributes in bell pepper in the field or after harvest.

Biocontrol of gray mold decay in peach fruit by integration of antagonistic yeast with salicylic acid and their effects on postharvest quality parameters

The potential of using Rhodotorula glutinis alone or in combination with salicylic acid (SA) for the control of postharvest gray mold decay of peach fruit, and their effects on postharvest quality of fruit was investigated. Washed cell suspensions of yeast controlled gray mold better than yeast in culture broth. Treatment of wounds with autoclaved cell cultures or cell-free culture filtrate did not prevent decay. Rapid colonization of the yeast in wounds was observed during the first day at 20 °C, then the populations stabilized for the remaining storage period. Spore germination and germ tube elongation of Botrytis cinerea in PDB was controlled by the living cell of R. glutinis: the percentage of spore germination of B. cinerea incubated with R. glutinis was reduced by 69.3% compared with control; similarly, the length of germ tube of B. cinerea incubated with R. glutinis was reduced by 65.8% compared with control. SA (100 μg/mL) could enhance the biocontrol activity of R. glutinis against gray mold decay in peach fruit. The application of SA and R. glutinis as stand-alone treatments did not produce significant control efficacy to natural infection of peach fruits. However, R. glutinis in combination with SA resulted in low average natural infection incidence in fruit, 16.67%, compared with 46.67% in the water-treated control fruit. SA, the yeast antagonist and the combination of them both had no significant effect on quality parameters after 7 days at 20 °C.

Postharvest decay control and quality retention in litchi (cv. McLean's Red) by combined application of modified atmosphere packaging and antimicrobial agents

The effects of modified atmosphere packaging (MAP) [bioriented polypropylene (BOPP-1 or BOPP-2)] in combination with antimicrobial agents Bacillus subtilis, 10 7 colony-forming units (cfu) ml −1; ethylenediamine tetraacetic acid, calcium disodium salt hydrate (EDTA) (0.1%); or 4-hexylresorcinol (4-HR) (0.15%) on postharvest decay control and quality retention of litchi cv. McLean's Red were assessed as possible replacements for commercial SO 2 fumigation. Fruits dipped in B. subtilis, EDTA or 4-HR (5 min) separately, blow dried (25 °C, 3 min), packed in BOPP-1, held for 18 d at 2 °C, 95% RH, and 2 d at 14 °C, 75% RH were significantly less decayed. The antagonist–BOPP-1 combination also promoted the best bacterial survival during storage. B. subtilis was observed to survive effectively in BOPP-1 (16% O 2, 6% CO 2; ∼90% RH), but its survival was adversely affected in BOPP-2 (5% O 2, 8% CO 2; ∼93% RH). Alternaria alternata and Cladosporium spp. were the major decay-causing fungi in BOPP-1 treatments, and Candida, Cryptococcus and Zygosaccharomyces were the predominant yeasts in BOPP-2 treatments. Combination treatments EDTA, 4-HR or B. subtilis in BOPP-1 inhibited polyphenol oxidase (PPO) and significantly reduced pericarp browning and severity. Although the combination treatments EDTA, 4-HR or B. subtilis in BOPP were equally effective in controlling decay and browning, the EDTA and 4-HR affected the natural pinkish-red colour of the pericarp by showing higher h° values (orange–pink). Among the combination treatments, B. subtilis+BOPP-1 had the best potential to control decay, retain the colour and the overall litchi fruit quality during a marketing chain of 20 d.

Integrated control of postharvest blue mold decay of pears with hot water treatment and Rhodotorula glutinis

The potential of using Rhodotorula glutinis alone or in combination with hot water for the control of postharvest blue mold decay of pear fruit, and their effects on postharvest quality of fruit was investigated. Spore germination of Penicillium expansum was inhibited by hot (46 °C) water. Both hot water for 10–20 min and R. glutinis, as stand-alone treatments, reduced the incidence of blue mold decay, but complete control was not achieved by either treatment. However, a combination of hot water treatment and R. glutinis completely controlled decay of inoculated fruit. In addition, the combination of hot water treatment with R. glutinis on naturally infected, intact fruit, reduced decay from 66.7% in the control fruit to 13.3% after 15 days at 20 °C, and from 46.7 to 6.7% after 4 °C for 60 days followed by 20 °C for 15 days. None of the treatments impaired fruit quality. The combination of hot water and R. glutinis could be an alternative to synthetic fungicides for the control of postharvest blue mold decay on pears.