Effects of yeast antagonist in combination with UV-C treatment on postharvest diseases of pear fruit

BioControl ◽  
2011 ◽  
Vol 57 (3) ◽  
pp. 451-461 ◽  
Author(s):  
Lingfei Xu ◽  
Yanmin Du
Keyword(s):  
Postharvest Diseases ◽  
Pear Fruit ◽  
Yeast Antagonist ◽  
Uv C

scholarly journals Prevalence and Incidence of Phacidiopycnis Rot in d'Anjou Pears in Washington State

Plant Disease ◽  
2004 ◽  
Vol 88 (4) ◽  
pp. 413-418 ◽  
Author(s):  
C. L. Xiao ◽  
R. J. Boal
Keyword(s):  
The United States ◽  
Gray Mold ◽  
Washington State ◽  
Postharvest Disease ◽  
Wound Infections ◽  
Postharvest Diseases ◽  
Pear Fruit ◽  
Blue Mold ◽  
Penicillium Spp ◽  
Organic Orchards

Phacidiopycnis rot, caused by Phacidiopycnis piri, is a newly recognized postharvest disease in pear fruit (Pyrus communis cv. d'Anjou) in the United States. To determine the prevalence and incidence of this disease, decayed fruit were sampled during packing and repacking operations from four packinghouses in 2001 and 2002. During March to May (repacking) in 2001, Phacidiopycnis rot was found in packed fruit that were stored in cardboard boxes from 22 of 26 grower lots (orchards), and accounted for 5 to 71% of the total decay. Phacidiopycnis rot, gray mold caused by Botrytis cinerea, and blue mold caused by Penicillium spp. accounted for an average of 34.1, 10.3, and 33.6% of decayed fruit from conventional orchards, respectively; and 22.8, 35.7, and 23.5% of decayed fruit from organic orchards, respectively. During November 2001 to January 2002 (packing), Phacidiopycnis rot was observed in fruit that were stored in field bins before packing from 30 of 33 grower lots, accounting for 18.4% of decayed fruit sampled. During March to May in 2002, Phacidiopycnis rot was responsible for 2 to 68% of decayed fruit sampled from 36 of 39 grower lots. Phacidiopycnis rot, gray mold, and blue mold accounted for an average of 19.6, 26.8, and 37.4% of decayed fruit from conventional orchards, respectively; and 42.2, 25.7, and 8.2% of decayed fruit from organic orchards, respectively. Most Phacidiopycnis rot that occurred in field bins before packing appeared to originate from wound infections; whereas after packing, approximately 60 and 30% of Phacidiopycnis rot originated from stem and calyx infections, respectively. This study indicates that Phacidiopycnis rot should be considered one of the targets for control of postharvest diseases in d'Anjou pears in the region.

scholarly journals A Postharvest Fruit Rot in d'Anjou Pears Caused by Sphaeropsis pyriputrescens sp. nov

Plant Disease ◽  
2004 ◽  
Vol 88 (2) ◽  
pp. 114-118 ◽  
Author(s):  
C. L. Xiao ◽  
J. D. Rogers
Keyword(s):  
Storage Period ◽  
Washington State ◽  
Fruit Rot ◽  
Postharvest Diseases ◽  
Pear Fruit ◽  
Oatmeal Agar ◽  
Colony Diameter ◽  
Light Yellow ◽  
Fruit Decay ◽  
Pathogenicity Tests

During a survey of postharvest diseases in stored pears conducted in the 2001-02 storage season, a new postharvest fruit rot in d'Anjou pears was discovered in Washington State. Symptoms of this disease were stem-end rot, calyx-end rot, and wound-associated rot, which presumably originated from infections of stem, calyx, and wounds on the fruit surfaces, respectively. The decayed area on the fruit was firm or spongy and appeared brown. During the late storage period from March to May 2002, this disease was observed in 19 of 39 lots and accounted for 2 to 21% of all decayed fruit. The causal agent, Sphaeropsis sp., was consistently recovered from decayed fruit with the symptoms described above. Two isolates of the fungus were used for pathogenicity tests on pear fruit. Decay symptoms developed on fruit inoculated with spore suspensions of the fungus on the stem, calyx, and wounds on the fruit surface. The fungus was reisolated from these decayed fruit. The fungus, Sphaeropsis pyriputrescens sp. nov., was characterized and described. On potato dextrose agar (PDA), oatmeal agar, and pear juice agar at 20°C, the fungus grew at mean rates of 21, 15, and 24 mm day-1 in colony diameter, respectively. On PDA, the fungus formed a circular colony with dense, hyaline hyphae and a few or some aerial mycelia. Colonies appeared light yellow to yellow on 2-week-old PDA cultures. The fungus grew at temperatures from 0 to 25°C, with optimum growth between 15 and 20°C, little or no growth at 30°C, and no growth at 35°C. This is a low-temperature species.

scholarly journals Cultural, Chemical, and Alternative Control Strategies for Rhizopus Soft Rot of Sweetpotato

Plant Disease ◽  
2016 ◽  
Vol 100 (8) ◽  
pp. 1532-1540 ◽  
Author(s):  
A. C. Scruggs ◽  
L. M. Quesada-Ocampo
Keyword(s):  
Relative Humidity ◽  
Storage Temperature ◽  
Control Strategies ◽  
Disease Incidence ◽  
Soft Rot ◽  
Postharvest Diseases ◽  
Alternative Control ◽  
Inoculum Level ◽  
Initial Inoculum ◽  
Uv C

Rhizopus soft rot, caused primarily by Rhizopus stolonifer, is one of the most common postharvest diseases of sweetpotato and is often considered the most devastating. Traditionally, Rhizopus soft rot has been effectively controlled using postharvest dips in dicloran fungicides; however, due to changes in market preferences, use of these fungicides is now limited. This, along with the lack of labeled and effective fungicides for control of Rhizopus soft rot in sweetpotato, creates the need for integrated strategies to control the disease. The effects of storage temperature (13, 23, and 29°C), relative humidity (80, 90, and 100%), and initial inoculum levels (3-, 5-, and 7-mm-diameter mycelial plugs) on progression of Rhizopus soft rot in ‘Covington’ sweetpotato were examined. Percent decay due to Rhizopus soft rot infection was significantly reduced (P < 0.0001) at a low temperature (13°C) but was not significantly affected by changes in relative humidity or initial inoculum level (P >0.05). Sporulation of R. stolonifer was also significantly reduced at the lowest temperature of 13°C. High relative humidity (>95%) significantly increased sporulation of R. stolonifer and sporulation also increased as initial inoculum level increased. Efficacy of chlorine dioxide (ClO2) fumigation, UV-C irradiation, and postharvest dips in alternative control products were also investigated for control of Rhizopus soft rot. Static ClO2 treatments were effective in reducing sporulation on treated roots but had no significant impact on incidence of Rhizopus soft rot. UV irradiation at 3.24 KJ/m2 1 h after inoculation as well as dips in aqueous ClO2 and StorOx 2.0 significantly (P < 0.05) reduced disease incidence. Understanding the epidemiological factors favoring Rhizopus soft rot and identifying alternative control strategies allow for improved recommendations to limit postharvest losses in sweetpotato.

scholarly journals Effects of postharvest application of UV-C radiation on the control of microorganisms and maintenance of quality in strawberries

2019 ◽  
Author(s):  
Gabriel Palma Petrielli ◽  
Franciane Colares Souza Usberti ◽  
Raysa Maduro Alves
Keyword(s):  
Fruits And Vegetables ◽  
Low Cost ◽  
Storage Conditions ◽  
Postharvest Diseases ◽  
Toxic Compounds ◽  
Postharvest Application ◽  
And Storage ◽  
Uv C ◽  
Different Doses ◽  
High Metabolic Activity

Because it is a highly perishable fruit, due to its high metabolic activity and water content, the strawberry has a shelf life limited by weight loss, texture alteration and microbiological deterioration. Such susceptibility to proliferation of microorganisms and the occurrence of postharvest diseases, especially some rot, stimulates the study of alternative sanitizing treatments that aims at the maintenance of fruit quality such as ultraviolet radiation, which it exhibits germicidal properties in the region UV-C (200-280nm). The non-formation of residual toxic compounds on the surface of the product, a low cost and the fact of being odorless are advantages of its use in fruits and vegetables.¹ In the present study the objective was to evaluate the efficacy and effects of UV-C radiation in strawberries by applying 0.0 (T1), 1.25 (T2), 2.50 (T3), 3.75 (T4) and 5.0 (T5) kJ/m² and storage at 5.37 ± 0.74 ºC and 53.38 ± 6.84% RH after irradiation. The experiment was conducted in a completely randomized blocks design with three replicates per treatment. In the results, it was not possible to observe some benefits of UV-C in strawberries in relation to their non-use, suggesting it needs further studies with different doses and storage conditions.

Biological Control of Postharvest Diseases of Citrus and Deciduous Fruit

1991 ◽  
Author(s):  
Charles Wilson ◽  
Edo Chalutz
Keyword(s):  
Mode Of Action ◽  
Large Scale ◽  
Fruits And Vegetables ◽  
Control Measures ◽  
Commercial Application ◽  
Control Procedure ◽  
Postharvest Diseases ◽  
Cooperative Research ◽  
Antagonistic Microorganisms ◽  
Yeast Antagonist

The objectives of this research were to develop control measures of postharvest diseases of citrus and deciduous fruits by using naturally-occurring, non-antibiotic-producing antagonists; study the mode of action of effective antagonists and optimize their application methods. Several antagonists were found against a variety of diseases of fruits and vegetables. One particularly effective yeast antagonist (US-7) was chosen for more in-depth studies. This antagonist outcompetes rot pathogens at the wound site for nutrients and space; it is better adapted than the pathogen to extreme environmental conditions such as temperature, humidity and osmotic changes, and is relatively resistant to common postharvest fungicides. Our data suggests that other modes of action may also be involved. These are induction of host resistance by the antagonists or its products, and direct interaction between the antagonists and the pathogen with the possible involvement of an extracellular material and/or cell wall degrading enzymes produced by the antagonist. However, these interactions were not fully elucidated. The antagonistic activity of US-7 and other biocontrol agents isolated, was enhanced by calcium salts. While the mode of action is not known, the addition of these salts had a significant effect both in laboratory experiments and in large-scale tests. Compatibility of the yeast antagonist with present packinghouse treatments and procedures was determined. An integrated control procedure was developed, utilizing the antagonists together with ultra-low dosages of fungicides and activity-enhancing additives. This cooperative research resulted in numerous publications describing the antagonistic agents. their mode of action and possible commercial application. Patents were developed from this research and a commercial company is pursuing the licensing of these patents and the testing of the procedure on a commercial scale. Our research findings have expanded the potential for using non-antibiotic-producing antagonistic microorganisms in the control of postharvest diseases of fruits and vegetables; thus meeting a critical need to find alternatives to the use of synthetic fungicides on food products.  

scholarly journals Fruit Surface Colonization and Biological Control of Postharvest Diseases of Pear by Preharvest Yeast Applications

Plant Disease ◽  
1999 ◽  
Vol 83 (9) ◽  
pp. 839-844 ◽  
Author(s):  
Jesse M. Benbow ◽  
David Sugar
Keyword(s):  
Biological Control ◽  
Rhodotorula Glutinis ◽  
Initial Population ◽  
Cryptococcus Laurentii ◽  
Postharvest Diseases ◽  
Pear Fruit ◽  
Candida Oleophila ◽  
Population Sizes ◽  
Fruit Surface ◽  
Total Yeast

The yeasts Cryptococcus infirmo-miniatus, Cryptococcus laurentii, and Rhodotorula glutinis, applied to Bosc and d'Anjou pear fruit in the field 3 weeks prior to harvest, maintained high population levels through harvest, while populations of Candida oleophila declined after 1 and 2 weeks, and by harvest were not significantly different from total yeast populations on untreated fruit. Yeasts were sprayed individually on fruit at concentrations of 1 to 3 × 108 CFU/ml, with approximately 2 ml applied per fruit. Initial population sizes for all four species averaged 5 × 106 CFU per fruit. C. infirmo-miniatus provided the most consistent decay control in fruit treated 3 weeks before harvest. C. infirmo-miniatus and R. glutinis also provided significant postharvest decay control in Bosc fruit treated 1 day before harvest.

scholarly journals A New Postharvest Fruit Rot in Apple and Pear Caused by Phacidium lacerum

Plant Disease ◽  
2016 ◽  
Vol 100 (1) ◽  
pp. 32-39 ◽  
Author(s):  
M. S. Wiseman ◽  
Y. K. Kim ◽  
F. M. Dugan ◽  
J. D. Rogers ◽  
C. L. Xiao
Keyword(s):  
Phylogenetic Analysis ◽  
Ribosomal Subunit ◽  
Morphological Characteristics ◽  
Apple Fruit ◽  
Fruit Rot ◽  
Morphological Data ◽  
Postharvest Diseases ◽  
Pear Fruit ◽  
Diseased Fruit ◽  
Molecular Phylogenetic

During surveys for postharvest diseases of apple and pear, an unknown postharvest fruit rot was observed in Washington State. The disease appeared to originate from infection of the stem and calyx tissue of the fruit or wounds on the fruit. An unknown pycnidial fungus was consistently isolated from the decayed fruit. Isolates from apple and pear were characterized and identified by molecular phylogenetic analysis and morphology. Pathogenicity of representative isolates on apple and pear fruit was tested under laboratory or field conditions. A BLAST search in GenBank showed that isolates differed from Phacidium lacerum and its synonym, Ceuthospora pinastri, by only 0 to 4 bp in sequences within part of the combined large ribosomal subunit + internal transcribed spacer + small ribosomal subunit regions. The phylogenetic analysis confirmed the taxonomic placement of the unknown fungus in the genus Phacidium, with the highest match being C. pinastri (formerly anamorphic P. lacerum) and with closely related taxa from GenBank forming congeneric clades. The fungus grew at 0 to 30°C and formed unilocular to multilocular pycnidial conidiomata on artificial media after approximately 5 to 7 days at room temperature. On potato dextrose agar incubated for a 12-h photoperiod, semi-immersed globose to subglobose pycnidial conidiomata were 250 to 1,000 μm in diameter (mean = 350), with 1 to 3 nonpapillate to slightly papillate ostioles and a buff conidial matrix. Conidia produced on phialides were 8 to 13 by 1.5 to 2.5 μm, hyaline, aseptate, cylindrical, with an abruptly tapered, typically slightly protuberant base, 2 to 3 guttules, and sometimes with a mucilaginous, flexuous, unbranched appendage which is attached to the apex of the conidium and disappears with age. Conidiogenous cells were flask shaped and 6 to 15 ×1.5 to 3 μm. Colony characteristics included felt-like aerial white mycelium, gray olivaceous at the center becoming greenish to colorless toward the margin, in concentric rings, with pycnidia forming in 5 to 7 days originating from the center of the plate. Morphological characteristics of the fungus had the greatest conformity with the description for C. pinastri. Based on molecular and morphological data, the fungus is identified as P. lacerum. ‘Fuji’ apple fruit and ‘d’Anjou’ pear fruit that were wounded, inoculated with representative isolates, and incubated at 0°C yielded the same symptoms as seen on decayed fruit collected from commercial fruit packinghouses. Stem-end rot, calyx-end rot, and wound-associated rot developed on fruit inoculated in the orchard after 3 months of cold storage. The fungus was reisolated from the diseased fruit. This is the first report of a fruit rot in apple and pear caused by P. lacerum. We propose Phacidium rot as the name of this disease.

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