scholarly journals Fumigation of Stored Pome Fruit with Hexanal Reduces Blue and Gray Mold Decay

HortScience ◽  
2007 ◽  
Vol 42 (3) ◽  
pp. 611-616 ◽  
Author(s):  
Peter L. Sholberg ◽  
Paul Randall

Stored apples and pears are subject to blue and gray mold decay incited by Penicillium expansum and Botrytis cinerea respectively. Hexanal, a C6 carbon aldehyde, used as a vapor provided effective control of both blue and gray molds in laboratory experiments on apple slices. A preliminary trial with ‘Anjou’ pears in bins showed that hexanal was not corrosive and could reduce gray mold in pears stored for 7 months. However details on the correct procedure for fumigating pome fruit were lacking, and further studies were needed to develop a reliable fumigation strategy. In trials with inoculated fruit, hexanal inactivated conidia of B. cinerea contaminating the pear surface when used at a rate of 2 mg·L−1 for 24 hours or 4 mg·L−1 for 18 hours. It was less effective on ‘Gala’ apples inoculated with conidia of P. expansum, but reduced blue mold decay to low levels at 15 ºC. On the other hand, hexanal increased gray and blue molds when used after wounds were made in inoculated fruit. The use of a preharvest treatment with cyprodinil (0.62 g·L−1) reduced both blue and gray molds in wounds with or without hexanal fumigation. Thus a strategy for controlling postharvest decay was developed by which fruit were treated 2 weeks before harvest with cyprodinil, followed by fumigation with hexanal immediately after harvest. The use of this strategy on ‘Anjou’ pears produced the highest number of mold-free fruit in 2003 and the least amount of gray and blue mold decay in 2003 and 2004 on pears stored for 4 months. Wounded apples only developed 1% rot compared with 10% in the control, indicating that hexanal fumigation of stored apples reduced contamination. Monitoring hexanal during fumigation showed that hexanal concentration declined slowly over a 24-hour period and could accurately be described by a third-order polynomial equation. Hexanal fumigation at low rates (2–3 mg·L−1) was not phytotoxic and improved aroma in ‘Anjou’ pears and ‘Gala’ apples with no harmful effects on apple or pear firmness, pH, titratable acidity, or soluble solids.

2012 ◽  
Vol 58 (2) ◽  
pp. 205-212 ◽  
Author(s):  
Hanna Bryk ◽  
Dorota Kruczyńska

The occurrence of storage diseases on fruit of seven scab resistant apple cultivars (Freedom, Rajka, Topaz, Rubinola, Enterprise, Goldstar, GoldRush) grafted on M.9 was investigated in 2001-2005. The trees were planted in 1995. It was found that after storage (4 and 6 months at 2<sup>°</sup>C, 85-90% RH) the most severe appeared to be bull's eye rot (<i>Pezicula</i> spp.). The most sensitive cultivars to this disease were: Topaz, Freedom, Goldstar, the least sensitive were Rubinola, Enterprise, Rajka. Other postharvest diseases like gray mold (<i>Botrytis cinerea</i>), blue mold (<i>Penicillium expansum</i>) and brown rot (<i>Monilinia fructigena</i>) were not common. 'Rajka' and 'Goldstar' were susceptible to bitter pit, and 'Freedom' to superficial scald.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6170 ◽  
Author(s):  
Guangxi Wu ◽  
Wayne M. Jurick II ◽  
Franz J. Lichtner ◽  
Hui Peng ◽  
Guohua Yin ◽  
...  

Blue mold is a postharvest rot of pomaceous fruits caused by Penicillium expansum and a number of other Penicillium species. The genome of the highly aggressive P. expansum strain R19 was re-sequenced and analyzed together with the genome of the less aggressive P. solitum strain RS1. Whole genome scale similarities and differences were examined. A phylogenetic analysis of P. expansum, P. solitum, and several closely related Penicillium species revealed that the two pathogens isolated from decayed apple with blue mold symptoms are not each other’s closest relatives. Among a total of 10,560 and 10,672 protein coding sequences respectively, a comparative genomics analysis revealed 41 genes in P. expansum R19 and 43 genes in P. solitum RS1 that are unique to these two species. These genes may be associated with pome fruit–fungal interactions, subsequent decay processes, and mycotoxin accumulation. An intact patulin gene cluster consisting of 15 biosynthetic genes was identified in the patulin producing P. expansum strain R19, while only a remnant, seven-gene cluster was identified in the patulin-deficient P. solitum strain. However, P. solitum contained a large number of additional secondary metabolite gene clusters, indicating that this species has the potential capacity to produce an array of known as well as not-yet-identified products of possible toxicological or biotechnological interest.


Plant Disease ◽  
2002 ◽  
Vol 86 (8) ◽  
pp. 848-853 ◽  
Author(s):  
Shiping Tian ◽  
Qing Fan ◽  
Yong Xu ◽  
Haibo Liu

Biocontrol capability of the yeasts Trichosporon sp. and Cryptococcus albidus against Botrytis cinerea and Penicillium expansum was evaluated in apple (cv. Golden Delicious) and pear (cv. Jingbai) fruits at 1°C in air and under controlled atmospheres (CA) with 3% O2 + 3% CO2 or 3% O2 + 8% CO2. Trichosporon sp. controlled gray mold and blue mold of apple fruits more effectively than C. albidus (P < 0.05). Apple fruits treated with Trichosporon sp. and C. albidus had a lower incidence of gray mold rot than blue mold rot in the same storage conditions. Biocontrol efficacy of the yeasts for controlling gray mold and blue mold was better in apples than in pears. Populations of the yeasts in drop-inoculated wounds in fruits increased rapidly after 20 days at 1°C both in air and in CA conditions. There was no significant difference in colony diameters of the two pathogens cultured in 0 to 15% CO2 concentrations after 7 days at 20°C, but the colony diameter of both B. cinerea and P. expansum at 20% CO2 was significantly less than in other treatments (P < 0.05). CA with 3% O2 + 8% CO2 inhibited the pathogenic fungi more than CA with 3% O2 + 3% CO2.


2008 ◽  
Vol 98 (4) ◽  
pp. 427-435 ◽  
Author(s):  
H. X. Li ◽  
C. L. Xiao

Penicillium expansum is the primary cause of blue mold, a major postharvest disease of apple. Fludioxonil and pyrimethanil are two newly registered postharvest fungicides for pome fruit in the United States. To evaluate the potential risk of resistance development in P. expansum to the new postharvest fungicides, one isolate of each of thiabendazole-resistant (TBZ-R) and -sensitive (TBZ-S) P. expansum was exposed to UV radiation to generate fungicide-resistant mutants. Four fludioxonil highly-resistant mutants (EC50 > 1,000 μg/ml) and four pyrimethanil-resistant mutants (EC50 > 10 μg/ml) were tested for sensitivities to thiabendazole, fludioxonil, and pyrimethanil, and fitness parameters including mycelial growth, sporulation on potato dextrose agar (PDA), sensitivity to osmotic stress, and pathogenicity and sporulation on apple fruit. The stability of resistance of the mutants was tested on PDA and apple fruit. Efficacy of the three fungicides to control blue mold incited by the mutants was evaluated on apple fruit. Six fungicide-resistant phenotypes were identified among the parental wild-type isolates and their mutants based upon their resistance levels. All four fludioxonil highly-resistant mutants were sensitive to pyrimethanil and retained the same phenotypes of resistance to TBZ as the parental isolates. All four pyrimethanil-resistant mutants had a low level of resistance to fludioxonil with a resistance factor >15. The two pyrimethanil-resistant mutants derived from a TBZ-S isolate became resistant to TBZ at 5 μg/ml. After 20 successive generations on PDA and four generations on apple fruit, the mutants retained the same phenotypes as the original generations. All mutants were pathogenic on apple fruit at both 0 and 20°C, but fludioxonil highly-resistant mutants were less virulent and produced fewer conidia on apple fruit than pyrimethanil-resistant mutants and their parental wild-type isolates. Compared with the parental isolates, all four fludioxonil highly-resistant mutants had an increased sensitivity to osmotic stress on PDA amended with NaCl, while the pyrimethanil-resistant mutants did not. Pyrimethanil was effective against blue mold caused by fludioxonil-resistant mutants at both 0 and 20°C. Pyrimethanil and fludioxonil reduced blue mold incited by pyrimethanil-resistant mutants during 12-week storage at 0°C but were not effective at 20°C. TBZ was not effective against pyrimethanil-resistant mutants derived from TBZ-S wild-type isolates at room temperature but provided some control at 0°C. The results indicate that: (i) a fitness cost was associated with fludioxonil highly resistant mutants of P. expansum in both saprophytic and pathogenic phases of the pathogen but not pyrimethanil-resistant mutants; (ii) pyrimethanil possessed a higher risk than fludioxonil in the development of resistance in P. expansum; and (iii) triple resistance to the three apple-postharvest fungicides could emerge and become a practical problem if resistance to pyrimethanil develops in P. expansum populations.


2001 ◽  
Vol 91 (11) ◽  
pp. 1098-1108 ◽  
Author(s):  
W. J. Janisiewicz ◽  
T. J. Tworkoski ◽  
C. P. Kurtzman

Eight strains of Metschnikowia pulcherrima isolated over a 4-year period from an unmanaged orchard and selected for their biocontrol activity against blue mold (caused by Penicillium expansum) of apples were characterized phenotypically, genetically, and for their biocontrol potential against blue mold on apples. All strains grew well and only differed slightly in their growth in nutrient yeast dextrose broth medium at 1°C after 216 h, but large differences occurred at 0°C, with strain T5-A2 outgrowing other strains by more than 25% transmittance after 360 h. This strain was also one of the most resistant to diphenylamine (DPA), a postharvest antioxidant treatment. All strains required biotin for growth in minimum salt (MS) medium, although strain ST2-A10 grew slightly in MS medium containing riboflavin or folic acid, as did ST3-E1 in MS medium without vitamins. None of the strains produced killer toxins against an indicator strain of Saccharomyces cerevisiae. Analysis of Biolog data from YT plates for all eight strains using the MLCLUST program resulted in separation of the strains into one major cluster containing four strains and four scattered strains from which strain ST1-D10 was the most distant from all other strains. This was particularly apparent in 3-D and principle component analysis. Genetic differentiation of the eight strains using maximum parsimony analysis of nucleotide sequences from domain D1/D2 of nuclear large subunit (26S) ribosomal DNA resulted in detection of two clades. Strain ST1-D10 grouped with the type strain of M. pulcherrima but the remaining seven strains grouped separately, which might possibly represent a new species. All strains significantly reduced blue mold on mature Golden Delicious apples during 1 month of storage at 1°C followed by 7 days at room temperature, but strains T5-A2 and T4-A2 were distinctly more effective under these conditions. Strain T5-A2 also was the most effective in tests on harvest mature apples treated with the lowest concentration of the antagonist and stored for 3 months at 0.5°C. Populations of all eight strains increased in apple wounds by approximately 2 log units after 1 month at 1°C followed by 5 days at 24°C. Our results indicate that M. pulcherrima is an excellent candidate for biological control of postharvest diseases of pome fruit. The variation in phenotypic, genetic, and biocontrol characteristics among strains of M. pulcherrima isolated from the same orchard should make it possible to select antagonists with characteristics that are most desirable for postharvest application.


2002 ◽  
Vol 92 (3) ◽  
pp. 281-287 ◽  
Author(s):  
Carla Nunes ◽  
Josep Usall ◽  
Neus Teixidó ◽  
Maribel Abadias ◽  
Immaculada Viñas

The potential enhancement of Candida sake (CPA-1) by ammonium molybdate to control blue and gray mold caused by Penicillium expansum and Botrytis cinerea, respectively, on Blanquilla pears was investigated. In laboratory trials, improved control of blue and gray molds was obtained with the application of ammonium molybdate (1, 5, 10, and 15 mM) alone or in combination with C. sake at 2 × 106 or 2 × 107 CFU ml-1 on Blanquilla pears stored at 20°C. In semicommercial trials at 1°C for 5 months, the efficacy of C. sake at 2 × 106 CFU ml-1 on reducing P. expansum and B. cinerea decay was enhanced more than 88% with the addition of ammonium molybdate 5 mM in the 1999-2000 season. In two seasons, the performance C. sake at 2 × 106 CFU ml-1 plus ammonium molybdate was similar to or greater than that of C. sake at 2 × 107 CFU ml-1. Similar control of blue mold was obtained on pears stored under low oxygen conditions. The preharvest application of ammonium molybdate did not reduce postharvest blue mold decay. The population of C. sake on pear wounds significantly decreased in the presence of ammonium molybdate 1 and 5 mM at 20 and 1°C.


2018 ◽  
Author(s):  
Guangxi Wu ◽  
Wayne M Jurick II ◽  
Franz J Lichtner ◽  
Hui Peng ◽  
Guohua Yin ◽  
...  

Blue mold is a postharvest rot of pomaceous fruits caused by Penicillium expansum and a number of other Penicillium species. The genome of the highly aggressive P. expansum strain R19 was re-sequenced and analyzed together with the genome of the less aggressive P. solitum strain RS1. Whole genome scale similarities and differences were examined. A phylogenetic analysis of P. expansum, P. solitum, and several closely related Penicillium species revealed that the two pathogens isolated from decayed apple with blue mold symptoms are not each other’s closest relatives. Among a total of 10,560 and 10,672 protein coding sequences respectively, a comparative genomics analysis revealed 41 genes in P. expansum R19 and 43 genes in P. solitum RS1 that are unique to these two species. These genes may be associated with pome fruit–fungal interactions, subsequent decay processes, and mycotoxin accumulation. An intact patulin gene cluster consisting of 15 biosynthetic genes was identified in the patulin producing P. expansum strain R19, while only a remnant, seven-gene cluster was identified in the patulin-deficient P. solitum strain. However, P. solitum contained a large number of additional secondary metabolite gene clusters indicating that this species has the potential capacity to produce an array of known, as well as not-yet-identified products, of possible toxicological or biotechnological interest.


Horticulturae ◽  
2018 ◽  
Vol 4 (3) ◽  
pp. 18 ◽  
Author(s):  
Ronan Colombo ◽  
Deived Carvalho ◽  
Maria Cruz ◽  
Ciro Sumida ◽  
Saeed Ahmed ◽  
...  

‘BRS Isis’ is a novel hybrid seedless table grape with large reddish bunches. This cultivar is cultivated in tropical and subtropical areas and has potential to be exported overseas; however, under these growth conditions, grapes can be severely damaged by gray mold (Botrytis cinerea), the main postharvest disease of table grapes. Thus, this study aimed to evaluate different pre- and postharvest strategies to extend the storage period of ‘BRS Isis’ seedless table grapes. The treatments consisted of grapes packed into carton boxes under cold storage (1 °C and high relative humidity), pre- and/or postharvest treatment with potassium bicarbonate or a biological control agent (Bacillus subtilis), all with Botrytis inoculation. Additionally, two controls, with and without Botrytis inoculation, were also evaluated. The experimental design was completely randomized with eight treatments and three replications, and each plot consisted of four bunches. After a 50-day cold storage period, the carton boxes were kept for five days at room temperature (22 °C). Gray mold incidence and water loss, as well as soluble solids (SS), pH, titratable acidity (TA), SS/TA ratio, and color attributes were evaluated during both periods. Cold storage effectively reduced gray mold in ‘BRS Isis’ seedless grape for a period of 50 days, even when grapes were inoculated; however, no difference among treatments was observed. Higher water loss was observed in both non-treated control treatments.


Agronomy ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 603 ◽  
Author(s):  
Ahmed ◽  
Ruffo Roberto ◽  
Youssef ◽  
Colombo ◽  
Shahab ◽  
...  

‘BRS Isis’ is a new hybrid seedless table grape tolerant to downy mildew with a good adaptation to the tropical and subtropical climates. Gray mold, caused by Botrytis cinerea Pers. ex Fr. is known as the most important postharvest mold in table grapes, causing extensive losses worldwide. As the postharvest behavior of ‘BRS Isis’ is still unknown, the objective of this work was to evaluate the postharvest preservation and B. cinerea mold control of this new grape cultivar, grown under the double-cropping a year system. Grape bunches were purchased from a field of ‘BRS Isis’ seedless table grapes trained on overhead trellises located at Marialva, state of Parana (South Brazil). Grapes were subjected to the following treatments in a cold room at 1 ± 1°C: (i) Control; (ii) SO2-generating pad; (iii) control with bunches inoculated with the pathogen suspension; (iv) SO2-generating pad with bunches inoculated with the pathogen suspension. The completely randomized experimental design was used with four treatments, each including five replicates. The incidence of gray mold and other physicochemical variables, including bunch mass loss, shattered berries, skin color index, soluble solids (SS), titratable acidity (TA), and SS/TA ratio of grapes, were evaluated at 50 days after the beginning of cold storage and at seven days at room temperature (22 ± 2°C). The ‘BRS Isis’ seedless grape, packaged with SO2-generating pads and plastic liners, has a high potential to be preserved for long periods under cold storage, at least for 50 days, keeping very low natural incidence of gray mold, mass loss, and shattered berries.


2002 ◽  
Vol 65 (1) ◽  
pp. 178-184 ◽  
Author(s):  
CARLA NUNES ◽  
JOSEP USALL ◽  
NEUS TEIXIDÓ ◽  
ROSARIO TORRES ◽  
IMMACULADA VIÑAS

The effectiveness of Candida sake (CPA-1) in combination with Pantoea agglomerans (CPA-2) for controlling Penicillium expansum and Botrytis cinerea on pears and apples was determined. The concentrations tested were 2 × 106 and 2 × 107 CFU/ml for C. sake and 2 × 107 and 8 × 107 CFU/ml for P. agglomerans. At room temperature, the two antagonists were combined in proportions of 0 to 100% in 25% increments. At the proportion of 50:50, no rot development was observed in pears, and the greatest control of blue mold in apples was observed at this proportion for all the tested concentrations. Under cold temperature on pears, the highest effectiveness of the mixture was observed when C. sake at 2 × 107 CFU/ml was combined with P. agglomerans at 2 × 107 or at 8 × 107 CFU/ml at the proportion 50:50. Under these conditions, no rot development of blue mold was reported, and gray mold lesion size was reduced by more than 95%. On apples, the mixture of C. sake at 2 × 107 CFU/ml and P. agglomerans at 8 × 107 CFU/ml at the proportion 50:50 reduced blue and gray mold incidence by 90%. Populations of the two antagonists had the same growth pattern at 20°C when they were applied individually or in combination, but the population level was always higher when they grew alone. In contrast, at 1°C, the population of both antagonists in combination formed a stable community with the same levels as individual application during the first 30 days; after that, C. sake dominated, and P. agglomerans decreased on apples and pears. At both temperatures, the maximum population level of C. sake was observed in apples, and the maximum population level of P. agglomerans was observed in pears.


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