Investigations on brown rot of apricots caused by Sclerotinia fructicola (Wint.) Rehm. I. The occurrence of latent infection in fruit

1956 ◽  
Vol 7 (6) ◽  
pp. 504 ◽  
Author(s):  
GC Wade
Keyword(s):  
Latent Infection ◽  
Brown Rot ◽  
Inhibitory Substance ◽  
Histological Studies ◽  
Green Fruit ◽  
Fruit Surface

Evidence is presented that infection of apricot fruit with Sclerotinia fructicola may occur early in the fruit's development but remain latent until ripening commences. Evidence from culturing from green fruit is supported by the results of spraying experiments with fungicides and by inoculation experiments. Latent infection is confined to the epidermis and is not associated with any particular position on the fruit surface. Histological studies indicate that infection takes place through the stomata. It is tentatively suggested that an inhibitory substance is present in green fruit, and maintains infections in a latent condition. The presence of a substance inhibitory towards a species of Histoplasma is demonstrated. This substance begins to disappear as ripening commences.

scholarly journals Factors Affecting Latent Infection of Prune Fruit by Monilinia fructicola

2001 ◽  
Vol 91 (9) ◽  
pp. 864-872 ◽  
Author(s):  
Yong Luo ◽  
Themis J. Michailides
Keyword(s):  
Growth Stage ◽  
Latent Infection ◽  
Developmental Stages ◽  
Seasonal Pattern ◽  
Brown Rot ◽  
Effect Of Temperature ◽  
Monilinia Fructicola ◽  
Inoculum Concentration ◽  
Factors Affecting ◽  
Commercial Harvest

Experiments were conducted in three prune orchards in California. In each orchard, inoculations with Monilinia fructicola, the causal agent of brown rot of stone fruits, were performed on branches of trees at bloom and fruit developmental stages. Five inoculum concentrations were used in each inoculation. Six and four wetness durations were created for each inoculum concentration at bloom and fruit developmental stages, respectively. Fruit were harvested 3 weeks before commercial harvest. The overnight freezing incubation technique was used to promote sporulation and to determine incidence of latent infection (ILI) of fruit brown rot. No differences in ILI among locations were found. A seasonal pattern of bloom and fruit susceptibility to latent infection was determined. Susceptibility to latent infection at bloom stage was at a moderate level and increased to reach the highest level at pit hardening stage. Subsequently, fruit susceptibility to latent infection decreased, reaching the lowest level in early June at embryo growth stage. Thereafter, the susceptibility increased again with fruit development and maturity until harvest. Linear relationships between ILI and inoculum concentration were obtained for most combinations of growth stage and wetness duration. Incidence of latent infection increased linearly with increased wetness duration at bloom stage and increased exponentially with increased wetness duration at early and late fruit developmental stages. The optimum temperatures for latent infection at pit hardening stage ranged from 14 to 18°C, but the effect of temperature on latent infection was reduced at resistant stages. The temperature range favorable to latent infection varied for different wetness durations.

scholarly journals Analysis of Factors Affecting Latent Infection and Sporulation of Monilinia fructicola on Prune Fruit

Plant Disease ◽  
2001 ◽  
Vol 85 (9) ◽  
pp. 999-1003 ◽  
Author(s):  
Yong Luo ◽  
Zhonghua Ma ◽  
Themis J. Michailides
Keyword(s):  
Latent Infection ◽  
Secondary Infection ◽  
Brown Rot ◽  
Monilinia Fructicola ◽  
Latent Infections ◽  
Inoculum Concentration ◽  
Factors Affecting ◽  
Plastic Bags ◽  
Causal Pathogen ◽  
Significant Factors

Two studies were conducted to determine the effects of water content (WC) on sporulation on thinned fruit and the effects of wetness duration, inoculum density, and temperature on secondary infection of prune fruit by Monilinia fructicola, the main causal pathogen of brown rot in California. In the first study, sporulation intensity and duration of sporulation of the pathogen were tested on inoculated thinned fruit with five levels (67.2, 53.8, 40.3, 26.9, and 13.4%) of WC. Regression analyses showed that both sporulation intensity and duration of sporulation increased as WC of thinned fruit increased. The predicted difference in duration of sporulation between fruit with 13.4 and 67.2% WC was about 3 days. In the second study, three inoculum concentrations (8,000, 16,000, and 24,000 conidia per milliliter) of M. fructicola were atomized onto prune fruit on trees in an orchard. Inoculated fruit and shoots were covered with plastic bags to maintain wetness duration for 4, 8, 12, or 16 h. An overnight freezing and incubation technique was used after harvest to determine the proportion of fruit with latent infection. Regression analysis demonstrated that inoculum concentration and wetness duration were significant factors affecting secondary infection. Temperature was less important. Increased inoculum concentration and wetness duration increased the percentage of fruit with latent infections. Increased temperature decreased the percentage of fruit with latent infections.

scholarly journals Risk Analysis for Latent Infection of Prune by Monilinia fructicola in California

2001 ◽  
Vol 91 (12) ◽  
pp. 1197-1208 ◽  
Author(s):  
Yong Luo ◽  
Themis J. Michailides
Keyword(s):  
Risk Analysis ◽  
Latent Infection ◽  
Developmental Stages ◽  
Brown Rot ◽  
Low Risk ◽  
Weather Data ◽  
Risk Level ◽  
Monilinia Fructicola ◽  
Inoculum Potential ◽  
Risk Levels

The quantitative relationships between incidence of latent infection (ILI) of prune by Monilinia fructicola and wetness duration (WD) for different bloom and fruit developmental stages and different inoculum concentrations were obtained. Three levels of ILI were considered as criteria for low, moderate, and high risks of latent infection, respectively. Seasonal patterns of WD leading to different risk levels of latent infection were obtained for low (IPL) and high (IPH) inoculum potential conditions in orchards. Longer WD was needed at a resistant than at a susceptible fruit developmental stage to induce similar levels of latent infection. The curves of WD leading to different levels of ILI over the growing season (risky WD curves) were used in risk analysis for latent infection. Multi-year historical WD data from 10 prune-growing locations in California were compared with risky WD curves. The percentage of days (P) with WD leading to a certain risk level of latent infection was calculated for each month from historical weather data. Under the IPL condition, the P distributions for low risk of latent infection were higher in March and April than in May and were the lowest in June for most locations. Under the IPH condition, the number of days that WD leading to low risk of latent infection in May increased compared with those under the IPL condition. The risk analysis approach was evaluated by using separate experimental data as incidence of fruit brown rot obtained from different prune orchards over years. Consistency between predicted overall risk levels of latent infection and observed incidence of fruit brown rot was obtained. The results demonstrated the usefulness of the risk analysis in decision support system for disease management.

scholarly journals Primary Inoculum Sources of Monilinia spp. in Spanish Peach Orchards and Their Relative Importance in Brown Rot

Plant Disease ◽  
2010 ◽  
Vol 94 (8) ◽  
pp. 1048-1054 ◽  
Author(s):  
M. Villarino ◽  
P. Melgarejo ◽  
J. Usall ◽  
J. Segarra ◽  
A. De Cal
Keyword(s):  
Latent Infection ◽  
Brown Rot ◽  
Monilinia Fructicola ◽  
Relative Importance ◽  
Inoculum Sources ◽  
Primary Inoculum ◽  
Ebro Valley ◽  
Growing Seasons ◽  
Fruit Orchards ◽  
Peach Orchard

Immediately following the identification of Monilinia fructicola in a Spanish peach orchard in the Ebro Valley in 2006, this orchard and two other orchards in the same valley were intensively sampled for potential tree and ground sources of primary Monilinia inoculum before and during three growing seasons between 2006 and 2008. Overwintered Monilinia spp. produced inoculum from only mycelium, and no apothecia were found in any of the three orchards over the three growing seasons. Mummies on trees were the main source of primary inoculum. More than 90% of Monilinia isolates on all fruit mummies were M. laxa. Positive relationships were found between (i) the number of mummified fruit and the incidence of postharvest brown rot (P = 0.05, r = 0.75, n = 8), and (ii) the number of mummified fruit and nonabscised aborted fruit in the trees and the number of conidia on the fruit surface (P = 0.04, r = 0.71; P = 0.01, r = 0.94, respectively, n = 8) and the incidence of latent infection (P = 0.03, r = 0.75; P = 0.001, r = 0.99; respectively, n = 8). In addition, the numbers of mummified fruit and pruned branches on the orchard floor were correlated with the number of airborne conidia in the orchard. Based on the results of these surveys, the control of brown rot in stone fruit orchards is discussed.

scholarly journals PLANT HORMESIS INDUCED BY ULTRAVIOLET LIGHT-C FOR INDUCING RESISTANCE OF BROWN ROT OF PEACHES

HortScience ◽  
1992 ◽  
Vol 27 (11) ◽  
pp. 1168h-1169
Author(s):  
C. Stevens ◽  
P. L. Pusey ◽  
V. A. Khan ◽  
J. Y. Lu ◽  
C. L. Wilson ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Ultraviolet Light ◽  
Prunus Persica ◽  
Latent Infection ◽  
Negative Relationship ◽  
Brown Rot ◽  
Host Responses ◽  
Pal Activity ◽  
Lyase Activity ◽  
Uv C

Low hormetic doses of ultraviolet light (UV-C) stress on exposed peaches (Prunus persica). reduced brown rot resulting from field and artificial inoculation from Monilinia fructicola. To test the hypothesis that UV-C induced resistance through host responses the following tests involving biochemical changes (phenlyalanine ammonia-lyase activity (PAL) and ethylene production (EP)), bioassay of antifungal activity of tissue extracts to the fungus, and latent infection of rot free peaches previously treated with and without UV-C were determined. Exposure of peaches to UV-C dose of 7.5×104 ergs/mm2 promoted an increase in PAL and EP compared to the control. As the PAL activity increased, percent storage rots decreased. Antifungal activity to the fungal conidia in UV-C treated peach extract showed that the percent conidia germination was reduced 3 folds. Preharvest infection of brown rot which indicated latent infection was significantly reduced. To test for the germicidal effect of UV-C on M. fructicola on the surface of peaches, an artificial epiphytic population of the fungus was deposited on the peaches. A negative relationship between UV-C dose of 1.3 to 40×104 ergs /mm2, colony forming units and number of decaying brown rot lesions were found.

scholarly journals Impact of Postharvest Handling on Preharvest Latent Infections Caused by Monilinia spp. in Nectarines

2020 ◽  
Vol 6 (4) ◽  
pp. 266
Author(s):  
Carlos Garcia-Benitez ◽  
Carla Casals ◽  
Josep Usall ◽  
Ismael Sánchez-Ramos ◽  
Paloma Melgarejo ◽  
...  
Keyword(s):  
Cold Storage ◽  
Latent Infection ◽  
Brown Rot ◽  
Gompertz Model ◽  
Storage Conditions ◽  
Economic Losses ◽  
Latent Infections ◽  
Post Harvest ◽  
Physiological Time ◽  
Postharvest Handling

Latent infections caused by Monilinia spp. in nectarines cause great economic losses since they are not detected and rejected at harvest and can appear at any time post-harvest, even at the consumer’s home. The effect of a pre-cooling chamber, water dump operation, and cold-storage chamber on the activation and/or development of preharvest latent infections caused by Monilinia spp. on nectarines were studied under different postharvest conditions: (a) cold storage for 0, 1, or 3 d at 4 °C at either 75% relative humidity (RH) or 100% RH before water dumping, (b) water dumping for 10 minutes at 15 °C, and (c) cold storage for 0, 3, or 10 d at 4 °C at either 75% RH or 100% RH after water dumping. These storage conditions were transformed to fungal physiological time. For visualization of the latent infections caused by Monilinia spp., the nectarines were placed in sterile paper bags and frozen at −20 °C for 48 h in order to damage the epidermis. To compare different handling scenarios, the incidence of latent infection was modelled for physiological time description by a modified Gompertz model. The activation and/or development of preharvest natural latent infections caused by Monilinia spp. at postharvest was mainly related to temperature and incubation time at postharvest. Storing nectarines with any postharvest handling less than 11 days at 4 °C avoids brown rot symptoms and reduced the activation and/or development of pre-harvest latent infections caused by Monilinia spp., while more cold days caused the exponential phase of latent infection activation and/or development. The Gompertz model employed could be used for predicting the activation and/or development of latent infection caused by Monilinia spp. at postharvest conditions and looks at the postharvest life. To our knowledge, this is the first time that the effects of post-harvest handling on latent infections in fruit have been studied.

scholarly journals Incidence of Latent Infection of Immature Peach Fruit by Monilinia fructicola and Relationship to Brown Rot in Georgia

Plant Disease ◽  
2000 ◽  
Vol 84 (8) ◽  
pp. 853-857 ◽  
Author(s):  
K. M. Emery ◽  
T. J. Michailides ◽  
H. Scherm
Keyword(s):  
Latent Infection ◽  
Disease Risk ◽  
Brown Rot ◽  
Biological Indicator ◽  
Fruit Rot ◽  
Monilinia Fructicola ◽  
Latent Infections ◽  
Ripening Stage ◽  
Peach Fruit ◽  
Immature Fruit

Peach fruit are most susceptible to infection by Monilinia fructicola during the preharvest ripening stage. Although various sources of inoculum for preharvest infection have been characterized, the role of latent infection of immature fruit in the carryover of M. fructicola from the spring (blossom blight phase) to the preharvest period (fruit rot phase) is unknown for the southeastern United States. From 1997 to 1999, immature peach fruit were collected at 14-day intervals from orchards in middle and northern Georgia. Fruit were surface disinfested and treated with paraquat (1997) or frozen overnight (1998 and 1999) to induce tissue senescence and activate latent infections. Across sites and years, the incidence of latent infection remained low until the final sampling date 7 to 12 days before harvest. The incidence of latent infection on the final sampling date ranged from 0 to 22.0% and correlated significantly with both the incidence of blossom blight earlier in the season (r = 0.9077, P = 0.0332) and the incidence of fruit rot at harvest (r = 0.9966, P = 0.0034). There also was a significant association between the incidence of latent infection at the onset of pit hardening (between 7 and 10 weeks before harvest) and subsequent fruit rot incidence (r = 0.9763, P = 0.0237). Weather variables (cumulative rainfall or rainfall frequency) alone did not correlate with fruit rot incidence (P > 0.05), whereas combined latent infection-rainfall variables did. The results suggest that latent infections can serve as a source of inoculum for subsequent fruit rot in peach orchards in Georgia. Despite its significant association with fruit rot incidence, the potential for using latent infection incidence as a biological indicator of disease risk at harvest may be limited; the assessment of latent infection during the fruit ripening stage (similar to the timing of the final sampling date in this study) would not provide sufficient lead time for preharvest disease management decisions, whereas an earlier assessment (e.g., at the onset of pit hardening) would require large sample sizes due to the low incidence of latent infection present during that period.

scholarly journals Peach brown rot control and the relationship of latent infection with postharvest disease

Revista CERES ◽  
2018 ◽  
Vol 65 (6) ◽  
pp. 517-526
Author(s):  
Elizandra Pivotto Pavanello ◽  
Magno Roberto Pasquetti Berghett ◽  
Erani Eliseu Schultz ◽  
Fabio Rodrigo Thewes ◽  
Suele Fernanda Prediger Schmidt ◽  
...  
Keyword(s):  
Latent Infection ◽  
Disease Incidence ◽  
Brown Rot ◽  
Postharvest Disease ◽  
Latent Infections ◽  
Active Ingredients ◽  
Important Approach ◽  
Relationship Of ◽  
The Relationship

ABSTRACT The peach brown rot, caused by Monilinia fructicola, is the main disease of the crop, causing significant losses during preharvest and postharvest. This study aimed to evaluate the performance of preharvest fungicide application on brown rot control and verify the role of latent infection and external contamination in postharvest disease. An experiment was carried out in the years 2014 and 2015 in order to evaluate the performance of six active ingredients (captan, iprodione, iminoctadine, tebuconazole, difenoconazole and azoxystrobin) during preharvest on brown rot control and the effect on latent infection. A second experiment was carried out to monitor the latent infection during growth and ripening of the fruit and in order to correlate it with the postharvest disease incidence. The data were submitted to analysis of variance (Anova) and the means were grouped by the Scott-Knott test (p < 0.05), using statistical software Sisvar. The active ingredients iprodione, tebuconazole and difenoconazole were the most efficient in controlling brown rot on the field, while iminoctadine has higher efficiency during postharvest control, acting on latent infections. The incidence of latent infections during fruit growth and ripening has a positive correlation with brown rot incidence at postharvest. The highest disease incidence after storage is due to the latent infections manifestation. Effective chemical control in the field, throughout the growing and ripening of fruit, is an important approach to postharvest brown rot control, even after cold storage and during shelf life at 20 °C.

scholarly journals Gray mold in immature fig fruit: pathogenicity and growth temperature

2016 ◽  
Vol 46 (9) ◽  
pp. 1524-1527 ◽  
Author(s):  
Eliane Aparecida Rogovski Czaja ◽  
Rafaele Regina Moreira ◽  
Luciane Cristina Rozwalka ◽  
Josiane Aparecida Gomes Figueiredo ◽  
Louise Larissa May De Mio
Keyword(s):  
Ribosomal Dna ◽  
Growth Temperature ◽  
Mycelial Growth ◽  
Its Region ◽  
Gray Mold ◽  
Fruit Rot ◽  
Optimum Temperature ◽  
Immature Fruit ◽  
Green Fruit ◽  
Fruit Surface

ABSTRACT: Several diseases can be associated with figs but recently a fruit rot was observed in green fruit. The purpose of this study was to determine the pathogenicity of Botrytis sp., to quantify incubation period (IP) and latent period (LP), to verify the optimum temperature for mycelial growth, and to identify the different species of Botrytis sp. isolated from immature figs. Botrytis sp. isolated from figs proved to be pathogenic to immature fruit with and without wounding the fruit surface and ostiole. The IP period was 3 days on fruit with wounds and 5 days on fruit inoculated within the ostiole (without wound). The LP was 6 days in all treatments. The optimum temperature for mycelial growth was 18°C. Inferred from sequences of a segment comprising the ITS region of ribosomal DNA concluded that the isolates are Botrytis cinerea.

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