scholarly journals Response of Two Fungi in the Apple Sooty Blotch Complex to Temperature and Relative Humidity

2000 ◽  
Vol 90 (4) ◽  
pp. 362-367 ◽  
Author(s):  
Eric M. Johnson ◽  
Turner B. Sutton
Keyword(s):  
Relative Humidity ◽  
Environmental Factors ◽  
Mycelial Growth ◽  
Agar Culture ◽  
Air Drying ◽  
Sooty Blotch ◽  
Conidial Viability

Peltaster fructicola and Leptodontium elatius, two of the causal fungi of apple sooty blotch, responded differently to temperature and relative humidity in vitro. Conidia of L. elatius germinated from 12 to 32°C at relative humidities ≥97%, whereas conidia of P. fructicola germinated from 12 to 24°C at relative humidities ≥95%. Germination of conidia of L. elatius was optimum at 32°C and 99% relative humidity compared with 24°C and 97 or 99% relative humidity for P. fructicola. When L. elatius and P. fructicola were grown in Parafilm culture, sporulation was greatest at relative humidities of 97 to 99%. In agar culture, mycelia of L. elatius expanded radially from 12 to 32°C, and that of P. fructicola at 12 to 28°C. Mycelia of P. fructicola did not survive exposure for 7 days or more to temperatures ≥32°C. Mycelial growth was inhibited at relative humidities <95% for both fungi and no growth occurred at 88% relative humidity. Conidia of P. fructicola were more sensitive to air drying than were those of L. elatius. Conidial viability of P. fructicola was reduced significantly after 8 h of air drying and nearly completely inhibited after 12 h. Conidia of L. elatius required 24 h of air drying before a significant reduction in conidial viability was observed. These results support the hypothesis that environmental factors influence the temporal and geographical distributions of the fungi associated with the apple sooty blotch disease.

scholarly journals Effect of Environmental Factors and Pesticides on Mycoparasitism of Sclerotinia minor by Coniothyrium minitans

Plant Disease ◽  
2006 ◽  
Vol 90 (11) ◽  
pp. 1407-1412 ◽  
Author(s):  
D. E. Partridge ◽  
T. B. Sutton ◽  
D. L. Jordan
Keyword(s):  
Soil Moisture ◽  
High Risk ◽  
Environmental Factors ◽  
Mycelial Growth ◽  
Optimum Conditions ◽  
Coniothyrium Minitans ◽  
Sclerotinia Minor ◽  
Peanut Production ◽  
Soil Temperature And Moisture

The effects of soil temperature and moisture, and nine pesticides commonly used in peanut production, on the mycoparasitic activity of Coniothyrium minitans on sclerotia of Sclerotinia minor were evaluated. In vitro mycelial growth and conidia germination of C. minitans were sensitive to azoxystrobin, chlorothalonil, fluazinam, pyraclostrobin, tebuconazole, and diclosulam. C. minitans survived and infected sclerotia of S. minor in the presence of azoxystrobin, chlorothalonil, diclosulam, fluazinam, flumioxazin, S-metolachlor, pendimethalin, pyraclostrobin, and tebuconazole. Mycoparasitic activity was reduced by all pesticides except S-metolachlor compared with the nontreated control. Optimum conditions for infection of sclerotia were temperatures from 14 to 22°C and soil moisture from -0.33 to -1 kPa × 102. Mycoparasitic activity of C. minitans remained high (98% sclerotia infected) at temperatures ranging from 14 to 22°C, but decreased at temperatures above 28°C. Viability of sclerotia was inversely related to the proportion infected by C. minitans (r = -0.9963, P = 0.001). Mycoparasitic activity also declined when soil moisture was greater than -1 kPa × 102 or less than -0.10 kPa × 102. These results indicate that C. minitans should not be applied when temperatures exceed 28°C, during extremes in soil moisture, or when there is a high risk of contact with pesticides before it becomes established in the soil.

Relative Susceptibility of Selected Apple Cultivars to Sooty Blotch and Flyspeck

2010 ◽  
Vol 11 (1) ◽  
pp. 14 ◽  
Author(s):  
Alan R. Biggs ◽  
Daniel R. Cooley ◽  
David A. Rosenberger ◽  
Keith S. Yoder
Keyword(s):  
New York ◽  
Relative Humidity ◽  
Environmental Factors ◽  
High Relative Humidity ◽  
Disease Avoidance ◽  
Relative Susceptibility ◽  
Incidence Data ◽  
Sooty Blotch ◽  
Sooty Blotch And Flyspeck ◽  
Apple Cultivars

Incidence data for sooty blotch and flyspeck (SBFS), apple diseases caused by a complex of fungi that includes Schizothyrium pomi, Peltaster fructicola, Leptodontidium elatius, and Geastrumia polystigmatis, were collected over several years from planting groups of new apple cultivars and selections planted at multiple locations in either 1995 (23 entries) or 1999 (22 entries) as part of the NE-183 Multistate Project. SBFS incidence on fruit was analyzed, and data from sites in Massachusetts, New York, and Virginia were compared to determine if there were differences among cultivars. Incidence of SBFS varied among cultivars in both the 1995 and 1999 plantings, and among locations in the 1999 plantings. These differences were primarily the result of harvest date, with cultivars that were harvested latest having the highest disease incidences. Lower SBFS incidence on the earlier maturing cultivars apparently resulted from disease avoidance, as these apples were exposed to fewer hours of wetting and high relative humidity, environmental factors favorable for growth of SBFS fungi. Management tactics targeting SBFS are especially critical for cultivars that mature late in the season. Accepted for publication 13 May 2010. Published 26 July 2010.

scholarly journals Characterization of Five New Monosporascus Species: Adaptation to Environmental Factors, Pathogenicity to Cucurbits and Sensitivity to Fungicides

2020 ◽  
Vol 6 (3) ◽  
pp. 169
Author(s):  
Allinny Luzia Alves Cavalcante ◽  
Andréia Mitsa Paiva Negreiros ◽  
Moisés Bento Tavares ◽  
Érica dos Santos Barreto ◽  
Josep Armengol ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Mycelial Growth ◽  
Relevant Information ◽  
Great Variability ◽  
Northeastern Brazil ◽  
Greenhouse Experiments ◽  
Wide Range ◽  
Pathogenicity Tests

In this study, five new recently described Monosporascus species, M. brasiliensis, M. caatinguensis, M. mossoroensis, M. nordestinus, and M. semiaridus, which were found on weeds collected from cucurbit cultivation fields in northeastern Brazil, are characterized regarding mycelial growth at different pH levels and salinity (NaCl) concentrations, their pathogenicity to selected cucurbit species, and their sensitivity to fungicides with different modes of action. Our results reveal great variability among the representative isolates of each Monosporascus spp. All of them showed a wide range of tolerance to different pH levels, and NaCl significantly reduced their in vitro mycelial growth, although no concentration was able to inhibit them completely. In pathogenicity tests, all seedlings of cucurbits evaluated, melon, watermelon, cucumber, and pumpkin, were susceptible to the five Monosporascus spp. in greenhouse experiments using artificial inoculation of roots. Moreover, all Monosporascus spp. were highly susceptible to the fungicides fludioxonil and fluazinam. Our findings provide relevant information about the response of these new Monosporascus spp. to environmental factors, plant genotypes and fungicides.

Effects of equilibrium relative humidity on in vitro growth of Botrytis cinerea and Alternaria alternata

1996 ◽  
Vol 36 (3) ◽  
pp. 383 ◽  
Author(s):  
S Alam ◽  
D Joyce ◽  
A Wearing
Keyword(s):  
Relative Humidity ◽  
Liquid Medium ◽  
Botrytis Cinerea ◽  
Alternaria Alternata ◽  
Mycelial Growth ◽  
Dry Matter ◽  
Diameter Growth ◽  
Colony Diameter ◽  
Equilibrium Relative Humidity

Mycelial growth in vitro of 2 fungal pathogens responsible for postharvest loss of horticulture produce, Botrytis cinerea and Alternaria alternata, was related to equilibrium relative humidity (e.r.h) at ambient temperature (20�C) using solutes to adjust the 'osmotic water potential' of the growth medium. Colony diameter growth of B. cinerea and A. alternata on solid medium (1/2 potato dextrose agar) was initially stimulated slightly when the e.r.h. was decreased from 99.7 (unamended medium) to 99.3% (-0.4 to -1.0 MPa). Thereafter, colony diameter growth continually decreased as a function of reducing e.r.h. over the range 99.3-94.3% e.r.h. (-1.0 to -8.0 MPa). Similar trends were recorded with both pathogens for their dry matter growth in liquid medium (Oxoid Czapek Dox) as a function of osmotic potential. Initial stimulation of dry matter growth at -1.0 MPa (equivalent to 99.3% e.r.h.) was not evident in liquid medium. Fungal growth data suggest that postharvest mycelial growth of Botrytis cinerea and Alternaria alternata on wounds, senescing tissue or secretions such as cell sap or nectar could be restricted through control of e.r.h. in packages of horticulture produce.

An Attempt at Biological Control of Blossom Blight of Rose Caused by Botrytis cinerea Using some Local Trichoderma spp. Strains

2020 ◽  
Vol 55 (1) ◽  
pp. 27-34
Author(s):  
G. Zadehdabagh ◽  
K. Karimi ◽  
M. Rezabaigi ◽  
F. Ajamgard
Keyword(s):  
Botrytis Cinerea ◽  
Mycelial Growth ◽  
Limiting Factor ◽  
Dual Culture ◽  
Trichoderma Spp ◽  
Khuzestan Province ◽  
Inhibitory Potential ◽  
Cut Rose

The northern of Khuzestan province in Iran is mainly considered as one of the major areas of miniature rose production. Blossom blight caused by Botrytis cinerea has recently become a serious limiting factor in rose production in pre and post-harvest. In current study, an attempt was made to evaluate the inhibitory potential of some local Trichoderma spp. strains against B. cinerea under in vitro and in vivo conditions. The in vitro results showed that all Trichoderma spp. strains were significantly able to reduce the mycelial growth of the pathogen in dual culture, volatile and non-volatile compounds tests compared with control, with superiority of T. atroviride Tsafi than others. Under in vivo condition, the selected strain of T. atroviride Tsafi had much better performance than T. harzianum IRAN 523C in reduction of disease severity compared with the untreated control. Overall, the findings of this study showed that the application of Trichoderma-based biocontrol agents such as T. atroviride Tsafi can be effective to protect cut rose flowers against blossom blight.

The Potential Migrated Mechanism of Water-Soluble Components in Pellets Prepared by Wet Extrusion/Spheronization: Effect of Drying Rate

2020 ◽  
Vol 17 ◽  
Author(s):  
Bingwei Wang ◽  
Jianping Liu ◽  
Zhenghua Li ◽  
Yulong Xia ◽  
Shuangshuang Zhang ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Water Soluble ◽  
In Vitro Dissolution ◽  
Drying Rate ◽  
Scanning Calorimetry ◽  
Drying Temperature ◽  
Wet Extrusion ◽  
Extrusion Spheronization ◽  
Soluble Components

Background: At present, there were numerous researches on the migration of components in tablets and granules, the investigation in the pharmaceutical literatrue concerning the effect of drying rate on the migration of water-soluble components of pellets was limited. Temperature and relative humidity (RH) were crucial parameters during the drying process which was an essential step in the preparation of pellets via wet extrusion/spheronization. To quantify these variables, the water loss percentage of pellets per minute was defined as drying rate. Objective: The study aimed to investigate the influence of drying rate on the migration of water-soluble components in wet pellets and the potential migrated mechanism. Methods: The pellets containing tartrazine as a water-soluble model drug and microcrystalline cellulose as a matrix former were prepared by extrusion/spheronization and dried at four different drying temperature and relative humidity. Afterward, the extent of migrated tartrazine was assessed regarding appearance, in-vitro dissolution test, Differential Scanning Calorimetry, X-Ray Powder Diffraction, Attenuated total reflectance Fourier transform infrared spectroscopy and Confocal Raman Mapping. Results: Results demonstrated that red spots of tartrazine appeared on the surface of pellets and more than 40% tartrazine were burst released within 5 minutes when pellets dried at 60℃/RH 10%. While pellets dried at 40℃/RH 80%, none of these aforementioned phenomena was observed. Conclusion: In conclusion, the faster drying rate was, the more tartrazine migrated to the exterior of pellets. Adjusting drying temperature and relative humidity appropriately could inhibit the migration of water-soluble components within wet extrusion/spheronization pellets.

Management of collar rot disease in chickpea by Trichoderma species

2020 ◽  
Vol 7 (03) ◽  
Author(s):  
PREM PANDEY ◽  
G. C. SAGAR ◽  
SUNDARMAN SHRESTHA2 ◽  
HIRAKAJI MANANDHAR ◽  
RITESH K. YADAV ◽  
...  
Keyword(s):  
Growth Inhibition ◽  
Mycelial Growth ◽  
Sclerotium Rolfsii ◽  
Maximum Growth ◽  
Pot Experiment ◽  
Trichoderma Spp ◽  
Trichoderma Species ◽  
Collar Rot ◽  
Rot Disease

Nine isolates of Trichoderma spp. were isolated from different agro- ecological regions of Nepal viz; Jumla, Palpa, Chitwan, Tarahara, Banke, Illam and Salyan and screened against Sclerotium rolfsii Sacc. Adreded soil borne phytopathogen causing collar rot of chickpea in chickpea; In-vitro efficacy of nine fungal antagonist (Trichoderma spp.) against Sclerotium rolfsii were screened. Pot experiment was done to find out the effective management of S. rolfsi through Tricoderma using different methods i.e. Seed treatment, soil drenching and soil application. All the tested isolates of Trichoderma spp. were found effective on mycelial growth inhibition and sclerotial parasitization of S. rolfsii. Trichoderma isolated from Palpa district showed maximum growth inhibition (%) of pathogen periodically after 48(93.78%), 72(96.00%), 96(97.96%) and 120(100.00%) hours of inoculation. Parasitized sclerotium showed minimum sclerotial germination on agar plates. Moreover, Trichoderma species isolated from Palpa districts showed second best percent mycelial growth inhibition periodically at 72(25.00%), 120(29.16%), 168(29.16%) and 216(29.16%).In pot experiment at 40 days after sowing, Seedling height was maximum in soil drenching with 30g per 100ml of water (22.27cm) and Mortality percentage of seedlings was least or highest disease control was observed in seed treated with 109cfu/ml (0.000%).

scholarly journals Diffusible Compounds Produced by Hanseniaspora osmophila and Gluconobacter cerinus Help to Control the Causal Agents of Gray Rot and Summer Bunch Rot of Table Grapes

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 664
Author(s):  
Matías Olivera ◽  
Ninoska Delgado ◽  
Fabiola Cádiz ◽  
Natalia Riquelme ◽  
Iván Montenegro ◽  
...  
Keyword(s):  
Mycelial Growth ◽  
Inhibitory Effect ◽  
Biocontrol Agents ◽  
Environmental Cost ◽  
Antifungal Compounds ◽  
Table Grapes ◽  
Dual Cultures ◽  
Bunch Rot ◽  
Direct Bioautography

Gray and summer bunch rot are important diseases of table grapes due to the high economic and environmental cost of their control with synthetic fungicides. The ability to produce antifungal compounds against the causal agents Botrytis, Aspergillus, Penicillium, and Rhizopus of two microorganisms isolated from table grapes and identified as Hanseniaspora osmophila and Gluconobacter cerinus was evaluated. In dual cultures, both biocontrol agents (together and separately) inhibited in vitro mycelial growth of these pathogens. To identify the compounds responsible for the inhibitory effect, extractions were carried out with organic solvents from biocontrol agents separately. Through dual cultures with pathogens and pure extracts, only the hexane extract from H. osmophila showed an inhibitory effect against Botrytis cinerea. To further identify these compounds, the direct bioautography technique was used. This technique made it possible to determine the band displaying antifungal activity at Rf = 0.05–0.2. The compounds present in this band were identified by GC-MS and compared to the NIST library. The most abundant compounds, not previously reported, corresponded to alkanes, ketones, alcohols, and terpenoids. H. osmophila and G. cerinus have the potential to control the causal agents of gray and summer bunch rot of table grapes.

scholarly journals Improving the Biocontrol Potential of Bacterial Antagonists with Salicylic Acid against Brown Rot Disease and Impact on Nectarine Fruits Quality

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 209
Author(s):  
Nadia Lyousfi ◽  
Rachid Lahlali ◽  
Chaimaa Letrib ◽  
Zineb Belabess ◽  
Rachida Ouaabou ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Disease Severity ◽  
Mycelial Growth ◽  
Brown Rot ◽  
Antagonistic Bacteria ◽  
Biological Treatments ◽  
Rot Disease ◽  
The Impact

The main objective of this study was to evaluate the ability of both antagonistic bacteria Bacillus amyloliquefaciens (SF14) and Alcaligenes faecalis (ACBC1) used in combination with salicylic acid (SA) to effectively control brown rot disease caused by Monilinia fructigena. Four concentrations of salicylic acid (0.5%, 2%, 3.5%, and 5%) were tested under in vitro and in vivo conditions. Furthermore, the impact of biological treatments on nectarine fruit parameters’ quality, in particular, weight loss, titratable acidity, and soluble solids content, was evaluated. Regardless of the bacterium, the results indicated that all combined treatments displayed a strong inhibitory effect on the mycelial growth of M. fructigena and disease severity. Interestingly, all SA concentrations significantly improved the biocontrol activity of each antagonist. The mycelial growth inhibition rate ranged from 9.79% to 88.02% with the highest reduction rate recorded for bacterial antagonists in combination with SA at both concentrations of 0.5% and 3.5%. The in vivo results confirmed the in vitro results with a disease severity varying from 0.00% to 51.91%. A significant biocontrol improvement was obtained with both antagonistic bacteria when used in combination with SA at concentrations of 0.5% and 2%. The lowest disease severity observed with ACBC1 compared with SF14 is likely due to a rapid adaptation and increase of antagonistic bacteria population in wounded sites. The impact of all biological treatments revealed moderate significant changes in the fruit quality parameters with weight loss for several treatments. These results suggest that the improved disease control of both antagonistic bacteria was more likely directly linked to both the inhibitory effects of SA on pathogen growth and induced fruit resistance.

scholarly journals Exposure Assessment of Airborne Bacteria Emitted from Swine Manure Composting Plant

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1283
Author(s):  
Ki-Youn Kim
Keyword(s):  
Relative Humidity ◽  
Environmental Factors ◽  
Swine Manure ◽  
Airborne Bacteria ◽  
Particulate Matters ◽  
Distribution Characteristics ◽  
E Coli ◽  
Enterococcus Spp ◽  
Staphylococcus Spp ◽  
Rotary Type

This study was performed to investigate the distribution characteristics of airborne bacteria emitted from swine manure composting plants. The types of swine manure composting plants selected for the survey in this study were as follows: screw type, rotary type, and natural dry type. Mean levels of airborne bacteria in swine manure composting plants were 7428 (±1024) CFU m−3 for the screw type, 3246 (±1407) CFU m−3 for the rotary type, and 5232 (±1217) CFU m−3 for the natural dry type, respectively. Based on the results obtained from this study, the swine manure composting plant operated by screw type showed the highest concentration of airborne bacteria, followed by the natural dry type and rotary type. The monthly concentration of airborne bacteria was the highest in August and the lowest in November, regardless of the type of swine manure composting plant. The respirable size of airborne bacteria accounted for about 50% of the total. The ratio of respirable to the total quantity of airborne bacteria was 50%. The correlation relationships between airborne bacteria and environmental factors (temperature, relative humidity, particulate matters, and odor) were not found to be significant in the swine manure composting plants. The predominant genera of airborne bacteria identified were Micrococcus spp., Staphylococcus spp., Escherichia(E-coli) spp., Enterococcus spp., and Enterobacteriaceae spp.

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