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1
Deckers, T., e W. Porreye. "PRIMARY INOCULUM FORMATION OF ERWINIA AMYLOVORA". Acta Horticulturae, n. 217 (novembre 1987): 143–44. http://dx.doi.org/10.17660/actahortic.1987.217.20.
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Bailey, D. J., e C. A. Gilligan. "Dynamics of Primary and Secondary Infection in Take-All Epidemics". Phytopathology® 89, n. 1 (gennaio 1999): 84–91. http://dx.doi.org/10.1094/phyto.1999.89.1.84.
Testo completoAbstract (sommario):
Using a combination of experimentation and mathematical modeling, the effects of initial (particulate) inoculum density on the dynamics of disease resulting from primary and secondary infection of wheat by the take-all fungus, Gaeumannomyces graminis var. tritici, were tested. A relatively high inoculum density generated a disease progress curve that rose monotonically toward an asymptote. Reducing the initial inoculum density resulted in a curve that initially was monotonic, rising to a plateau, but which increased sigmoidally to an asymptotic level of disease thereafter. Changes in the infectivity of particulate inoculum over time were examined in a separate experiment. Using a model that incorporated terms for primary and secondary infection, inoculum decay, and host growth, we showed that both disease progress curves were consistent with consecutive phases dominated, respectively, by primary and secondary infection. We examined the spread of disease from a low particulate inoculum density on seminal and adventitious root systems separately. Although seminal roots were affected by consecutive phases of primary and secondary infection, adventitious roots were affected only by secondary infection. We showed that the characteristic features of disease progress in controlled experiments were consistent with field data from crops of winter wheat. We concluded that there is an initial phase of primary infection by G. graminis var. tritici on winter wheat as seminal roots grow through the soil and encounter inoculum, but the rate of primary infection slows progressively as inoculum decays. After the initial phase, there is an acceleration in the rate of secondary infection on both seminal and adventitious roots that is stimulated by the increase in the availability of infected tissue as a source of inoculum and the availability of susceptible tissue for infection.
3
Lenhard, Justin R., e Zackery P. Bulman. "Inoculum effect of β-lactam antibiotics". Journal of Antimicrobial Chemotherapy 74, n. 10 (6 giugno 2019): 2825–43. http://dx.doi.org/10.1093/jac/dkz226.
Testo completoAbstract (sommario):
AbstractThe phenomenon of attenuated antibacterial activity at inocula above those utilized for susceptibility testing is referred to as the inoculum effect. Although the inoculum effect has been reported for several decades, it is currently debatable whether the inoculum effect is clinically significant. The aim of the present review was to consolidate currently available evidence to summarize which β-lactam drug classes demonstrate an inoculum effect against specific bacterial pathogens. Review of the literature showed that the majority of studies that evaluated the inoculum effect of β-lactams were in vitro investigations of Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Haemophilus influenzae and Staphylococcus aureus. Across all five pathogens, cephalosporins consistently displayed observable inoculum effects in vitro, whereas carbapenems were less susceptible to an inoculum effect. A handful of animal studies were available that validated that the in vitro inoculum effect translates into attenuated pharmacodynamics of β-lactams in vivo. Only a few clinical investigations were available and suggested that an in vitro inoculum effect of cefazolin against MSSA may correspond to an increased likeliness of adverse clinical outcomes in patients receiving cefazolin for bacteraemia. The presence of β-lactamase enzymes was the primary mechanism responsible for an inoculum effect, but the observation of an inoculum effect in multiple pathogens lacking β-lactamase enzymes indicates that there are likely multiple mechanisms that may result in an inoculum effect. Further clinical studies are needed to better define whether interventions made in the clinic in response to organisms displaying an in vitro inoculum effect will optimize clinical outcomes.
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Kim, Seung-Han, Dong-Geun Kim, Jae-Tak Yoon, Sung-Gook Choi e Joon-Tak Lee. "Primary Inoculum of Strawberry Anthracnose in Nursing Field". Research in Plant Disease 8, n. 4 (1 dicembre 2002): 228–33. http://dx.doi.org/10.5423/rpd.2002.8.4.228.
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LOPEZ-HERRERA, C. J. "Eradication of Primary Inoculum ofBotrytis cinereaby Soil Solarization". Plant Disease 78, n. 6 (1994): 594. http://dx.doi.org/10.1094/pd-78-0594.
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Lung-Escarmant, Brigitte, e Dominique Guyon. "Temporal and Spatial Dynamics of Primary and Secondary Infection by Armillaria ostoyae in a Pinus pinaster Plantation". Phytopathology® 94, n. 2 (febbraio 2004): 125–31. http://dx.doi.org/10.1094/phyto.2004.94.2.125.
Testo completoAbstract (sommario):
Epidemiological investigations were performed in a 3-ha maritime pine (Pinus pinaster) plantation established on a site heavily infested by Armillaria ostoyae. Geostatistics were used to examine the density and the distribution of the initial inoculum. Disease dynamics were monitored for 17 years after planting. On the whole site, the cumulative mortality rate reached 35% over this period, plateauing at 12 years. Disease progress curves differed according to the density of the initial inoculum, although in all the cases, the Gompertz model described the epidemics well. The epidemiological contributions of both primary (initially colonized stumps) and secondary inoculum (newly dead pines) were evaluated by analyzing their spatial relation to annual mortality. Newly dead pines acted as secondary inoculum from year 3 and their role increased with time. When the initial inoculum density was low, the contribution of secondary inoculum to epidemic development increased faster and halted sooner than when the density of primary inoculum was high. Regardless of its density, the primary inoculum acted throughout the dynamic phase of the epidemic. When the inoculum density was low, the probability of mortality during the first 6 years of the epidemic depended on the tree distance from the nearest stumps colonized by Armillaria sp. When the inoculum density was high, the probability of mortality was higher and not related to the distance between trees and colonized stumps.
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Van der Heyden, Hervé, Guillaume J. Bilodeau, Odile Carisse e Jean-Benoit Charron. "Monitoring of Peronospora destructor Primary and Secondary Inoculum by Real-Time qPCR". Plant Disease 104, n. 12 (dicembre 2020): 3183–91. http://dx.doi.org/10.1094/pdis-03-20-0687-re.
Testo completoAbstract (sommario):
Onion downy mildew (ODM), caused by Peronospora destructor, is a serious threat for onion growers worldwide. In southwestern Québec, Canada, a steady increase in occurrence of ODM has been observed since the mid-2000s. On onion, P. destructor can develop local and systemic infections producing numerous sporangia which act as initial inoculum locally and also for neighboring areas. It also produces oospores capable of surviving in soils and tissues for a prolonged period of time. A recent study showed that ODM epidemics are strongly associated with weather conditions related to production and survival of overwintering inoculum, stressing the need to understand the role of primary (initial) and secondary inoculum. However, P. destructor is an obligate biotrophic pathogen, which complicates the study of inoculum sources. This study aimed at developing a molecular assay specific to P. destructor, allowing its quantification in environmental samples. In this study, a reliable and sensitive hydrolysis probe-based assay multiplexed with an internal control was developed on the internal transcribed spacer (ITS) region to quantify soil- and airborne inoculum of P. destructor. The assay specificity was tested against 17 isolates of P. destructor obtained from different locations worldwide, other members of the order Peronosporales, and various onion pathogens. Validation with artificially inoculated soil and air samples suggested a sensitivity of less than 10 sporangia g−1 of dry soil and 1 sporangium m−3 of air. Validation with environmental air samples shows a linear relationship between microscopic and real-time quantitative PCR counts. In naturally infested soils, inoculum ranged from 0 to 162 sporangia equivalent g−1 of dry soil, which supported the hypothesis of overwintering under northern climates. This assay will be useful for primary and secondary inoculum monitoring to help characterize ODM epidemiology and could be used for daily tactical and short-term strategic decision-making.
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Safar, Korai M., Mahar R. Bux, Uqaili M. Aslam, Bhattacharjee A. Shankar e Ramesh K. Goel. "The feasibility of putrescible components of municipal solid waste for biomethane production at Hyderabad, Pakistan". Waste Management & Research: The Journal for a Sustainable Circular Economy 36, n. 2 (9 gennaio 2018): 169–82. http://dx.doi.org/10.1177/0734242x17748363.
Testo completoAbstract (sommario):
This study analyzes the feasibility of putrescible components of municipal solid waste (PCMSW) such as food waste (FW) and yard waste (YW) for methane production in Pakistan. The batch experiments have been conducted at two different inoculums to substrate ratios (ISRs) by using various inoculums under mesophilic condition. The highest methane yield of FW and YW is achieved to be 428 Nml g-1 volatile solids (VS) added and 304 Nml g-1 VS added respectively by using buffalo dung inoculum at ISR-5. While, lowest methane yield of FW and YW is obtained as 236 Nml g-1 VS added and 151Nml g-1 VS added respectively by using effluent from a continuous stirrer tank reactor as inoculum at ISR-3. The first order decay model has been introduced, which gives best fit for methane potential of PCMSW with buffalo dung inoculum. Additionally, the feasibility of PCMSW in terms of power generation potential has been analyzed. About 60.63 million m3/year energy can be generated by converting PCMSW into methane gas leading to power generation. The finding of this study concludes that the replacement of imported energy and reduction up to 1.62% in other primary energy sources would be achieved, if PCMSW are properly converted into energy through anaerobic digestion in Pakistan.
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Khan, J., L. E. del Rio, R. Nelson, V. Rivera-Varas, G. A. Secor e M. F. R. Khan. "Survival, Dispersal, and Primary Infection Site for Cercospora beticola in Sugar Beet". Plant Disease 92, n. 5 (maggio 2008): 741–45. http://dx.doi.org/10.1094/pdis-92-5-0741.
Testo completoAbstract (sommario):
Cercospora beticola survives as stromata in infected crop residue. Spores produced on these survival structures serve as primary inoculum during the next cropping season. This study was conducted to determine how long C. beticola can survive at different soil depths, the mechanism of inoculum dispersal, and the primary infection site in sugar beet. Longevity of C. beticola was studied over a 3-year period under field conditions at Fargo, ND. C. beticola-infected leaves were placed at depths of 0, 10, and 20 cm and retrieved after 10, 22, and 34 months. Survival of C. beticola inoculum declined with time and soil depth. Inoculum left on the soil surface, 0 cm in depth, survived the longest (22 months) compared with that buried at 10 cm (10 months) and 20 cm (10 months). C. beticola dispersal from the primary source of inoculum was studied in the field for three growing seasons. Sugar beet plants were surrounded with plastic cages with and without ground cover, or exposed with and without ground cover. Significantly higher disease severity was observed on exposed plants than caged plants with or without ground cover, suggesting that wind was the major dispersal factor for C. beticola inoculum. The primary infection site by C. beticola was determined in a greenhouse study. Leaves, roots, and stems of healthy sugar beet plants were inoculated with C. beticola. Cercospora leaf spot symptoms were observed only on plants that were leaf inoculated, suggesting that the leaf was the primary infection site for C. beticola.
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Gutierrez, W. A., H. D. Shew e T. A. Melton. "Sources of Inoculum and Management for Rhizoctonia solani Damping-off on Tobacco Transplants under Greenhouse Conditions". Plant Disease 81, n. 6 (giugno 1997): 604–6. http://dx.doi.org/10.1094/pdis.1997.81.6.604.
Testo completoAbstract (sommario):
Damping-off and target spot are important diseases of tobacco transplants produced under greenhouse conditions. Identification of sources of inoculum for these diseases caused by Rhizoctonia solani is an important first step in disease management. Control strategies based on sanitation and the eradication of primary inoculum were studied. Potting mix and Styrofoam trays used in transplant production were assayed to determine if they were sources of primary inoculum. Eleven sources of potting mix were sampled over a 2-year period. None of the mixes contained viable inoculum of R. solani. R. solani was isolated from previously used trays after 1 year of storage by removing and plating pieces of Styrofoam from individual tray cells on alkaline water agar (AWA). Sclerotia and melanized hyphae of R. solani were observed in the cracks present in the cells of the trays. Dry heat (70 to 80°C for 2 h) and chemical (sodium hypochlorite and sodium chloride) treatments reduced the levels of inoculum on trays up to 45% compared to controls, but only methyl bromide and steam treatments (80°C for 0.5 to 2.0 h) eradicated inoculum of R. solani from trays. Elimination of primary inoculum from previously used trays effectively controlled target spot and stem rot diseases caused by R. solani.
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Sujkowski, L. S., G. R. Parra, M. L. Gumpertz e J. B. Ristaino. "Temporal Dynamics of Phytophthora Blight on Bell Pepper in Relation to the Mechanisms of Dispersal of Primary Inoculum of Phytophthora capsici in Soil". Phytopathology® 90, n. 2 (febbraio 2000): 148–56. http://dx.doi.org/10.1094/phyto.2000.90.2.148.
Testo completoAbstract (sommario):
The effect of components of primary inoculum dispersal in soil on the temporal dynamics of Phytophthora blight epidemics in bell pepper was evaluated in field and growth-chamber experiments. Phytophthora capsici may potentially be dispersed by one of several mechanisms in the soil, including inoculum movement to roots, root growth to inoculum, and root-to-root spread. Individual components of primary inoculum dispersal were manipulated in field plots by introducing (i) sporangia and mycelia directly in soil so that all three mechanisms of dispersal were possible, (ii) a plant with sporulating lesions on the soil surface in a plastic polyvinyl chloride (PVC) tube so inoculum movement to roots was possible, (iii) a wax-encased peat pot containing sporangia and mycelia in soil so root growth to inoculum was possible, (iv) a wax-encased peat pot containing infected roots in soil so root-to-root spread was possible, (v) noninfested V8 vermiculite media into soil directly as a control, or (vi) wax-encased noninfested soil as a control. In 1995 and 1996, final incidence of disease was highest in plots where sporangia and mycelia were buried directly in soil and all mechanisms of dispersal were operative (60 and 32%) and where infected plants were placed in PVC tubes on the soil surface and inoculum movement to roots occurred with rainfall (89 and 23%). Disease onset was delayed in 1995 and 1996, and final incidence was lower in plants in plots where wax-encased sporangia (6 and 22%) or wax-encased infected roots (22%) were buried in soil and root growth to inoculum or root-to-root spread occurred. Incidence of root infections was higher over time in plots where inoculum moved to roots or all mechanisms of dispersal were possible. In growth-chamber studies, ultimately all plants became diseased regardless of the dispersal mechanism of primary inoculum, but disease onset was delayed when plant roots had to grow through a wax layer to inoculum or infected roots in tension funnels that contained small volumes of soil. Our data from both field and growth-chamber studies demonstrate that the mechanism of dispersal of the primary inoculum in soil can have large effects on the temporal dynamics of disease.
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van den Ende, J. E., e M. G. Pennock-Vos. "PRIMARY SOURCES OF INOCULUM OF BOTRYTIS ELLIPTICA IN LILY". Acta Horticulturae, n. 430 (dicembre 1997): 591–96. http://dx.doi.org/10.17660/actahortic.1997.430.94.
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Horsfield, Andrew, e Trevor Wicks. "Sources of primary inoculum ofTranzschelia discolorin Australian almond orchards". Australasian Plant Pathology 39, n. 4 (2010): 350. http://dx.doi.org/10.1071/ap10037.
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Gilligan, Christopher A., e Adam Kleczkowski. "Population dynamics of botanical epidemics involving primary and secondary infection". Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 352, n. 1353 (29 maggio 1997): 591–608. http://dx.doi.org/10.1098/rstb.1997.0040.
Testo completoAbstract (sommario):
In this paper we study the dynamical properties of models for botanical epidemics, especially for soil–borne fungal infection. The models develop several new concepts, involving dual sources of infection, host and inoculum dynamics. Epidemics are modelled with respect to the infection status of whole plants and plant organs (the G model) or to lesion density and size (the SW model). The infection can originate in two sources, either from the initial inoculum (primary infection) or by a direct transmission between plant tissue (secondary infection). The first term corresponds to the transmission through the free–living stages of macroparasites or an external source of infection in certain medical models, whereas the second term is equivalent to direct transmission between the hosts in microparasitic infections. The models allow for dynamics of host growth and inoculum decay. We show that the two models for root and lesion dynamics can be derived as special cases of a single generic model. Analytical and numerical methods are used to analyse the behaviour of the models for static, unlimited (exponential) and asymptotically limited host growth with and without secondary infection, and with and without decay of initial inoculum. The models are shown to exhibit a range of epidemic behaviour within single seasons that extends from simple monotonic increase with saturation of the host population, through temporary plateaux as the system switches from primary to secondary infection, to effective elimination of the pathogen by the host outgrowing the fungal infection. For certain conditions, the equilibrium values are shown to depend on initial conditions. These results have important consequences for the control of plant disease. They can be applied beyond soil–borne plant pathogens to mycorrhizal fungi and aerial pathogens while the principles of primary and secondary infection with host and inoculum dynamics may be used to link classical models for both microparasitic and macroparasitic infections.
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Bennett, Rebecca S., Michael G. Milgroom e Gary C. Bergstrom. "Population Structure of Seedborne Phaeosphaeria nodorum on New York Wheat". Phytopathology® 95, n. 3 (marzo 2005): 300–305. http://dx.doi.org/10.1094/phyto-95-0300.
Testo completoAbstract (sommario):
Population genetic and epidemiological studies have resulted in different hypotheses about the predominant source of primary inoculum in the Phaeosphaeria nodorum-wheat pathosystem (i.e., sexually derived, windborne ascospores versus asexual or seedborne inoculum). We examined the genetic structure of seedborne populations of P. nodorum as a further step toward evaluating the hypothesis that seedborne inoculum is an important contributor to foliar epidemics in New York's rotational wheat fields. In all, 330 seedborne isolates from seven field populations were genotyped at 155 amplified fragment length polymorphism loci. Seedborne populations possessed high levels of genotypic diversity, with virtually every isolate (326/330) having a unique haplotype. As in previous population genetic studies of P. nodorum, we found low levels of gametic disequilibrium, although we could reject the null hypothesis of random mating with the index of association test for two populations. Thus, genotypically diverse and seemingly panmictic populations of P. nodorum that have been observed in wheat foliage could be derived from seedborne primary inoculum. Although sexual reproduction and recombination may contribute to the diversity of foliar populations of P. nodorum, population genetic data do not rule out seed as a source of primary inoculum. Further experimentation will be needed to determine definitively the relative importance of windborne ascospores and seed-borne asexual inoculum in epidemics of Stagonospora nodorum blotch in New York.
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Bailey, D. J., A. Kleczkowski e C. A. Gilligan. "An Epidemiological Analysis of the Role of Disease-Induced Root Growth in the Differential Response of Two Cultivars of Winter Wheat to Infection by Gaeumannomyces graminis var. tritici". Phytopathology® 96, n. 5 (maggio 2006): 510–16. http://dx.doi.org/10.1094/phyto-96-0510.
Testo completoAbstract (sommario):
Epidemiological modeling combined with parameter estimation of experimental data was used to examine differences in the contribution of disease-induced root production to the spread of take-all on plants of two representative yet contrasting cultivars of winter wheat, Ghengis and Savannah. A mechanistic model, including terms for primary infection, secondary infection, inoculum decay, and intrinsic and disease-induced root growth, was fitted to data describing changes in the numbers of infected and susceptible roots over time at a low or high density of inoculum. Disease progress curves were characterized by consecutive phases of primary and secondary infection. No differences in root growth were detected between cultivars in the absence of disease and root production continued for the duration of the experiment. However, significant differences in disease-induced root production were detected between Savannah and Genghis. In the presence of disease, root production for both cultivars was characterized by stimulation when few roots were infected and inhibition when many roots were infected. At low inoculum density, the transition from stimulation to inhibition occurred when an average of 5.0 and 9.0 roots were infected for Genghis and Savannah, respectively. At high inoculum density, the transition from stimulation to inhibition occurred when an average of 4.5 and 6.7 roots were infected for Genghis and Savannah, respectively. Differences in the rates of primary and secondary infection between Savannah and Genghis also were detected. At a low inoculum density, Genghis was marginally more resistant to secondary infection whereas, at a high density of inoculum, Savannah was marginally more resistant to primary infection. The combined effects of differences in disease-induced root growth and differences in the rates of primary and secondary infection meant that the period of stimulated root production was extended by 7 and 15 days for Savannah at a low and high inoculum density, respectively. The contribution of this form of epidemiological modeling to the better management of take-all is discussed.
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Elbeshbishy, Elsayed, George Nakhla e Hisham Hafez. "Biochemical methane potential (BMP) of food waste and primary sludge: Influence of inoculum pre-incubation and inoculum source". Bioresource Technology 110 (aprile 2012): 18–25. http://dx.doi.org/10.1016/j.biortech.2012.01.025.
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Guo, Chunna, Xiaoping Liao, Mingru Wang, Feng Wang, Chaoqun Yan, Xia Xiao, Jiang Sun e Yahong Liu. "In VivoPharmacodynamics of Cefquinome in a Neutropenic Mouse Thigh Model of Streptococcus suis Serotype 2 at Varied Initial Inoculum Sizes". Antimicrobial Agents and Chemotherapy 60, n. 2 (14 dicembre 2015): 1114–20. http://dx.doi.org/10.1128/aac.02065-15.
Testo completoAbstract (sommario):
ABSTRACTStreptococcus suisserotype 2 is an emerging zoonotic pathogen and causes severe disease in both pigs and human beings. Cefquinome (CEQ), a fourth-generation cephalosporin, exhibits broad-spectrum activity against Gram-positive bacteria such asS. suis. This study evaluated thein vitroandin vivoantimicrobial activities of CEQ against four strains ofS. suisserotype 2 in a murine neutropenic thigh infection model. We investigated the effect of varied inoculum sizes (106to 108CFU/thigh) on the pharmacokinetic (PK)/pharmacodynamic (PD) indices and magnitudes of a particular PK/PD index or dose required for efficacy. Dose fractionation studies included total CEQ doses ranging from 0.625 to 640 mg/kg/24 h. Data were analyzed via a maximum effect (Emax) model using nonlinear regression. The PK/PD studies demonstrated that the percentage of time that serum drug levels were above the MIC of free drug (%ƒT>MIC) in a 24-h dosing interval was the primary index driving the efficacy of both inoculum sizes (R2= 91% andR2= 63%). CEQ doses of 2.5 and 40 mg/kg body weight produced prolonged postantibiotic effects (PAEs) of 2.45 to 8.55 h. Inoculum sizes had a significant influence on CEQ efficacy. Compared to the CEQ exposure and dosages in tests using standard inocula, a 4-fold dose (P= 0.006) and a 2-fold exposure time (P= 0.01) were required for a 1-log kill using large inocula of 108CFU/thigh.
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Carisse, Odile, e Annie Lefebvre. "A Model to Estimate the Amount of Primary Inoculum of Elsinoë ampelina". Plant Disease 95, n. 9 (settembre 2011): 1167–71. http://dx.doi.org/10.1094/pdis-11-10-0798.
Testo completoAbstract (sommario):
In Eastern Canada, anthracnose, caused by the fungus Elsinoë ampelina, is a serious disease on susceptible grape cultivars. In the absence of management tools, anthracnose management relies almost exclusively on fungicide applications programmed at fixed intervals. Therefore, a better understanding of the factors affecting primary inoculum release and abundance would help in the timing of the first fungicide applications. The temporal dynamics of airborne primary inoculum released from cane cankers were investigated from 2007 to 2010. One to three times per week, starting in the first week of April, six 12-cmlong cane pieces were randomly selected from diseased canes that had overwintered on a vineyard floor. The concentration of E. ampelina conidia was expressed as the number of conidia per square millimeter of canker. In total, 27, 32, 33, and 118 samplings were conducted in 2007, 2008, 2009, and 2010, respectively, with the 118 samplings conducted on three sites at 49, 35, and 34 samplings for site 1, 2, and 3, respectively. Each year, the number of conidia per square millimeter of canker was expressed as the proportion of seasonal inoculum (PSI) at the same site and analyzed as a function of degree-days (DD; base temperature = 0°C) accumulated since 1 April (cumulative degreedays [CDD]). The nonlinear sigmoid model in the form PSI = 1.003/(1 + e–((CDD – 566.133)/139.204)) provided adequate fit to the observed data (P < 0.0001, R2 = 0.97). When the model was validated against independent data, the model adequately predicted PSI; however, reliability was improved by adding a “dry days” threshold of 6 days during which accumulation of DD is stopped. This study shows that primary inoculum of grape anthracnose is available early in the season before bud break; meaning that emerging leaves could be infected provided that weather conditions are favorable. The results also show that there is an overlap in the availability of primary and secondary inoculum, mainly during the period of rapid leaf growth, a situation that may explain the explosive nature of the disease. The results suggest that, on susceptible cultivars and when there is a history of anthracnose in the vineyard, a fungicide spray program should be initiated early in the season, as soon as leaves are present.
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Amekan, Yumechris, Dyah Sekar A. P. Wangi, Muhammad Nur Cahyanto, Sarto Sarto e Jaka Widada. "Effect of Different Inoculum Combination on Biohydrogen Production from Melon Fruit Waste". International Journal of Renewable Energy Development 7, n. 2 (10 luglio 2018): 101–9. http://dx.doi.org/10.14710/ijred.7.2.101-109.
Testo completoAbstract (sommario):
The natural microbial consortium from many sources widely used for hydrogen production. Type of substrate and operating conditions applied on the biodigesters of the natural consortium used as inoculum impact the variation of species and number of microbes that induce biogas formation, so this study examined the effect of different inoculum source and its combination of biohydrogen production performance. The hydrogen producing bacteria from fruit waste digester (FW), cow dung digester (CD), and tofu waste digester (TW) enriched under strictly anaerobic conditions at 37OC. Inoculums from 3 different digesters (FW, CD, and TW) and its combination (FW-CD, CD-TW, FW-TW, and FW-CD-TW) were used to test the hydrogen production from melon waste with volatile solids (VS) concentration of 9.65 g/L, 37°C and initial pH 7.05 ± 0.05. The results showed that individual and combined inoculum produced the gas comprising hydrogen and carbon dioxide without any detectable methane. The highest cumulative hydrogen production of 743 mL (yield 207.56 mL/gVS) and 1,132 mL (yield 231.02 mL/gVS) was shown by FW and FW-CD-TW, respectively. Butyric, acetate, formic and propionic were the primary soluble metabolites produced by all the cultures, and the result proves that higher production of propionic acid can decrease hydrogen yield. Clostridium perfringens and Clostridium baratii prominently seen in all single and combination inoculum. Experimental evidence suggests that the inoculum from different biodigesters able to adapt well to the environmental conditions and the new substrate after a combination process as a result of metabolic flexibility derived from the microbial diversity in the community to produce hydrogen. Therefore, inoculum combination could be used as a strategy to improve systems for on-farm energy recovery from animal and plant waste to processing of food and municipal waste.Article History: Received February 5th 2018; Received in revised form May 7th 2018; Accepted June 2nd 2018; Available onlineHow to Cite This Article: Amekan, Y., Wangi, D.S.A.P., Cahyanto, M.N., Sarto and Widada, J. (2018) Effect of Different Inoculum Combination on Biohydrogen Production from Melon Fruit Waste. Int. Journal of Renewable Energy Development, 7(2), 101-109.https://doi.org/10.14710/ijred.7.2.101-10
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Hamada, Natasha Akemi, Rafaele Regina Moreira, Cristiano Nunes Nesi e Louise Larissa May De Mio. "Pathogen Dispersal and Glomerella Leaf Spot Progress Within Apple Canopy in Brazil". Plant Disease 103, n. 12 (dicembre 2019): 3209–17. http://dx.doi.org/10.1094/pdis-08-18-1375-re.
Testo completoAbstract (sommario):
Glomerella leaf spot (GLS) of apple is caused by three different Colletotrichum species complexes. This study evaluated the dispersal of Colletotrichum spores related to GLS temporal progress and defoliation. Spores were monitored by air and water runoff in different plant heights, and the temporal progress of GLS and defoliation were assessed. Spores of the pathogen were first cached in the lower part of the tree closer to the ground, confirming the importance of dead leaves on the ground as main source of primary inoculum. In plots with high primary inoculum, the disease increases exponentially during favorable weather conditions. The highest initial inoculum was found in the lower part of the tree, but the highest rate of the disease progress in the upper.
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Krell, Rayda K., Larry P. Pedigo, John H. Hill e Marlin E. Rice. "Potential Primary Inoculum Sources of Bean pod mottle virus in Iowa". Plant Disease 87, n. 12 (dicembre 2003): 1416–22. http://dx.doi.org/10.1094/pdis.2003.87.12.1416.
Testo completoAbstract (sommario):
A survey of Bean pod mottle virus (BPMV) in Iowa counties was conducted and the virus was found throughout the state. A long-term monitoring study (1989 to 2002) of the main BPMV vector, the bean leaf beetle, Cerotoma trifurcata, indicated that, in 2002, populations reached the highest abundance recorded in 14 years. Three potential sources for an early season primary inoculum source were found: (i) soybean (Glycine max) seed, (ii) overwintered bean leaf beetles, and (iii) alternate BPMV host plants. Examination of 5,804 and 8,064 soybean seedlings of two cultivars yielded 0 and 3 seedlings, respectively, infected with BPMV. In a separate test, BPMV was detected in mottled and nonmottled soybean seed. Some mottled seed did not contain BPMV, indicating that soybean seed coat mottling is an unreliable indicator for presence of the virus in seed. Of 194 naturally overwintered bean leaf beetles, only 1 transmitted BPMV to soybean. BPMV was detected serologically only in 1 alternate host, Desmodium canadense, out of 23 naturally occurring plant species collected from the field. The three inoculum sources discovered in Iowa in this study could be important primary sources when vector populations are high and indicate starting points for future epidemiological investigations.
23
Morlock, Glenn P., Frances C. Tyrrell, Dorothy Baynham, Vincent E. Escuyer, Nicole Green, Youngmi Kim, Patricia A. Longley-Olson et al. "Using Reduced Inoculum Densities of Mycobacterium tuberculosis in MGIT Pyrazinamide Susceptibility Testing to Prevent False-Resistant Results and Improve Accuracy: A Multicenter Evaluation". Tuberculosis Research and Treatment 2017 (2017): 1–9. http://dx.doi.org/10.1155/2017/3748163.
Testo completoAbstract (sommario):
The primary platform used for pyrazinamide (PZA) susceptibility testing of Mycobacterium tuberculosis is the MGIT culture system (Becton Dickinson). Since false-resistant results have been associated with the use of this system, we conducted a multicenter evaluation to determine the effect of using a reduced cell density inoculum on the rate of false resistance. Two reduced inoculum densities were compared with that prescribed by the manufacturer (designated as “BD” method). The reduced inoculum methods (designated as “A” and “C”) were identical to the manufacturer’s protocol in all aspects with the exception of the cell density of the inoculum. Twenty genetically and phenotypically characterized M. tuberculosis isolates were tested in duplicate by ten independent laboratories using the three inoculum methods. False-resistant results declined from 21.1% using the standard “BD” method to 5.7% using the intermediate (“A”) inoculum and further declined to 2.8% using the most dilute (“C”) inoculum method. The percentages of the resistant results that were false-resistant declined from 55.2% for the “BD” test to 28.8% and 16.0% for the “A” and “C” tests, respectively. These results represent compelling evidence that the occurrence of false-resistant MGIT PZA susceptibility test results can be mitigated through the use of reduced inoculum densities.
24
Mueller, E. E., R. L. Groves e C. Gratton. "Crop and Non-Crop Plants as Potential Reservoir Hosts of Alfalfa mosaic virus and Cucumber mosaic virus for Spread to Commercial Snap Bean". Plant Disease 96, n. 4 (aprile 2012): 506–14. http://dx.doi.org/10.1094/pdis-02-11-0089.
Testo completoAbstract (sommario):
Diseases caused by aphid-transmitted viruses such as Alfalfa mosaic virus (AMV) and Cucumber mosaic virus (CMV) have increased in snap bean (Phaseolus vulgaris) in the Midwestern United States. Plants immediately surrounding agricultural fields may serve as primary virus inocula for aphids to acquire and transmit to bean crops. The project objectives were to (i) identify potentially important AMV and CMV reservoirs among naturally infected plants and (ii) determine the relationship between the virus inoculum potential (VIP) in adjacent crop field margins and virus incidence in P. vulgaris. From 2006 to 2008, surveys were conducted to quantify the virus incidence and percentage cover (2008 only) of plants present within 5 m of the P. vulgaris crop. In all, 4,350 individual plants representing 44 species were assayed, with overall AMV and CMV incidences averaging 12 and 1.5%, respectively. A VIP index was developed and used to rank the importance of virus-susceptible plants in adjacent field margins. The overall VIP index for AMV in field margins was weakly associated with AMV incidence in P. vulgaris and no relationship was observed between local CMV inoculum and P. vulgaris incidence, suggesting that factors additional to local inoculum sources may influence CMV epidemics in P. vulgaris.
25
Rossi, Vittorio, e Tito Caffi. "The Role of Rain in Dispersal of the Primary Inoculum of Plasmopara viticola". Phytopathology® 102, n. 2 (febbraio 2012): 158–65. http://dx.doi.org/10.1094/phyto-08-11-0223.
Testo completoAbstract (sommario):
Although primary infection of grapevines by Plasmopara viticola requires splash dispersal of inoculum from soil to leaves, little is known about the role of rain in primary inoculum dispersal. Distribution of rain splashes from soil to grapevine canopy was evaluated over 20 rain periods (0.2 to 64.2 mm of rain) with splash samplers placed within the canopy. Samplers at 40, 80, and 140 cm above the soil caught 4.4, 0.03, and 0.003 drops/cm2 of sampler area, respectively. Drops caught at 40 and 80 cm (1.5 cm in diameter) were larger than drops at 140 cm (1.3 cm). Leaf coverage by splashed drops, total drop number, and drop size increased with an increase in the maximum intensity of rain (mm/h) during any rain period. Any rainfall led to infection in potted grapevines placed outside on leaf litter containing oospores, if the litter contained germinated oospores at the time of rain; infection severity was unrelated to rain amount or intensity. Results from vineyards also indicate that any rain can carry P. viticola inoculum from soil to leaves and should be considered a splash event in disease prediction systems. Sampling for early disease detection should focus on the lower canopy, where the probability of splash impact is greatest.
26
Scagel, C. F., K. Reddy e J. M. Armstrong. "Mycorrhizal Fungi in Rooting Substrate Influences the Quantity and Quality of Roots on Stem Cuttings of Hick's Yew". HortTechnology 13, n. 1 (gennaio 2003): 62–66. http://dx.doi.org/10.21273/horttech.13.1.0062.
Testo completoAbstract (sommario):
In a commercial nursery propagation system for hick's yew (Taxu×media `Hicksii'), we assessed whether or not the addition of inoculum of the vesicular-arbuscular mycorrhizal fungus (VAMF) Glomus intraradices into the rooting substrate during cutting propagation increased rooting, and how the quantity of inoculum influenced rooting. At 15 and 22 weeks (108 and 156 d) after cuttings were treated with root hormones and stuck, root initiation was higher on cuttings stuck in the rooting substrate containing VAMF inoculum. Increasing the quantity of inoculum in the rooting substrate increased root growth during the early stages of rooting. However the highest level of inoculum tested increased adventitious root initiation without increased root growth. Our results indicate that if VAMF inoculum is used during propagation from cuttings, there are optimal levels required to alter the initiation and growth of roots. For hick's yew, 1:100 or 2:100 (by volume) rates of G. intraradices in the rooting substrate increased the number of primary roots and growth of adventitious roots on cuttings above that achieved by using rooting hormone alone.
27
Desilets, H., S. Rochefort, J. Coulombe, S. Yelle e J. Brodeur. "Potential of Propane Flamers for Reduction of Apple Scab Primary Inoculum on Orchard Ground". HortScience 32, n. 2 (aprile 1997): 267–70. http://dx.doi.org/10.21273/hortsci.32.2.267.
Testo completoAbstract (sommario):
The potential impact of propane flamers on the development and release of ascosporic inoculum of Venturia inaequalis (Cke.) Wint. from infected dead apple (Malus domestica Borkh.) leaves that overwintered on the soil of an experimental orchard was assessed. Thermal reduction of scab primary inoculum was first conducted under controlled conditions using an indoor testing facility. At the time of ascospore maturation, heavily infected leaves were submitted to temperature rises ranging from 150 to 200 °C with open-flame burners, thus reducing the number of ascospores subsequently released by 76% and 87%, respectively. During Spring 1995, thermal treatments of overwintered dead leaves were performed directly on the ground of an apple orchard with an experimental propane flamer design to generate uniform heat at ground level. Four thermal treatment strategies, involving two dates of flaming and two heat intensities, were tested. Flaming orchard ground, when performed in early May, before significant development of ground cover, reduced the number of ascopores released from infected dead leaves by half. A significant residual effect of the treatments on ascospore ejection was still observed 2 and 4 weeks after the treatments, thus indicating that ascospore maturation inside the leaves may be reduced by heat treatment. These results indicate potential for propane flamers to reduce apple scab primary inoculum in orchards.
28
Lin, Shan, e Francesca Peduto Hand. "Determining the Sources of Primary and Secondary Inoculum and Seasonal Inoculum Dynamics of Fungal Pathogens Causing Fruit Rot of Deciduous Holly". Plant Disease 103, n. 5 (maggio 2019): 951–58. http://dx.doi.org/10.1094/pdis-09-18-1694-re.
Testo completoAbstract (sommario):
Fruit rot of deciduous holly, caused by species of the genera Alternaria, Colletotrichum, Diaporthe, and Epicoccum, is affecting plant production in Midwestern and Eastern U.S. nurseries. To determine the sources of inoculum, dormant twigs and mummified fruit were collected, and leaf spot development was monitored throughout the season from three Ohio nurseries over two consecutive years. Mummified fruit was the main source of primary inoculum for species of Alternaria and Epicoccum, whereas mummified fruit and bark were equally important for species of Colletotrichum and Diaporthe. Brown, irregular leaf spots developed in the summer, and disease incidence and severity increased along with leaf and fruit development. Coalesced leaf spots eventually resulted in early plant defoliation. When tested for their pathogenicity on fruit, leaf spot isolates were able to infect wounded mature fruit and induce rot symptoms, which indicated that leaf spots could serve as a source of secondary inoculum for fruit infections. In addition, spore traps were used to monitor seasonal inoculum abundance in the nurseries. Fruit rot pathogens were captured by the spore traps throughout the season, with peak dissemination occurring during flowering. In this study, we also attempted to understand the role of environmental factors on leaf spot development. Although leaf spot incidence and severity were negatively correlated to mean maximum, minimum and average temperature, a decrease in temperature also coincided with leaf senescence. The role of temperature on leaf spot development should be further studied to fully interpret these results.
29
Jeffers, S. N. "Phytophthora Crown Rot of Apple Trees: Sources ofPhytophthora cactorumandP. cambivoraas Primary Inoculum". Phytopathology 78, n. 3 (1988): 328. http://dx.doi.org/10.1094/phyto-78-328.
Testo completo
30
Patterson, C. L. "Role of Microsclerotia as Primary Inoculum ofMicrodochium panattonianum,Incitant of Lettuce Anthracnose". Plant Disease 75, n. 2 (1991): 134. http://dx.doi.org/10.1094/pd-75-0134.
Testo completo
31
Nissa, Rossy Choerun, Dadan Sumiarsa, Wawan Kosasih, Bonita Firdiana e Akbar Hanif Dawam Abdullah. "SYNTHESIS L-LACTIC ACID FROM FERMENTATION OF CASSAVA PULP BY USING TEMPEH INOCULUM". Jurnal Sains Materi Indonesia 23, n. 1 (1 novembre 2021): 1. http://dx.doi.org/10.17146/jsmi.2021.23.1.6265.
Testo completoAbstract (sommario):
SYNTHESIS L-LACTIC ACID FROM FERMENTATION OF CASSAVA PULP BY USING TEMPEH INOCULUM. This study used cassava waste pulp as a fermentation substrate to produce lactic acid using a tempeh inoculum. Tempeh inoculum is a mixed culture of Rhizopus with Rhizopus oligosporus as the primary fungus. Lactic acid is an organic acid most widely used in the food, pharmaceutical, cosmetic and chemical industries. One of the important uses of lactic acid is as a raw material for producing Polylactic Acid (PLA) biopolymers, namely polymers that can decompose naturally in a relatively fast time. The analysis was performed using the Response Surface Methodology (RSM) method and the Box Behnken Design (BBD) experimental design with substrate concentration parameters, inoculum concentration, and incubation time on lactic acid. The fermentation process is carried out using a flask shaker at a temperature of 30 ºC, pH 6.0, and a rotational speed of 150 rpm. The optimum yield for lactic acid is 6.65 g/L. It was acquired at substrate 20 g/L, inoculum concentration 0.30 % (w/v) at an incubation time of 72 hours.
32
Bailey, D. J., N. Paveley, J. Spink, P. Lucas e C. A. Gilligan. "Epidemiological Analysis of Take-All Decline in Winter Wheat". Phytopathology® 99, n. 7 (luglio 2009): 861–68. http://dx.doi.org/10.1094/phyto-99-7-0861.
Testo completoAbstract (sommario):
Take-all dynamics within crops differing in cropping history (the number of previous consecutive wheat crops) were analyzed using an epidemiological model to determine the processes affected during take-all decline. The model includes terms for primary infection, secondary infection, inoculum decay, and root growth. The average rates of root production did not vary with cropping history. The force of primary infection increased from a low level in 1st wheat crops, to a maximum in 2nd to 4th wheat crops, and then to intermediate levels thereafter. The force of secondary infection was low but increased steadily during the season in first wheat crops, was delayed but rose and fell sharply in 2nd to 4th wheat crops, and for 5th and 7th wheat crops returned to similar dynamics as that for 1st wheat crops. Chemical seed treatment with silthiofam had no consistent effect on the take-all decline process. We conjecture that these results are consistent with (i) low levels of particulate inoculum prior to the first wheat crop leading to low levels of primary infection, low levels of secondary infection, and little disease suppression; (ii) net amplification of inoculum during the first wheat crop and intercrop period; (iii) increased levels of primary and secondary infection in subsequent crops, but higher levels of disease suppression; and (iv) an equilibrium between the pathogen and antagonist populations by the 5th wheat, reflected by lower overall rates of primary infection, secondary infection, disease suppression and hence, disease severity.
33
Cabrefiga, Jordi, Maria Victoria Salomon e Pere Vilardell. "Improvement of Alternaria Leaf Blotch and Fruit Spot of Apple Control through the Management of Primary Inoculum". Microorganisms 11, n. 1 (30 dicembre 2022): 101. http://dx.doi.org/10.3390/microorganisms11010101.
Testo completoAbstract (sommario):
Alternaria spp. is the causal agent of apple leaf blotch and fruit spot, diseases of recent appearance in Spain. The overwinter inoculum of Alternaria spp. is the source of primary infections in apple, thus the aim of this work was to optimize the control of infection through two environmentally friendly inoculum-management strategies, the removal of winter fallen leaves and the treatment of leaves with the biological agent Trichoderma asperellum to inhibit or prevent inoculum development in commercial orchards. The results of commercial orchard trials showed that leaf aspiration and application of T. asperellum on the ground have efficacy to reduce fruit spot between 50 and 80% and leaf blotch of between 30 and 40% depending on the year. The efficacies on the reduction of leaf blotch were slightly lower than of fruit spot. Disease reduction has been related to a reduction of total spores released during the season. Results of dynamics of spore release indicate that factors influencing spore release were rainfall and temperature. In conclusion, the use of environmentally friendly strategies combined with standard fungicides, and with monitoring environmental conditions, might allow a reduction in the number of phytosanitary applications, thus achieving the goal of reducing their use.
34
Ji, Tao, Irene Salotti, Chaoyang Dong, Ming Li e Vittorio Rossi. "Modeling the Effects of the Environment and the Host Plant on the Ripe Rot of Grapes, Caused by the Colletotrichum Species". Plants 10, n. 11 (25 ottobre 2021): 2288. http://dx.doi.org/10.3390/plants10112288.
Testo completoAbstract (sommario):
Ripe rot caused by Colletotrichum spp. is a serious threat in many vineyards, and its control relies mainly on the repeated use of fungicides. A mechanistic, dynamic model for the prediction of grape ripe rot epidemics was developed by using information and data from a systematic literature review. The model accounts for (i) the production and maturation of the primary inoculum; (ii) the infection caused by the primary inoculum; (iii) the production of a secondary inoculum; and (iv) the infection caused by the secondary inoculum. The model was validated in 19 epidemics (vineyard × year combinations) between 1980 and 2014 in China, Japan, and the USA. The observed disease incidence was correlated with the number of infection events predicted by the model and their severity (ρ = 0.878 and 0.533, respectively, n = 37, p ≤ 0.001). The model also accurately predicted the disease severity progress during the season, with a concordance correlation coefficient of 0.975 between the observed and predicted data. Overall, the model provided an accurate description of the grape ripe rot system, as well as reliable predictions of infection events and of disease progress during the season. The model increases our understanding of ripe rot epidemics in vineyards and will help guide disease control. By using the model, growers can schedule fungicides based on the risk of infection rather than on a seasonal spray calendar.
35
Roumagnac, P., O. Pruvost, F. Chiroleu e G. Hughes. "Spatial and Temporal Analyses of Bacterial Blight of Onion Caused by Xanthomonas axonopodis pv. allii". Phytopathology® 94, n. 2 (febbraio 2004): 138–46. http://dx.doi.org/10.1094/phyto.2004.94.2.138.
Testo completoAbstract (sommario):
Bacterial blight of onion is a severe disease, which emerged over the past decade in several onion-producing areas. This disease currently is observed in both the Old and New Worlds. Although the causative agent, Xanthomonas axonopodis pv. allii, is potentially seedborne, seed transmission and significance of seedborne initial inoculum for the development of bacterial blight of onion previously has not been assessed. This article describes experimental work designed to evaluate the biological importance of seedborne X. axonopodis pv. allii as an initial inoculum source, and examine the temporal and spatial dynamics of the disease. Over 3 years, outbreaks of bacterial blight of onion always were induced in experimental plots sown with naturally contaminated seed lots, with a contamination rate determined as 0.04%. Analyses of disease patterns indicated a likely seedborne origin for the inoculum associated with the early stages of epidemics. Spatial analyses performed with several statistical methods indicated aggregated patterns of disease incidence data. Primary foci enlarged over time, and a few distinct secondary foci sometimes were established after occurrence of wind-driven rains (with gusts up to 15 m s-1). Distances between primary and secondary foci ranged from less than 1 m (satellite foci) to 25 m. It remains possible that longdistance dispersal of inoculum was at least partly involved in the later stages of epidemics.
36
Taylor, Robert G., e Karim Moshrefi. "Calcium, Nitrogen, and Rhizobium Effects on Arachis Hypogaea L. Valencia C". Peanut Science 14, n. 1 (1 gennaio 1987): 31–33. http://dx.doi.org/10.3146/i0095-3679-14-1-8.
Testo completoAbstract (sommario):
Abstract Nutritional needs of numerous plants (Arachis hypogaea L.) cultivars have been extensively examined, especially responses to N fertilizer, Ca availability in the soil solution, and the use of rhizobium soil inoculum. The nutritional effects of these three factors and their interactions on particular processes at various stages of growth and development of the plant were examined. Three levels of Ca and four N treatments were tested in a greenhouse on two sets of the Valencia C peanut cultivar, one receiving a soil inoculum and the other did not. Nutritional and soil inoculum treatment effects on primary stalk length, flower production, peg and pod development, and nodulation occurrence were statistically examined. Calcium and N were found to strongly, and independently, influence plant nodulation. Soil inoculation had no influence on flowering, peg or pod production. However, both Ca and N independently influenced these processes. Synergism between Ca and N appeared to influence peg development but not pod development. Additionally, the presence of rhizobium inoculum did not increase pod development. The presence of rhizobium soil inoculum which promoted nodule formation, was not closely related to fruit production but was related to the growth of the aerial portion of the plant.
37
Bennett, Rebecca S., Michael G. Milgroom, Raazesh Sainudiin, Barry M. Cunfer e Gary C. Bergstrom. "Relative Contribution of Seed-Transmitted Inoculum to Foliar Populations of Phaeosphaeria nodorum". Phytopathology® 97, n. 5 (maggio 2007): 584–91. http://dx.doi.org/10.1094/phyto-97-5-0584.
Testo completoAbstract (sommario):
A marked-isolate, release-recapture experiment was conducted to assess the relative contributions of seed-transmitted (released isolates) versus all other inocula to foliar and grain populations of Phaeosphaeria nodorum in winter wheat rotated with nonsusceptible crops in New York and Georgia, United States. Seed infected with two distinct groups of marked isolates of P. nodorum containing rare alleles (identified by amplified fragment length polymorphisms [AFLPs]) and balanced for mating type were planted in experimental field plots in two locations in each state. Recapture was done by isolating P. nodorum from leaves showing necrotic lesions at spring tillering and flowering stages, and mature grains from spikes showing glume blotch. Isolates from these samples were genotyped by AFLPs and categorized as released or nonreleased to infer sources of inoculum. Both infected seed and other sources of the pathogen contributed significant primary inocula to populations recovered from leaves and harvested grain. Seed-transmitted genotypes accounted for a total of 57% of all isolates recovered from inoculated plots, with a range of 15 to 90% of the populations of P. nodorum collected over the season in individual, inoculated plots at the four locations. Plants in the noninoculated control plots also became diseased and 95% or more of the isolates recovered from these plots were nonreleased genotypes. Although other potential sources of P. nodorum within and adjacent to experimental plots were not ruled out, nonreleased genotypes likely were derived from immigrant ascospores potentially from sources at a considerable distance from the plots. Our results suggest that, although reduction of seedborne inoculum of P. nodorum may delay foliar epidemics, this strategy by itself is unlikely to result in high levels of control in eastern North America because of the additional contribution from alternative sources of inoculum.
38
Mancini, Stefano, Elias Bodendoerfer, Natalia Kolensnik-Goldmann, Sebastian Herren, Kim Röthlin, Patrice Courvalin e Erik C. Böttger. "Evaluation of standardized automated rapid antimicrobial susceptibility testing of Enterobacterales-containing blood cultures: a proof-of-principle study". Journal of Antimicrobial Chemotherapy 75, n. 11 (7 agosto 2020): 3218–29. http://dx.doi.org/10.1093/jac/dkaa336.
Testo completoAbstract (sommario):
Abstract Background Rapid antimicrobial susceptibility testing (RAST) of bacteria causing bloodstream infections is critical for implementation of appropriate antibiotic regimens. Objectives We have established a procedure to prepare standardized bacterial inocula for Enterobacterales-containing clinical blood cultures and assessed antimicrobial susceptibility testing (AST) data generated with the WASPLabTM automated reading system. Methods A total of 258 blood cultures containing Enterobacterales were examined. Bacteria were enumerated by flow cytometry using the UF-4000 system and adjusted to an inoculum of 106 cfu/mL. Disc diffusion plates were automatically streaked, incubated for 6, 8 and 18 h and imaged using the fully automated WASPLabTM system. Growth inhibition zones were compared with those obtained with inocula prepared from primary subcultures following the EUCAST standard method. Due to time-dependent variations of the inhibition zone diameters, early AST readings were interpreted using time-adjusted tentative breakpoints and areas of technical uncertainty. Results and conclusions Inhibition zones obtained after 18 h incubation using an inoculum of 106 cfu/mL prepared directly from blood cultures were highly concordant with those of the EUCAST standard method based on primary subcultures, with categorical agreement (CA) of 95.8%. After 6 and 8 h incubation, 89.5% and 93.0% of the isolates produced interpretable results, respectively, with CA of >98.5% and very low numbers of clinical categorization errors for both the 6 h and 8 h readings. Overall, with the standardized and automated RAST method, consistent AST data from blood cultures containing Enterobacterales can be generated after 6–8 h of incubation and subsequently confirmed by standard reading of the same plate after 18 h.
39
Sutton, Donald K., William E. MacHardy e William G. Lord. "Effects of Shredding or Treating Apple Leaf Litter with Urea on Ascospore Dose of Venturia inaequalis and Disease Buildup". Plant Disease 84, n. 12 (dicembre 2000): 1319–26. http://dx.doi.org/10.1094/pdis.2000.84.12.1319.
Testo completoAbstract (sommario):
Ascospores produced on diseased leaves in the leaf litter constitute the primary inoculum causing scab in commercial apple orchards in the northeastern United States. Two sanitation practices, shredding the leaf litter with a flail mower and urea application, were evaluated for their potential to reduce the risk of primary scab. Three measures of a treatment's potential were made: leaf litter density was evaluated to determine reduction of the source or primary inoculum; trapped ascospores were counted to measure the reduction of primary inoculum; and scab lesions on trees and seedlings were counted to determine reduction in disease incidence and severity on leaves and fruit. The results show that in the northeastern United States, shredding the leaf litter in November or April will reduce the risk of scab by 80 to 90% if all of the leaf litter is shredded. If 10 to 35% of the leaf litter cannot be shredded because of the limited offset of the flail mower and spread of the tree canopy, then the risk of scab is reduced by 50 to 65%. Urea applied to the leaf litter in November (when approximately 95% of the leaves had fallen) reduced the number of ascospores trapped by 50%. Urea applied to the leaf litter in April (before bud break) reduced the number of ascospores trapped by 66%. The reductions are discussed in relation to a sanitation action threshold that links sanitation to a strategy that reduces the fungicide dose to control primary scab in an orchard assessed with a moderate amount of foliar scab the previous autumn.
40
Villarino, M., P. Melgarejo, J. Usall, J. Segarra e A. De Cal. "Primary Inoculum Sources of Monilinia spp. in Spanish Peach Orchards and Their Relative Importance in Brown Rot". Plant Disease 94, n. 8 (agosto 2010): 1048–54. http://dx.doi.org/10.1094/pdis-94-8-1048.
Testo completoAbstract (sommario):
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.
41
Tshomo, K., I. J. Horner, M. Walter, A. Stewart e M. V. Jaspers. "Treatment of overwintering apple leaves to reduce primary inoculum of apple black spot". New Zealand Plant Protection 56 (1 agosto 2003): 95–99. http://dx.doi.org/10.30843/nzpp.2003.56.6044.
Testo completoAbstract (sommario):
Field trials were conducted in Hawkes Bay and Lincoln into methods of treating overwintering apple leaves to reduce ascospore production by the apple black spot pathogen Venturia inaequalis The leaf treatments comprised three levels of nutrient amendments (including a water control) and five levels of saprophytic fungal isolates (including a nofungus control) in a factorial design Leaves were left to overwinter on the orchard floor and in spring the V inaequalis ascospores released were trapped on glass slides and counted Ascospore numbers were reduced (Plt;005) by the leaf amendment urea which alone caused 73 reduction but not by the BioStarttrade; product The effect of fungal isolates was not significant (P012) although when combined with the water treatment the isolates Chaetomium Phoma and Epicoccum spp and Trametes versicolor reduced numbers of ascospores by 33 27 15 and 28 respectively compared to the nofungus control When combined with urea the Chaetomium isolate reduced ascospore numbers by 92 and 82 compared to the nil fungus/water control treatments in Hawkes Bay and Lincoln respectively indicating that this treatment has potential for reducing primary inoculum of apple black spot
42
Pearson, Roger C. "Cleistothecia, the Source of Primary Inoculum for Grape Powdery Mildew in New York". Phytopathology 77, n. 11 (1987): 1509. http://dx.doi.org/10.1094/phyto-77-1509.
Testo completo
43
De la Torre-González, Francisco Javier, José Alberto Narváez-Zapata, Patricia Taillandier e Claudia Patricia Larralde-Corona. "Mezcal as a Novel Source of Mixed Yeasts Inocula for Wine Fermentation". Processes 8, n. 10 (16 ottobre 2020): 1296. http://dx.doi.org/10.3390/pr8101296.
Testo completoAbstract (sommario):
Mezcal yeasts were evaluated for their potential as grape-juice fermenters, characterizing their fermentation performance, both in terms of primary and volatile metabolites. Experiments were first carried-out in a semi-synthetic medium and then on grape juice, and population dynamics of the chosen mixed inoculum was assessed in grape juice. Accordingly, we initially tested 24 mezcal yeasts belonging to ten different species, and chose those that were more productive and stress tolerant for the mixed (dual) inoculum, having a final selection of three Saccharomyces cerevisiae strains (plus Fermichamp, a commercial wine strain) and three non-Saccharomyces strains, belonging to Kluyveromyces marxianus, Torulaspora delbrueckii, and Zygosaccharomyces bailii species. For the combination S. cerevisiae/T. delbrueckii (Sc/Td) mixed inoculum, we observed increasing isoamyl alcohol and phenyl ethyl acetate concentrations, as compared with the use of individual Saccharomyces strains, which resulted in a fruitier aroma profile. Alcohol final concentration was in average lower for the Sc/Td inoculum (fermentation power, FP, 13.6) as compared with the individual mezcal Saccharomyces strains (FP 14.3), and it was the highest when Td was co-cultured with the commercial strain (FP 14.6). Overall, our results show the feasibility of using yeasts isolated from mezcal as a novel source of inoculum for wine-type fermentation.
44
Mao, YX, GA Chilvers e JJ Burdon. "Computer Modelling of Damping-Off Epidemics in Relation to Host Density and Number of Disease Foci". Australian Journal of Botany 36, n. 5 (1988): 589. http://dx.doi.org/10.1071/bt9880589.
Testo completoAbstract (sommario):
In a previous experimental study of post-emergence damping-off epidemics in populations of cress seedlings, rate of advance ( A ) of spreading disease fronts and apparent infection rates ( r ) were measured separately in relation to differences in host density. In this study, a computer model was built to simulate those damping-off epidemics, with the aim of relating A and r. Over a range of host densities it was found that r could be predicted from the known quantitative relationship between A and host density, provided that the number of primary infection foci was also taken into account. Scrutiny of the earlier experimental results revealed that the number of primary infection foci separately influenced the sub- sequent infection rate. The importance of number of foci in this instance is attributed to the very steep inoculum gradient characteristic of this disease, which limits inoculum transmission to plants around the periphery of disease patches so that disease increase is controlled more by the sum of disease perimeters than by the sum of diseased infectious plants as in air-borne diseases. It is expected that other slow-spreading soil-borne diseases with steep inoculum gradients will follow this same pattern.
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Johansen, J. E., e R. Bakke. "Enhancing hydrolysis with microaeration". Water Science and Technology 53, n. 8 (1 aprile 2006): 43–50. http://dx.doi.org/10.2166/wst.2006.234.
Testo completoAbstract (sommario):
Effects of microaeration on hydrolysis of primary sludge are investigated in 500 ml batch reactors at 377 °C. Two experiments, one with a microaerobic inoculum and one with a combination of a microaerobic and an anaerobic inoculum, are carried out to also investigate the role of the inoculum. Assuming an acidogenic, methanogenic and aerobic biomass yield of 0.1, 0.05 and 0.45 mgC/mgC, respectively, a 50–60% hydrolysis increase, during the 4 day experiment, is observed with a ratio between aerobic and anaerobic metabolism in the range 0.5–0.7. The extra hydrolysed products are oxidized to carbon dioxide and incorporated into new biomass. The oxygen utilization to carbon dioxide production ratio was ∼1:1 on a mol basis. Effects of the oxygen supplied on the hydrolysis of carbohydrates, proteins and lipids are analyzed based on measurements and balances of dissolved carbon, nitrogen and COD. The total observed hydrolysis increase can be accounted for by increased hydrolysis of carbohydrates and proteins. Lipids are only hydrolysed when anaerobic inoculum is added, but no effect of oxygen availability is detected.
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Masangkay, Rhomela F., Timothy C. Paulitz, Steven G. Hallett e Alan K. Watson. "Factors Influencing Biological Control of Sphenoclea zeylanica with Alternaria alternata f. sp. sphenocleae". Plant Disease 83, n. 11 (novembre 1999): 1019–24. http://dx.doi.org/10.1094/pdis.1999.83.11.1019.
Testo completoAbstract (sommario):
Alternaria alternata f. sp. sphenocleae is an endemic disease causing a few small necrotic foliar lesions and occasionally a foliar blight on Sphenoclea zeylanica, a problem weed in paddy rice. The effects of inoculum concentration, dew period, and plant age on the biocontrol of S. zeylanica with A. alternata f. sp. sphenocleae were studied under controlled environmental conditions. S. zeylanica plants are susceptible from seedling to maturity. When higher inoculum concentrations (106 conidia ml-1, 108 conidia m-2) were applied to plants of different ages with a long dew period, 100% leaf area damage occurred earlier than when lower inoculum concentrations (104 conidia ml-1, 106 conidia m-2) were used. At the higher inoculum concentrations, a significantly (α < 0.01) higher percent reduction in plant height was obtained, and all plants were killed. A dew period of 8 h was sufficient to cause 100% mortality when plants were inoculated with 106 conidia ml-1, whereas a dew period of 16 h was required with 104 conidia ml-1 to achieve the same effect. At all dew periods, a significantly (α < 0.01) higher percent dry weight reduction was obtained with higher inoculum concentrations. Field performance of this bioherbicide candidate relies on the primary infection established by inoculum application, as secondary infections have not been observed. Effective use rates can be reduced during the rainy season, while higher rates are required during the dry season.
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Kawchuk, L. M., e J. Nielsen. "Improved bunt inoculation of wheat utilizing adventitious shoots". Canadian Journal of Botany 65, n. 6 (1 giugno 1987): 1284–85. http://dx.doi.org/10.1139/b87-180.
Testo completoAbstract (sommario):
A procedure is described of injecting inoculum of dwarf or common bunt at the bases of the internodes of wheat. Physical stimulation by wounding of the intercalary meristem located above the nodes resulted in the formation of adventitious shoots. If inoculum of dwarf or common bunt is injected at the time of stimulation, the spike of the resulting shoot is usually infected. This procedure shortened the period between teliospore germination and production of sori, gave a high infection rate, and induced several infected spikes on one primary stem.
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Kumar, Shrvan, Dhanbir Singh, Subhash Dhancholia e Asha Sinha. "Effect of wheat seed dressing fungicides, botanicals and bio-control agent on Karnal bunt incidence in natural condition". Journal of Applied and Natural Science 9, n. 4 (1 dicembre 2017): 2211–13. http://dx.doi.org/10.31018/jans.v9i4.1513.
Testo completoAbstract (sommario):
In this study the efficacy of four fungicides, three botanicals and one bio-control agent under field conditions revealed that all the treatments gave reduction of Karnal bunt over check at significant level (P=0.05). Maximum disease control was achieved with Tilt 25EC (48.72%) followed by Bavistin 50WP (47.08 %), Vitavax 75WP (45.30%) and Raxil 2DS (37.61%). Among botanicals L. camara was adjudged best as it gave 41.88 per cent disease control. However, seed treatment of T. viride (Ecoderma) resulted in 28.21 percent disease control. In all treatments over all disease control level was ranged between 28.21 to 48.72 per cent. For effective disease management, source of primary inoculum must be destroy. Primary inoculum of Karnal bunt is present in seed. There-fore, eco-friendly seed treatment of wheat is necessary process for diseases management.
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Cieniewicz, Elizabeth, Madison Flasco, Melina Brunelli, Anuli Onwumelu, Alice Wise e Marc F. Fuchs. "Differential Spread of Grapevine Red Blotch Virus in California and New York Vineyards". Phytobiomes Journal 3, n. 3 (gennaio 2019): 203–11. http://dx.doi.org/10.1094/pbiomes-04-19-0020-r.
Testo completoAbstract (sommario):
Limited information is available on the spread dynamics of grapevine red blotch virus (GRBV, genus Grablovirus, family Geminiviridae) in vineyards. In this study, we investigated red blotch disease progress in three vineyards with a disparate initial inoculum prevalence. Secondary spread was documented in Cabernet Sauvignon and Cabernet franc vineyards in California, but not in a Merlot vineyard in New York. Increase in annual disease incidence (4.8, 0.13, and 0%) was unrelated to the estimated initial source of inoculum at planting (1, 40, and 40%) in the Cabernet franc, Cabernet Sauvignon, and Merlot vineyards, respectively. Limited genetic diversity of GRBV populations in newly infected vines supported localized spread in California vineyards, and suggested the planting material as the primary source of inoculum. Among the community of hemipteran insects visiting two of the three study vineyards, populations of Spissistilus festinus, the vector of GRBV, were absent in the Merlot vineyard and low in the Cabernet Sauvignon vineyard. Furthermore, all cover crop samples collected from GRBV-infected California vineyards each spring of 2016 to 2018, particularly legume species which are preferred hosts of S. festinus, tested negative for GRBV, suggesting a minimal role, if any, in GRBV spread as inoculum reservoirs. Together our findings illustrate differential disease progress in distinct vineyard ecosystems, and support the elimination of virus inoculum sources as an actionable disease management strategy across vineyards.
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Holb, Imre, e Bart Heijne. "Comparative Study of Dutch and Hungarian Environmentally-friendly Apple Orchards on Potential Ascospore Dose of Apple Scab". Acta Agraria Debreceniensis, n. 1 (12 maggio 2002): 31–36. http://dx.doi.org/10.34101/actaagrar/1/3533.
Testo completoAbstract (sommario):
In a 2-year study, Dutch and Hungarian environmentally-friendly apple orchards were compared as regards the amount of apple scab primary inoculum. The PAD (potential ascospore dose) method was used to quantify the potential amount of primary inoculum (ascospores) per m2 orchard floor. Applying this method, the number of lesions per m2 of leaf in the autumn (LD), the proportion of the orchard floor covered by leaf litter at bud break (LLD) and potential ascospore dose (PAD) were determined. In autumn, LD values ranged between 2.2 and 13.5 in the integrated orchards, while in the organic orchards the values were between 42.5 and 106.2, with especially high values in the Dutch organic orchard. LLD values ranged between 24 and 43% at bud break in both countries. PAD values were 10-60 times higher than those of the integrated orchards. The PAD values were between 673 and 4275 ascospore/m2 orchard floor in the integrated orchards, while in the organic orchards these values were 37102 and 52390 ascospore/m2 orchard floor, respectively. On the basis of the recorded primary inoculum quantity, the Dutch integrated apple orchard is considered to be excellently protected, while the Hungarian orchard has a medium level of protection. However, both countries’ organic orchards can be regarded overall as being very poorly protected. Accordingly, in the integrated orchards the predicted epidemic risk is low or medium, while in the organic orchards it is very high on the basis of PAD values.