scholarly journals Biological Diabrotica Management and Monitoring of Metarhizium Diversity in Austrian Maize Fields Following Mass Application of the Entomopathogen Metarhiziumbrunneum

2021 ◽  
Vol 11 (20) ◽  
pp. 9445
Author(s):  
Maria Zottele ◽  
Johanna Mayerhofer ◽  
Hannah Embleton ◽  
Katharina Wechselberger ◽  
Jürg Enkerli ◽  
...  
Keyword(s):  
Biological Control ◽  
Population Structure ◽  
Biological Control Agent ◽  
Background Level ◽  
Dry Weight ◽  
Field Trials ◽  
Control Agent ◽  
Indigenous Populations ◽  
Colony Forming Units ◽  
Cultivation Techniques

Inundative mass application of Metarhizium brunneum BIPESCO 5 (Hypocreales, Clavicipitaceae) is used for the biological control of Diabrotica v. virgifera (Coleoptera, Chrysomelidae). Long-term field trials were performed in three Austrian maize fields—with different cultivation techniques and infestation rates—in order to evaluate the efficacy of the treatment to control the pest larvae. In addition, the indigenous Metarhizium spp. population structure was assessed to compare the different field sites with BIPESCO 5 mass application. Annual application of the product Granmet-PTM (Metarhizium colonized barley kernels) significantly increased the density of Metarhizium spp. in the treated soil above the upper natural background level of 1000 colony forming units per gram dry weight soil. Although a decrease in the pest population over time was not achieved in heavily infested areas, less damage occurred in treated field sites in comparison to control sites. The Metarhizium population structure was significantly different between the treated field sites. Results showed that inundative mass application should be repeated regularly to achieve good persistence of the biological control agent, and indicated that despite intensive applications, indigenous populations of Metarhizium spp. can coexist in these habitats. To date, crop rotation remains the method of choice for pest reduction in Europe, however continuous and preventive application of M. brunneum may also present an alternative for the successful biological control of Diabrotica.

Evaluation of pruning wound protection products for the management of almond canker diseases in California

Plant Disease ◽  
2021 ◽  
Author(s):  
Leslie Amanda Holland ◽  
Renaud Travadon ◽  
Daniel P. Lawrence ◽  
Mohamed Taieb Nouri ◽  
Florent P Trouillas
Keyword(s):  
Biological Control ◽  
Fungal Pathogens ◽  
Tree Mortality ◽  
Biological Control Agent ◽  
Field Trials ◽  
Control Agent ◽  
Thiophanate Methyl ◽  
Pruning Wound ◽  
Wound Protection ◽  
Canker Pathogens

Almond trunk and branch canker diseases constitute a major cause of tree mortality in California. Numerous fungal pathogens have been associated with these canker diseases and pruning wounds act as major infection courts. Prior to this study, there were no products registered in California for the management of these diseases. In this study, fungicidal products including synthetic chemistries, biocontrols, paint and a sealant were evaluated for preventing fungal pathogen infection via pruning wounds. In four field trials conducted over two dormant seasons, sixteen pruning wound treatments were tested using hand-held spray applications, against five almond canker pathogens, namely Botryosphaeria dothidea, Neofusicoccum parvum, Cytospora sorbicola, Ceratocystis destructans, and Eutypa lata. The fungicide thiophanate-methyl (Topsin M) provided 82% overall disease prevention against four fungal pathogens. The biological control agent, Trichoderma atroviride SC1 (Vintec), tested at three application rates, resulted in 90 to 93% protection of pruning wounds in field trials, and for individual pathogens ranged from 81-100% protection for the three rates. At the time of this publication, Vintec is being considered for registration as a biological control product for the prevention of almond canker diseases, while Topsin M is recommended to growers for the prevention of almond canker diseases. This research indicates that effective protection of pruning wounds from infection by almond canker pathogens can be achieved with a one-time spray application of thiophanate-methyl or the biocontrol, T. atroviride SC1 (recommended 2 g/liter) after pruning.

scholarly journals Mechanistically Compatible Mixtures of Bacterial Antagonists Improve Biological Control of Fire Blight of Pear

2011 ◽  
Vol 101 (1) ◽  
pp. 113-123 ◽  
Author(s):  
V. O. Stockwell ◽  
K. B. Johnson ◽  
D. Sugar ◽  
J. E. Loper
Keyword(s):  
Biological Control ◽  
Plant Disease ◽  
Fire Blight ◽  
Biological Control Agent ◽  
Field Trials ◽  
Control Agent ◽  
Extracellular Protease ◽  
Peptide Antibiotics ◽  
Biological Control Agents ◽  
Control Activity

Mixtures of biological control agents can be superior to individual agents in suppressing plant disease, providing enhanced efficacy and reliability from field to field relative to single biocontrol strains. Nonetheless, the efficacy of combinations of Pseudomonas fluorescens A506, a commercial biological control agent for fire blight of pear, and Pantoea vagans strain C9-1 or Pantoea agglomerans strain Eh252 rarely exceeds that of individual strains. A506 suppresses growth of the pathogen on floral colonization and infection sites through preemptive exclusion. C9-1 and Eh252 produce peptide antibiotics that contribute to disease control. In culture, A506 produces an extracellular protease that degrades the peptide antibiotics of C9-1 and Eh252. We hypothesized that strain A506 diminishes the biological control activity of C9-1 and Eh252, thereby reducing the efficacy of biocontrol mixtures. This hypothesis was tested in five replicated field trials comparing biological control of fire blight using strain A506 and A506 aprX::Tn5, an extracellular protease-deficient mutant, as individuals and combined with C9-1 or Eh252. On average, mixtures containing A506 aprX::Tn5 were superior to those containing the wild-type strain, confirming that the extracellular protease of A506 diminished the biological control activity of C9-1 and Eh252 in situ. Mixtures of A506 aprX::Tn5 and C9-1 or Eh252 were superior to oxytetracycline or single biocontrol strains in suppressing fire blight of pear. These experiments demonstrate that certain biological control agents are mechanistically incompatible, in that one strain interferes with the mechanism by which a second strain suppresses plant disease. Mixtures composed of mechanistically compatible strains of biological control agents can suppress disease more effectively than individual biological control agents.

scholarly journals Biological Control of the Weedy Plant (Rumex crispus) at the Seedling Growth Stage by the Green Dock Beetle (Gastrophysa viridula)

2019 ◽  
Vol 28 (1) ◽  
pp. 21-31
Author(s):  
Khalid S. Alshallash Khalid S. Alshallash
Keyword(s):  
Biological Control ◽  
Seedling Growth ◽  
Growth Stage ◽  
Biological Control Agent ◽  
Dry Weight ◽  
Control Agent ◽  
Growth Stages ◽  
Rumex Crispus ◽  
Shoot Number ◽  
The Impact

In four glasshouse experiments, the effectiveness of the adult green dock beetle Gastrophysa viridula (Coleoptera: Chrysomelidae), at the effective number of applied individuals, for use as a biological control agent of curled dock, Rumex crispus (Polygonaceae) were studied. The feeding of the beetle was investigated at four different numbers of beetle (0, 1, 2, 3) and at four seedling growth stages of the plant, defined by the average of leaf area per plant (1-1.22 , 2-4.45, 3-11.56, and 4-71.52 cm2/plant). Grazing by one, two or three dock beetles did not result in a significant reduction in dock dry weight or shoot numbers at the youngest growth stage. However, both at later seedling growth stages were significantly affected (P ? 0.0001), at any beetles number. The increase of beetle numbers caused nonsignificant increased effect, in some trials, confirming the impact of a single beetle. Three months after beetle grazing, dock seedlings of first, second and third growth stages were not able to regrow, however, some plants at the 4th growth stage, re-emerged. This suggested that the highest effect of beetle's feeding occurs on the early seedling stages. Statistical analysis showed a positive correlation (0.77) between dry weight and shoot number at all the four seedling growth stages, thus confirming the impact of the beetle on both the dry weight and shoot numbers. Combining beetle grazing with other control methods at older dock seedling stages could, therefore, provide better suppression

scholarly journals Californian thistle and its variable response to the biological control agent Sclerotinia sclerotiorum

2016 ◽  
Vol 69 ◽  
pp. 258-262
Author(s):  
B. Smith ◽  
S.G. Casonato ◽  
A. Noble ◽  
G. Bourd?t
Keyword(s):  
Biological Control ◽  
New Zealand ◽  
Sclerotinia Sclerotiorum ◽  
Biological Control Agent ◽  
Field Trials ◽  
Control Agent ◽  
Cirsium Arvense ◽  
Variable Response ◽  
Fungal Isolates ◽  
Californian Thistle

Californian thistle (Cirsium arvense) is a problematic weed particularly in permanent pastures The fungus Sclerotinia sclerotiorum has potential as a bioherbicide to control this weed but its variable efficacy in historical field trials suggest that there are differences in susceptibility to S sclerotiorum within the species To test this hypothesis the responses of 32 New Zealand provenances of C arvense to a foliageapplied myceliumonbarley preparation of S sclerotiorum were compared under common conditions Significant differences between provenances were found supporting the hypothesis that there is variation within C arvense in New Zealand in its susceptibility to S sclerotiorum Further work will examine differences in the efficacy of fungal isolates against different C arvense provenances

scholarly journals Bacillus velezensis WZ-37, a New Broad-Spectrum Biocontrol Strain, Promotes the Growth of Tomato Seedlings

Agriculture ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 581
Author(s):  
Xiuling Chen ◽  
Haifeng Huang ◽  
Shumei Zhang ◽  
Yao Zhang ◽  
Jingbin Jiang ◽  
...  
Keyword(s):  
Biological Control ◽  
Broad Spectrum ◽  
Biological Control Agent ◽  
Storage Period ◽  
Dry Weight ◽  
Gray Mold ◽  
Control Agent ◽  
Soluble Solids ◽  
Bacillus Velezensis ◽  
Tomato Seedlings

A biological control agent is arguably an ideal alternative to chemical fungicide for the prevention and control of gray mold disease. During this process, a biological control produces low levels of pollution, generates few residues that pose no risk to the environment, and pathogens cannot gain resistance to it easily. A new antifungal strain isolated from plant rhizosphere exhibited high antifungal activity against the phytopathogens Botrytis cinerea, Fusarium oxysporum f. sp. cucumerinum, F. moniliforme, Sclerotinia sclerotiorum, Colletotrichum orbiculare, Alternaria nees, F. equiseti, and F. oxysporum f. sp. lycopersici. It was identified as Bacillus velezensis WZ-37 by morphological and physiological indices and comparisons of 16S rRNA and gyrB genes. WZ-37 can significantly inhibit the mycelia growth of B. cinerea by 96.97%. It can reduce a tomato fruit’s decay rate after 21 days of storage by 33.33% (13.34% less for the control) without significantly affecting its firmness and soluble solids. Plant height, stem diameter, and the fresh and dry weight of tomato seedlings were significantly increased when their seeds were soaked in a WZ-37 suspension (106 cfu/mL) for 3 h and grown for 21 days in soil. WZ-37 has broad-spectrum biocontrol and can prolong a tomato’s storage period and enhance its seedlings’ growth, making it a promising candidate strain for broad-spectrum biocontrol applications in agriculture.

scholarly journals Biological Control of Crown Gall of Grapevine, Rose, and Tomato by Nonpathogenic Agrobacterium vitis Strain VAR03-1

2008 ◽  
Vol 98 (11) ◽  
pp. 1218-1225 ◽  
Author(s):  
A. Kawaguchi ◽  
K. Inoue ◽  
Y. Ichinose
Keyword(s):  
Biological Control ◽  
Crown Gall ◽  
Biological Control Agent ◽  
Inhibitory Effect ◽  
Control Agent ◽  
Inhibitory Effects ◽  
Agrobacterium Vitis ◽  
Colony Forming Units ◽  
Nonpathogenic Strain ◽  
A Cell

A nonpathogenic strain of Agrobacterium vitis VAR03-1 was tested as a biological control agent for crown gall of grapevine (Vitis vinifera). When roots of grapevine, rose (Rose multiflora), and tomato (Lycopersicon esculentum) were soaked in a cell suspension of antagonists before planting in soil infested with tumorigenic A. vitis, A. rhizogenes, and A. tumefaciens, respectively, treatment with VAR03-1 significantly reduced the number of plants with tumors and disease severity in the three plant species. The inhibitory effects of treatment with VAR03-1 and the nonpathogenic A. rhizogenes strain K84 on crown gall of rose and tomato were almost identical, and the inhibitory effect of VAR03-1 on grapevine was superior to that of K84. Moreover, VAR03-1 greatly controlled crown gall of grapevine due to tumorigenic A. vitis in the field. VAR03-1 established populations averaging 106 colony forming units (CFU)/g of root in the rhizosphere of grapevine and persisted on roots for 2 years. VAR03-1 was bacteriocinogenic, producing a halo of inhibition against those three species of Agrobacterium. This is the first report that a nonpathogenic strain, VAR03-1, can effectively control crown gall caused by tumorigenic A. vitis, A. rhizogenes, and A. tumefaciens.

Field Trials of Sclerotinia sclerotiorum to Control Canada Thistle (Cirsium arvense)

Weed Science ◽  
1986 ◽  
Vol 34 (3) ◽  
pp. 377-380 ◽  
Author(s):  
Brenda S. Brosten ◽  
David C. Sands
Keyword(s):  
Biological Control ◽  
Root System ◽  
Sclerotinia Sclerotiorum ◽  
Biological Control Agent ◽  
Field Trials ◽  
Control Agent ◽  
Cirsium Arvense ◽  
Subsequent Reduction ◽  
Canada Thistle

An isolate of Sclerotinia sclerotiorum (Lib.) de Bary collected from a Canada thistle [Cirsium arvense (L.) Scop. # CIRAR] plant in Montana proved pathogenic on Canada thistle in field trials. In addition to attacking the thistle crown and causing wilting and death of the shoots, S. sclerotiorum also infected the root system. The high percentage of thistle shoot kill (20 to 80%) after treatment, and subsequent reduction in plant thistle density the following year, demonstrated the potential of S. sclerotiorum as a biological control agent for Canada thistle in Montana.

scholarly journals Assessment of the Environmental Fate of the Biological Control Agent of Fire Blight, Pseudomonas fluorescens EPS62e, on Apple by Culture and Real-Time PCR Methods

2006 ◽  
Vol 72 (4) ◽  
pp. 2421-2427 ◽  
Author(s):  
Marta Pujol ◽  
Esther Badosa ◽  
Charles Manceau ◽  
Emilio Montesinos
Keyword(s):  
Biological Control ◽  
Pseudomonas Fluorescens ◽  
Real Time ◽  
Real Time Pcr ◽  
Environmental Fate ◽  
Biological Control Agent ◽  
Field Trials ◽  
Control Agent ◽  
Cell Counting ◽  
Standard Curve

ABSTRACT The colonization of apple blossoms and leaves by Pseudomonas fluorescens EPS62e was monitored in greenhouse and field trials using cultivable cell counting and real-time PCR. The real-time PCR provided a specific quantitative method for the detection of strain EPS62e. The detection level was around 102 cells g (fresh weight)−1 and the standard curve was linear within a 5-log range. EPS62e actively colonized flowers reaching values from 107 to 108 cells per blossom. In apple flowers, no significant differences were observed between population levels obtained by real-time PCR and plating, suggesting that viable but nonculturable (VBNC) cells and residual nondegraded DNA were not present. In contrast, on apple leaves, where cultivable populations of EPS62e decreased with time, significant differences were observed between real-time PCR and plating. These differences indicate the presence of VBNC cells or nondegraded DNA after cell death. Therefore, the EPS62e population was under optimal conditions during the colonization of flowers but it was stressed and poorly survived on leaves. It was concluded that for monitoring this biological control agent, the combined use of cultivable cell count and real-time PCR is necessary.

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