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 Identification of the Fungal Pathogens of Postharvest Disease on Peach Fruits and the Control Mechanisms of Bacillus subtilis JK-14

Toxins ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 322 ◽  
Author(s):  
Shuwu Zhang ◽  
Qi Zheng ◽  
Bingliang Xu ◽  
Jia Liu
Keyword(s):  
Biological Control ◽  
Bacillus Subtilis ◽  
Fungal Pathogens ◽  
Biological Control Agent ◽  
Storage Period ◽  
Control Agent ◽  
Antagonistic Activity ◽  
Postharvest Disease ◽  
Economic Losses ◽  
Control Mechanisms

Postharvest fungal disease is one of the significant factors that limits the storage period and marketing life of peaches, and even result in serious economic losses worldwide. Biological control using microbial antagonists has been explored as an alternative approach for the management of postharvest disease of fruits. However, there is little information available regarding to the identification the fungal pathogen species that cause the postharvest peach diseases and the potential and mechanisms of using the Bacillus subtilis JK-14 to control postharvest peach diseases. In the present study, a total of six fungal isolates were isolated from peach fruits, and the isolates of Alternaria tenuis and Botrytis cinerea exhibited the highest pathogenicity and virulence on the host of mature peaches. In the culture plates, the strain of B. subtilis JK-14 showed the significant antagonistic activity against the growth of A. tenuis and B. cinerea with the inhibitory rates of 81.32% and 83.45% at 5 days after incubation, respectively. Peach fruits treated with different formulations of B. subtilis JK-14 significantly reduced the mean disease incidences and lesion diameters of A. tenuis and B. cinerea. The greatest mean percent reduction of the disease incidences (81.99% and 71.34%) and lesion diameters (82.80% and 73.57%) of A. tenuis and B. cinerea were obtained at the concentration of 1 × 107 CFU mL−1 (colony forming unit, CFU). Treatment with the strain of B. subtilis JK-14 effectively enhanced the activity of the antioxidant enzymes-superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in A. tenuis and B. cinerea inoculated peach fruits. As such, the average activities of SOD, POD and CAT were increased by 36.56%, 17.63% and 20.35%, respectively, compared to the sterile water treatment. Our results indicate that the isolates of A. tenuis and B. cinerea are the main pathogens that cause the postharvest peach diseases, and the strain of B. subtilis JK-14 can be considered as an environmentally-safe biological control agent for the management of postharvest fruits diseases. We propose the possible mechanisms of the strain of B. subtilis JK-14 in controlling of postharvest peach diseases.

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 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.

scholarly journals Draft Genome Sequence of Bacillus velezensis Strain E68, Isolated from an Oil Battery

2020 ◽  
Vol 9 (24) ◽  
Author(s):  
Nathan Liang ◽  
Suha Jabaji
Keyword(s):  
Biological Control ◽  
Fungal Pathogens ◽  
Biological Control Agent ◽  
Draft Genome ◽  
Gene Clusters ◽  
Control Agent ◽  
Biosynthetic Gene ◽  
Bacillus Velezensis ◽  
Biosynthetic Gene Clusters ◽  
Content Type

ABSTRACT Bacillus velezensis strain E68 is a biosurfactant-producing bacterium isolated from an oil battery near Chauvin, Alberta, Canada. Strain E68 exhibited antimicrobial activity against fungal pathogens and could potentially serve as a biological control agent. Its genome was sequenced and annotated, revealing the presence of multiple lipopeptide biosynthetic gene clusters.

Predisposition of Melaleuca (Melaleuca quinquenervia) to Invasion by the Potential Biological Control Agent Botryosphaeria ribis

Weed Science ◽  
1996 ◽  
Vol 44 (3) ◽  
pp. 603-608 ◽  
Author(s):  
Min B. Rayachhetry ◽  
George M. Blakeslee ◽  
Ted D. Center
Keyword(s):  
Biological Control ◽  
Low Temperature ◽  
Tree Mortality ◽  
Biological Control Agent ◽  
Control Agent ◽  
Melaleuca Quinquenervia ◽  
Xylem Water Potential ◽  
Simulated Drought ◽  
Canker Development ◽  
Low Temperature Treatments

Enhancement of the canker causing ability of Botryosphaeria ribis on melaleuca was studied with respect to stress from simulated drought, low temperature, and defoliation treatments. Low xylem water potential was related to increased level of canker development and subsequent tree mortality. Canker development was enhanced by low temperature treatments with alternating exposure to 6 C for 3 d followed by 4 d at 30 (±5) C for 8 wk. Partial defoliation did not affect canker development but complete defoliation of B. ribis-inoculated ramets resulted in tree mortality within 4 wk. Callusing of melaleuca wounds was either reduced or prevented in stressed trees. These observations suggest that stress induced on the tree enhances the tree-killing efficacy of this fungus.

Evaluation of Biological and Chemical Pruning Wound Protectants to Control Grapevine Trunk Diseases Pathogens Eutypa lata and Neofusicoccum parvum

2021 ◽  
Author(s):  
Robert Blundell ◽  
Akif Eskalen
Keyword(s):  
Recovery Rate ◽  
Fungal Pathogens ◽  
Field Trials ◽  
Positive Control ◽  
Neofusicoccum Parvum ◽  
Eutypa Lata ◽  
Grapevine Trunk Diseases ◽  
Pruning Wound ◽  
Wound Protection ◽  
Trunk Diseases

Grapevine trunk diseases, caused by many different fungal pathogens, are one of the most economically important diseases affecting the grapevine industry worldwide. Pruning wounds are the main point of entry for these fungal pathogens and thus, disease control is focused on preventative pruning wound protection by chemical products and/or biological control agents (BCAs). In this study we evaluated a broad variety of already registered or at the experimental stage of chemical and BCAs in greenhouse and in field trials for the protection of table- and wine-grape vines against infection of Eutypa lata and Neofusicoccum parvum, major pathogens responsible for Eutypa and Botryosphaeria dieback, respectively. Our study showed that Trichoderma asperellum and Trichoderma gamsii consistently provided pruning wound protection in greenhouse and field trials, with a mean percent disease control (MPDC) of 88% and 100% for E. lata and N. parvum, respectively, when compared to the water treated-inoculated positive control (P<0.05). The chemical protectants, thiophanate-methyl + myclobutanil and fluopyram and trifloxystrobin were also able to effectively protect wounds with a MPDC of up to 86% when compared to the water treated-inoculated positive control (P<0.05). When biological treatments were evaluated for recovery from treated canes at the end of the growing season, Trichoderma-based treatments had a rate of recovery between 0 and 100%, Aureobasidium-based treatments had a recovery rate between 25 and 100%, and Bacillus-based treatments had a recovery rate between 0 and 25%.

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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