LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 19

Search options

  1. Article: Survey on Latent Infection of Canker-Causing Pathogens in Budwood and Young Trees from Almond and Prune Nurseries in California.

    Luo, Yong / Niederholzer, Franz / Camiletti, Boris X / Michailides, Themis J

    Plant disease

    2024  Volume 108, Issue 3, Page(s) 550–557

    Abstract: Almond band canker and prune Cytospora canker have become more severe in the last decade, especially in young orchards, in California. To test our hypothesis that young trees from nurseries could carry the canker-causing pathogens at latency phase to new ...

    Abstract Almond band canker and prune Cytospora canker have become more severe in the last decade, especially in young orchards, in California. To test our hypothesis that young trees from nurseries could carry the canker-causing pathogens at latency phase to new orchards through transplanting, a multiyear survey on latent infection of canker-causing pathogens of budwood and young trees of almond and prune nurseries in California was conducted. A total of more than 1,730 samples including shoots of rootstocks and scions and grafting union cuttings were collected from 11 nurseries. A real-time quantitative PCR assay was applied to quantify the latent infection levels by six canker-causing pathogen taxa:
    MeSH term(s) Humans ; Prunus dulcis/genetics ; Trees ; Nurseries, Infant ; Plant Diseases ; California
    Language English
    Publishing date 2024-02-29
    Publishing country United States
    Document type Journal Article
    ZDB-ID 754182-x
    ISSN 0191-2917
    ISSN 0191-2917
    DOI 10.1094/PDIS-07-23-1449-SR
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  2. Article ; Online: Development of a Stockpile Heated and Ambient Air Dryer (SHAD) for Freshly Harvested Almonds

    Mayanja, Ismael Kilinya / Coates, Michael C / Niederholzer, Franz / Donis-González, Irwin R.

    Applied engineering in agriculture. , v. 37, no. 3 p.417-425

    2021  

    Abstract: HighlightsAlmonds are conventionally sun-dried on the orchard floor. Collection and removal of dried nuts from the orchard generates significant dust.Almonds were dried on-farm directly from the almond tree eliminating field drying.SHAD dryer uses a ... ...

    Abstract HighlightsAlmonds are conventionally sun-dried on the orchard floor. Collection and removal of dried nuts from the orchard generates significant dust.Almonds were dried on-farm directly from the almond tree eliminating field drying.SHAD dryer uses a combination of heated and ambient air to dry almonds in a stockpile.The dryer has a SMER of 0.64 kg/kWh, MER of 1.02 kg/h, and COP of 1.33.Abstract. Dust generated by farming activities is a safety hazard to farmworkers and an environmental contaminant. During the almond (Prunus dulcis) harvest in California, dust is primarily generated by the mechanized movement of almonds disturbing the bare soil of the orchard floor, during the sun-drying, windrowing process, and as they are transferred into trucks for transport to processing facilities. Off-ground dust-less harvesting will only be achieved when the almond industry adopts feasible mechanical drying methods. Therefore, a stockpile heated and ambient air dryer (SHAD) was developed to determine the feasibility of dehydrating almonds (Var. ‘Monterey’). A stockpile containing 4,155 kg of almonds was created and almonds were dehydrated from their initial 12.6% almond kernel dry-basis moisture content (MCdb) to final MCdb of 6.04%. Drying was achieved as a combination of heated air at a temperature of 55°C in the drying plenum with airflow of 0.078 m3/s per m3 of fresh almonds. After drying, almond quality parameters were measured, including damage by molds or decay, insect injury, and presence of internal cavities. Drying energy consumption, cost, and performance indicators were also determined. The differences in MCdb between the bottom, middle, and top layers of the almond stockpile were significant (p = 0.05). Post-hoc Tuckey test was conducted which indicated that the MCdb in the top layer was significantly lower than almond MCdb in the middle and bottom layers. Results showed that damage by molds or decay, insect injury, and internal cavities were 1.81%, 0%, and 1.77%, respectively, after drying. Therefore, the overall almond quality was not compromised. The drying process cost $11.65 per tonne of the initial weight of almonds with a Specific Moisture Extraction Rate (SMER) of 0.64 kg/kWh, Moisture Extraction Rate (MER) of 1.02 kg/h, and a Coefficient of Performance (COP) of 1.33. Comparison with other dryers in the literature shows that SMER and MER were within limits. However, a low COP was observed. Keywords: Dust, Energy, Postharvest, Stockpile drying, Tree nut.s
    Keywords Prunus dulcis ; agriculture ; air ; air flow ; almonds ; dust ; energy ; farm labor ; industry ; insects ; mechanization ; orchards ; seeds ; shad ; soil ; temperature ; water content ; California
    Language English
    Size p. 417-425.
    Publishing place American Society of Agricultural and Biological Engineers (ASABE)
    Document type Article ; Online
    ZDB-ID 54345-7
    ISSN 0883-8542
    ISSN 0883-8542
    DOI 10.13031/aea.14364
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

  3. Article: Pear Scab: Components of Potential Ascospore Dose and Validation of an Ascospore Maturity Model.

    Spotts, Robert A / Cervantes, Louis A / Niederholzer, Franz J A

    Plant disease

    2019  Volume 84, Issue 6, Page(s) 681–683

    Abstract: Variables necessary to calculate potential ascospore dose (PAD) for Venturia pirina, the causal agent of pear scab, were measured: area of individual leaves averaged 20.0 ... ...

    Abstract Variables necessary to calculate potential ascospore dose (PAD) for Venturia pirina, the causal agent of pear scab, were measured: area of individual leaves averaged 20.0 cm
    Language English
    Publishing date 2019-03-06
    Publishing country United States
    Document type Journal Article
    ZDB-ID 754182-x
    ISSN 0191-2917
    ISSN 0191-2917
    DOI 10.1094/PDIS.2000.84.6.681
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  4. Article: Limited Evidence for Accumulation of Latent Infections of Canker-Causing Pathogens in Shoots of Stone Fruit and Nut Crops in California.

    Luo, Yong / Niederholzer, Franz J A / Lightle, Dani M / Felts, Dan / Lake, John / Michailides, Themis J

    Phytopathology

    2021  Volume 111, Issue 11, Page(s) 1963–1971

    Abstract: Prevalence of latent infections of the canker-causing ... ...

    Abstract Prevalence of latent infections of the canker-causing fungi
    MeSH term(s) California ; Crops, Agricultural/microbiology ; Fruit ; Juglans ; Nuts ; Plant Diseases ; Prunus ; Prunus dulcis
    Language English
    Publishing date 2021-11-07
    Publishing country United States
    Document type Journal Article
    ZDB-ID 208889-7
    ISSN 1943-7684 ; 0031-949X
    ISSN (online) 1943-7684
    ISSN 0031-949X
    DOI 10.1094/PHYTO-01-21-0009-R
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  5. Article: Limited Evidence for Accumulation of Latent Infections of Canker-Causing Pathogens in Shoots of Stone Fruit and Nut Crops in California

    Luo, Yong / Niederholzer, Franz J. A. / Lightle, Dani M. / Felts, Dan / Lake, John / Michailides, Themis J.

    Phytopathology. 2021 Nov., v. 111, no. 11

    2021  

    Abstract: Prevalence of latent infections of the canker-causing fungi Botryosphaeria dothidea and species of Cytospora, Diplodia, Lasiodiplodia, Neofusicoccum, and Phomopsis in young shoots of almond, prune, and walnut trees in California was studied to test the ... ...

    Abstract Prevalence of latent infections of the canker-causing fungi Botryosphaeria dothidea and species of Cytospora, Diplodia, Lasiodiplodia, Neofusicoccum, and Phomopsis in young shoots of almond, prune, and walnut trees in California was studied to test the hypotheses that latent infections accumulate from current-season shoots to 1-year-old shoots in the orchard and there are distinct associations among pathogen taxa present as latent infections in the same shoot. Samples of newly emerged and 1-year-old shoots were periodically collected in each almond, prune, and walnut orchard for two growing seasons. A real-time quantitative PCR assay was used to quantify latent infection with three parameters: incidence, molecular severity, and latent infection index. Diplodia spp. were absent from most samples. For almond, Lasiodiplodia spp. and Cytospora spp. were detected with a maximum incidence >90%, while B. dothidea and Neofusicoccum spp. incidence was <20% in most cases. In prune orchards, the incidence levels of B. dothidea were >50% in most cases, while those of Cytospora spp. and Lasiodiplodia spp. were 30 to 60% and 30 to 100%, respectively. For walnut, many samplings showed higher incidence in 1-year-old (30 to 80%) than in newly emerged shoots (10 to 50%). Accumulation of latent infection between the two shoot age classes was detected in only a few cases. The percentages of samples showing coexistence of two, three, and four pathogen taxa in the same shoot were 20 to 25, <10, and <5%, respectively. Pairwise associations among pathogen taxa in the same shoot were significant in many cases.
    Keywords Botryosphaeria dothidea ; Cytospora ; Diaporthe ; Diplodia ; Lasiodiplodia ; Neofusicoccum ; almonds ; carrier state ; orchards ; pathogens ; plant pathology ; quantitative polymerase chain reaction ; stone fruits ; walnuts ; California
    Language English
    Dates of publication 2021-11
    Size p. 1963-1971.
    Publishing place The American Phytopathological Society
    Document type Article
    ZDB-ID 208889-7
    ISSN 1943-7684 ; 0031-949X
    ISSN (online) 1943-7684
    ISSN 0031-949X
    DOI 10.1094/PHYTO-01-21-0009-R
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

  6. Article: Evaluation of an unmanned aerial vehicle as a new method of pesticide application for almond crop protection

    Li, Xuan / Giles, Durham Ken / Niederholzer, Franz J / Andaloro, John T / Lang, Edward B / Watson, Lawrence J

    Pest management science. 2021 Jan., v. 77, no. 1

    2021  

    Abstract: BACKGROUND: Unmanned Aerial Vehicles (UAVs), a new method of application to deliver pesticides, is rapidly being adopted for commercial use in crop protection in East Asia with increasing worldwide interest. Pest control in mature almond orchards with ... ...

    Abstract BACKGROUND: Unmanned Aerial Vehicles (UAVs), a new method of application to deliver pesticides, is rapidly being adopted for commercial use in crop protection in East Asia with increasing worldwide interest. Pest control in mature almond orchards with dense foliar canopies presents greater coverage challenges than field crops and smaller orchard or vineyard crops. We investigated the use of an electric hexacopter to provide acceptable spray deposition and canopy penetration to be considered credible for use in an almond pest control program. RESULTS: The performance of the aerial and ground methods at different spray volumes were compared by analyzing spray deposition on water sensitive papers, insecticide residues on filter papers and residues on whole unhulled almonds at three canopy elevations. Overall residue levels of chlorantraniliprole insecticide on whole unhulled almonds across all pooled canopy strata were similar between UAV applied at 46.8 L/ha and 93.5 L/ha and the comparative air blast sprayer treatments applied at 935 L/ha. However, significant interactions between canopy elevation and spray method showed distinct residue patterns between the two application methods. Penetration and spray deposition at the lower canopy were observed and validated for the UAV application. Pest efficacy was evaluated by measuring nut damage at harvest. CONCLUSION: This study presents promising data that support the potential innovative integration of UAV's into crop protection programs for large canopy crops such as almonds and may guide future research for developing relevant label recommendations.
    Keywords air ; almonds ; canopy ; insecticides ; orchards ; pest control ; pesticide application ; pests ; plant protection ; spray deposition ; sprayers ; unmanned aerial vehicles ; vineyards ; East Asia
    Language English
    Dates of publication 2021-01
    Size p. 527-537.
    Publishing place John Wiley & Sons, Ltd.
    Document type Article
    Note NAL-AP-2-clean ; JOURNAL ARTICLE
    ZDB-ID 2001705-4
    ISSN 1526-4998 ; 1526-498X
    ISSN (online) 1526-4998
    ISSN 1526-498X
    DOI 10.1002/ps.6052
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

  7. Article ; Online: Phylogenomic analyses and comparative genomics of Pseudomonas syringae associated with almond (Prunus dulcis) in California.

    Maguvu, Tawanda E / Frias, Rosa J / Hernandez-Rosas, Alejandro I / Holtz, Brent A / Niederholzer, Franz J A / Duncan, Roger A / Yaghmour, Mohammad A / Culumber, Catherine M / Gordon, Phoebe E / Vieira, Flavia C F / Rolshausen, Philippe E / Adaskaveg, James E / Burbank, Lindsey P / Lindow, Steven E / Trouillas, Florent P

    PloS one

    2024  Volume 19, Issue 4, Page(s) e0297867

    Abstract: We sequenced and comprehensively analysed the genomic architecture of 98 fluorescent pseudomonads isolated from different symptomatic and asymptomatic tissues of almond and a few other Prunus spp. Phylogenomic analyses, genome mining, field pathogenicity ...

    Abstract We sequenced and comprehensively analysed the genomic architecture of 98 fluorescent pseudomonads isolated from different symptomatic and asymptomatic tissues of almond and a few other Prunus spp. Phylogenomic analyses, genome mining, field pathogenicity tests, and in vitro ice nucleation and antibiotic sensitivity tests were integrated to improve knowledge of the biology and management of bacterial blast and bacterial canker of almond. We identified Pseudomonas syringae pv. syringae, P. cerasi, and P. viridiflava as almond canker pathogens. P. syringae pv. syringae caused both canker and foliar (blast) symptoms. In contrast, P. cerasi and P. viridiflava only caused cankers, and P. viridiflava appeared to be a weak pathogen of almond. Isolates belonging to P. syringae pv. syringae were the most frequently isolated among the pathogenic species/pathovars, composing 75% of all pathogenic isolates. P. cerasi and P. viridiflava isolates composed 8.3 and 16.7% of the pathogenic isolates, respectively. Laboratory leaf infiltration bioassays produced results distinct from experiments in the field with both P. cerasi and P. syringae pv. syringae, causing significant necrosis and browning of detached leaves, whereas P. viridiflava conferred moderate effects. Genome mining revealed the absence of key epiphytic fitness-related genes in P. cerasi and P. viridiflava genomic sequences, which could explain the contrasting field and laboratory bioassay results. P. syringae pv. syringae and P. cerasi isolates harboured the ice nucleation protein, which correlated with the ice nucleation phenotype. Results of sensitivity tests to copper and kasugamycin showed a strong linkage to putative resistance genes. Isolates harbouring the ctpV gene showed resistance to copper up to 600 μg/ml. In contrast, isolates without the ctpV gene could not grow on nutrient agar amended with 200 μg/ml copper, suggesting ctpV can be used to phenotype copper resistance. All isolates were sensitive to kasugamycin at the label-recommended rate of 100μg/ml.
    MeSH term(s) Copper ; Genomics ; Ice ; Phylogeny ; Prunus dulcis/genetics ; Pseudomonas ; Pseudomonas syringae
    Chemical Substances Copper (789U1901C5) ; Ice
    Language English
    Publishing date 2024-04-11
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2267670-3
    ISSN 1932-6203 ; 1932-6203
    ISSN (online) 1932-6203
    ISSN 1932-6203
    DOI 10.1371/journal.pone.0297867
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  8. Article ; Online: Evaluation of spray application methods for navel orangeworm control in almonds.

    Markle, James C / Niederholzer, Franz Ja / Zalom, Frank G

    Pest management science

    2016  Volume 72, Issue 12, Page(s) 2339–2346

    Abstract: Background: Gear Up/Throttle Down (GUTD) and Inward Only strategies represent potential alternatives to conventional airblast applications to reduce spray drift. This study evaluates Inward Only and a modified version of GUTD in almonds, the largest US ... ...

    Abstract Background: Gear Up/Throttle Down (GUTD) and Inward Only strategies represent potential alternatives to conventional airblast applications to reduce spray drift. This study evaluates Inward Only and a modified version of GUTD in almonds, the largest US tree crop, at the recommended hull split treatment timing for control of navel orangeworm (NOW), the key almond insect pest.
    Results: Conventional treatment produced the most drift (15.6% of total bifenthrin load), while the GUTD and Inward Only treatments produced only 7.6 and 9.7% respectively. For all methods, 92-94% of the drift was found in the first 15.2 m downwind of the orchard. NOW control was lower for the Inward Only treatment compared with the GUTD and conventional treatments. NOW control was consistently lower at 4.88 m height relative to 2.44 m in all treatments, reflecting the reduced deposition higher in the tree canopy recorded in deposition samples.
    Conclusion: While Inward Only treatments reduced spray drift relative to the conventional application method, poorer control of NOW, the key insect pest of almonds, in the Inward Only treatment would likely limit its voluntary use by growers. However, GUTD holds promise for use at the hull split treatment timing to address spray drift. © 2016 Society of Chemical Industry.
    MeSH term(s) Animals ; California ; Insect Control/instrumentation ; Insect Control/methods ; Insecticides/administration & dosage ; Larva/drug effects ; Moths/drug effects ; Ovum/drug effects ; Prunus dulcis
    Chemical Substances Insecticides
    Language English
    Publishing date 2016-12
    Publishing country England
    Document type Journal Article
    ZDB-ID 2001705-4
    ISSN 1526-4998 ; 1526-498X
    ISSN (online) 1526-4998
    ISSN 1526-498X
    DOI 10.1002/ps.4279
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  9. Article ; Online: Evaluation of an unmanned aerial vehicle as a new method of pesticide application for almond crop protection.

    Li, Xuan / Giles, Durham Ken / Niederholzer, Franz J / Andaloro, John T / Lang, Edward B / Watson, Lawrence J

    Pest management science

    2020  Volume 77, Issue 1, Page(s) 527–537

    Abstract: Background: Unmanned Aerial Vehicles (UAVs), a new method of application to deliver pesticides, is rapidly being adopted for commercial use in crop protection in East Asia with increasing worldwide interest. Pest control in mature almond orchards with ... ...

    Abstract Background: Unmanned Aerial Vehicles (UAVs), a new method of application to deliver pesticides, is rapidly being adopted for commercial use in crop protection in East Asia with increasing worldwide interest. Pest control in mature almond orchards with dense foliar canopies presents greater coverage challenges than field crops and smaller orchard or vineyard crops. We investigated the use of an electric hexacopter to provide acceptable spray deposition and canopy penetration to be considered credible for use in an almond pest control program.
    Results: The performance of the aerial and ground methods at different spray volumes were compared by analyzing spray deposition on water sensitive papers, insecticide residues on filter papers and residues on whole unhulled almonds at three canopy elevations. Overall residue levels of chlorantraniliprole insecticide on whole unhulled almonds across all pooled canopy strata were similar between UAV applied at 46.8 L/ha and 93.5 L/ha and the comparative air blast sprayer treatments applied at 935 L/ha. However, significant interactions between canopy elevation and spray method showed distinct residue patterns between the two application methods. Penetration and spray deposition at the lower canopy were observed and validated for the UAV application. Pest efficacy was evaluated by measuring nut damage at harvest.
    Conclusion: This study presents promising data that support the potential innovative integration of UAV's into crop protection programs for large canopy crops such as almonds and may guide future research for developing relevant label recommendations.
    MeSH term(s) Crop Protection ; Far East ; Insecticides ; Pesticides/analysis ; Prunus dulcis
    Chemical Substances Insecticides ; Pesticides
    Language English
    Publishing date 2020-09-19
    Publishing country England
    Document type Journal Article
    ZDB-ID 2001705-4
    ISSN 1526-4998 ; 1526-498X
    ISSN (online) 1526-4998
    ISSN 1526-498X
    DOI 10.1002/ps.6052
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  10. Article ; Online: Evaluating insecticide coverage in almond and pistachio for control of navel orangeworm (Amyelois transitella) (Lepidoptera: Pyralidae).

    Siegel, Joel P / Strmiska, Mathew M / Niederholzer, Franz Ja / Giles, D Ken / Walse, Spenser S

    Pest management science

    2018  Volume 75, Issue 5, Page(s) 1435–1442

    Abstract: Background: Insecticide application is essential to control navel orangeworm (Amyelois transitella) in California almond and pistachios. Coverage is difficult because of tree height and applicator practices. Studies were conducted to characterize ... ...

    Abstract Background: Insecticide application is essential to control navel orangeworm (Amyelois transitella) in California almond and pistachios. Coverage is difficult because of tree height and applicator practices. Studies were conducted to characterize insecticide deposition by both ground and air, and to develop alternatives to the use of water-sensitive cards to assess spray coverage.
    Results: We used almond challenge bioassays to demonstrate that insecticide application failed first in the upper canopy (5.2-6.1 m) when application speed exceeded 2.9 kph. In pistachios, we used filter paper and insecticide extraction from hulls to demonstrate that deposition increased with application volume. Typically, in ground applications, coverage decreased with height, whereas for application by air, coverage was greatest at the top of the canopy (6 m) and decreased as the spray penetrated the canopy. In the best ground applications there was no loss over height. We were able to demonstrate a dose-response relationship for methoxyfenozide using contact toxicity bioassays.
    Conclusion: Coverage was best at or below the recommended speed of 3.2 kph and improved when water volume increased. There was a 50% loss in insecticide efficacy at the height of 4-4.8 m; we suggest that future monitoring concentrate on this portion of the canopy. The best ground application provided uniform deposition throughout the canopy, whereas the applications by air were most effective in the upper canopy. The use of filter paper can provide information for chemical deposition and enable contact toxicity bioassays, whereas water-sensitive paper cannot do this. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.
    MeSH term(s) Animals ; Insect Control/methods ; Insecticides ; Larva ; Lepidoptera ; Pistacia ; Prunus dulcis ; Reference Standards ; Time Factors
    Chemical Substances Insecticides
    Language English
    Publishing date 2018-12-22
    Publishing country England
    Document type Journal Article
    ZDB-ID 2001705-4
    ISSN 1526-4998 ; 1526-498X
    ISSN (online) 1526-4998
    ISSN 1526-498X
    DOI 10.1002/ps.5265
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

To top