Critical timing of fungicide application for pruning wound protection to control grapevine 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%.

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Combining an HA + Cu (II) Site-Targeted Copper-Based Product with a Pruning Wound Protection Program to Prevent Infection with Lasiodiplodia spp. in Grapevine

Plants ◽

10.3390/plants10112376 ◽

2021 ◽

Vol 10 (11) ◽

pp. 2376

Author(s):

Pedro Reis ◽

Ana Gaspar ◽

Artur Alves ◽

Florence Fontaine ◽

Cecília Rego

Keyword(s):

Grapevine Trunk Diseases ◽

Pruning Wound ◽

Wound Protection ◽

Protection Strategies ◽

Botryosphaeria Dieback ◽

Trunk Diseases ◽

The Impact ◽

Fungistatic Effect

The genus Lasiodiplodia has been reported from several grape growing regions and is considered as one of the fastest wood colonizers, causing Botryosphaeria dieback. The aim of this study was to (i) evaluate the efficacy of Esquive®, a biocontrol agent, on vineyard pruning wound protection, applied single or, in a combined protection strategy with a new site-targeted copper-based treatment (LC2017), and (ii) compare their efficacy with chemical protection provided by the commercially available product, Tessior®. For two seasons, protectants were applied onto pruning wounds, while LC2017 was applied throughout the season according to the manufacturer’s instructions. Pruning wounds of two different cultivars were inoculated with three isolates of Lasiodiplodia spp. Efficacy of the wound protectants, varied between both years of the assay and according to the cultivar studied but were able to control the pathogen to some extent. The application of LC2017 did not show clear evidence of improving the control obtained by the sole application of the other products tested. Nevertheless, LC2017 showed a fungistatic effect against Lasiodiplodia spp., in vitro, and has previously shown an elicitor effect against grapevine trunk diseases. Therefore, this combination of two protection strategies may constitute a promising long-term approach to mitigate the impact of Botryosphaeria dieback.

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Pruning Wound Protection Strategies for Simultaneous Control of Eutypa and Botryosphaeria Dieback in New Zealand

Plant Disease ◽

10.1094/pdis-05-18-0728-re ◽

2019 ◽

Vol 103 (3) ◽

pp. 519-525 ◽

Cited By ~ 7

Author(s):

Mark R. Sosnowski ◽

Dion C. Mundy

Keyword(s):

New Zealand ◽

Eutypa Lata ◽

Grapevine Trunk Diseases ◽

Pruning Wound ◽

Wound Protection ◽

Simultaneous Control ◽

Protection Strategies ◽

Botryosphaeria Dieback ◽

Trunk Diseases ◽

Neofusicoccum Luteum

The grapevine trunk diseases Eutypa and Botryosphaeria dieback threaten the sustainability of vineyards worldwide. This study aimed to develop practical and efficient wound protection strategies, which will lead to widespread adoption of preventative control for these diseases and increased longevity of vineyards. Five fungicides (tebuconazole, carbendazim, fluazinam, mancozeb, and flusilazole) were evaluated for efficacy against Eutypa lata and Neofusicoccum luteum infection on pruning wounds of ‘Sauvignon blanc’ in a New Zealand vineyard. All five fungicides controlled infection by both pathogens to varying degrees, with mean percent disease control of 70 to 90% for E. lata and 33 to 93% for N. luteum. This has led to the first known registration of a fungicide, fluazinam (Gem), for simultaneous control of both Eutypa and Botryosphaeria dieback. Furthermore, application of carbendazim with tractor-driven sprayers provided similar control of E. lata and N. luteum to that when applied by hand with a paintbrush. This constitutes the first report of Botryosphaeria dieback control with fungicides applied with tractor-driven sprayers.

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Arthropods Vector Grapevine Trunk Disease Pathogens

Phytopathology ◽

10.1094/phyto-11-13-0303-r ◽

2014 ◽

Vol 104 (10) ◽

pp. 1063-1069 ◽

Cited By ~ 20

Author(s):

P. Moyo ◽

E. Allsopp ◽

F. Roets ◽

L. Mostert ◽

F. Halleen

Keyword(s):

Cropping Systems ◽

Integrated Approach ◽

Molecular Techniques ◽

Inoculum Source ◽

Phaeomoniella Chlamydospora ◽

Grapevine Trunk Diseases ◽

Pruning Wound ◽

Trunk Disease ◽

Grapevine Trunk Disease ◽

Trunk Diseases

Arthropod-mediated dispersal of pathogens is known in many cropping systems but has never been demonstrated for grapevine trunk disease pathogens. Arthropods from vineyards were screened for the presence of pathogens associated with Petri disease and esca using cultural and molecular techniques. The ability of the most abundant pathogen-carrying species to inoculate healthy grapevine vascular tissues was also determined. Millipedes and ants were allowed to associate with a DsRed- Express-transformed Phaeomoniella chlamydospora, after which they were exposed to freshly pruned healthy grapevines under controlled conditions and wounds were monitored for subsequent infection. In addition, the possibility of millipede excreta, commonly found on pruning wounds in the field, to act as inoculum source was determined. A diverse arthropod fauna was associated with declining grapevines and many of these carried trunk disease pathogens. However, spiders, the ant Crematogaster peringueyi, and the millipede Ommattoiulus moreleti were the most abundant pathogen carriers. The ant and millipede species fed on pruning wound sap and effectively transmitted trunk disease pathogens. Millipede excreta contained viable spores of Phaeomoniella chlamydospora and may serve as an inoculum source. Numerous arthropods, including beneficial predators, are potential vectors of grapevine trunk disease pathogens. Our results highlight the need for an integrated approach, including targeted management of ants and millipedes at the time of pruning, to limit the spread of grapevine trunk diseases.

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Control of the fungi Lasiodiplodia theobromae, the causal agent of dieback, in cv. syrah grapevines

Acta Scientiarum Agronomy ◽

10.4025/actasciagron.v43i1.44785 ◽

2020 ◽

Vol 43 ◽

pp. e44785

Author(s):

Carine Rusin ◽

Fabio Rossi Cavalcanti ◽

Patrícia Carla Giloni de Lima ◽

Cacilda Márcia Duarte Rios Faria ◽

Marcus André Kurtz Almança ◽

...

Keyword(s):

Bacillus Subtilis ◽

Plant Extracts ◽

Trichoderma Harzianum ◽

Garlic Extract ◽

Limiting Factors ◽

Lasiodiplodia Theobromae ◽

Grapevine Trunk Diseases ◽

Wound Protection ◽

Trunk Diseases

Grapevine trunk diseases are among the most important limiting factors of worldwide viticulture. In this context, we aimed to verify the effect of chemical fungicides, biological agents and plant extracts on the control of Lasiodiplodia theobromae in pruning wounds and their physiological effects in cv. Syrah grapevines. Plant extracts (clove, cinnamon, garlic, rosemary and lemongrass), commercial fungicides (difeconazole, tebuconazole, mancozeb, sulfur, pyraclostrobin, fosetyl-Al, and azoxystrobin), chitosan, Trichoderma harzianum and Bacillus subtilis were used for the in vitro trials. The protection of pruning wounds in the potted vines was studied using fosetyl-Al, tebuconazole, Trichoderma harzianum, Bacillus subtilis, garlic extract and clove extract. The experiments were carried out through two vegetative cycles: 2015/2016 and 2016/2017. The length of wood discoloration, pathogen re-isolation percentage, fresh mass of the pruning material, peroxidase activity, fluorescence, chlorophyll index, phenological stages, shoot length and leaf area were evaluated. The treatments with clove, garlic extract, tebuconazole, pyraclostrobin, mancozeb, fosetyl-Al and B. subtilis reduced mycelial growth by more than 90%. In the grapevines, the use of T. harzianum decreased the re-isolation of L. theobromae, but no differences were verified for the other plant evaluations. We concluded that the use of T. harzianum would be a potential option for wound protection without altering the physiological aspects of cv. Syrah grapevines.

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Seasonal Susceptibility of Grapevine Pruning Wounds and Cane Colonization in Catalonia, Spain Following Artificial Infection with Diplodia seriata and Phaeomoniella chlamydospora

Plant Disease ◽

10.1094/pdis-10-15-1186-re ◽

2016 ◽

Vol 100 (8) ◽

pp. 1651-1659 ◽

Cited By ~ 9

Author(s):

Georgina Elena ◽

Jordi Luque

Keyword(s):

Seasonal Changes ◽

Fungal Pathogens ◽

Artificial Infection ◽

Diplodia Seriata ◽

Phaeomoniella Chlamydospora ◽

Grapevine Trunk Diseases ◽

Pruning Wound ◽

Incubation Periods ◽

Trunk Diseases ◽

Made In

Diplodia seriata and Phaeomoniella chlamydospora are two fungal pathogens associated with grapevine trunk diseases worldwide. This study aimed to evaluate the period during which grapevine pruning wounds remain susceptible to fungal infection and to describe the colonization of canes artificially inoculated with these pathogens. In the first experiment, pruning wounds made in either fall or winter were separately inoculated with each pathogen at different times after pruning. Wound susceptibility to both pathogens decreased as the period between pruning and inoculation increased, from high percentages recorded in the first inoculation round (D. seriata, 97.5% and P. chlamydospora, 75%) down to approximately 10% 12 weeks after pruning. Pruning wounds remained more susceptible to D. seriata after a late pruning in winter whereas no overall seasonal changes in wound susceptibility were detected for P. chlamydospora. In the second experiment, canes were pruned by leaving two different lengths between the top node and the pruning wound before inoculations. Pathogens were recovered at different incubation periods and from different sites along the canes to estimate fungal cane colonization. A longer pruned internode made cane colonization by P. chlamydospora difficult, as indicated by fungal recoveries lower than 10% at the lowest recovery site, whereas D. seriata was less inhibited.

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Biological and chemical pruning wound protectants reduce infection of grapevine trunk disease pathogens

California Agriculture ◽

10.3733/ca.2021a0018 ◽

2022 ◽

Vol 75 (3) ◽

pp. 128-134

Author(s):

Robert Blundell ◽

Akif Eskalen

Keyword(s):

Fungal Pathogens ◽

Field Station ◽

Neofusicoccum Parvum ◽

Production Region ◽

Eutypa Lata ◽

Grapevine Trunk Diseases ◽

Pruning Wound ◽

Simultaneous Control ◽

Trunk Diseases ◽

Precipitation Events

Grapevine trunk diseases (GTDs) are currently considered some of the most important challenges for viticulture, curtailing vineyard longevity and productivity in nearly every raisin, table and wine grape production region in California and worldwide. Pruning wounds provide the main entry point for fungal pathogens responsible for these diseases; pathogens enter the wounds following precipitation events. The aim of this study was to evaluate the efficacy of selected chemical and experimental biological fungicides for protection of pruning wounds against two of the most common and virulent fungal pathogens causing GTDs: Eutypa lata and Neofusicoccum parvum. This study was conducted on sauvignon blanc at the UC Davis Department of Plant Pathology Field Station. Results showed that several chemical and biological fungicides, notably the chemical fungicide Luna Sensation, the biofungicide Vintec and a combination of the biofungicides Bio-Tam and CrabLife Powder, provided significant protection against at least one of the two canker pathogens used in this study. However, the majority of products tested did not provide simultaneous control of both E. lata and N. parvum pathogens, highlighting the continuing challenge of controlling GTDs.

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Production of Phytotoxic Metabolites by Botryosphaeriaceae in Naturally Infected and Artificially Inoculated Grapevines

Plants ◽

10.3390/plants10040802 ◽

2021 ◽

Vol 10 (4) ◽

pp. 802

Author(s):

Pierluigi Reveglia ◽

Regina Billones-Baaijens ◽

Jennifer Millera Millera Niem ◽

Marco Masi ◽

Alessio Cimmino ◽

...

Keyword(s):

Fungal Pathogens ◽

Protocatechuic Acid ◽

Physiological Factors ◽

Diplodia Seriata ◽

Grapevine Trunk Diseases ◽

Botryosphaeria Dieback ◽

Trunk Diseases ◽

One Year ◽

Pathogen Dna

Grapevine trunk diseases (GTDs) are considered a serious problem to viticulture worldwide. Several GTD fungal pathogens produce phytotoxic metabolites (PMs) that were hypothesized to migrate to the foliage where they cause distinct symptoms. The role of PMs in the expression of Botryosphaeria dieback (BD) symptoms in naturally infected and artificially inoculated wood using molecular and analytical chemistry techniques was investigated. Wood samples from field vines naturally infected with BD and one-year-old vines inoculated with Diplodia seriata, Spencermartinsia viticola and Dothiorella vidmadera were analysed by cultural isolations, quantitative PCR (qPCR) and targeted LC-MS/MS to detect three PMs: (R)-mellein, protocatechuic acid and spencertoxin. (R)-mellein was detected in symptomatic naturally infected wood and vines artificially inoculated with D. seriata but was absent in all non-symptomatic wood. The amount of (R)-mellein detected was correlated with the amount of pathogen DNA detected by qPCR. Protocatechuic acid and spencertoxin were absent in all inoculated wood samples. (R)-mellein may be produced by the pathogen during infection to break down the wood, however it was not translocated into other parts of the vine. The foliar symptoms previously reported in vineyards may be due to a combination of PMs produced and climatic and physiological factors that require further investigation.

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Assessment of Conjugate Complexes of Chitosan and Urtica dioica or Equisetum arvense Extracts for the Control of Grapevine Trunk Pathogens

Agronomy ◽

10.3390/agronomy11050976 ◽

2021 ◽

Vol 11 (5) ◽

pp. 976

Author(s):

Natalia Langa-Lomba ◽

Laura Buzón-Durán ◽

Pablo Martín-Ramos ◽

José Casanova-Gascón ◽

Jesús Martín-Gil ◽

...

Keyword(s):

Urtica Dioica ◽

Gas Chromatography Mass Spectrometry ◽

Equisetum Arvense ◽

Grapevine Trunk Diseases ◽

Trunk Diseases ◽

Synergistic Behavior ◽

Reported Data ◽

Basic Substances

In the work presented herein, we analyze the efficacy of three basic substances that comply with European Regulation (EC) No 1107/2009, namely chitosan, horsetail (Equisetum arvense L.) and nettle (Urtica dioica L.), for the control of grapevine trunk diseases (GTDs) in organic farming. The E. arvense and U. dioica aqueous extracts, prepared according to SANCO/12386/2013 and SANTE/11809/2016, have been studied by gas chromatography–mass spectrometry (GC-MS), identifying their main active constituents. The three basic substances, either alone or in combination (forming conjugate complexes), have been tested in vitro against eight Botryosphaeriaceae species, and in vivo, in grafted plants artificially inoculated with Neofusicoccum parvum and Diplodia seriata. A clear synergistic behavior between chitosan and the two plant extracts has been observed in the mycelial growth inhibition tests (resulting in EC90 values as low as 208 μg·mL−1 for some of the isolates), and statistically significant differences have been found in terms of vascular necroses lengths between treated and non-treated plants, providing further evidence of aforementioned synergism in the case of D. seriata. The reported data supports the possibility of extending the applications of these three basic substances in Viticulture beyond the treatment of mildew.

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

Plant Disease ◽

10.1094/pdis-11-20-2371-re ◽

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.

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