Impact of sown fallows on the Xiphinema index populations in different soil types

The nematode Xiphinema index is, economically, the major virus vector in viticulture, transmitting specifically the Grapevine Fanleaf Virus (GFLV), the most severe grapevine virus disease worldwide. The management of this disease has long been to use soil fumigation, harmful for both the applicator and the environment. The objective of this study was to evaluate an alternative approach using plants to reduce vector nematode populations between uprooting and replanting. Of thirty botanical species, tested in previous greenhouse trials, the seven best performing plants were evaluated for their capacity to reduce X. index populations in soil compared to bare soil in 5 field trials on different soil types in Bordeaux and Burgundy. In most trials, sown fallows reduced the number of X. index nematodes more efficiently than bare soil. All plants tested in field, except Trifolium pratense, showed their efficacy in field on survival of nematodes X. index but this efficiency varied according to species and site. The best results were obtained with Medicago hybride, Tagetes minuta, Avena sativa and Vicia villosa. Over the following years we will be evaluating if a decrease of the populations of the nematode vector does lead to a significant drop or delay of GFLV contamination for the newly planted vines

Grapevine decline is associated with difference in soil microbial composition and activity

Grapevine decline is a top concern in viticulture worldwide and is often associated with many biotic and abiotic factors. Grape trunk diseases and viruses are some of the most frequently identified causes of vine dieback. However, a decline is sometimes observed when no mineral deficiency or excess, or pathogenic causes can be identified. Soil enzymatic and microbial activities are relevant bio-indicators since they are known to influence vine health. Grapevine associated microbiota, linked to vine fitness, is known to be influenced by soil microbiota coming from the microbial pool inhabiting the vineyard. This work describes the microbial diversity and activity of four different vineyard plots of the Bordeaux region, selected due to the presence of localised declining areas unexplained yet by disease symptoms. Soils were sampled in declining areas and areas within the same plot showing no decline symptoms, during autumn and spring periods. Significant differences in enzymatic activities, microbial biomass and activity were found among soils even if those soils presented quite similar physicochemical characteristics that could not explain these observed declines. The results of enzymatic assays distinguished patterns in autumn and spring periods with an overall greater enzymatic activity in soils from non-declining areas. This work suggests that soils displaying decline symptoms present a dysbiosis in functionality and diversity which is linked to vine health

Elaboration of soft and flexible silicone stencils for the wafer-level micropatterning of polymers

International audienc

La progresión de la yesca en Francia: factores e hipótesis que pueden explicarla

La Yesca es hoy la enfermedad de la madera la más preocupante en Francia. Su progreso desde el final del siglo XX, incluso antes de la prohibición de arsenito de sodio, fue tal que algunos la han considerado como una “enfermedad emergente”. Después de recordar los principales datos del Observatorio Nacional para evaluar la situación de las principales “Enfermedades de la Madera de la Vid” durante la última década, este artículo sugiere varias hipótesis que pueden explicar la progresión de este síndrome. Se complementa con una sección sobre los síntomas y la dinámica de su aparición, que no había sido revisado durante casi un siglo. Los resultados de las observaciones finas y regulares en viñedo en Francia o en el extranjero, dan lugar a una redefinición de los síntomas de la yesca y conducen a nuevas preguntas. Este texto está inspirado en gran parte de un artículo publicado en 2012 y presentado en una conferencia del AFPP (Asociación Francesa para la Protección de las Plantas)

First detection of <em>Tomato black ring virus</em> (TBRV) in a French vineyard

Aim: Grapevine plants from the Bordeaux wine region (France) showing symptoms of fanleaf degeneration, but negative for the two main fanleaf viruses were screened by ELISA for other nepoviruses that could explain the symptoms. Methods and results: ELISA tests were performed over a 3-year period (2009-2011) on leaves and woody canes. A total of 665 grapevine plants grafted with Merlot, Cabernet franc and Cabernet-Sauvignon, were found free from Grapevine fanleaf virus (GFLV) and Arabis mosaic virus (ArMV) but infected with Tomato black ring virus (TBRV). The Longidorid nematode species Longidorus attenuatus, known as the TBRV vector in grapevine, was detected from soil samples collected in the infected area. Conclusion: Both the virus and its vector might have originated from a vegetable garden established prior to vine planting, considering that the TBRV-infected area with the most fanleaf degeneration symptoms co-localizes with this previous garden. Significance and impact of the study: This is the first record of TBRV infection in a grapevine plot in France

Long-Term Esca Monitoring Reveals Disease Impacts on Fruit Yield and Wine Quality

Esca is a widespread grapevine trunk disease, and a global increase in esca incidence has been observed in recent decades. Estimates attribute considerable economic losses to esca, and the disease is considered one of the major causes of vine mortality and vineyard dieback. However, accurate quantification of esca incidence is difficult due to symptom inconsistency, and there are very few studies precisely quantifying yield losses and impacts on fruit composition and wine quality. This study carried out an extensive esca surveying program; annually monitoring approximately 57,000 vines across 12 estates in the Bordeaux region for 9 years. In conjunction with this surveying program, we quantified the yield losses of vines with known esca symptom histories and assessed their fruit composition and resulting wine quality. The study revealed that, because of year-to-year variation in symptom expression, accurate rates of esca can only be obtained through monitoring over many years. We found that yield losses in individual vines exhibiting esca can reach up to 50% but they are rarely unproductive, and when scaled to the parcel scale yield losses are low, never exceeding 1 hl/ha. In addition, the quality of the grapes produced is similar to that obtained from vines without symptoms. Finally, the majority of mortality observed in vineyards was not due to esca, with only 40% of dead vines exhibiting an esca history. These results suggest that the impact of esca is likely overestimated and that it is necessary to more broadly investigate other factors contributing to vine mortality and vineyard dieback. Copyright © 2022 The Author(s). This is an open-access article distributed under the CC BY 4.0 International license

Impact of sown fallows on the Xiphinema index populations in different soil types

The nematode Xiphinema index is, economically, the major virus vector in viticulture, transmitting specifically the Grapevine Fanleaf Virus (GFLV), the most severe grapevine virus disease worldwide. The management of this disease has long been to use soil fumigation, harmful for both the applicator and the environment. The objective of this study was to evaluate an alternative approach using plants to reduce vector nematode populations between uprooting and replanting. Of thirty botanical species, tested in previous greenhouse trials, the seven best performing plants were evaluated for their capacity to reduce X. index populations in soil compared to bare soil in 5 field trials on different soil types in Bordeaux and Burgundy. In most trials, sown fallows reduced the number of X. index nematodes more efficiently than bare soil. All plants tested in field, except Trifolium pratense, showed their efficacy in field on survival of nematodes X. index but this efficiency varied according to species and site. The best results were obtained with Medicago hybride, Tagetes minuta, Avena sativa and Vicia villosa. Over the following years we will be evaluating if a decrease of the populations of the nematode vector does lead to a significant drop or delay of GFLV contamination for the newly planted vines

Impact of sown fallows on the Xiphinema index populations in different soil types

The nematode Xiphinema index is, economically, the major virus vector in viticulture, transmitting specifically the Grapevine Fanleaf Virus (GFLV), the most severe grapevine virus disease worldwide. The management of this disease has long been to use soil fumigation, harmful for both the applicator and the environment. The objective of this study was to evaluate an alternative approach using plants to reduce vector nematode populations between uprooting and replanting. Of thirty botanical species, tested in previous greenhouse trials, the seven best performing plants were evaluated for their capacity to reduce X. index populations in soil compared to bare soil in 5 field trials on different soil types in Bordeaux and Burgundy. In most trials, sown fallows reduced the number of X. index nematodes more efficiently than bare soil. All plants tested in field, except Trifolium pratense, showed their efficacy in field on survival of nematodes X. index but this efficiency varied according to species and site. The best results were obtained with Medicago hybride, Tagetes minuta, Avena sativa and Vicia villosa. Over the following years we will be evaluating if a decrease of the populations of the nematode vector does lead to a significant drop or delay of GFLV contamination for the newly planted vines