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After the first report of grapevine decline caused by Botryosphaeriaceae in Sicily in 2007, epidemiological studies carried out in mature vineyards until 2011 confirmed the widespread occurrence of “Botryosphaeria dieback” and the “Esca complex” disease. Dieback symptoms were also recently observed in two young vineyards in Partanna and Castellammare del Golfo in western Sicily (Trapani province). Declining vines were inspected for grapevine trunk disease (GTD) symptoms, and were uprooted and submitted for analyses. Fungal isolates were collected and identified using culturing and molecular analyses. One isolate per identified species was inoculated to three grapevine shoots to evaluate pathogenicity and fulfil Koch’s postulates. Several GTD Botryosphaeriaceae pathogens in the genera Cadophora, Ilyonectria, Neonectria, Phaeoacremonium and Phaeomoniella were isolated from the symptomatic young vines. Artificial inoculation confirmed the pathogenicity of these fungi. In addition, virulence variability was observed among the isolates, with P. chlamydospora causing the largest lesions. The different species were associated with specific symptoms and/or host vine parts, especially in the roots and around the grafting areas. Several fungi associated with Petri disease and black foot were shown to be responsible of young vine decline.

Wine grape production is an important economic asset in many nations, however, a significant proportion of vines succumb to grapevine trunk pathogens, reducing yields and causing economic losses. Cover crops, plants that are grown in addition to main crops in order to maintain and enhance soil composition, may also serve as a line of defense against these fungal pathogens by producing volatile root exudates and/or harboring suppressive microbes. We tested whether cover crop diversity reduced disease symptoms and pathogen abundance. In two greenhouse experiments, we inoculated soil with a 106 conidia suspension of Ilyonectria liriodendri, a pathogenic fungus, then conditioned soil with cover crops for several months to investigate changes in pathogen abundance and fungal communities. After removal of cover crops, Chardonnay cuttings were grown in the same soil to assess disease symptoms. When grown alone, white mustard was the only cover crop associated with reductions in necrotic root damage and abundance of Ilyonectria. The suppressive effects of white mustard largely disappeared when paired with other cover crops. In this study, plant identity was more important than diversity when controlling for fungal pathogens in vineyards. This research aligns with other literature describing the suppressive potential of white mustard in vineyards.

The susceptibility of the grapevine rootstocks most commonly used in Spain to black-foot (Ilyonectria liriodendri and Dactylonectria macrodidyma-complex) and petri disease (Cadophora luteo-olivacea, Phaeomoniella chlamydospora and five species of Phaeoacremonium) pathogens was evaluated. Rooted cuttings of rootstocks 110R, 1103P, 140Ru, 161-49C, 196-17C, Fercal and SO4 were inoculated with black-foot pathogens by dipping their roots in conidial suspensions (5×105 conidia mL-1), planted in pots containing sterilized peat moss and placed in a greenhouse. After four months of incubation, root disease severity index and dry weights of shoots and roots were recorded for each plant. Regarding petri disease pathogens, one-year-old grapevine cuttings of five rootstocks (41B, 140Ru, 161-49C, 1103P and 110R) were vacuum-inoculated with spore suspensions (106 conidia mL-1) of the fungal species and planted in two fields. After four months, the proportion of vines that sprouted in spring was visually determined. At the end of the growing season, dormant plants were uprooted, washed, and assessed for undried shoot weight. Then, the stem of each grapevine cutting was transversally split at 10 cm from the base of the plant to estimate the percentage of vascular tissue discoloured on a scale of 0 to 4. All rootstocks inoculated with Ilyonectria and Dactylonectria species were affected by the disease in some degree, the rootstock 110R being the most susceptible to black-foot. Petri disease pathogens caused a significant reduction of sprouting and shoot weight, as well as a significant increase of disease severity percentage in all grapevine rootstocks with the exception of 161-49C. Both 110R and 140Ru were the most susceptible. Grapevine rootstocks showed different levels of disease resistance, being the rootstock 110R the most susceptible to both diseases and the 161-49C rootstock the most tolerant to petri disease infection.

A questionnaire covering all aspects of grapevine propagation including cultural and sanitation practices in mother blocks and harvest and transport of cuttings from mother blocks to nurseries, nursery operations and field nursery management, was mailed to all Management Committee members of the European COST Action FA1303 “Sustainable Control of Grapevine Trunk Diseases” for distribution to the identifiable nurseries in each European country. The main objective was to develop understanding of the current propagation practices and to identify those likely to have the greatest impacts on the quality of planting material, especially with regard to the control measures used against fungal trunk pathogen infections. The questionnaire was sent to 666 vine nurseries, and 146 replies were received (21.9% response rate) The study identified several risks factors which could increase infection by fungal trunk pathogens during the propagation processes, as well as a clear need for further research into the effects of treatments on grapevine viability, including hot water treatment, and the potential of biological agents and other strategies such as ozonation to control grapevine trunk diseases in nurseries., Z. Bihari, A. Kun and N. Rakonczas (Hungary), P. Larignon, L. Audeguin and O. Zekri (France), M. Fischer and J. Eder (Germany), J. Armengol, J. Reyes, T. Sánz and N. Gómez (Spain), I. Tsvelkov (Bulgaria), M. Baranek (Czech Republic), D. Rusjan (Slovenia), O. Viret (Switzerland), L. Tomoiaga (Romania), G. Mordenti (Italy), J. Kaliterna (Croatia), J. Sofia and C. Rego (Portugal), A. Berraf (Algeria), S. Tjamos (Greece) and D. Ezra (Israel). D. Gramaje was supported by the DOC-INIA program from the National Institute for Agronomic Research (INIA), co-funded by the European Social Fund.

Sporadic and costly failure of newly planted vines is an ongoing problem in the Australian wine industry. Failed vines are frequently infected with wood pathogens, including the fungi associated with Young Vine Decline. Hot water treatment (HWT) and other nursery practices have also been implicated in vine failure. We undertook a survey of Australian grapevine nurseries to develop an understanding of current propagation practices and to facilitate the development of reliable propagation procedures that consistently produce high quality vines. A survey covering all aspects of grapevine propagation including sources of cuttings, HWT, sanitation and cold storage was mailed to all 60 trading Australian vine nurseries. In all, 25 nurseries responded, a response rate of 41.7%. Practices were found to vary widely both within and between nurseries. The vast majority of respondents (20) reported that they currently used, or had used, HWT, but the reliability of HWT was questioned by most nursery operators. A majority (18) felt that some Vitis vinifera varieties were more sensitive to HWT than others. Hydration also emerged as an important factor that had the potential to affect vine quality. All respondents used hydration and although the majority used treated water, cuttings were not generally seen as a source of cross contamination. Our study identified a clear need for further research into the effects of HWT on cutting physiology and the role of hydration in the epidemiology of grapevine pathogens, and the importance of incorporating the results of such research into practical and comprehensive propagation guidelines for vine nurseries.