Vineyard-specific climate projections help growers manage risk and plan adaptation in the Paso Robles AVA

California's wine grape growers will face increasing challenges under a changing climate as most production occurs near the boundaries of current varieties' climatic thresholds. As part of this study, we developed a method for transforming downscaled climate information from the publicly available Cal-Adapt database into useful and useable climate projections for vineyard managers and advisors in the Paso Robles American Viticultural Area. We shared vineyard-specific projections during interviews of 20 managers and advisors. Overall, interviewees expressed trust in the projections and found them helpful in reducing their psychological distance from climate change. The projections prompted consideration of strategies for managing future climate risk and planning adaptation, with the majority of adaptations associated with long-term decisions such as row orientation, variety selection, dry farming, crop diversification and relocation. Agri-climatic decision support tools such as the one prototyped here may prove especially helpful for incorporating climate adaptation into the long-term business planning and vineyard redevelopment decisions facing managers and advisors in the near future. This approach could be extended to other California wine grape regions or to other perennial crops with expected vulnerabilities to climate change.

Ampelographic presentation of some indigenous grape varieties of Greece

Технические сорта винограда Греции представляют собой сокровище для ценителей вина во всем мире из-за своей уникальности. Здесь возделываются сотни сортов для производства вин любого типа, на любой вкус, что дает возможность рассматривать страну как одного из самых «разноплановых» производителей вина, а греческие виноградники - одними из самых богатых на сортовое разнообразие в мире. В статье представлено ампелографическое описание некоторых широко известных греческих технических сортов винограда. Greek indigenous wine grape varieties are treasure for wine lovers around the world because of the diversity and uniqueness of Greek wines. There are hundreds of indigenous wine varieties in Greece, making the country one of the most "diverse" wine producers, and Greek vineyard - one of the richest in the world. The local wine varieties of Greece are an irresistible arsenal for wine production of every type and style, to suit any taste. The paper presents the ampelographic description of some well-known local wine varieties of Greek growing regions.

Adoption of Best Management Practices for Grapevine Leafroll and Red Blotch Diseases: A Survey of West Coast Growers

Grapevine leafroll (GLD) and red blotch (RBD) diseases threaten the sustainability of the USA wine grape industry. To understand factors influencing the adoption of disease management practices, we surveyed wine grape industry professionals in California, Oregon, and Washington (n=154). Economic factors were the fundamental cost of implementing management practices and the ability to sell product from diseased vines (salability). Respondents with reduced salability were more likely to adopt virus testing, replace infected vines, and view these practices as economically favorable. Salability was a strong driver for adoption among Californian respondents, but lesser so in Washington where wineries appeared more willing to accept infected product. Respondents who had acquired technical knowledge of disease ecology were more likely to adopt management practices and to perceive them as economical. Conversely, when there was a lack of knowledge of GLD ecology, notably that mealybugs transmit the pathogen, , adoption was reduced and practices were considered less economical,. Factors affecting adoption were broadly generalizable across diseases. However, knowledge of GLD ecology was more strongly associated with adoption, likely reflecting the remaining knowledge gaps in RBD related to vector ecology and field spread. An emphasis on grower knowledge acquisition and the development of economical disease management practices can improve adoption of best management practices for viral diseases of grapevine.

Identification and Regionalization of Cold Resistance of Wine Grape Germplasms (V. vinifera)

With the extreme changes of the global climate, winter freezing injury has become an important limiting factor for the development of the global grape industry. Therefore, there is a significant need for the screening of cold-resistant wine grape germplasms and cold regionalization for cold-resistant breeding and the development of grapevine cultivation in cold regions. In this study, the low-temperature half-lethal temperature (LT50) values were determined for the annual dormant branches of 124 wine grape germplasms (V. vinifera) to evaluate their cold resistance. The LT50 values of the 124 tested germplasms ranged from −22.01 °C to −13.18 °C, with six cold-resistant germplasms below −20 °C. Based on the LT50 values, the 124 germplasms were clustered into four types, with cold resistance from strong to weak in the order of type Ⅱ > type Ⅰ > type Ⅳ > type Ⅲ, corresponding to the four cold hardiness zones. Zones 1, 2, 3, and 4 included 6, 22, 68, and 28 germplasms, respectively, with decreasing cold resistance. The number of germplasms in different hardiness zones followed a normal distribution, with the most in zone 3. In Type Ⅱ, the fruit skin color of germplasms was positively correlated with cold hardiness, while the temperature of origin was negatively correlated with cold hardiness. The average LT50 of germplasms in different origin regions ranged from −17.44 °C to −16.26 °C, with differences among some regions. The cold regionalization analysis resulted in the distribution of 124 germplasms in four temperature regions in China with six germplasms in region A (−22 °C ≤ LT50 ≤ −20 °C), 30 germplasms in region B (−20°C ≤ LT50 ≤ −18°C), 71 germplasms in region C (−18 °C ≤ LT50 ≤ −15 °C), and 17 germplasms in region D (−15 °C ≤ LT50 ≤ −13 °C). Strong cold-resistant wine grape germplasms (V. vinifera) were identified, and these could be used as parental material for cold-resistant breeding. In some areas in China, soil-burial over-wintering strategies are used, but our results suggest that some wine grapes could be cultivated without requiring winter burial during overwintering. The results of this study should provide guidance for the selection of promising strains for cold-resistant breeding for expanded cultivation of improved varieties for wine grape production in China.