Effects of climate change on bioclimatic indices in vineyards along Lake Neuchatel, Switzerland

In this study, we investigated the consequences of climate change on bioclimatic indices in vineyards along the edge of Lake Neuchatel in Switzerland. Like in other vineyards all around the world, the typicity of wines and the phenology of vines have changed, particularly since the 1970s. Trends in the growing season average temperature and in Huglin’s heliothermal index show that the climate in the Neuchatel vineyards changed from very cool or cool to temperate during the last decades. Trends in the cool night index and in the prior to harvest cool night index both indicate that in the near future this wine region will frequently experience temperate instead of cool nights during the weeks leading up to harvest. Our results highlight the need for adaptation strategies, such as an upward elevational shift for Pinot Noir, as climatic conditions will become too warm at its current location in the next decades. They also show that conditions in this region are already favorable for more thermophilic varieties such as Merlot. In the context of global warming, this kind of analysis should be conducted throughout winegrowing regions in order to develop efficient adaptation strategies at the microclimatic scale.

Climatic indices in viticulture

В статье рассмотрен вопрос важности анализа климатических условий местности при закладке виноградников. Дан обзор различных подходов к количественной оценке параметров климата. Освещена необходимость расчётов не только отдельных показателей температуры, влажности, освещённости, но и применения комплексных индексов, отражающих совместное влияние климатических факторов на процессы роста и развития виноградного растения. Приведены как традиционные, широко известные (сумма активных и эффективных температур воздуха, гидротермический коэффициент Селянинова), так и редко применяемые индексы (гелиотермический индекс Branas G., биоклиматический индекс Constantinescu Gh.). Рассмотрена методика оценки климатических ресурсов применительно к винограду, предложенная Международной организацией винограда и вина, согласно которой рекомендовано использовать такие показатели как средняя температура вегетационного периода, индекс Уинклера (Winkler Index), биологически эффективная сумма температур, индекс Хьюглина (Huglin Heliothermal Index), индекс холодных ночей (Cool Night Index), индекс Фрегони (Fregoni Index), индекс сухости (Drought index). Приведены формулы для расчёта величины рассматриваемых индексов. Выделены наиболее часто применяемые индексы из перечня, рекомендованного Международной организацией винограда и вина. The article deals with the importance of the analysis of climatic conditions of the area for planting of the vineyards. Various approaches to the quantitative assessment of climate parameters are reviewed. The necessity of calculations of not only separate indicators of temperature, humidity, light intensity, but also of the application of complex indices reflecting joint influence of climatic factors on the processes of growth and development of grapes is highlighted. Both traditional, well-known (sum of active and effective air temperatures, hydrothermal coefficient of Selyaninov) and rarely used indices (solar thermal index of Branas G., bioclimatic index of Constantinescu Gh.) are given. The method of assessment of climatic resources in relation to grapes, proposed by the International Organization of Vine and Wine, according to which it is recommended to use such indicators as the average temperature of the growing period, the Winkler Index, biologically effective amount of temperature, the Huglin Heliothermal Index, the Cool Night Index, the Fregoni Index, the Drought index. The formulas for calculating the value of the considered indices are given. The most frequently used indices from the list recommended by the International Organization of Vine and Wine are highlighted.

Modelling within-region spatiotemporal variability in grapevine phenology with high resolution temperature data

Aim: While it is well recognised that climate can vary spatially so that grapevine phenology significantly varies within a winegrowing region, the magnitude of temporal variability in climate determining factors to engender a significant difference in phenology over time can only currently be described in general terms. This study’s aim was to quantify and compare the temporal variability, and its interaction with spatial variability, in grapevine phenology and three derived viticulture climate indexes for three viticulture regions in eastern Australia with varying topographies, latitudes and continentalities.Methods and Results: Maximum and minimum temperature data were spatially interpolated to produce fine scale topoclimate maps at 30 m resolution for every day of a 20 year period from 1998 to 2018 for the three viticulture regions. Grapevine phenology modelling using a heat accumulation methodology was then applied to estimate growing season temperature, cool night index and post-harvest growing degree days (GDD) for every 30 m map pixel of the three regions in each of the 20 growing seasons.Conclusions: Summary statistics that quantify the spatial and year-to-year temporal variability and the interaction of spatial and temporal variability (i.e. spatiotemporal variability) demonstrated significant differences in grapevine phenology between each of three regions. The key conclusion was that within-region temporal variability in growing season temperature, cool night index and post-harvest GDD exceeded within-region spatial variability.Significance and impact of the study: This is the first study to quantify temporal variability in modelled grapevine phenology, compare this with the level of spatial variability and also consider the interaction of spatial and temporal variability in grapevine phenology within viticultural regions. This study opens many potential lines of further investigation into the effect of temporal variability on wine production and the cultural terroir factors that develop within a wine region as a result, particularly in the context of forecast future increases in inter-annual temperature variability.

Classification of Croatian winegrowing regions based on bioclimatic indices

The aim of this work was to classifie vine growing regions of Croatia using bioclimatic indices. For the analysis of climatic conditions, linear trends of bioclimatic indices were determined using meteorological observations for all avaliable climatological stations located in vine growing regions of Croatia. Analysis were performed for two different climatological periods: 1961-1990 and 1988-2017. Four commonly used bioclimatic indices were determined: the Winkler index, the Huglin index, Cool night index and Growing season average temperature.

Climate and Phenology: Behavior of Autochthonous Italian Grapevine Varieties in the Uplands of Southern Brazil

<p>The present study aimed to characterize the mesoclimate of the municipality of Água Doce, Brazil, and its influence on the phenological development and thermal requirements of autochthonous Italian varieties (<em>Vitis vinifera</em> L). The climate data were provided by a local automatic weather station. The principal phenological stages of red varieties (Aglianico, Ancellotta, Lambrusco, Malvasia Nera, Negroamaro, Nero d’Avola, Primitivo, Sangiovese, and Rebo) and white varieties (Fiano, Garganega and Vermentino) are analyzed. Results show that the mean temperature measured during the phenological cycles from September to April were higher than the climatological average (1961 to 2012). According to the Winkler, Huglin, and Cool Night bioclimatic indexes, the region is classified as “Region II”, cold and with cool nights, respectively. The average heat summation for the phenological cycles of the varieties was 1740 GDD (205 days, 2009-2010), 1463 GDD (187 days, 2010-2011), and 1408 GDD (176 days, 2011-2012). The Lambrusco variety presented the longest phenological cycle (203 days), while Garganega presented the shortest one (178 days). The lower temperatures of Água Doce, when compared to those in other regions where the varieties are traditionally produced, determine longer growing cycles and a shift in the timing of the phenological stages.</p>

Influence of differentiated night temperature on the growth of young bean plants (Phaseolus vulgaris L.)

The plants were grown under controlled conditions at 24/24°C and 24/14°C day/night temperatures in growth chambers. It was shown that the cool night conditions which decreased dry matter growth of plants and leaves area, inhibited dark respiration and lowered Ca content in leaves. Under these conditions the specific leaf weight (SLW) and the content of N, P, K, calculated for 1 dm² of leaves area increased. The intensity of plant leaves photosynthesis from differentiated night temperature was similar.

Low Night Temperature Increases Ovary Size in Sweet Pepper Cultivars

Cool night temperatures have been reported to induce ovary swelling and consequent fruit deformation in bell pepper (Capsicum annuum L.), resulting in unmarketable fruit. This response is a serious limitation to the success of winter production systems for bell pepper. Limited work has been done with other types of sweet pepper, so it is unknown how universal this response is. Furthermore, most prior work has examined effects on ovary diameter only, and there is limited characterization of other ovary traits in response to cool night temperature. The objectives of the present study were to determine the effects of low night temperature on ovary characteristics in different sweet pepper cultivars and to determine the parts of the ovary that are most affected by these factors. Three types of sweet pepper (bell, long-fruited, and cherry) were exposed to 22/20 or 22/12 °C day:night temperatures and flowers at anthesis were continuously harvested throughout the experiments. Ovary fresh weight (FW), diameter, and length across all types (and cultivars within type) were greater under 22/12 °C compared with 22/20 °C. The increase in ovary FW was the result of increases in both ovary wall and placenta FW. In general, all cultivars exhibited increases in ovary size under 12 °C compared with 20 °C night temperature. Differences in ovary FW resulting from night temperature became more pronounced with time. These results indicate that low night temperature effects on ovary swelling may be a universal response among sweet pepper types. Three to 4 weeks are required for maximum swelling response, suggesting that flower buds must be exposed to low night temperatures within the first week after flower bud initiation, because previous work found that flower bud initiation in bell pepper takes ≈4 weeks. However, the duration of low night temperatures necessary for this response remains unknown.