Characterization of the wine grape thermohydrological conditions in the tropical Brazilian growing region: long-term and future assessments.

Over the last years, Brazil has appeared among the newtropicalwine producing countries.Thejoined effect of rising air temperature and decreasing precipitation makes it important to quantify the trend of the thermohydrological conditions of the commercial vineyards. The aims of the current research were to classify and delimit these conditions for the winemaking processes under different time scenarios in the BrazilianNortheastern region. Bioclimatic indicatorswere used togetherwith long-termweather ata and projections of the IPCC emission scenarios under simulated pruning dates. The results showed that decreasing of precipitation should be good for wine production when irrigation water is available, but rising air temperature will affect the wine quality and stability mainly for pruning done from November to March. The best pruning periods are around May for any time scenario considered. In general, more care should be taken for pruning happening in other periods of the year, regarding the effect of increasing thermal conditions on wine quality.The classification and delimitation done, joined with other ecological characteristics, are important for a rational planning of the commercial wine production expansion, mainly in situations of climate and land use changes together with rising water competition in the Brazilian Northeast region

Climatic water indices for viticulture.

Abstract ? The objective of this work was to evaluate the performance of vineyard water indices in different grape-growing regions. The climate data used come from the historical series of weather stations located in 18 countries. The evaluated indices were the following: dryness, Zuluaga, humidity, aridity, moisture, and the grapevine water index. The grapevine water index and the indices of drought, moisture, and aridity exhibit similar performances, which makes them suitable to be used equivalently in climatological studies of grapevine regions. Index terms: Vitis vinifera, climatology, evapotranspiration, viticulture. Resumo ? O objetivo deste trabalho foi avaliar o desempenho de índices hídricos da videira em diversas regiões vitícolas. Os dados climáticos utilizados são provenientes das séries históricas de estações meteorológicas localizadas em 18 países. Avaliaram-se os seguintes índices: de seca, o de Zuluaga, o de excedente hídrico, de aridez, de umidade e o índice hídrico da videira. O índice hídrico da videira e os índices de seca, umidade e aridez apresentam desempenhos semelhantes, o que os torna passíveis de serem utilizados de forma equivalente em estudos climatológicos de regiões vitivinícolas.Scientific Note

Climatic aptitude for irrigated wine grapes in the Brazilian Northeast under different prunning dates and time scenarios. Part A: baseline conditions.

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Climatic aptitude for irrigated wine grapes in the Brazilian Northeast under different prunning dates and time scenarios. Part B: future projections.

According to the report from the IPCC (2007), the semi-arid regions are going to be the most affected areas by increasing water consumption, as a consequence of rising air temperatures. Long-term weather data were used together with future projections throughout simp1e regression models which relate the reference evapotranspiration (ET o), crop coefficient (Kc) and the accumulated degree-days (DDac), to quantify the wine grape water requirements for a growing season - GS (VWRas) of the cv. Syrah, in the Brazilian Northeast, considering the baseline conditions and the scenarios for 2020, 2050 and 2080. VWRas, together with the growing season precipitation (P GS),allowed the development of a vineyard water index (VWIGs), which together with the mean air temperature (TGS)was used for characterization of areas with different agro-climatic aptitude in producing grapes for wine elaboration according to time scenarios, varying the pruning dates. The highest increases in VWRas, comparing the baseline conditions and the projected years, happened during periods of the lowest averaged water requirements, in Ceará (CE), Rio Grande do Norte (RN) and Piauí (PI) States, while during the highest water requirement conditions, the highlighted states were Piauí (PI) and Maranhão (MA). lt was observed that the region may present thermal limitations for the wine quality along the years as a consequence of increasing air temperatures during the growing seasons, depending on the pruning date, being expected higher alcohol and sugar contents as well as lower acidity, in the areas and pruning dates with larger TGS values. Less problems in wine quality caused by the c1imate changes were verified for the Bahia, Pemambuco, Paraíba, Alagoas, Sergipe States and the west side of Maranhão State, for pruning dates occurring inMay. Keywords: tropical wine, c1imate suitability, water requirements, temperature, thermal limitationsResumo

Climatic aptitude for irrigated wine grapes in the Brazilian Northeast under different prunning dates and time scenarios. Part A: baseline conditions.

Modelling of crop water variables on a large scale is important when aiming for sustainable development while ensuring water availability in situations involving all depending sectors on water resources. Long term weather data, representing a baseline condition, were used together with simple regression models involving crop coefficient (Kc), reference evapotranspiration (ETO) and accumulated degree days (DDac) to quantify the vineyard water requirements (VWR) for wine grapes in the Brazilian Northeast, considering a four months mean growing season (GS). VWR joined with precipitation, allowed the development of a vineyard water indicator (VWI), which was applied together with the monthly average values of air temperature during a growing season to characterize areas with different agro-climatic aptitude for grape production for winemaking process, varying the pruning dates. Considering the whole region, the variation of the averaged VWR pixel values were from 300 mm for pruning dates in March to 410 mm, when these dates occur in September. In general, the highest VWR values are for pruning dates from July to October, while the lower rates were when the pruning is done between January and April. lt was observed that the Brazilian Northeast region could have some thermal limitation for the wine quality and stability. These limitations will depend on the pruning periods, being higher sugar in grapes, while in wines, lower acidity and higher potential alcohol and pH, under warmer conditions. Highlights were for Bahia, Pemambuco, Paraíba, Alagoas, Sergipe States as well as the west side of Maranhão for pruning dates in May, considered as the best areas for commercial wine production for growing seasons starting at this time of the year. The analyses spatially presented, can subsidize water allocation criterions, when aiming for improvements on vine water availability avoiding environmental damage by rapid climate and land use change.Resumo

Climatic aptitude for irrigated wine grapes in the Brazilian Northeast under different prunning dates and time scenarios. Part B: future projections.

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