The influence of culture medium on the dynamics of fermentation of wine yeasts

Context and purpose of the study. The breeding of PIWI varieties has a long tradition in the Czech Republic. In the last two years, 9 new PIWI varieties have been registered.

This work aimed at setting up a multivariate and geostatistical methodology to map natural terroir units of the viticultural areas at the province scale (1:125,000).

Temperature has a decisive influence on the growth and development of plants (Carbonneau et al., 1992). In particular, in the case of the vine, the temperature is an omnipresent variable in the climatic indices (Huglin, 1986). For reasons of convenience, these indices use the temperature of the air measured under shelter in a meteorological station, making the implicit hypothesis of a concordance between this temperature and that of the sites of perception of the thermal stimulus by the plant. However, development may be more dependent on soil temperature than air temperature (Kliewer, 1975). Morlat (1989) thus verified that the variability in the precocity of the vine, positively correlated with the quality of the harvest and of the wine in the Loire Valley, was mainly explained by differences in temperature of the root zones.

A good knowledge of the soil physicochemical properties, as well as its ability to retain and put the necessary water available to the plants, is essential when it comes at the design of an irrigation plan.

Heatwaves, defined as three or more consecutive days above average historical maximum temperatures, are having a significant impact on agricultural crop yields and quality, especially in arid or semi-arid regions with reduced water availability during the growing season.