Correlation between agronomic performance and resistance gene in PIWi varieties in the field

Defoliation is one of the green operations more used in viticulture, whose results can be very different depending on the variety and the moment of realization. Early leaf removal consists of the elimination

Over the past two years, the AWRI has received 69 wine samples suspected of being affected by mousy off-flavour. The character has been mostly observed in white wines.

The trial was conducted in variety/rootstock Riesling/Kober 5 BB in the vineyard district of Vrsac. The vineyard was planted in 1996 on a south-facing slope, with rectangular type pruning of 3×1 m. The training system is of symmetric cordon type and mixed type pruning is practiced.

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.

The inherent variability of Nature poses challenges for researchers to draw clear conclusions from field experiments. Identifying and assessing adaptations to climate change requires agronomic field trials.