Effects of early leaf removal on grape quality of Albariño vines subjected to different water regimes

Grapevine is one of the crops that may suffer more negative impacts
under climate change, due not only to changes in temperature but also due to water available. Some of the most direct effects of climate variability on grapevines are the changes in the onset and timing of phenology events and changes in the length of the growing season, which may have further effects on grape quality. The aim of this research was to analyze the changes in vine phenology of some red varieties (Tempranillo, Grenache and Carignan) cultivated in Rioja Oriental (Rioja DOCa), under different climate change scenarios.

Context and purpose of the study ‐ An advancement of grapevine phenological development has been observed worldwide in the last two decades. In South Australia this phenomenon is even more accentuated since grapevine is often grown in a hot climate. The main consequences are earlier harvests at higher sugar levels which also result in more alcoholic wines. These are deemed undesirable for the Australian wine industry with consumer preferences shifting towards lower alcohol wines. Vineyard practices can be implemented to control and delay ripening. Amongst them, apical late leaf removal has been successfully applied in Europe to delay ripening by up to two weeks in Sangiovese, Aglianico and Riesling. In those studies, no negative effects were observed on grape colour, phenolics and on the carbohydrate storage capacity of the vines. To date, this technique has not been studied in Australia. In this study late leaf removal, apical to the bunch zone was applied to the variety Semillon for four seasons and compared to an untreated control.

Plants have been shown to redistribute water between root sections and soil layers along a gradient of decreasing water availability. One benefit of this hydraulic redistribution is that water can be transported from roots in wet soil to others in dry soil, delaying the onset of water stress and increasing root longevity in dry environments. Grapevines are thought to redistribute water laterally across the trunk from wet to dry portions of the root system. However, it is unknown whether the phloem contributes to such water redistribution.

The use of bees as pollinators in vine varieties with physiologically female flowers (Picolit, Bicane, Ceresa, Moscato rosa, etc.) (Cargnello, 1983) and as bio-indicators for biodiversity and environmental sustainability is well-known. Furthermore, there are interests in: 1-a. Making the viticulture of Belluno (Province of Veneto in North-eastern Italy, which is also famous for the Dolomites -a UNESCO World Heritage-) regain the socioeconomic role which it is entitled to and which it had got in its past by aiming at the enhancement of local grape variety in harmony with others, for example with the neighboring area of the Conegliano and Valdobbiadene Prosecco Superiore DOCG; 2-a. Maintaining and further improving the important natural and healthy environment of Belluno, and making its territory and the “lookout” means of the environmental sustainability, including its vineyards, even more naturally original and sustainable 4.1C.

Exposure to solar radiation affects berry composition through photomorphogenesis or changes in temperature. Flavonol synthesis is upregulated by UV‐B radiation