## 1 Introduction  
Modern viticulture is challenged from various sides. On the one hand, labor shortages and a trend towards larger winery sizes create the demand for increased mechanization and automatisation of vineyard and winery tasks. On the other hand, climate change threatens traditional forms of viticulture. A general tendency in German viticulture was reported by [PERSON] et al. [1] and indicates a northbound shift of viticultural areas, as well as an ascent to higher elevations and an acceleration of all phenological phases due to increasing temperatures. [PERSON] et al. [2] predict a global average increase in growing season temperature of 2 \({}^{\circ}\)C during the first half of the 21 st century with different magnitude for specific wine regions, i.e., a possible shift into another climate maturity type. Changes in average season temperature (Northern Hemisphere: Apr-Oct; Southern Hemisphere: Oct-Apr) show a high variability but seem to be less pronounced in cool climate regions,i.e., Rhine valley showing an average warming of 1.51 \({}^{\circ}\)C [2]. Generally, phenological stages, such as bud break, flowering and veraison are projected to occur earlier in the year in European viticulture [3; 4]. [PERSON] and [PERSON] [5] report an earlier bud break, which might increase the risk of spring frost damages in grapevines in some regions. Flowering is projected to occur 15 days earlier by mid of the 21 st century and 30 days until the end of 21 st century in Bordeaux [6]. Moreover, temperature increases have already advanced the onset of ripening since the 1980's and are expected to advance veraison up to 30 days in the future European viticulture (2041-2070) under the predicted conditions of climate change [3]. [PERSON] et al. [7] report that future ripening of grapes could occur under higher temperatures due to earlier veraison. An earlier ripening period will expose the ripening grapes to higher temperatures [4], and lead to a higher degree of alcohol, a lower concentration of organic acids, especially malic acid, and to changes in the aroma composition of wines [8]. This may ultimately impact on the typicity of regional wine profiles. The earlier onset of ripening will also lead to an increased pressure of fungal infections by _Botrytis cinerea_ or other pathogens during the ripening phase. Optimum temperature for _B. cinerea_ infection has been reported at 20.8 \({}^{\circ}\)C [9], well-above the temperature prevailing during grape ripening in cool to moderate climates. Several approaches have been proposed to counteract these climate change-related effects. The spraying of buds with oil or the painting of stems with white chalk has been reported to delay bud break [10]. Late pruning [11] and double pruning have been described to delay phenological development and delay ripening [12; 13; 14]. Moreover, the application of anti-transpirant agents to the canopy has also been shown to be successful in delaying phenological development and sugar accumulation in the grapes [15]. [PERSON] et al. [16] delayed ripening by pre-veraison auxin applications on bunches. The manipulation of leaf area to fruit weight-ratio has been tested at various phenological stages. Whereas, leaf removal, prior to flowering, reduced the yield, and hence, promoted sugar accumulation [17], leaf removal after flowering, and after veraison [18; 19], delayed ripening substantially. Another way to modify leaf area to fruit weight-ratio, and thus, delay ripening is through the vine training system. The grapevine training system, known as Semi-Minimal-Pruned Hedge (SMPH) has first been described by [PERSON] et al. [20]. Whereas, machine pruned systems, trained to a VSP-type trellis, have been reported much earlier under the name of hedge pruning or box pruning [21]. SMPH is a vine training system, which blends features of traditional VSP-type trellis systems with the concept of minimal pruning.