Semi-Minimal Pruned Hedge: A Potential Climate Change Adaptation Strategy in Viticulture

Abstract

The low-input viticultural training system ‘Semi-minimal pruned hedge’ (SMPH) is progressively being more widely applied in the Central European grapegrowing regions. The present study examined the influence of (i) the training system (SMPH versus the vertical shoot position (VSP) system), (ii) the timing of shoot topping in SMPH, and (iii) the effects of mechanical thinning in SMPH on the bunch rot epidemic, grape maturity, and yield. Six-year field trials on Pinot blanc in Luxembourg demonstrated that yield levels in non-thinned SMPH treatments were 74% higher, and total soluble solids (TSS) at harvest 2.2 brix lower than in VSP. Non-thinned SMPH delayed the bunch rot epidemic and the maturity progress by 18 and 11 days compared to VSP, respectively. Different shoot-topping timings in SMPH did not affect the tested parameters. Mechanical thinning regimes reduced the yield by 28% (moderate thinning) and 53% (severe thinning) compared to non-thinned SMPH and increased TSS by 0.8 and 1.3 brix, respectively. Delayed bunch rot epidemic and maturity progress give rise to the opportunity for a longer maturity period in cooler conditions, making this system of particular interest in future, warmer climatic conditions. Providing that yield levels are managed properly, SMPH might represent an interesting climate change adaptation strategy.

Climate change is implicating a two-fold impact on air temperature increase in the ripening period under the conditions of the Luxembourgish grapegrowing region

“…To maintain the wine typicity of the region, potential adaptation strategies to mitigate the consequences of climatic change in general and higher ripening temperatures in particular might consist of measures leading to a temporal delay of the maturation period. This might be achieved by a shift towards cooler sites (e.g., with higher elevations or lower exposition) or regions (e.g., at higher latitudes), cultivars or clones with a later ripening characteristic, maturity-retarding rootstocks, the application of antitranspirants (Gatti et al, 2016) or specific crop cultural measures including training systems (Molitor et al, 2019), delayed winter pruning (Friend and Trought, 2007) and adapted canopy management (Parker et al, 2016, Stoll et al, 2013, Trought et al, 2015.…”

A Review of the Potential Climate Change Impacts and Adaptation Options for European Viticulture

“…To avoid grapes ripening under high-temperature conditions, training systems that delay ripening may be beneficial under future climate conditions. Minimal pruning systems in their various forms (i.e., semi-minimal pruned hedge) can delay maturity and bunch rot formation [212]. (ii) Lower sugar accumulation.…”

Evaluating Strategies for Adaptation to Climate Change in Grapevine Production–A Systematic Review

“…We note a lack of comparison of the water use efficiency of different training systems, including traditional forms like goblet systems (Medrano et al, 2015 ). In Central Europe, under relatively cool climates, light pruning systems such as semi minimal pruning are promoted as an adaptation to climate change, as they present higher yields with lower alcohol degrees than vertical-shoot positioning systems (Clingeleffer, 2010 ; Molitor et al, 2019 ). However, the large water requirements of such systems would not be adapted to rainfed systems under semi-arid climate.…”