GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 Different yield regulation strategies in semi-minimal-pruned hedge (SMPH) and impact on bunch architecture

Different yield regulation strategies in semi-minimal-pruned hedge (SMPH) and impact on bunch architecture

Abstract

Context and purpose of the study – Yields in the novel viticulture training system Semi-Minimal-Pruned Hedge (SMPH) are generally higher compared to the traditional Vertical Shoot Positioning (VSP). Excessive yields have a negative impact on the vine and wine quality, which can result in substantial losses in yield in subsequent vintages (alternate bearing) or penalties in fruit quality. Therefore yield regulation is essential. The bunch architecture in SMPH differs from VSP. Generally there is a higher amount but smaller bunches with lower single berry weights in SMPH compared to VSP. By means of different yield-regulating measures, i.e. biochemical thinning concepts, harvester thinning and Darwin-rotor (Fruit Tec Maschinenbau, Markdorf, Germany) the bunch architecture in SMPH is altered. A loose bunch architecture minimizes the risk of bunch rot and improves grape health. The aim of the study was to investigate the impact of different yield regulation strategies in SMPH on the bunch architecture.

Material and methods – Under field conditions, three different thinning methods were tested on the two fungus-resistant grape varieties Rondo, Regent, and additionally Riesling at Geisenheim, Germany (49°59´20” N; 7°55´56 ” E). Both biochemical and mechanical thinning concepts were pursued. The biochemical grape thinning treatment was applied during flowering with the plant growth regulator gibberellic acid (Gibb3; Plantan GmbH, Buchholz, Germany). The mechanical thinning was performed using a harvester at berry pea size stage of fruit development and the Darwin-rotor, which was originally developed for horticultural crops and commonly used for mechanical blossom thinning by horizontally rotating strings. In the vineyard it has been used for thinning young canes a week after budburst (E-L-scale: 9). The three thinning treatments were compared to non-treated VSP and SMPH control and bunch architecture has been investigated.

Results – Lower bunch weight, berry weight and rachis weight were detected in all SMPH treatments compared to VSP. Statistically significant lower bunch weight was detected for SMPH using harvester thinning compared to SMPH thinning with gibberellic acid, thinning with Darwin-rotor and a non-treated SMPH control. No differences in rachis weight were observed between the SMPH treatments. Our results indicate a looser bunch architecture using a harvester and gibberellic acid for yield regulation compared to a non-treated SMPH control. Whereas thinning with the Darwin-rotor resulted in an increase of berry diameter and bunch weight hence more compact bunches.

DOI:

Publication date: September 29, 2023

Issue: GiESCO 2019

Type: Poster

Authors

Jan SCHÄFER*, Matthias FRIEDEL and Manfred STOLL

Hochschule Geisenheim University, Von-Lade-Str. 1, D-65366 Geisenheim, Germany

Contact the author

Keywords

Semi-Minimal-Pruned Hedge (SMPH), yield regulation, thinning, bunch architecture, Darwin-rotor, gibberellic acid

Tags

GiESCO | GiESCO 2019 | IVES Conference Series

Citation

Related articles…

The impacts of simulated heatwaves on the induction and maintenance of bud cold tolerance in cultivated and wild-type Vitis species

Low temperatures are required for the acquisition and maintenance of bud cold tolerance, which are necessary for grapevines to survive freezing temperatures in winter.

Tutela legale delle denominazioni di origine nel mondo (con aspetti applicativi)

Uno degli aspetti più importanti nel commercio internazionale dei vini a denominazione è quello del riconoscimento dei diritti di esclusiva garantiti sui e dal territorio geografico d’o­rigine. Al fine di cautelarsi nei confronti della sempre più agguerrita concorrenza mondiale, è opportuno adottare adeguate protezioni ufficiali e legali delle denominazioni che possono derivare sia dalla “naturalità” del prodotto stesso che dalla “originalità” più particolare.

Wine growing terroirs: management of potential. New issues at stake for AOCs in France

Terroirs represent a heritage that must be studied and managed with appropriate methods; recourse to agronomic and oenological sciences alone is necessary, but is in no way sufficient without the contribution of the humanities.

Differential responses of red and white grape cultivars trained to a single trellis system – the VSP

Commercial grape production relies on training grapevine cultivars onto a variety of trellis systems. Training allows for well-lit leaves and clusters, maximizing fruit quality in addition to facilitating cultivation, harvesting, and diseases control. Although grapevines can be trained onto an infinite variety of trellis systems, most red and white cultivars are trained to the standard VSP (Vertical Shoot Positioning) system. However, red and white cultivars respond differently to VSP in fruit composition and growth characteristics, which are yet to be fully understood. Therefore, the objective of this study was to examine the influence of the VSP trellis system on fruit composition of three red, Cabernet Sauvignon, Merlot and Syrah, and three white, Chardonnay, Riesling, and Gewurztraminer cultivars grown under uniform growing conditions in the same vineyard. All cultivars were monitored for maturity and harvested at their physiologically maximum possible sugar concentration to compare various fruit quality attributes such as Brix, pH, TA, malic and tartaric acids, glucose and fructose, potassium, YAN, and phenolic compounds including total anthocyanins, anthocyanin profile, and tannins. A distinct pattern in fruit composition was observed in each cultivar. In regards to growth characteristics, Syrah grew vigorously with the highest cluster weight. Although all cultivars developed pyriform seeds, the seed size and weight varied among all cultivars. Also varied were mesocarp cell viability, brush morphology, and cane structure. This knowledge of the canopy architectural characteristics assessed by the widely employed fruit compositional attributes and growth characteristics will aid the growers in better management of the vines in varied situations.

Early defoliation positively enhances bioactive composition of berries with no effect on cuticle characteristics

Leaf removal in the fruit-zone has been employed to improve cluster light exposure and ventilation and therefore increase metabolite accumulation and reduce botrytis incidence in berries. When applied before flowering (early defoliation – ED), it can also decrease cluster compactness and regulate yield in high-yielding varieties. This study aimed to evaluate the impact of ED on the physiology and metabolism of Aragonez (syn. Tempranillo) berries along the ripening period. The experiment was set up in 2013 at a commercial vineyard located in the Lisbon winegrowing region.