GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 GiESCO 2019 9 Sustainable viticulture’ the “semi‐minimal” pruned “hedge” system for grape vines long term experience on cv. Sangiovese (Vitis vinifera L.)

Sustainable viticulture’ the “semi‐minimal” pruned “hedge” system for grape vines long term experience on cv. Sangiovese (Vitis vinifera L.)

Abstract

Context and purpose of the study ‐ In previous experiments carried out in Bologna on Sangiovese grapevines raised with the Australian “Minimal Pruning” system, it has been shown that this system left an excessive burden of buds on the vine (650/meter of row) and inhibited the plant from correctly activating its physiologic self‐regulating mechanisms, thus causing alternancy and drops in the sugar content. However, “Minimal Pruning” also reduced labor time and resulted in loose grape bunches on the vine, which are less prone to fungal diseases. Considering the importance of these last results, the University of Bologna has experimented with a cultivation method based on the Australian technique, but modified so as to reduce the bud load and regulate production without losing the advantages of low cost and healthier grapes. The new system, trained to a “Hedge” form with “Semi‐Minimal” mechanical pruning, has been tested on Sangiovese grapevines since 1990 and has undergone important structural modifications, which might also make it suitable for other grape varieties.

Material and methods ‐ The initial research on the Sangiovese grapevine trained as a Hedge compared it to the classic Spur‐Pruned Cordon (SPC). The Hedge productive surface was 1.2 meters tall and was managed with mechanical “Semi‐Minimal” pruning (400 buds/m of row, i.e. 40% less than Australian “Minimal Pruning”), while the classic SPC was managed with traditional manual pruning (18‐buds/meter of row). Between 2000 and 2008, the main growth, production and quality characteristics of SPC and Hedge were identified and an assessment was made of the likelihood of shoot density in the lower areas of the Hedge (as already mentioned, 1.2 m tall) to verify the acrotony effect.Moreover from 2013 to 2018 a second model of Hedge, 0.8 m tall (“Shorter Hedge”) was used on Sangiovese grapevines (235 buds/meter of row, i.e. 65% less than Australian “Minimal Pruning”). For the “Shorter Hedge” the principal 2013‐2018 behavioral parameters were identified and the spatial distribution of shoots and bunches along the productive Hedge wall was also verified.

Results ‐ The results of the first investigation (2000‐2008) showed that in respect to the SPC (18‐buds/m), the 1.2 m tall Hedge (400 buds/m) gave rise to a larger crop of similar quality to that of the SPC, with a greater number of bunches that were smaller, looser and completely free from botrytis. Nevertheless, in the lower part of the 1.2 m tall Hedge, a small drop in the number of shoots produced was observed after few years.In the second investigation, carried out between 2013 and 2018 on the Sangiovese “Shorter Hedge”, with a 0.8 m tall productive surface (235 buds/m), the data confirmed that the lesser height of the yield wall and the relate lower bud number improved the self‐regulation and equilibrium of the vines, markedly reducing the annual variability of the different grape parameters. Overall, the vines always produced quantitatively and qualitatively to satisfaction, with many small bunches free from rot. During the trial, a decreasing of shoot and cluster density was not observed in the lower parts of the 0.8 m tall Hedge.Today, after almost 20 years of research, the Hedge system has shown itself to be capable of being practically applied to other grape varieties thanks to its reduced management costs, complete adaptability to integrated mechanization and the positive results regarding the yield and grape quality.

DOI:

Publication date: June 22, 2020

Issue: GiESCO 2019

Type: Article

Authors

Cesare INTRIERI, Ilaria FILIPPETTI, Gianluca ALLEGRO, Gabriele VALENTINI, Chiara PASTORE, Emilia COLUCCI

Dipartimento di Scienze e Tecnologie Agroalimentari- Università di Bologna

Contact the author

Keywords

Grapevine, Training System, Self-regulation, Mechanization, Semi-Minimal pruning

Tags

GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Effect of one-year cover crop and arbuscular mycorrhiza inocululation in the microbial soil community of a vineyard

The microbial composition of the soil is an important factor to consider in viticulture, since its influence on the “terroir” and on the organoleptic properties of the wine have been demonstrated. Different agronomic techniques have the potential to modify the composition and functionality of the soil microbial community. Maintaining green covers is known to increase soil microbial diversity. The direct application of inoculum of beneficial microorganisms to the soil has also been used to increase their abundance. However, the environmental conditions of each site seem to have a determining weight in the result of these practices. In this study, we compared the effect on the microbial community of a cover crop with legumes in autumn and the inoculation of grapevines with commercial inoculum bases on Rhizophagus irregularis and Funeliformis mosseae in the previous spring. The study has been carried out in a vineyard in Binissalem, Mallorca, Spain. After applying the treatments, we will analyze the soil microbial communities using the data obtained from Illumina amplification of soil DNA from the 16S and ITS regions to analyze bacteria and fungi community, respectively. In addition, we will record the physicochemical characteristics of the soil at each sampling point. The result showed that agronomic management, in the short term, has less influence than soil characteristics on the composition of the soil microbiome. With these results, we can conclude that in a vineyard, agricultural techniques should focus on improving the characteristics of the soil to improve the biodiversity of the soil microbiota.

Sustainable fertilisation of the vineyard in Galicia (Spain)

Excessive fertilization of the vineyard leads to low quality grapes, increased costs and a negative impact on the environment. In order to establish an integrated management system aimed at a sustainable fertilization of the vineyards, nutritional reference levels were established. For this purpose, 30 representative vineyards of the Albariño variety were studied, in which soil and petiole analyses were carried out for two years and grape yield and quality at harvest were measured. In both years of study, soil pH, calcium, sodium and cation exchange capacity were positively correlated with calcium content and negatively correlated with manganese in grapes. Irrigated vineyards had higher levels of aluminium in soil and lower levels of calcium in petiole. Climatic conditions were very different in the years of the study. The year 2019 was colder than usual, in 2020 there was a marked water stress with high summer temperatures. This resulted in medium-high acidity in grapes in 2019 and low acidity in 2020, with sugar levels being similar both years. A very marked decrease in must amino nitrogen was observed in 2020, with ammonia nitrogen remaining stable. The correlation of acidity and sugar values in grapes with soil and petiole analysis data made it possible to establish reference levels for the nutritional diagnosis of the Albariño variety in this region. Based on these results, an easy-to-use TIC application is currently being created for grapegrowers, aimed at improving the sustainability of the vineyard through reasoned fertilization. This study has now been extended to other Galician vine varieties.

Delaying irrigation initiation linearly reduces yield with little impact on maturity in Pinot noir

When to initiate irrigation is a critical annual management decision that has cascading effects on grapevine productivity and wine quality in the context of climate change. A multi-site trial was begun in 2021 to optimize irrigation initiation timing using midday stem water potential (ψstem) thresholds characterized as departures from non-stressed baseline ψstemvalues (Δψstem). Plant material, vine and row spacing, and trellising systems were concomitant among sites, while vine age, soil type, and pruning systems varied. Five target Δψstem thresholds were arranged in an RCBD and replicated eight times at each site: 0.2, 0.4, 0.6, 0.8, and 1.0 MPa (T1, T2, T3, T4, and T5, respectively). When thresholds were reached, plots were irrigated weekly at 70% ETc. Yield components and berry composition were quantified at harvest. To better generalize inferences across sites, data were analyzed by ANOVA using a mixed model including site as a random factor. Across sites, irrigation was initiated at Δψstem = 0.24, 0.50, 0.65, 0.93, and 0.98 MPa for T1, T2, T3, T4, and T5, respectively. Consistent significant negative linear trends were found for several key yield and berry composition variables. Yield decreased by 12.9, 15.9, 19.5, and 27.4% for T2, T3, T4, and T5, respectively, compared to T1 (p < 0.0001) across sites that were driven by similarly linear reductions in berry weight (p < 0.0001). Comparatively, berry composition varied little among treatments. Juice total soluble solids decreased linearly from T1 to T5 – though only ranged 0.9 Brix (p = 0.012). Because producers are paid by the ton, and contracts simply stipulate a target maturity level, first-year results suggest that there is no economic incentive to induce moderate water deficits before irrigation initiation, regardless of vineyard site. Subsequent years will further elucidate the carryover effects of delaying irrigation initiation on productivity over the long term.

Rapid damage assessment and grapevine recovery after fire

There is increasing scientific consensus that climate changeis the underlying cause of the prolonged dry and hot conditions that have increased the risk of extreme fire weather in many countries around the world. In December 2019, a bushfire event occurred in the Adelaide Hills, South Australia where 25,000 hectares were burnt and in vineyards and surrounding areas various degrees of scorching and infrastructure damage occurred. The ability to coordinate and plan recovery after a fire event relies on robust and timely data. The current practice for measuring the scale and distribution of fire damage is to walk or drive the vineyard and score individual vines based on visual observation. The process is time consuming, subjective, or semi-quantitative at best. After the December 2019 fires, it took many months to access properties and estimate the area of vineyard damaged. This study compares the rapid assessment and mapping of fire damage using high-resolution satellite imagery with more traditional ground based measures. Satellite imagery tracking vineyard recovery in the season following the bushfire is being correlated to field assessments of vineyard productivity such as canopy health and development, fertility and carbohydrate storage. Canopy health in the seasons following the fires correlated to the severity of the initial fire damage. Severely damaged vines had reduced canopy growth, were infertile or had very low fertility as well as lower carbohydrate levels in buds and canes during dormancy, which reduced productivity in the seasons following the bushfire event. In contrast, vines that received minor damage were able to recover within 1-2 years. Tools that rapidly and affordably capture the extent and severity of damage over large vineyard area will allow producers, government and industry bodies to manage decisions in relation to fire recovery planning, coordination and delivery, improving the efficiency and effectiveness of their response.

Bioclimatic shifts and land use options for Viticulture in Portugal

Land use, plays a relevant role in the climatic system. It endows means for agriculture practices thus contributing to the food supply. Since climate and land are closely intertwined through multiple interface processes, climate change may lead to significant impacts in land use. In this study, 1-km observational gridded datasets are used to assess changes in the Köppen–Geiger and Worldwide Bioclimatic (WBCS)