1,721,065 research outputs found
La pettinatura meccanica per la gestione meccanizzata della Doppia Cortina
No full textLa forma di allevamento GDC (Geneva Double Curtain) è largamente diffusa nell’areale padano in relazione alla sua adattabilità ai terreni di pianura e pedecollinari con media e buona fertilità dove fornisce interessanti risultati produttivi sia in termini quantitativi che qualitativi. Alla base dell’efficace gestione di questo sistema di allevamento vi è il mantenimento di una netta separazione delle cortine che può essere garantita sia da una corretta potatura invernale che da un’adeguata pettinatura della chioma. La pettinatura, tradizionalmente eseguita manualmente, può essere resa più rapida ed efficiente con l’impiego di specifiche attrezzature. Nel corso del 2019 in un vigneto di Trebbiano romagnolo allevato a GDC in provincia di Ravenna, è stata effettuata una valutazione comparativa della pettinatura manuale, eseguita da due operatori collocati su una piattaforma mobile, rispetto alla pettinatura meccanica eseguita da un prototipo che, grazie all’azione di organi meccanici convogliatori e di un flusso d’aria che agisce sui tralci orientandone la posizione, consente di sostituire quasi totalmente l’azione dell’uomo nel posizionamento dei germogli nell’interfila. L’operazione meccanica è stata eseguita ad una velocità media di 3 km/h ottenendo una capacità di lavoro di 0,51 ha/h circa 5 volte superiore da quella garantita dal cantiere manuale, 0,1 ha/h. Conseguentemente, anche i tempi di impiego della manodopera sono stati nettamente inferiori con la pettinatura meccanica 5,8 h/ha rispetto a 23 h/ha richiesti nell’intervento manuale. Ipotizzando una superficie media di impiego di 20 ha e simulando i costi di richiesti per l’acquisto e la gestione del mezzo meccanico la pettinatura con il prototipo consente di ridurre il costo di intervento di circa il 40% (175 €/ha contro circa 300 €/ha per il cantiere manuale)
Post-budburst hand finishing of winter spur pruning can delay technological ripening without altering phenolic maturity of Merlot berries
Full text linkBackground and Aims: Global warming can lead to technological ripening occurring in advance of phenolic maturity for red wine cultivars. This study evaluated the effect of post-budburst winter pruning on the phenology, yield components, berry composition and phenolic maturity in Vitis vinifera L. cv. Merlot. Methods and Results: Mechanically pre-pruned vines followed up with hand pruning during winter (Control) were compared to vines that were mechanically pre-pruned and followed up with hand pruning after budburst when distal buds developed shoots with either three unfolded leaves (DF3) or eight unfolded leaves (DF8). Late pruning delayed budburst, flowering and, to a lesser extent, veraison. The delays were greater for DF8 than DF3 treatments. Yield decreased by about 40 and 71% in DF3 and DF8 vines, respectively, while sugar accumulation and reduction of TA were delayed by both pruning treatments. The concentration of anthocyanin and tannin and of extractable anthocyanin and tannin (of skin and seeds analysed separately) were not influenced by the DF3 treatment while tannin concentration increased in DF8 berries. Conclusions: Delaying hand pruning of mechanically pre-pruned vines until after budburst of distal nodes can delay technological ripening without affecting the concentration of anthocyanin and tannin of berries. Yield, however, is substantially reduced. Significance of the Study: We verified the feasibility of a cost-effective technique that can be adopted to counteract the hastening of sugar accumulation and organic acid decline caused by global warming on valuable black grapes
The evolution of phenolic compounds in vitis vinifera l. Red berries during ripening: Analysis and role on wine sensory—a review
Full text linkThe study of phenolic maturity in Vitis vinifera L. requires a multidisciplinary approach to understand how the evolution of berry flavonoids and cell wall material influence the colour and the textures of red wine. This is a challenging issue which involves researchers of viticulture and enology, and the results of their work are of particular interest for the producers of high-quality red wines. This review reports the current knowledge regarding phenolic maturity, describing the sensorial traits of the different compounds, the evolution of berry flavonoids and the methodologies used to evaluate their characteristics. Finally, the role of cell wall material in influencing the extractability of anthocyanins and proanthocyanidins was shown. By means of a critical review of the results, it can be hypothesised that prolonged ripening improved colour characteristics and mouthfeel properties, thanks to the higher amounts of extractable skin flavonoids associated with lower amounts of seed proanthocyanidins, and to the increased affinity of the cell wall material for the proanthocyanidins most involved in the perception of unpleasant astringency
Zeolite application and irrigation during ripening reduced berry sunburn damage and yield loss in cv. Sangiovese (Vitis vinifera L.)
Full text linkClimate change poses significant challenges to the grapevine cultivation for wine production. In the last years, the occurrence of extreme weather events such as intense heat waves and prolonged period of drought increased sunburn damage with negative consequences to yield and berry composition. Short-term adaptation strategies are urgently needed to mitigate these effects. In this light, our study aimed to evaluate the efficacy of zeolite application on the canopy and irrigation during ripening on sunburn damage, yield, and berry composition in cv. Sangiovese (Vitis vinifera L.). Over 3 years (2021-2023), canopy management and irrigation treatments were arranged in a strip-plot design. Canopy management treatments included leaf removal on the cluster zone, with and without zeolite application, and no defoliated control; irrigation treatments comprised irrigation from berry softening and no irrigation. Both zeolite application and irrigation reduced sunburn damage, thus mitigating yield loss. Regarding berry composition, zeolite application did not alter the main parameters whereas irrigation led to reductions in sugar and anthocyanin concentrations. These findings suggest that zeolite application and irrigation during ripening represent promising and cost-effective solutions for grape growers facing climate change-induced challenges. However, further studies are necessary to optimize timing of irrigation to avoid detrimental effects on anthocyanin accumulation
Irrigation during ripening may reduce sunburn damages on berries of Vitis vinifera L. 'Sangiovese'
No full textIn the Mediterranean wine-growing areas, high temperatures often hasten sugar accumulation causing, in black berry varieties, the decoupling between technological and phenolic maturity. Moreover, heat waves, occurring more frequently in the last decades, may cause severe sunburn damages on clusters with serious consequences on yield. Considering these issues, the approach to vineyard management has recently been reconsidered and also irrigation may be applied in an innovative way. The present study aimed to investigate the effects of irrigation during ripening on sunburn berry incidence and yield, and grape composition at harvest. The trial was conducted in 2021 on adult vines of Vitis vinifera L. ‘Sangiovese’, trained to vertical shoot positioned (VSP) spur-pruned cordon. Treatments were laid out in a strip-plot design and the main factors were irrigation and cluster exposure. Irrigation treatments were: a) irrigation from the beginning of veraison to harvest to maintain vines well-watered; b) no irrigation. Cluster exposure treatments were: c) removal of main and lateral leaves from the eight basal nodes of each shoot at the beginning of veraison; d) no leaf removal. From veraison to harvest, berry temperature was continuously measured with thermocouples inserted under berry skin, while the incidence and severity of sunburn damages were recorded weekly on all the cluster of the tagged plant. Midday stem water potential was also measured from the end of July to late August. At harvest, yield parameters were measured and grape composition analyzed, while frozen berries were used for anthocyanin analysis with HPLC. As expected, leaf removal caused berry necrosis and berry shrivel due to the increase of berry temperature, but irrigation halved the severity of those sunburn damages. Sugar and anthocyanin concentrations were slightly affected by leaf removal but decreased significantly with irrigation. This study documented an interesting approach to tackle sunburn damages and to slow down sugar accumulation, which still needs to be modulated to avoid detrimental effects on anthocyanin accumulation
L'effetto della luce sul Grechetto gentile
No full textEffetto della defogliazione sulle caratteristiche compositive delle uve di Grechetto gentil
Effects of sunlight exposure on flavonol content and wine sensory of the white winegrape grechetto gentile
Full text linkThe aim of this research was to study the effect of sunlight exposure on the composition of white grapes and wine sensory attributes. In 2014 and 2015, vines of the white winegrape Grechetto gentile were subjected to cluster zone leaf removal (LR) after fruit set. Small-scale vinifications of Control and LR-treated grapes were conducted following a standardized protocol designed to identify differences in astringency and bitterness, and the relationship between these mouthfeel attributes and the concentrations of phenolic compounds was investigated. In both years, berry flavonols increased after cluster zone LR, and were also higher in the corresponding wines. Berry tannins showed only minor changes in response to the higher solar irradiance from LR and were not different in the wines. In 2014, wine from the LR-treated vines was judged to be more bitter and astringent, whereas no difference was found between wines of 2015. The higher concentration of flavonols may have contributed to the higher intensity of phenolic mouthfeel in the first year, whereas the very high pH and alcohol content of all the wines in the second year may have masked differences in perception of astringency and bitterness
Maturità fenolica: monitorare i processi evolutivi
No full textmaturità fenolica nel Sangiovese, effetto della parete cellulare delle bacche sulla estraibilità di antociani e tannini in Merlo
Regeneration of Populus nigra transgenic plants expressing a Kunitz proteinase inhibitor (KTi3) gene
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