Abstract Water saving under drought stress is assured by stomatal closure driven active (ABA-mediated) and/or passive (hydraulic-mediated) mechanisms. There currently no comprehensive model nor any general consensus about the actual contribution and relative importance of each above factors in modulating planta . In present study, we assessed (hydraulic) vs (ABA mediated) mechanisms V. vinifera plants facing stress. Leaf gas exchange decreased progressively to zero during embolism-induced...

The effectiveness of early leaf removal on high-yielding cultivars Sangiovese and Trebbiano (<i>Vitis vinifera</i> L.) was investigated as a tool for reducing crop potential inducing looser clusters that are less susceptible to rot. Fruit set, cluster weight, berry number per cluster, size, compactness were reduced by all defoliation treatments compared non-defoliated shoots. Physiological assessment performed in one-year study indicated prebloom the six basal leaves elicited no difference...

Background and Aims: The number of pre-bloom source leaves is a primary determinant subsequent fruitset. Accordingly, we tested whether pre- post-bloom hand (HD) mechanical (MD) defoliation are effective in limiting the yield high-cropping cultivar such as Sangiovese 3-year field study. Methods Results: first six basal any laterals were removed by hand, same area was subjected to MD, latter removing 48.3% leaf manually. Both treatments significantly reduced fruitset, per shoot, bunch weight,...

Early defoliation is a novel cultural practice for crop management in grapevines. The effects of timing (prebloom or fruit set) and method (manual mechanical) early on yield grape wine composition <i>Vitis vinifera</i> L. cv. Graciano Carignan grapevines were investigated. Leaf removal induced substantial increase both cluster exposure canopy porosity. Yield was significantly reduced by varieties. per shoot between 30 70% manual mechanical leaf prebloom. In varieties, postflowering...

Viticulture is widely practiced in dry regions, where the grapevine greatly exposed to water stress. Optimizing plant use efficiency (WUE) without affecting crop yield, grape and wine quality crucial limiting of for irrigation significantly improving viticulture sustainability. This study examines vineyards particle film technology (engineered kaolin) compares it a film-forming antitranspirant (pinolene), traditionally used limit leaf loss, an untreated control. The trial was carried out...

Crop-regulation techniques applied as preflowering defoliation (D), early cluster thinning at (ECT), and lag-phase of berry growth (LCT) were tested over three seasons on high-yielding <i>Vitis vinifera</i> L. Sangiovese compared to non-defoliated, unthinned control vines. Treatment severity consisted removing primary leaves any laterals developed from nodes 1 6 in D 50% clusters chosen among distal or those inserted weak shoots ECT LCT plots. Although yield per vine was not reduced (−32%)...

Based on earlier findings showing the effectiveness of preflowering leaf removal at reducing yield in several <i>Vitis vinifera</i> L. genotypes, a 3-year study was carried out Sangiovese vines to evaluate how technique also affects vegetative growth, wood carbohydrates reserves, and specific physiological traits such as intrinsic water use efficiency (WUEi) chlorophyll fluorescence. Early defoliation (D) applied before flowering with elimination ~80% area compared non-defoliated control (C)...

Analysis of the spectral response vegetation using optical sensors for non-destructive remote monitoring represents a key element crop monitoring. Considering wide presence on market unmanned aerial vehicle (UAVs) based commercial solutions, need emerges clear information performance these products to guide end-user in their choice and utilization precision agriculture applications. This work aims compare two UAV products, represented by DJI P4M SENOP HSC-2 acquisition multispectral...

Background and Aims: Little work has been conducted on the effects that summer pruning operations have relative growth of grapevine berry parts. Our paper studies whether pre-bloom leaf removal is able to modify proportions seed, skin flesh in ripe grapevines berries related must composition. Methods Results: Pre-bloom defoliation (D) first six basal leaves main shoots was applied field-grown cvs Barbera Lambrusco salamino (Vitis vinifera L.) Italy's Po Valley compared with non-defoliated...

Grape berry composition mainly consists of primary and secondary metabolites. Both are sensitive to environment viticultural management. As a consequence, climate change can affect modify wine quality typicity. Leaf removal techniques impact by modulating the source-to-sink balance and, in turn, may mitigate some undesired effects due change. The present study investigated between technological maturity parameters such as sugars organic acids, phenolic anthocyanins response source-sink...

Background and Aims Postveraison limitation of canopy photosynthesis delays grape berry ripening reduces sugar accumulation, thus lowering the alcohol content subsequent wines. This study was designed to evaluate whether similar results could be obtained by defoliation apical bunch zone using a leaf-plucking machine when approximately 16–17°Brix. Methods Results In 2011 2012, treatments were applied postveraison cv. Sangiovese vines (D) on either side each row mechanical leaf...

Background and Aims Global warming is inducing a general earliness in the onset of grapevine phenological stages including ripening, phenomenon that occurs often hottest seasons which leads to unbalanced wines. Our aim was assess physiological basis late leaf removal applied above bunch area as tool for delaying ripening. Methods Results Potted cv. Sangiovese grapevines were subjected treatments preveraison (DEF-I) postveraison (DEF-II) by pulling out six seven primary leaves laterals, if...

The influence of timing and method basal defoliation on the profile content anthocyanins flavonols in Tempranillo grapes was investigated. Basal leaf removal manually mechanically performed at two phenological stages, prebloom fruit set. Phenolic composition determined grape extracts by HPLC-UV-Vis 13 anthocyanin flavonol compounds were identified quantified. Regardless defoliation, led to more ripened terms higher soluble solids reduced acidity favored accumulation anthocyanins, which...

Hyperspectral aerial imagery is becoming increasingly available due to both technology evolution and a somewhat affordable price tag. However, selecting proper UAV + hyperspectral sensor combo use in specific contexts still challenging lacks documental support. While an more straightforward as it mostly relates with compatibility, autonomy, reliability cost, has much be considered. This note provides assessment of two sensors (push-broom snapshot) regarding practicality suitability, within...

Although vertical shoot positioned (VSP) training systems, either cane- or spur-pruned, are adopted in the great majority of vineyards worldwide, lianas nature grapevine and presence long flexible canes confer high plasticity render structural pruning changes quite easy. The focus this review is if, light most consistent features triggered by global warming (e.g., longer growing season, earlier phenology, faster ripening, higher incidence overheating stress sunburn, frequency extreme weather...

The interactions of leaf age and gas exchange, together with modifications induced by fruiting exogenous kinetin treatments, were investigated in field-grown Sangiovese (<i>Vitis vinifera</i> L.) grapevines. Analyses carried out both on a seasonal basis within each sampling date as function the natural gradient along shoot showed that maximum Pn occurred at 30 to 35 days age. A progressive decline started about 50 four-month-old leaves retained 45% Pn. Very young, rapidly expanding (&lt; 15...

The interactions of water stress timing and crop level on growth, gas exchange, relations ripening potted Pinot Noir grapevines were examined. Pre-veraison induced a greater reduction shoot berry growth more rapid limitation net photosynthesis (Pn) stomatal conductance (g(s)) as compared to post-veraison stress. At the end stress, when mid-day pre-dawn leaf potential below -1.1 -0.6 MPa, in Pn stressed vines was marked 2- 4-cluster plants versus 1-cluster plant. Crop had almost no...