Stomatal responsiveness to evaporative demand (air vapour pressure deficit (VPD)) ranges widely between species and cultivars, mechanisms for stomatal control in response VPD remain obscure. The interaction of irrigation soil moisture with on conductance is particularly difficult predict, but nevertheless critical instantaneous transpiration vulnerability desiccation. sensitivity was investigated Semillon, an anisohydric Vitis vinifera L. variety whose leaf water potential (Ψl) frequently...

The extent of oxidative stress during ripening saskatoon (Amelanchier alnifolia Nutt.) fruit was examined. Lipid peroxidation development from the mature green to fully ripe (purple) stage evidenced by accumulation ethane and 2-thiobarbituric acid reactive substances. Fruit polar lipid free fatty concentrations also declined ripening. Moreover, double bond index acids in fraction fell ripening, reflecting a progressive increase saturation membrane lipids. This partly due 65% decline...

The hypothesis that vines of the Semillon wine grape variety show anisohydric behaviour was tested, i.e. tissue hydration is unstable under fluctuating environmental conditions. Stomatal conductance and transpiration rates from leaves were measured during day at night. Leaf water potential (Ψl) in negatively correlated to vapour pressure deficit (VPD) both predawn day. Furthermore, Ψl fell significantly lower values than any nine other varieties examined. Night-time stomatal (gn) (En) up...

Trends in the accumulation of mineral elements into grape berry components give information about vascular flow berry. Shiraz berries were dissected receptacle, skin, pulp, brush and seeds 10 these was followed through development. The separated two categories according to their pattern first group continued accumulate throughout growth ripening, comprised of  phloem-mobile potassium, phosphorus, sulphur, magnesium, boron, iron copper. second accumulated mostly prior veraison, included...

This paper gives two contributions to the state-of-the-art for viticulture technology research. First, we present a comprehensive review of computer vision, image processing, and machine learning techniques in viticulture. We summarize latest developments vision systems with examples from various representative studies, including, harvest yield estimation, vineyard management monitoring, grape disease detection, quality evaluation, phenology. focus on how can be integrated into current...

Background and Aims: Leaf stomatal density, i.e. number of stomata per unit area leaf, is a primary determinant the carbon water relations plants. However, little known about plasticity grapevine density during leaf formation in response to environmental factors. In this study, we determined responses soil temperature atmospheric dioxide development following dormancy gain further understanding relations, adaptation climate change. Methods Results: Using potted plants Vitis vinifera (L.) cv....

Preharvest weight loss of <i>Vitis vinifera</i> L. cv. Shiraz berries may be the result cuticle disruption leading to high transpiration rates relative earlier stages ripening. Scanning electron microscopy showed very few but functional stomata on young and wax-filled older and, aside from slight cracks along stomatal protuberance, did not reveal any fissures in surface that lead increased rates. Preveraison berry epicuticular wax platelets were defined intricate, while postveraison...

Mesocarp cell death (CD) during ripening is common in berries of seeded Vitis vinifera L. wine cultivars. We examined if hypoxia within linked to CD. The internal oxygen concentration ([O2]) across the mesocarp was measured from Chardonnay and Shiraz, both seeded, Ruby Seedless, using an micro-sensor. Steep [O2] gradients were observed skin decreased toward middle mesocarp. As progressed, minimum approached zero cultivars correlated profile CD Seed respiration declined ripening, a large...

Background and Aims Environmental factors such as root-zone temperature can influence plant development. Linkages between spring soil temperature, carbohydrate reserve mobilisation, nutrient uptake nitrogen partitioning were investigated in Shiraz grapevines to gain better understanding of how this abiotic factor alter root canopy Methods Results Plants exposed a cool, an ambient or warm over 9-week period from budburst. Root starch mobilisation was correlated the sum cumulative heat units...

Shiraz berries commonly lose weight during the later part of ripening and loss vascular flows into berry may be a contributing factor. Changes in flow through streams were assessed by monitoring accumulation potassium calcium at preveraison, postveraison, shrinkage stages development. Potassium, predominantly phloem-mobile element, accumulated most strongly postveraison less phase. Calcium, xylem-mobile before veraison, but after veraison patterns variable. Girdling excision pedicels to...

Daytime root-zone temperature may be a significant factor regulating water flux through plants. Water can also occur during the night but nocturnal stomatal response to environmental drivers such as remains largely unknown. Here and daytime leaf gas exchange was quantified in 'Shiraz' grapevines (Vitis vinifera) exposed three temperatures from budburst fruit-set, for total of 8 weeks spring. Despite lower density, night-time conductance transpiration rates were greater plants grown warm...

Anatomical studies on the movement of a xylem tracer dye were combined with functional changes in grape berry volume during final stages ripening to gauge effectiveness. Movement into pre-veraison fruit was compared post-veraison by feeding solution acid fuchsin excised shoots bunches still attached, and then sectioning for photo-microscopy. Those comparisons confirmed published showing an apparent blockage along major vessels within brush tissue fruit. However, our approach yielded...

Temperature and light are key climatic factors which affect grapevine physiology in the growing season. Our aim was to investigate interactive effects of temperature intensity on reproductive growth responses 'Shiraz' vines vineyard conditions. Well-watered were covered with no shade, light, medium heavy shade covers a over three consecutive seasons. Several heat events, i.e., air temperatures exceeding 40 °C for several days, occurred two Heavy reduced canopy by 3.2-6 cooler season 4-6...

The efficiency of a vineyard management system is directly related to the effective nutritional disorders, which significantly downgrades vine growth, crop yield and wine quality. To detect we successfully extracted wide range features using hyperspectral (HS) images identify healthy individual nutrient deficiencies grapevine leaves. Features such as mean reflectance, first derivative variation index, spectral ratio, normalised difference vegetation index (NDVI) standard deviation (SD) were...

Ripening berries of Vitis vinifera (L) cv. Shiraz can show pre-harvest weight loss at sub-optimal sugar content (shrinkage). This later-age decline in berry implies that water from mature has begun to exceed inflow the parent grapevine. Such decrease net been attributed a cessation xylem flow subsequent veraison, followed by phloem into during later stages ripening. We address this issue present paper, and continuing increase both potassium calcium throughout measured changes fresh (phloem...

Background and Aims: High rainfall events after the onset of ripening commonly cause skin grape berries to split. The aim was verify suggestion, based on vineyard observations, that susceptibility grapes splitting decreases during ripening, establish role cell vitality in this process. Methods Results: detached, berries, cv. Shiraz, assessed by immersing them sucrose solutions or deionised water. At highest decreased only slightly over 30 days. Thereafter, greatly until becoming negligible...

In cultivated grapevines (Vitis vinifera L.), suboptimal photoassimilatory conditions during flowering can lead to inflorescence necrosis and shedding of flowers young ovaries and, consequently, poor fruit set. However, before this study it was not known whether carbohydrate reserves augment set when concurrent photoassimilation is limited. Carbohydrate are most abundant in grapevine roots soil temperature moderates their mobilisation. Accordingly, we grew potted Chardonnay at 15°C (cool) or...

Background and Aim Berry shrivel during ripening is cultivar dependent correlated with berry cell death (CD). We hypothesised that under heat stress water stress, regions of the pericarp in Shiraz berries would become hypoxic depending on porosity, this induce CD. Methods Results measured CD [O2] across developed factorial combination two thermal regimes (ambient heated) irrigation (irrigated non-irrigated) Barossa Valley, South Australia. Heating increased ambient temperature by 0.6°C for...