The response of grapevine carbohydrate reserves and seasonal growth development to defruiting at the onset ripening or complete defoliation commercial harvest was examined four sites in two hot, inland regions New South Wales, Australia. Early over consecutive seasons increased total nonstructural carbohydrates (TNC) roots, a lesser extent wood, resulted yield increases up 60% third season when fruit allowed remain on vine until harvest. In contrast, caused decline TNC concentrations reduced...

Potted Shiraz grapevines, in a glasshouse, were exposed to two different soil temperatures (13°C and 23°C) evaluate the effects on vegetative growth floral development from dormancy anthesis. Soil temperature had no effect time of budbreak, anthesis, or number flowers per inflorescence. At anthesis total biomass was similar for both treatments, whereas shoot greater warm soil. From root trunk decreased cool only warmer soil, but by twice as much that During decreases nonstructural...

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...

Yeast cells have a minimum N requirement to ferment must through dryness, so that grape content (hence N) becomes critical in meeting prerequisite. Viticultural practices aimed at are of special relevance because interactions between rootstock and vineyard nitrogen supply strongly influence scion mineral nutrient status as well shoot vigour, via those processes, fruit composition. Such outcomes were investigated field trial involving Shiraz on three rootstocks viz. Teleki 5C, Schwarzmann...

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...

Trials were established in four Semillon hot-climate vineyards to determine the importance of postharvest period for vines grown under different cropping levels and management practices. Two sites chosen high-yielding, furrow-irrigated Riverina region, two lower-yielding, drip-irrigated neighboring Hilltops region New South Wales, Australia. Treatments imposed over consecutive seasons alter either length or effectiveness at each site. Complete defoliation harvest eliminate carbon...

The overwintering carbohydrate reserve status of grapevines has been linked to fruiting responses in the following season, providing a possible avenue for yield management through manipulation accumulation. Conducted across four consecutive seasons, this study examined extent which accumulation could be altered Shiraz using existing, or variations cultural practices. Removal one-third two-thirds clusters at veraison increased average total nonstructural (TNC) concentrations wood by 7%...

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...

Root sugar accumulation was studied in two grapevine varieties contrasting tolerance to water stress. During a 10-day withholding treatment, the drought-tolerant variety, Grenache, sustained less negative predawn and midday leaf potentials as well root potential compared with sensitive Semillon. Grenache vines also maintained lower stomatal conductance transpiration than Semillon throughout drying period. In both there of sucrose roots concentrations were inversely correlated status....

Grapevine ( Vitis vinifera ) berries are sugar and nitrogen (N) sinks between veraison fruit maturity. Limited photoassimilation, often caused by water constraints, induces reserve total nonstructural carbohydrate (TNC) remobilization, contributing to berry accumulation, while N accumulation can be affected vine supply. Although postveraison root remobilization toward the has been identified through 14 C tracing studies, it is still unclear when this occurs during two phases of (rapid slow)....

Elucidating the effect of source-sink relations on berry composition is interest for wine grape production as it represents a mechanistic link between yield, photosynthetic capacity and quality. However, specific effects carbohydrate supply are difficult to study in isolation leaf area or crop adjustments can also change fruit exposure, lead compensatory growth responses. A new experimental system was therefore devised slow sugar accumulation without changing canopy structure yield. This...

Chardonnay grapes from a rootstock trial in the Murray Valley region of South Australia were sampled for two seasons and concentrations free amino acids grape extract ('juice') determined. The lowest assimilable amino-N measured vines on 140 Ruggeri 101–14 rootstocks, highest their own roots, Schwarzmann K51–40. Free sufficient to sustain fermentation through completion. Arginine generally too low expect significant urea wine. Amino-S much lower varied less than concentrations. effect any...

Background and Aims: Water nutrients exported from vineyards through surface subsurface pathways have the potential to adversely affect water quality downstream. This project aimed improve scientific understanding of quantity Nitrogen (N) leaking Australian vineyards. Methods Results: Seasonal balance N in soil solution was monitored one Rutherglen Shiraz six Riverina Chardonnay Surface run-off vineyard each wine region. Six were planted 2 years prior 10 study commencement. Two vineyards,...

Aim: The nutrient reserves in the grapevine perennial structure perform a critical role supplying with nutrients when demand cannot be sustained by root uptake. seasonal changes these largely depend on developmental stage and associated growth requirements. These stored are, turn, influenced environmental conditions vineyard management practices, such as production levels water availability. aim of this study was to assess dynamics major wine grape variety grown Australia determine key...