Environmental effects on cv Cabernet Sauvignon (Vitis vinifera L.) grown in Hawke's Bay, New Zealand.: 1. Phenology and characterisation of viticultural environments

Six Cabernet Sauvignon vineyard sites in Hawke's Bay (New Zealand), selected out of 28 sites observed in 1996/97, were studied over three consecutive seasons in order to characterise viticultural environments of this region for this cultivar. Indices of precocity of vine phenology were used to analyse the relationship between phenology at the selected sites and vegetative growth, productivity, fruit ripening and wine sensory characteristics. Marked differences in indices of precocity existed between sites. These differences were mostly correlated with vine vegetative growth and canopy indices. There was no relationship between yield and vine phenology. Indices of precocity were correlated with certain juice constituents measured on a common date, as well as the sensory scores of wines produced by microvinification from grapes harvested on different dates and maturity levels. Vineyard sites that differed in indices of precocity also differed in their environmental characteristics, particularly in soil physical properties and water balance.     

Ubiquitous net volatilization of polycyclic aromatic hydrocarbons from soils and parameters influencing their soil-air partitioning

Soils are a major reservoir of organic pollutants, and soil-air partitioning and exchange are key processes controlling the regional fate of pollutants. Here, we report and discuss the soil concentrations of polycyclic aromatic hydrocarbons (PAHs), their soil fugacities, the soil-air partition coefficients (K(SA)) and soil-air gradients for rural and semirural soils, in background areas of N-NE Spain and N-NW England. Different sampling campaigns were carried out to assess seasonal variability and differences between sampling sites. K(SA) values were dependent on soil temperature and soil organic quantity and type. Soil fugacities of phenanthrene and its alkyl homologues were 1-2 orders of magnitude higher than their ambient air fugacities for all sampling sites and periods. The soil to air fugacity ratio was correlated with soil temperature and soil redox potential. Similar trends for other PAHs were found but with lower fugacity ratios. The ubiquitous source of PAHs from background soils to the atmosphere found in all temperate regions in different seasons provides an indirect evidence of potential in situ generation of two to four ring PAHs and their alkyl homologues in the surface soil. We discuss this hypothetical biogenic source and other potential processes that could drive the high soil to air fugacity ratios of some PAHs.     

Grapevine growth of shoots and fruit linearly correlate with water stress indices based on root-weighted soil matric potential

Over two consecutive seasons, six deficit irrigation regimes were imposed on Colombard vines on Ramsey rootstock. The soil water availability was quantified by logarithmic transformation of the absolute value of a root-weighted measure of soil matric potential. Stem water potential declined linearly with decreasing soil water availability. Water stress indices were calculated by integrating the daily values of soil water availability over specific periods. Declines in both fruit and vegetative growth were linearly correlated with increases in the values of water stress indices during the respective growth periods. In the berries, concentrations of total soluble solids, tartrate and potassium were not correlated with the water stress index during the period of fruit growth; malate concentration declined linearly with increasing values of this index. Responses of pH and titratable acidity to variation in the water stress index were not consistent in the two seasons.     

Scion photosynthesis and leaf gas exchange in Vitis vinifera L. cv. Shiraz: Mediation of rootstock effects via xylem sap ABA

Limited water resources are placing pressure on the wine grape industry to improve vineyard water use efficiency by continuing improvements in vineyard management. One way to improve vineyard water use efficiency is to improve transpiration efficiency, and judicious use of scion-rootstock combination can play a role. Accordingly, this paper examines the influence of rootstocks on the water use physiology of a common scion variety (Shiraz) and assesses the importance of variation in xylem sap abscisic acid (ABA) as an indicator of relative water use efficiency of different scion-rootstock combinations. Shiraz scions (clone BVRC12) grafted to seven rootstock varieties (along with an ungrafted control), were observed over two consecutive seasons in a field trial located in Adelaide, South Australia. Those two seasons (2001/02 and 2002/03) offered sharp contrasts with respect to soil and atmospheric water stress. Rootstock genotype had a significant impact on scion gas exchange, water status, canopy growth and yield in both seasons. Those impacts were associated with an inverse relationship between xylem sap ABA and stomatal conductance. We suggest that strategic analysis of xylem sap ABA may provide a marker for comparative water-use physiology of different stock-scion combinations, while recognising that irrigation pre-history, and associated degree of vine water stress, will be a further source of variation in grapevine water use.     

Weight loss from ripening berries of Shiraz grapevines (Vitis vinifera L. cv. Shiraz)

Environmental and phenological correlatives associated with the onset of weight loss during ripening in Vitis vinifera cv. Shiraz berries were examined. An irrigation experiment concerned with transient water deficit effects on berry growth over four consecutive seasons provided source data. Timing of maximum berry weight was more closely correlated with the number of days after flowering than with temperature summation. Prior to maximum berry weight, Brix was more closely correlated with days after flowering than with temperature summation, while the number of days from flowering to 10 and 15Brix was remarkably uniform despite contrasting seasons. Driving variables for weight loss during advanced ripening remain a matter of conjecture, but loss of berry water under highly evaporative conditions of late summer is a likely contributor.     

Herbicide runoff along highways. 1. Field observations

Herbicides are widely applied along highways to control roadside vegetation, and surface water is frequently nearby. To determine whether herbicide runoff along highways threatens water quality, a field study was conducted at two sites in northern California for three rainy seasons. The herbicides oryzalin, isoxaben, diuron, glyphosate, and clopyralid were selected for study to include compounds with significant variation in physical/chemical properties. Concentrations of herbicides in runoff were monitored for up to 11 storms following herbicide application, and 24 samples were collected per storm, providing unprecedented temporal detail. Flow-weighted event mean concentrations were calculated for each herbicide in each storm and ranged from below detection limits to 43.13 microg/L for oryzalin. The least soluble compounds, isoxaben and oryzalin, were detected in all storms monitored while the more soluble compounds, diuron and clopyralid, declined to levels below detection limits before monitoring was concluded. Very small amounts of glyphosate were mobilized, but its transformation product aminomethylphosphonic acid was detected at higher concentrations, in more storm events, and at greater depth in the soil profile. A first-order model successfully described the declining herbicide concentrations in spray zone soil and in surface runoff for all sites and herbicides. Fitted first-order coefficients were always higher for runoff than for soil, indicating that the herbicide that persists in the source zone becomes less available for runoff as the time since application increases. The percentage of the applied herbicide that was detected in surface runoff over a season ranged from 0.05% to 43.5%, and the most critical variables in controlling the variation were the solubility of the herbicide and the runoff volume. For a given herbicide and site, the most critical factors in determining seasonal herbicide loss to surface water were the timing and intensity of the first storm following application, affecting total seasonal runoff by up to 2 orders of magnitude. Minimizing runoff of herbicides along highways will thus require careful attention to the intrinsic mobility of the compound and the timing of its application.     

Aging effects on the availability of herbicides to runoff transfer

Realistic estimation of sorption parameters is essential to predict long-term herbicide availability in soils and their contamination of surface water and groundwater. This study examined the temporal change of an effective partition coefficient Kd(eff) for the herbicides simazine, diuron, and oryzalin from a 0.12 ha field experiment during 7 vineyard growing seasons. Kd(eff) is the ratio of solvent extractable herbicide concentrations in the top soil (0-2 cm) to the average concentrations in runoff water and is considered to assess the effective availability of herbicides to runoff transfer. Kd(eff) increased largely with aging time since application, from values similar to those of the literature (determined in 24 h batch conditions, Kd(ref)), up to 88, 164, and 30 times these initial values for simazine, diuron, and oryzalin respectively. The seasonal variation of Kd(eff) values between years and compounds could be adequately described by a unique model, taking into account the cumulative rainfall since application and Kd(ref) of each compound. This simple model was able to represent the influence of the soil moisture content and its changes in the different biological and physicochemical processes that may contribute to the (bio)available, sorbed, or entrapped state of any of the studied herbicides with aging time under Mediterranean climate.     

Influence of a grass layer on vineyard soil temperature

Vineyard grass cover can modify soil variables such as temperature and water content, which in turn influence berry quality at harvest. Such effects require further documentation and this study was conducted to determine how a grass layer could change soil thermal behaviour compared to bare soil. Soil temperature, soil water content and net radiation were measured in a Médoc vineyard, Château Talbot (France). The field used for the experiment was divided into two parts, one with a bare ploughed soil and the other with a partial grass cover. The same measurements were taken on both parts. Bare soil temperatures were generally higher, and the difference between the two treatments was greater in the middle of the inter-row, just under the grass layer. Nevertheless, net radiation above the vegetation, which represents the radiative available energy, was the same for the two plots. Soil conduction heat flux (G) was calculated from temperature measurements. Under the grass layer, the horizontal component of G was barely detectable, whereas under bare soil, G was essentially vertical. The grass layer was therefore acting as an insulating layer, preventing exchanges between soil and atmosphere. Soil temperature and thermal behaviour are heavily influenced by soil surface management practices. The field experiment provided a large data set of measurements which will be used to calibrate a heat and mass transfer model.     

Use of stomatal conductance and pre-dawn water potential to classify terroir for the grape variety Kékfrankos

Background and Aims: A 3‐year study was carried out in order to evaluate the ecophysiology, yield and quality characteristics of Vitis vinifera L. cv. Kékfrankos (syn. Limberger) at Eger‐Nagyeged hill (steep slope) and at Eger‐K?lyuktet? (flat) vineyard sites located in the Eger wine region, Hungary. The aim of this paper was to analyse the effect of ‘vintage’ and ‘terroir’ on the seasonal changes of Kékfrankos ecophysiology and its possible relationship with yield and wine composition. Methods and Results: Grapevine physiological responses (midday‐ and pre‐dawn water potential, pressure–volume analysis and gas‐exchange), growing stages, yield and wine composition of each vineyard were studied. Lower grapevine water supply was detected at Eger‐Nagyeged hill in each season due to its steep slope and soil characteristics. Pressure‐volume curves indicated that there was no osmotic adjustment in the leaves of this variety. Higher osmotic concentration was measured at turgor loss and full turgor in the leaves of the unstressed vineyard (Eger‐K?lyuktet?) presumably due to higher photosynthetic activity. Differences in soil water content of the vineyards resulted in a slightly altered cell wall elasticity. Stomatal conductance, transpiration rate and photosynthetic production per unit leaf area were affected by water availability. Lower yield in Eger‐Nagyeged hill was partly associated with decreased photosynthetic production of the canopy. Improved wine quality of Eger‐Nagyeged hill was due to moderate water stress which induced higher concentration of anthocyanins and phenolics in the berries. The duration of the phenological stages was dependent on vintage temperature characteristics rather than on vineyard site. Conclusion: There was a close relationship between environmental conditions, Kékfrankos gas‐exchange, water relations, yield and wine composition. Water deficit plays an important role in creating a terroir effect, resulting in decreased yield, better sun exposure of leaves and clusters and thus higher concentration of phenolics and anthocyanins. Although quality is mainly influenced by vintage differences, vineyard characteristics are able to buffer unfavourable vintage effects even within a small wine region. Significance of the Study: Stomatal conductance, pre‐dawn water potential and climatic data may be reliable parameters for terroir classification, although variety–terroir interactions must always be considered.     

Effects of site, season and viticultural practices on grape seed development

The effects of vineyard site, season, clone and viticultural management practices were examined as possible sources of variability in seed development between populations of grape berries, cvs Traminer, Riesling and Pinot Noir. Mean values for number and weight of seeds per berry were similar in most seasons and sites, but some were significantly different. In some but not all cases, smaller means for seed number per berry were associated with larger mean weight per seed. Trellising, training, pruning level, canopy manipulation and regulation of bunch number per vine had little effect on seed complement per berry except that mean weight per seed was smaller with minimal pruning. Reduction in water supply imposed after flowering did not alter seed number but reduced seed weight. Berries of boron-deficient vines had fewer and smaller seeds. The implications of seed development for berry development are discussed.     

An assessment of air-soil exchange of polychlorinated biphenyls and organochlorine pesticides across central and southern Europe

Estimating the net flux direction of polychlorinated biphenyls and organochlorine pesticides is importantfor understanding the role of soil as a sink or source of these chemicals to the atmosphere. In this study, the soil-air equilibrium status was investigated forvarious soil categories in Central and Southern Europe using an extensive database of coupled soil and time-integrated air samples. Samples were collected from 47 sites over a period of 5 months to assess both site-specific as well as seasonal variations in fugacity fractions, calculated as a potential measure of soil-air exchange. Sampling sites were carefully selected to represent a variety of background, rural, urban, and industrial areas. Special attention was given to sites in the former Yugoslavia, a country affected by recent conflicts, where soils were found to be highly contaminated with polychlorinated biphenyls (PCBs). Industrial soils from the Czech Republic, heavily polluted as a result of previous pesticide production, were also included in the survey. Soil was found to be a sink for highly chlorinated PCBs and for dichlorodiphenyltrichloroethane (DDT); for dichlorodiphenyldichloroethylene (DDE), the status was closer to equilibrium, with a tendency for net deposition during winter and net volatilization during summer. For lower-molecular-weight PCB congeners, as well as for alpha-HCH, soil tends to be a source of pollution to the air, especially, but not exclusively, during summer. Fugacity fractions were found to decrease during the colder seasons, especially for the more volatile compounds, although in both the war-damaged areas and the heavily contaminated industrial sites, seasonal variability was very low, with fugacity fractions close to 1, indicating strong net soil-to-air transfer for all seasons. The original assumption that residents of the Western Balkans are still exposed to higher levels of PCBs due to the recent wars was confirmed. In general, the soil-air transfer of PCBs and organochlorine pesticides was found to be site-specific and dependent on the physicochemical properties of the contaminant in question, the soil properties, the historical contamination record and a site's vicinity to sources, and the local meteorological conditions.     

An assessment of rootstocks for Sunmuscat (Vitis vinifera L.): a new drying variety

Sunmuscat scions, either grafted onto one of seven rootstock, or as own-rooted vines, were grown under irrigation according to the practices of warm-climate viticulture in north-western Victoria. The trial was located within a commercial vineyard on a sandy loam soil, and represented a typical replant situation. Grapevine performance was assessed over five seasons, viz. 1999–2004 inclusive, in terms of yield per vine, berry weight, juice composition and vigour (based on trunk girth). The highest yielding rootstock over the trial period was 1103 Paulsen (28.9 kg /vine) followed by 140 Ruggeri and Ramsey (26.1 and 25.8 kg /vine respectively), S04 (22.5 kg /vine), Schwarzmann, 101-14 and Teleki 5A (19.9, 18.7 and 18.4 kg /vine respectively). Scions on their own roots returned lowest yield (15.5 kg /vine). Berry weights were largest for the three high yielding rootstocks (2.3 g) and smallest with own roots (2.0 g). Total soluble sugars in harvested fruit were largely unaffected by rootstock in most seasons, although taken over all seasons, fruit from scions grafted onto Ramsey rootstock had the lowest levels, while Teleki 5A had the highest levels (viz. 23.4^oBrix and 24.7^oBrix respectively). Comparative vigour for all seven graft combinations was inferred from trunk circumference. There was a 2-fold difference in rootstock girth below the graft union (viz. 265 mm for 1103 Paulsen, compared to 135 mm for S04), whereas differences in the scion girth above the graft union were minor (only 16%). Relative compatibility of scion and stock was inferred from 'girth ratio' of trunk circumference above compared with below the graft union. Girth ratio was highest for Sunmuscat scions grafted onto SO4 rootstock, and lowest for scions on 1103 Paulsen. Scion girth and vine yield were broadly correlated.     

Vineyard variability in Marlborough,New Zealand: characterising variation in vineyard performance and options for the implementation of Precision Viticulture

Background and Aims: Vineyards are variable. However, to date, no spatial analysis of vineyard variability has been conducted in New Zealand. We were interested to quantify variability in a Marlborough vineyard and to produce a spatial platform onto which modelled information on phenology and juice composition could be integrated. Methods and Results: A combination of remote and proximal sensing of vine vigour, direct measurement of trunk circumference, yield mapping and high resolution electromagnetic induction (EM38) soil survey was used to examine vineyard variability in a 5.9 ha Marlborough vineyard planted to Vitis vinifera L. cv. Sauvignon Blanc. Yield variation was little more than twofold, in spite of substantial variation in vine vigour which was associated with variation in the land (soil, topography) underlying the vineyard. Conclusions: A focus on tools that facilitate enumeration of variation in vine vigour may offer the greatest value to Marlborough practitioners interested in adopting Precision Viticulture approaches to grapegrowing and winemaking. EM38 soil survey appeared to be useful for describing vineyard soil variation, but because the soils that predominate over the alluvial Wairau Plains in Marlborough are shallow and stony, very low values of apparent electrical conductivity (ECa) over a narrow range were observed. However, ECa was closely correlated with trunk circumference, an index of vine vigour. In contrast to Australian studies, neither ECa, plant cell density (derived from remotely sensed imagery) nor trunk circumference were good predictors of grapevine yield. It is hypothesised that this is largely a reflection of differences in vine training systems (hand cane pruning in Marlborough vs mechanical pruning in Australia) and the greater degree of selection of buds when vines are hand pruned. Significance of the Study: This is the first such study conducted in New Zealand and provides results that contrast with similar studies conducted in Australia. Nevertheless, the maps produced are expected to provide a valuable platform for a follow‐up study aimed at understanding spatial variation in vine phenology and juice composition. The study also highlighted the power of kriging as a means of interpolating useful vineyard maps from relatively sparse, unevenly distributed sampling data.     

Spatial and seasonal variations of Hexachlorocyclohexanes (HCHs) and hexachlorobenzene (HCB) in the Arctic atmosphere

Weekly high-volume air samples were collected between 2000 and 2003 at six Arctic sites, i.e., Alert, Kinngait, and Little Fox Lake (LFL) in Canada, Point Barrow in Alaska, Valkarkai in Russia, and Zeppelin in Norway. Hexachlorocyclohexanes (HCHs) and hexachlorobenzene (HCB) were quantified in all samples. Comparison showed that alpha-HCH and HCB were homogeneously distributed in the circumpolar atmosphere and uniform throughout the seasons. However, significantly higher atmospheric concentrations of alpha-HCH and HCB and strongertemperature dependence of alpha-HCH and gamma-HCH were found at LFL in Yukon (YK), which is unique among the sites by virtue of its high altitude and low latitude, resulting in higher precipitation rates and summer temperatures. Strong temperature dependence of alpha- and gamma-HCH at this location suggests that secondary emissions, i.e., re-evaporation from surfaces, were more important at this site than others. It is hypothesized that a higher precipitation rate at LFL facilitated the transfer of alpha-HCH from the atmosphere to surface media when technical HCH was still in use worldwide. On the other hand, higher temperature at LFL enhanced reevaporation to the atmosphere after the global ban of technical HCH. In contrast to alpha-HCH and HCB, larger spatial and seasonal differences were seen for gamma-HCH (a currently used pesticide), which likely reflect the influence of different primary contaminant sources on different Arctic locations. Fugacity ratios suggest a net deposition potential of HCB from air to seawater, whereas seawater/air exchange direction of alpha-HCH varies in the circumpolar environment.     

Meta-analysis of the effect of initial serum protein concentration and empirical prediction model for growth of neonatal Holstein calves through 8 weeks of age

A data set was constructed from individual calf means gathered in the Nurture Research Center (Lewisburg, OH) and used in a meta-analysis to parameterize an empirical model predicting growth measures for neonatal calves. The data set contained 993 observations from 20 research trials conducted in all seasons of multiple years. Growth measures gathered included average daily gain (ADG) preweaning, postweaning, and through 8 wk of age. Independent variables gathered included age at weaning; total starter intake (SI); total milk replacer intake (MRI); milk replacer CP (MRCP) and fat (MRfat) contents; number of days with abnormal fecal scores (AFS); average environmental temperature preweaning, postweaning, and through 8 wk of age; minimum and maximum temperature during the entire 8 wk; body weight at d 0; and initial serum protein concentration. Additionally, the interactions of SI, MRI, and MRCP and MRfat were considered for the model. Backward elimination multiple regressions were conducted using a mixed model with a random effect of trial. The final model for total ADG indicated that increasing SI or MRI improves calf growth. Also, increasing MRCP or MRfat increased growth. Increased sickness (as measured by increased AFS) or increased body weight at d 0 decreased ADG. Growth of neonatal dairy calves appears to be more controlled by nutrient intake and their interactions than by surrogates for health status of the calves (AFS and initial serum protein concentration) or environmental temperature.     

Impacts of lindane usage in the Canadian prairies on the Great Lakes ecosystem. 1. Coupled atmospheric transport model and modeled concentrations in air and soil

A coupled atmospheric transport, soil-air, water-air exchange model was developed to investigate the impacts of gamma-hexachlorocyclohexane (gamma-HCH or lindane) usage in the Canadian prairies over the Great Lakes region. The fate of gamma-HCH in air and soil is governed by atmospheric dynamics and physical and chemical processes that are described by the coupled model. These processes include transport and turbulent diffusion in the atmosphere, dry and wet deposition, exchange at the interfacial boundaries of air-water and soil-air, and removal processes from the soil such as diffusion, leaching, and degradation. Numerical experiments were conducted for the period of May 1, 1998-April 30, 1999, starting with application of lindane in the spring. The coupled model was executed with two lindane emission (usage) inventories in the model domain. The first scenario contained all known fresh emission sources in Canada-98% was usage in the prairies; the second excluded emission sources from Ontario and Quebec. The model showed that, in the absence of the reemission from past application of lindane, usage of lindane in Ontario and Quebec has a negligible impact on air concentrations in these regions and that the lindane budget in the Great Lakes ecosystem is mostly attributed to applications of lindane in the canola fields in Canadian prairie provinces. Model-predicted air concentrations and seasonal trends agreed well with measured data over the same time period for several background sites operated under the Integrated Atmospheric Deposition Network. Air temperature was shown to play a key role on surface-air exchange dynamics of gamma-HCH. A future paper will assess loadings to the Great Lakes based on these validated model results.     

Developmental variation in sensitivity of Vitis vinifera L. (Shiraz) berries to soil water deficit

A large-scale, long-term irrigation experiment was established near Waikerie in the South Australian Riverland to investigate the feasibility of controlling berry size and ripening at the vineyard scale with modern irrigation systems. Irrigation treatments were devised to impose water stress, by withholding irrigation, during four periods of berry development after flowering of Vitis vinifera (variety Shiraz). Varying water deficits were achieved during each period and between the four seasons, which were climatically diverse. In one season water deficit during the period after flowering resulted in the greatest reduction in berry weight compared with that of well-watered vines, however, in another, water deficit during this period had no effect on berry weight. By comparison, berries appeared to be insensitive to water deficit during the month before harvest in all four seasons. A soil water deficit index was derived to compare the varying levels of water deficit between treatments and seasons on berry development. Deficit effects on berry development were assessed using either comparative growth rate or berry weight near harvest. Regression analysis of berry development against soil water deficit indicated that berries were most sensitive to water stress during the post flowering period.     

Spatio‐temporal dynamics of grape anthocyanin accumulation in a Tempranillo vineyard monitored by proximal sensing

Background and Aims: The spatio‐temporal variability of phenol grape composition in a vineyard can be characterised by using precision viticulture tools. Characterising anthocyanin variation in grapes requires a large number of observations, which can be done by using proximal sensors in the field. This study characterises the dynamics of spatial‐temporal variability in fruit anthocyanin content at different stages from veraison to harvest using a newly available non‐destructive fluorescence method. Methods and Results: The study was conducted in a Tempranillo (Vitis vinifera L.) vineyard (Navarra, Spain) during the 2010 season. A handheld, non‐destructive fluorescence‐based proximal sensor was used to monitor the anthocyanins of the berries at six different times between veraison and harvest. The fluorescence‐based anthocyanin indices were significantly correlated with the anthocyanin contents in berries (R² ranged from 0.74 to 0.78). The variability of the anthocyanin content decreased during the ripening period, reaching a minimum at harvest. Although the mean anthocyanin content of fruit increased from veraison until mid‐September, when a fairly stable value was reached that remained constant until harvest, spatial patterns within the vineyard changed over the whole ripening period. The spatial correlations between the anthocyanin content at each monitoring date and harvest time revealed that larger similarities in the spatial distribution of anthocyanins occurred at veraison and 10 days before harvest. Conclusions: Grape anthocyanins accumulated from veraison until around 1 month before harvest, whereas their spatial pattern within the vineyard changed throughout the whole ripening period. Significance of the Study: Knowledge of the spatial‐temporal variation of the anthocyanin content within a vineyard may assist decision making regarding sampling and vineyard management, especially if vineyard segmentation is employed.     

Models of growing season weather impacts on breadmaking quality of spring wheat from producer fields in western Canada

BACKGROUND: The purpose of this study was to quantify growing season weather and wheat quality at individual producer fields to understand weather impacts and develop weather‐based models of spring wheat quality. RESULTS: Ninety‐six hard red spring wheat samples of two genotypes supplied by western Canadian producers in 2003 and 2004 underwent comprehensive analysis for breadmaking quality. For each individual field, daily rainfall, maximum and minimum air temperature were observed and used to calculate several measures of heat. Modeled water use, demand and stress were also calculated and all weather variables were accumulated over different phenological stages. Relationships between weather variables and wheat quality variables were determined by multivariate regression analysis separated into four steps, each adding more complex information into the models. There was substantial variation in weather conditions and wheat quality between years with generally higher quality and stronger dough in the warmer and drier year, 2003. The two genotypes displayed many differences in response to the environment. Prediction of wheat quality improved with increasing complexity of weather models and close to 50% of the variation in quality could be explained by multivariate models. CONCLUSIONS: Results showed that even for top‐grade milling wheat of similar protein content, significant differences exist in breadmaking quality of wheat from different farms. The improvement in r² when using modeled environmental variables indicates that crop water use and water stress are important for wheat quality. The development of Canada Western Red Spring quality prediction models for western Canada based on growing season weather shows promise. Copyright © 2008 Society of Chemical Industry     

Grapevine dormant pruning weight prediction using remotely sensed data

Aerial image analysis was utilised to predict dormant pruning weights between two growing seasons. We utilised an existing in-row spacing trial in order to examine the relationship between dormant pruning weights and remotely sensed data. The experimental vineyard had a constant between-row spacing (2.44 m) and five different in-row spacings (0.91, 1.52, 2.13, 2.74 and 3.35 m) resulting in spatial variation in canopy volume and dormant pruning weights (kg/metre of row). It was shown that the ratio vegetation index (NIR/R) was linearly correlated with field-wide measurements of pruning weight density (dormant pruning weight per metre of canopy) for both the 1998 and 1999 growing seasons (r²= 0.68 and 0.88, respectively). Additionally, it was shown that the regression parameters remained consistent between the two growing seasons allowing for an inter-annual comparison such that the vegetation index vs canopy parameter relationship determined for the 1998 growing season was used to predict field-wide pruning weight densities in the 1999 growing season prior to harvest.