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Background and Aims: Terpenes are volatile organic compounds that influence the composition of many winegrape cultivars. Terpene accumulation is variable between seasons and locations, influencing vintage composition. Crop load management (CLM) is a cultural practice utilised to improve grape composition; however, the impact of CLM on terpene biosynthesis and accumulation in winegrapes remains largely unknown. Methods and Results: Crop load management was applied to Gewürztraminer vines at two developmental stages: bunch closure [early (E)] and veraison [late (L)], and two crop loads: 50% removal [light crop (LC)] and 25% removal [medium crop (MC)] and compared to a Control [high crop (HC)] over three seasons. We considered early‐harvest (22.5°Brix in HC) and harvest (23.4°Brix in HC) dates. The LC treatments improved TSS at both harvests; however, LC‐E accelerated ripening compared to LC‐L. The concentration of total free terpenes was highest in LC‐E only at early‐harvest. Free α‐phellandrene, β‐citronellol, geranic acid, geraniol, myrcene and nerol dictated this pattern. Although LC‐E increased glycosylated geraniol at early‐harvest, the concentration of total glycosylated terpenes was not altered. The expression of four terpene synthase (TPS) genes was increased by LC‐E at early‐harvest. Conclusions: The LC‐E treatment accelerated technological maturity, and increased the expression of TPSs and free terpene accumulation at the early‐harvest stage. Significance of the Study: This work provides valuable insight into the capacity of CLM to modulate terpenes in aromatic winegrapes. [ABSTRACT FROM AUTHOR]

A greenhouse research was conducted to monitor lead (Pb) translocation dynamics in spinach (Spinacia oleracea L.) mediated by nickel (Ni) application. Each of the four levels of Pb (0, 100, 150, and 300 mg/kg) and Ni (0, 100, 150, and 300 mg/kg) was applied in different combinations in the pot experiment. A fully matured spinach crop was harvested and divided into biomass samples from the roots and above ground. ICP-OES was used to determine the concentrations of Pb and Ni in the samples. The increase in Pb application rate in soil resulted in a decrease in dry matter yield of plant roots and above-ground biomass, according to the findings. Pb accumulation was also found in significant amounts in roots and above-ground biomass. Pb was accumulated in greater quantities in the spinach roots than in the above-ground biomass. Pb uptake in spinach roots and above-ground biomass decreased when high dose of Ni was applied. The Ni application in spinach crop had a negative impact on various parameters of Pb uptake, including translocation factor, bioconcentration factor, translocation efficiency, and crop removal of Pb. Pb toxicity was reduced when higher doses of Ni (100 to 300 mg/kg) were applied to Pb-contaminated soil. The findings of this study could help researchers better understand how Pb and Ni interact, as well as how to treat soil that has been contaminated by industrial wastewater containing nickel and lead. [ABSTRACT FROM AUTHOR]

In order to quantify the reduction potential for nitrous oxide (N2O) release from arable soils through the removal of crop residues, we conducted an experiment after sugar beet (Beta vulgaris L.) harvest with three treatments: (i) ploughing of the crop residues (+CR:D), (ii) returning residues after ploughing on the surface (+CR:S), and (iii) removal of the residues and ploughing (−CR). N2O fluxes were measured over 120 days in south Germany. High positive correlations between N2O fluxes and the CO2 fluxes and soil nitrate contents suggested denitrification as the main N2O source. N2O emissions in +CR:D was higher than in +CR:S (2.39 versus 0.93 kg N2O−N ha−1 120 d−1 in +CR:D and +CR:S). Residue removal in −CR reduced the N2O emission compared to +CR:D by 95% and to +CR:S by 87%. We further conducted a meta-analysis on the effect of crop residue removal on N2O emissions, where we included 176 datasets from arable soils with mainly rain fed crops. The overall effect of residue removal showed a N2O reduction of 11%. The highest N2O reduction of 76% was calculated for the removal subgroup with C/N-ratio < 25. Neither the remaining C/N-ratio subgroups nor the grouping variables “tillage” or “residue quantity” differed within their subgroup.

The manipulation of grape yield is widely practised to improve grape and wine quality. Merlot and Cabernet Sauvignon vines in the Zagreb vineyard hills, north-western Croatia, were subjected to three crop removal treatments [cluster thinning (CT), berry thinning (BT), CT+BT, and untreated control] in a randomised block design experiment. CT and CT+BT treatments reduced the grape yield but increased the mean cluster weight compared to control vines. BT alone had a little effect on the yield components. Control grapes generally had the lowest soluble solids (°Oe) and highest titratable acidity (g/l). In most cases, control wines had the lowest total phenols, flavan-3-ols, and anthocyanin concentrations, while CT+BT treatment had the highest ones followed by CT treatment. It was concluded that CT+BT produced wines with generally increased total phenols, flavan-3-ols, and anthocyanins, as well as many individual phenolic compounds. Thus, grape yield per vine seems to be strongly connected with the grape and wine compositions. The final cost-effectiveness of this canopy interventions still remains questionable.

Aim: The research aims to determine if removing all bunches from alternate shoots had the same effect on berry maturity parameters of Sauvignon blanc as removing alternating bunches – apical versus basal – from each shoot. Methods and results: Shortly after fruit set, 50% crop was removed from four-cane vertical shoot positioned (VSP) pruned vines using the two different methods. At the same time, all the shoots were trimmed to six or 12 main leaves. Soluble solids (°Brix), pH, titratable acidity and berry weight were measured weekly from pre-veraison to harvest. Leaf area and yield were also measured at harvest. There were no differences in fruit composition between the two methods of crop removal. However, reducing leaf number per shoot from 12 to six leaves delayed veraison, reduced soluble solids accumulation and reduced berry weight with no additional effect from the thinning treatments. Conclusions: The thinning methods produced no differences in berry maturity parameters of Sauvignon blanc, indicating that carbohydrates can be readily translocated from shoots with no bunches to those with bunches. Significance and impact of the study: Carbohydrate translocation can occur at the whole-vine level where shoots behave as an integrated system and not as individual shoot units, especially under source-limited conditions.

Yield management is important subject in modern grape growing and winter pruning and cluster thinning treatments were used for yield control. Standard cluster thinning is generally labor intensive and expensive method and grape growers try to new methods, which are alternative to cluster thinning for reducing berry set. The goal of the present research was to investigate the effects of chemical thinning treatments such as ethephon (ETH), gibberellic acid (GA), naphthalene acetic acid (NAA) and non-chemical thinning treatments such as early leaf removal (ELR) and standard cluster thinning (SCT) on decreasing grape yield and enhancing berry composition of cv. Shiraz. In this study, percentages of berry set of cv. Shiraz were decreased by both chemical and non-chemical thinning treatments compared to Control. The results from these two different thinning methods shown certainly significant differences in berry composition of cv. Shiraz. Eventually, the best results in improved quality characteristics of cv. Shiraz were obtained from ELR treatment and treatments of ELR, ETH, GA NAA and SCT successively resulted in considerable enhancements in quality attributes of cv. Shiraz. [ABSTRACT FROM AUTHOR]

Background and Aims This study investigated: (i) the importance of changing the leaf area: fruit mass ratio ( LA : FM) by crop removal and/or shoot trimming on total soluble solids ( TSS) concentration and content, pH, titratable acidity ( TA) and berry mass; (ii) the extent to which changes in LA : FM ratio altered the synchrony TSS : TA ratio; and (iii) whether the responses were consistent for Pinot Noir and Sauvignon Blanc. Methods and Results Vertical shoot positioned-trained vines were trimmed shortly after fruitset or at veraison to six or 12 main leaves per shoot and crop thinned by removing 0, 50 or 75% of the bunches. TSS and pH, TA and fresh berry mass were measured weekly from pre-veraison to harvest. TSS concentration accumulation in berries was slowed with shoot trimming and accelerated by crop removal, with crop removal having a greater effect. Trimming shoots at fruitset in combination with no crop removal resulted in the greatest delay in veraison (the start of TSS accumulation) and slowest rate of TSS accumulation. TSS content mirrored TSS concentration for LA : FM manipulations at fruitset but fewer differences were detected for LA : FM changes at veraison. In contrast, TA and pH were largely unaffected. Conclusions Changes to the LA : FM ratio via crop removal or shoot trimming modified berry TSS accumulation but not TA. Such desynchronisation was consistent for both cultivars. Significance of the Study Crop and/or leaf removal represent valuable means to manipulate the time to achieve target fruit TSS concentration and TA. The similar responses of the two cultivars indicate that LA : FM manipulation could potentially have common responses for different cultivars. The desynchronisation of berry components highlights the need to consider each berry component individually and in a dynamic manner by sampling throughout the ripening phase. [ABSTRACT FROM AUTHOR]

Background and Aims The extent to which the carbohydrate source-sink ratio influences the time of veraison of different V itis vinifera L. cultivars was studied for Sauvignon Blanc and Pinot Noir. The aims were to: (i) determine how changing the leaf area: fruit mass ( LA : FM) ratio shortly after fruitset alters the timing of veraison; (ii) establish the relative importance of adjusting the vine yield or the leaf area on the timing of veraison; and (iii) evaluate the relative effect on the timing of veraison, leaf area and yield parameters of the two cultivars at similar LA : FM ratios. Methods and Results Four cane, vertical shoot positioned trained vines were trimmed shortly after fruitset to retain six or 12 leaves per shoot and thinned by removing 0, 50 or 75% of the bunches. The timing of veraison was assessed by colour change for Pinot Noir, berry softness for Sauvignon Blanc and the day at which a mean of 8° Brix was reached for both cultivars. Manipulating leaf area had a greater effect on the date of veraison than crop removal, which had no effect, except when vines were trimmed to six leaves. Sauvignon Blanc was always later than Pinot Noir for the time to reach 8° Brix at all LA : FM ratio manipulations. Conclusions Restricting potential carbohydrate sources post-flowering delayed veraison, while removing crop had less influence. Significance of the Study Reduced leaf area can delay the time of veraison, which could counter the earlier timing that could occur from climate change or warmer than average seasons. Conversely, increased leaf area could enable target soluble solids to be achieved in cooler seasons. [ABSTRACT FROM AUTHOR]

The manipulation of grape yield is widely practised to improve grape and wine quality. Merlot and Cabernet Sauvignon vines in the Zagreb vineyard hills, north-western Croatia, were subjected to three crop removal treatments [cluster thinning (CT), berry thinning (BT), CT+BT, and untreated control] in a randomised block design experiment. CT and CT+BT treatments reduced the grape yield but increased the mean cluster weight compared to control vines. BT alone had a little effect on the yield components. Control grapes generally had the lowest soluble solids (°Oe) and highest titratable acidity (g/l). In most cases, control wines had the lowest total phenols, flavan-3-ols, and anthocyanin concentrations, while CT+BT treatment had the highest ones followed by CT treatment. It was concluded that CT+BT produced wines with generally increased total phenols, flavan-3-ols, and anthocyanins, as well as many individual phenolic compounds. Thus, grape yield per vine seems to be strongly connected with the grape and wine compositions. The final cost-effectiveness of this canopy interventions still remains questionable. [ABSTRACT FROM AUTHOR]

Most fertilizer phosphorus (P) rate recommendations for the north-central United States are based on combination of a critical soil-test P value and a mass-balance calculation of fertilizer P required to maintain critical soil-test P. Accurate estimates of grain P removal are an essential component of P mass-balance calculation. Current north-central extension service guidelines recommend that estimates of corn and soybean grain P removal should be calculated using constant grain P concentrations. We reviewed research from the north-central region to determine the extent to which variation in grain P concentration accounts for differences in crop P removal and to determine whether predictions of grain P concentration can be improved through consideration of soil-test P, crop yield, and fertilizer P application. We found that soil-test P, grain yield, and fertilizer P are predictor variables that may significantly improve estimates of grain P concentration for corn and soybeans. [ABSTRACT FROM PUBLISHER]

A nitrogen balance for the southern San Joaquin Valley of California has been calculated, using techniques and methodology developed for the Upper Santa Ana River Basin of southern California. The two areas differed considerably in both size (the latter being much smaller) and agricultural function. Data were compiled on N inputs, use, and outputs for many sources within the study area. Such data enabled construction of a flow diagram depicting best estimates of N pools and fluxes within the San Joaquin Valley basin. Results show N inputs into the study area from various sources were somewhat greater than output to the atmosphere and by plant removal. Inputs to the soil N pool were about 9 kg/ha more in 1971 than in 1961. Since the soil N pool was estimated to be about 11 metric tons/ha, this represented an increase of about 0.1%. However, since the increases of N are not evenly distributed over the study area, high N concentrations can develop in some local areas. [ABSTRACT FROM AUTHOR]

In order to quantify the reduction potential for nitrous oxide (N2O) release from arable soils through the removal of crop residues, we conducted an experiment after sugar beet (Beta vulgaris L.) harvest with three treatments: (i) ploughing of the crop residues (+CR:D), (ii) returning residues after ploughing on the surface (+CR:S), and (iii) removal of the residues and ploughing (−CR). N2O fluxes were measured over 120 days in south Germany. High positive correlations between N2O fluxes and the CO2 fluxes and soil nitrate contents suggested denitrification as the main N2O source. N2O emissions in +CR:D was higher than in +CR:S (2.39 versus 0.93 kg N2O−N ha−1 120 d−1 in +CR:D and +CR:S). Residue removal in −CR reduced the N2O emission compared to +CR:D by 95% and to +CR:S by 87%. We further conducted a meta-analysis on the effect of crop residue removal on N2O emissions, where we included 176 datasets from arable soils with mainly rain fed crops. The overall effect of residue removal showed a N2O reduction of 11%. The highest N2O reduction of 76% was calculated for the removal subgroup with C/N-ratio < 25. Neither the remaining C/N-ratio subgroups nor the grouping variables "tillage" or "residue quantity" differed within their subgroup. [ABSTRACT FROM AUTHOR]