Winter Pruning Research Articles

Responses of shoot growth, return flowering, and fruit yield to post-pruning practices and growth regulator application in olive trees

Winter mechanical hedge pruning of olive trees can result in a strong post-pruning shoot growth response and a low return flowering intensity the following year. However, post-pruning practices including tip heading, watersprout thinning, and the application of the growth inhibitor mepiquat chloride (MC) may positively reduce subsequent vegetative growth and promote flowering. Two experiments were carried out with the aim of addressing the following questions: (1) Do these post-pruning practices applied on trees that received simulated mechanical pruning during the winter reduce growth and increase flowering in the spring of the following year?; and (2) What is the optimal MC dose in unpruned trees needed to increase flowering the following spring? In the first experiment, five-year-old olive trees (cv. Arbequina) growing in a fairly low density orchard (208 trees ha−1) were hedge pruned at the end of winter using manual clippers on the east and west sides to simulate mechanical disk pruning, and the post-pruning treatments were applied at the pit hardening stage (early summer). In the second experiment, foliar or soil application of MC was performed at pit hardening in unpruned trees. The results show that tip heading of new shoots led to a large number of lateral shoots that flowered little, or not at all, the following spring. In contrast, the watersprout thinning treatment had sufficient flowering to significantly increase fruit number and yield the following year compared to tip heading. Foliar application of MC (1500 ppm) after winter pruning did not inhibit new shoot growth, return flowering was low, and yield was less than the watersprout thinning treatment. The lack of a post-pruning response to foliar MC was likely related to the dose used (1500 ppm). In the second experiment, a foliar application of MC at 3000 ppm was associated with greater return flowering and yield than an untreated control. In conclusion, thinning of vigorous watersprouts at the pit hardening stage three months after simulated winter mechanical hedge pruning can improve fruit number and yield the next year, especially on a per canopy volume basis. Furthermore, the responses to foliar MC application in unpruned trees suggest that more detailed post-pruning studies with MC application doses in the 2000–3000 ppm range and at additional phenological stages should be performed over several consecutive years to assess whether this practice could be a suitable management tool.

Potential of vermicompost and limestone in reducing copper toxicity in young grapevines grown in Cu-contaminated vineyard soil

Foliar fungicide application in grapevines increases the content of heavy metals such as copper (Cu) in vineyard soils, which may reach phytotoxic levels. The application of soil amendments such as limestone and vermicompost may reduce Cu availability and phytotoxicity. The study aimed to assess growth, physiological status and changes in root morphology in young grapevines grown for 12 months in Cu-contaminated soil with and without the application of soil amendments. Samples of a Typic Hapludalf soil were collected in a vineyard with more than 30 years of cultivation. The following treatments were used: 1) control (without amendment), 2) application of organic vermicompost (86.7 g kg−1) and 3) application of limestone (3 Mg ha−1). Grapevines (Paulsen 1103 rootstock) were transplanted and grown for 12 months in PVC soil columns. We assessed parameters of growth, photosynthesis and root morphology. Grapevines grown in soil treated with limestone showed increased growth, dry matter yield and photosynthetic efficiency. The highest Cu concentrations in root tissue were found in grapevines grown in control soil. The application of vermicompost in this study did not alleviate Cu toxicity. Grapevines grown in soil treated with vermicompost showed high manganese (Mn) concentration in shoots before the winter pruning, reflecting the high Mn concentrations in soil solution that caused Mn phytotoxicity, resulting in plant death after the winter pruning. The vermicompost used in this study is not suitable for agronomic use. The use of limestone was an effective strategy to reduce Cu availability and phytotoxicity.

Response of four Portuguese grapevine cultivars to infection by Phaeomoniella chlamydospora

Little is known of the response of Portuguese Dao wine appellation’s most common grapevine cultivars to the causal agents of esca and Petri diseases, despite the high incidence of both diseases in the region and the consequent economic losses. Phaeomoniella chlamydospora has been considered one of the major causal agents of these diseases in that region. The present study evaluated the responses of four of the most propagated Dao’s grapevine cultivars – Alfrocheiro, Aragonez, Jaen and Touriga Nacional – to infection by three different Portuguese isolates of P. chlamydospora . Field trials were conducted in 2012, 2013 and 2015. The cultivar Alfrocheiro was the most susceptible to P. chlamydospora while cv. Jaen was the least. Variation in parameters such as lesion length and pathogen recovery from infected spurs (within trial years) suggest relation of pathogenicity with weather data, particularly temperature. Differences in aggressiveness among isolates were also detected, with one, a non-native, being the most aggressive. These results provide valuable information for local winegrowers, identifying, for the first time, susceptibility differences among local cultivars to P. chlamydospora , and suggesting adjustments to recommended pruning strategies, specifically to leave long spurs and avoid late winter pruning, thus reducing grapevine trunk colonization by P. chlamydospora.

Impact of delayed winter pruning on phenology and ripening kinetics of Pinot Noir grapevines

Climate change impacts viticulture with even stronger effects on sparkling wines. Innovative cultural practices represent effective short-term solutions. Among these, postponement of winter pruning later than budburst delayed both vegetative and reproductive cycles as well as technological maturity of several varieties from different wine regions. This research aims to assess the impact of delayed winter pruning on grapevine performance as a function of training system.The trial was carried out in a Pinot Noir vineyard sited at 385 m asl in Central Italy. Delayed winter pruning was performed when unpruned canes had shoots showing three unfolded leaves (BBCH 13) and compared to standard winter pruning within two separate experiments focused on: i) cane pruning, and ii) spur pruning. Grapevine phenology, vegetative growth, fruit ripening kinetics and productivity of selected vines were assessed over three years. Delayed winter pruning postponed budburst by 20 and 31 days in Guyot and spur pruned cordons, respectively; then, differences diminished over time showing a maximum delay of 17 days at bloom and 7–10 days at harvest. Despite a decrease in yield (ranging from −35 to −47% in cane and spur pruning, respectively), delayed winter pruning increased titratable acidity (40–89%) and reduced sugars (721%) as compared to control vines. Although effects of delayed pruning were stronger in spur pruned vines, delayed winter pruning was effective also on cane-pruned vines, therefore adapting to varieties marked by low basal-node fruitfulness

Standardization of pruning for high density Sardar guava orchards under hot and humid climate of Eastern India

Response of guava to three levels of winter and summer pruning (30, 50 and 70%) was studied in a trial conducted during 2014–16 on eight-year-old guava plants spaced at 2.5 m × 1.25 m. In general, pruning encouraged shoot emergence, irrespective of time and intensity, however, winter pruning resulted in production of more shoots or laterals (27.02 ± 3.85 shoots/m of branch) as compared to treatments of summer pruning (14.55 ± 3.3). Shoot emergence increased with the severity of pruning. Shoot pruning during winters was found effective in enhancing flowering intensity (38.58 ± 4.25%), fruit set (73.68 ± 0.48%) and fruit yield (6.12 ± 1.13 kg/plant), whereas, summer pruning did not show significant influence on these parameters. Among three treatments of winter pruning, 70% shoot pruning was the best treatment and recorded the maximum values for flowering intensity (42.83%), fruit set (74.15%) and fruit yield (7.25 kg/plant or 23.2 t/ha). The same treatment recorded the highest cumulative yield of rainy and winter season (8.65 kg/plant or 27.68 t/ha) as well. With respect to fruit quality, all the pruning treatments recorded significant improvement in total soluble solids and vitamin C contents for both rainy and winter season crops over the control. However, differences remained at par among all the pruning treatments. The treatment 70% shoot pruning during summer yielded fruits with maximum TSS and vitamin C content in both the crops i.e., rainy and winter season. Thus, it can be concluded that under hot and humid climate of Odisha, high density guava orchards could be pruned during winters at 70% intensity to realise high yield potential of guava in the region.

Combined influence of bud load and bud position along the cane on vegetative and reproductive parameters of grape cv. Grillo

Cultivar Grillo vines are characterized by problems with flower biology (the fertility of basal buds) and fructification (millerandage). In this study, to manage the variability in bunch weight with winter pruning and to program others canopy management practices (i.e. early defoliation), three different treatments of bud load were set up by leaving the cane with 3, 6 or 10 buds. The effects of bud load and cane length were studies regarding bud fertility, shoot leaf area, and the number of flowers and berries, as well as the relationship between leaf area and percentage of fruit set, leaf area/flower and percentage of fruit set, and the number of hens and chicks berries. Shoots in the distal position had higher values of fertility and inflorescences with a greater number of flowers, while no ‘apical’ effect of the buds emerged. A good relationship was found between fruit set and the number of flowers, leaf area at flowering and yield, and square centimeters/flower and percentage of fruit set. Cane length was found to be a valid tool for managing bunch weight variability; the value of the leaf area/flower can be used to program early defoliation practice carried out to manage berry set.

Effects of delayed winter pruning on vine performance and grape composition in cv. Merlot

Delaying winter pruning until after budburst is a technique that can retard vine phenological phases and reduce grape sugar concentration at harvest. Given these characteristics, many studies have recently been conducted to verify the ability of pruning after budburst to contrast the negative effects of climate change. In our trial, vines of the cv. Merlot, trained to a VSP spur pruned cordon, were pre-pruned leaving 8 nodes per shoot and hand finished when the shoots sprouted by the apical nodes were at BBCH13 (treatment LP) and BBCH18 stage (treatment VLP). Vines refinished during winter were used as control (WP). Anthocyanins and tannins of skin and seeds were analysed after both exhaustive extraction (total content) and extraction conducted with a hydroalcoholic solution (extractable portion). Vines refinished after budburst showed reduced leaf area, yield, cluster and berry weights; technological maturity of these vines was delayed as lower sugar concentration and pH were observed at harvest. Treatment VLP had a stronger effect than LP on these parameters. Considering phenolic compounds, the skin and seed tannin concentration increased only in VLP, while no effect was found on anthocyanins. In conclusion, delaying pruning until after budburst revealed interesting prospects for contrasting the negative effects of climate change.

Management of pruning and evaluation in blackberry cultivars in relation to productive characteristics and bioactive compounds.

The goal of this work was to evaluate blackberry cultivars in terms of productivity and bioactive compounds. Two experiments were conducted: in the first experiment four cultivars were evaluated (Cherokee, Guarani, BRS-Tupy and Xavante). In the second experiment, the effects of pruning management in the BRS-Tupy cultivar were evaluated with the following treatments: drastic winter pruning (zero primocane), and maintenance of two, three or four primocanes in the winter pruning. Vegetative, productive and fruit quality characteristics were determined, including measurement of bioactive compounds. Among the cultivars, the cultivar BRS-Tupy was superior in terms of productive characteristics, but for content of anthocyanins and flavonoids, the cultivar Xavante stood out (191.97 and 68.44 mg 100 g-1, respectively). Drastic winter pruning produced lower fruit quality. The number of primocanes has a directly proportional influence on the soluble solids content and productivity component. For farmers who want fruits with greater levels of bioactive compounds, the use of cultivar Xavante is recommended; however, for those who aim for productive aspects, we suggest the use of cultivar BRS-Tupy with four primocanes per plant.

Grape harvesting periods based on degree-days in Paraná state, Brazil

Grape harvesting period can be decisive for greater profitability to vine growers and for production quality. Thus, the objective of this work was to evaluate grape harvesting periods based on degree-days (DD) during different pruning periods, and under the risk of frosts in the State of Paraná. Based on a series of maximum and minimum temperatures data from 21 conventional stations managed by IAPAR, from 1976 to 2010, this study evaluated the risk of frosts and the degree-days required to complete each cycle in several regions of the state. Results showed that the occurrence of frosts is a restrictive factor for vine crops pruning in regions with higher altitudes and latitudes. For cultivars with low degree-days needs, results showed that in the Northeast of the state harvest could occur from the second ten-day-period of September, with winter pruning by July 5, making the commercialization during periods of less grapes offer. In this same region, cultivars with more needs of degree-days could be harvested between the first and second ten-day period of November. For the Central, Southern and Eastern regions, the risk of frosts in the month of July is high and pruning may result in cold damages to new shoots and vines. Therefore, harvesting must occur from January to May in these regions.

Optimising vine management to increase yields and improve quality of Zespri® SunGold kiwifruit (Actinidia chinensis var. chinensis ‘Zesy002’)

When summer pruning kiwifruit vines, the objective is to grow the required wood types to produce next season’s crop. The main task when winter pruning is to remove excess wood, retaining only the required number of winter buds to be able to produce the desired crop load and fruit size profile for the next season. As a general principle, it is better to select and grow smaller-diameter fruiting wood (canes) during summer, because these require less pruning, which will result in improvements in fruit yield and quality. This principle was tested with the new gold-fleshed Actinidia chinensis var. chinensis ‘Zesy002’ (marketed as Zespri® SunGold kiwifruit). Two sets of vines with either relatively small or large average cane diameters (12.7 and 13.7 mm, respectively) were established in a replicated block design, during summer pruning in year 1. Winter bud and flower numbers were adjusted on these vines in years 2 and 3 to produce vines with either standard or high crop loads. In year 2, vines with small canes and high crop load produced the equivalent of 95.0 t ha‑1 (26,394 class I trays ha‑1) compared with 77.4 t ha‑1 on vines with a standard crop load. Large cane vines produced 91.4 and 84.8 t ha‑1 on high and standard crop-load vines, respectively. Average fruit dry matter (DM) was 18.0 and 18.5% on vines with high and standard crop load, respectively. In year 3, following a mild winter, vines produced fewer flowers per winter bud than in previous years, especially on the small cane/high crop load vines. These vines produced just 75.8 t ha‑1 in year 3, a yield reduction of 20.2% compared with the previous season. Large cane/high crop load vines produced 83.8 t ha‑1 in year 3, a reduction of 8.3%. This study confirms that even relatively small changes in average cane diameter can have a significant impact on the ability of ‘Zesy002’ kiwifruit vines to produce consistently high yields.

Root pruning enhances wheat yield, harvest index and water-use efficiency in semiarid area

Improved management practices are necessary to increase grain yield and water-use efficiency of rainfed winter wheat in semiarid environments. Yield and its components, evapotranspiration, and accumulation and apparent remobilisation of stem water soluble carbohydrates (WSC) were measured to understand the effects of root pruning and its interactions with seeding rate, water and nitrogen supply. Two factorial studies under straw mulching with continuous wheat were established in the Loess Plateau of China. Study 1 was repeated over four seasons and included six treatments from the combination of three root treatments, i.e. root pruning in winter before dormancy (RPw), root pruning at the re-green stage in spring (RPs) and untreated control (CK), and two seeding rates. Study 2 was repeated over three seasons and included twelve treatments from the combination of two root treatments (RPs and CK), two nitrogen rates and three pre-sowing soil water levels. Yield ranged from 2571 to 7722 kg ha−1, harvest index from 0.28 to 0.56, and water-use efficiency from 5 to 20 kg ha−1 mm−1. Root pruning improved grain yield, harvest index and water-use efficiency by 6–11% across environmental conditions. Grain yield increased more (i) by pruning roots in spring than in winter, (ii) in high plant density than in low plant density crops, and (iii) in low-yielding conditions. It is concluded that spring root pruning is a viable option to improve wheat yield and water use efficiency under straw mulching in semiarid environment.

Nitrogen Distribution in Annual Growth of 'Italia' Table Grape Vines.

Little information is available about nitrogen (N) content and its concentration in table grape vines. Knowledge of the quantity of N accumulated by the vine organs during the season could support sustainable fertilization programs for table grape vineyards. The aim of the present study was to determine the N content and its concentration in different annual organs, including summer and winter pruning materials, clusters at harvest, and fallen leaves at post-harvest. Specifically, biomass and N were analyzed at six phenological growth stages (flowering, berry-set, berry growth, veraison, ripening, and harvest) from 2012 to 2015. Nitrogen concentration was highest (>40 g/kg d.w.) in the leaves of the secondary shoots at flowering, whereas values >30 g/kg were measured in the leaves of the primary shoots. Nitrogen concentration in the clusters at harvest was 5.3–7.6 g/kg with an accumulation of 18.6–25.4 g/vine in the seasons. The decrease of N content in the primary leaves after flowering indicated a remobilization toward the clusters, which acted as a stronger sink. Later in the season (veraison-ripening), leaves translocated N to permanent organs and primary stems. Pruned wood and fallen leaves accounted for the largest N removal from the vine after clusters, 6.0–7.9 and 9.2–10.2 g/vine, respectively. With regard of the vine annual biomass, the growth followed a sigmoidal model reaching 7300–7500 g of d.w./vine at harvest. Vine leaf area, including both primary and secondary leaves, peaked at veraison (17–21 m2). Vines accumulated ≅35 g/vine of N at harvest, not considering the N removed with the intense summer pruning practices (≅7 g/vine) and the fraction mobilized toward the storage organs (10–15 g/vine). The overall N required by the vine was around 50–55 g/vine, which corresponded to ≅80 kg of N/ha in a vineyard with 1500 vines and a yield of 40 t/ha. Summer and winter pruning practices removed 29–31 g/vine of N which will be partly available (to be considered in the fertilization schedule) for the vine in the successive years if pruned residues were incorporated and mineralized in the soil.

Cordon Renewal Strategies for Declining Merlot Grapevines

Summary Goals: Some of the older vineyards in Washington have been exposed to recurring winter freeze events. Over the years this has resulted in gradual vine decline and reduced yields, prompting growers to consider vine renewal or replanting strategies. Unlike vineyard replanting, successful cordon renewal may result in a full crop within one to two years. The purpose of this study was to evaluate the potential of four different cordon renewal strategies to revive an aging and declining, cordon-trained and spur-pruned Merlot (Vitis vinifera) vineyard. Key Findings: None of the cordon renewal strategies tested succeeded in restoring adequate vigor in these vines. However, retaining three short canes (five to eight buds each) per cordon increased three-year average and cumulative yields compared with cordon removal, disbudding, and standard spur pruning. Higher yields were mainly due to higher numbers of clusters as a result of higher numbers of fruitful shoots. Cordon removal and retraining led to more uniform recovery than the other strategies, but no yield during the first year and intermediate yields during the next two years made this strategy economically less attractive than the short-cane approach. Complete disbudding of the cordon to encourage renewal of spur positions resulted in yields that were no better than those obtained with continued standard spur pruning. Disbudding also led to bushy growth initially, which may increase the cost of canopy management during the first year. In the first year, the low-yielding disbudding treatment resulted in somewhat higher fruit sugar accumulation. Otherwise, fruit composition was similar in all four pruning treatments, and the slight differences that were occasionally observed were within the expected range of technological maturity for high quality fruit. Impact and Significance: A three-year pruning trial conducted in a declining, cordon-trained Merlot vineyard indicated that retaining three short canes (five to eight buds each) resulted in higher crop production than other winter pruning methods. Although adaptive pruning strategies may have some potential to delay the need for replanting in vineyards that have incurred cumulative cold injury, such strategies may be effective only in conjunction with other cultural practices that enable vines to maintain or regain sufficient shoot vigor.

Canopy management strategies to control yield and grape composition of Montepulciano grapevines

Background and Aims Higher temperature during the season is forcing growers in Central Italy to explore ways to reliably control vine yield and grape ripening, while maintaining grape composition. The most common approaches include altering winter pruning, shoot thinning (St), leaf removal and bunch thinning. These studies, however, rarely evaluated these practices in concert and over multiple seasons. Methods and Results From 2009 to 2013, five treatments were applied to Vitis vinifera L. cv. Montepulciano: winter pruning only (Wp, Control); Wp plus St; St plus pre-flowering defoliation (St + Dpa); St plus pre-veraison defoliation (St + Dpv); and St + Dpv plus bunch thinning (St + Dpv + Bt) applied prior to veraison. Effects on canopy architecture, yield, ripening and berry composition were measured. Compared to Wp, St, St + Dpv and St + Dpv + Bt treatments reduced leaf area and leaf layer number in the fruiting zone, while St + Dpv + Bt reduced yield. No treatment slowed ripening. The treatment St + Dpa reduced yield and the incidence of Botrytis cinerea, and improved fruit composition, but increased TSS in berries. All treatments were ceased after 2013 and the vines were pruned in winter only. The treatment St + Dpa imposed in 2013 had a strong carry-over effect on yield but not TSS in 2014. Conclusions Shoot thinning alone reduced canopy density but failed to reduce yield or improve fruit composition. Both the St + Dpv and St + Dpv + Ct treatments provided a more open fruit zone, had no effect on yield and increased TSS in fruit at harvest. Shoot thinning plus pre-flowering defoliation decreased yield and improved berry composition in a Mediterranean climate; however, given its observed carry-over effects on yield this approach should be applied only in alternate years, suggesting the need for further research exploring additional viticultural practices. Significance of the Study Despite some benefits of St, defoliation and bunch thinning on their own or even in concert, no combination tested was consistently effective for controlling vine yield and grape ripening, while maintaining grape composition.

Impact of simulated mechanical hedge pruning and wood age on new shoot demography and return flowering in olive trees

More vigorous watersprouts and fewer low vigor shoots form as wood age increases at the cutting points with greater canopy pruning depth in olive trees, which reduces return flowering. Such information is relevant to long-term olive orchard pruning strategies in hedgerows. Demographic analysis of growth responses to pruning in fruit trees seeks the quantification of the typology of new shoots originating from the remaining branches. Pruning of hedgerows using mechanical discs is becoming increasingly common in orchards, but little information is available as to how such pruning, which does not discriminate between branch size, wood age at the cutting point, branch type, or position, modifies subsequent new shoot demography. Hence, the experiment described in this study in young olive trees (cv. Arbequina) assessed the following questions: (1) Is the type and growth of new shoots associated with the intensity of mechanical pruning and/or the wood age on which they grow? (2) How many growing seasons does it take for new shoots formed after pruning to flower? The principal hypothesis was that a greater proportion of vigorous watersprouts form compared to low vigor shoots as wood age at the cutting points increases with canopy pruning depth, and that the watersprouts have low flowering potential. Both new shoot growth and return flowering were monitored on exposed supporting wood over several growing seasons after implementing three winter (25W, 50W, and 75W) pruning levels of increasing intensity and one summer pruning (75S) treatment along with an unpruned control (CON). As hypothesized, a greater number and elongation of vigorous watersprouts were found as wood age increased at the cutting points with greater winter pruning intensity, and the watersprouts had low levels of return flowering even 3 full years after pruning compared to the CON. Growth of low vigor shoots was relatively more important than watersprout growth in the severe summer pruning treatment, although 3 years after the summer pruning flowering was not fully recovered. In contrast, the more lightly pruned winter treatments (25W, 50W) did not show significant differences in flowering with the CON at the end of 3 years. Thus, mechanical hedge pruning in olive trees should be light-to-moderate to avoid the formation of watersprouts on older wood, which leads to long-term reductions in flowering.

RELATIVELY SAFE TREATMENTS (PARTIAL / COMPLETE COVERAGE SPRAY) FOR THE CONTROL OF SCOLYTUS AMYGDALI (COLEOPTERA: SCOLYTIDAE) IN APRICOT ORCHARDS IN EGYPT

Anew relatively safe and commercial partial/complete coverage spray to control Scolytus amygdali (Coleoptera: Scolytidae) in the apricot orchard (applied only twice instead of 6 current MOA recommended chemical treatments/season) at El- Kattatba district, (Menofia Governorate). Percentages reduction of infestation for the following 7 applications for one-year treatment (2015), two successive years (2015 and 2016), and three successive years (2015, 2016 and 2017) were, respectively, as follow: A: Horticultural treatments: 1) dormant winter pruning (27.73 increased to 34.87 then 38.88%), 2) summer pruning (15.06 increased to 17.65 then 19.24%), 3) dormant and summer pruning (34.06 increased to 39.50 then 45.69%). B: Chemical treatment: 4) MOA recommended chemical treatments (3 treatments during spring and 3 treatments during autumn) (80.57 increased to 85.08 then 89.58%), 5) new commercial partial/complete coverage chemical treatments (1 treatment during spring and 1 treatment during autumn) (61.35 increased to 71.01 then 79.16%). Third: Horticultural (winter and summer pruning as an additive control) together with chemical treatments: 6) pruning together with MOA recommended treatments resulted in 86.03% increased to 88.24% then 96.39%, and 7) pruning together with new partial/complete coverage treatment resulted in 68.78% increased to 78.15% then 91.78%. The new commercial and relatively safe partial/complete coverage chemical control eliminates the pesticide use (2 treatments insteat of 6) and reduces residues, prevent the outbreaks of secondary species, decrease the environmental pollution, encourage the role of the biological control agents and obtain better production of decontamination of fruits through using limited insecticides.

Delaying winter pruning, after pre-pruning, alters budburst, leaf area, photosynthesis, yield and berry composition in Sangiovese (Vitis viniferaL.)

Background and Aims Earlier ripening of grapes due to global warming could be mitigated by delaying hand pruning on pre-pruned canes. Hand pruning on pre-pruned vines was delayed until after distal buds on canes had burst for Sangiovese (Vitis vinifera L.) vines, and the effect on phenology, canopy development, leaf gas exchange, yield and berry development and composition was assessed. Methods and Results Pre-pruned vines, which were subsequently hand-pruned during winter, were compared to vines where hand pruning was delayed (DP) until shoots from distal nodes of canes had burst and developed 3–4 (DP3) or 7–8 (DP7) expanded leaves. Delayed pruning delayed budburst by about 30 days in DP3 vines and 37–47 days in DP7 vines, which led to a slowing of canopy development and berry growth. Veraison was delayed by between 10 and 20 days. Yield was substantially reduced by delaying hand pruning but the concentration of phenolic substances and the acidity of berries was increased. Conclusions Delaying hand pruning on vines that had already been pre-pruned delayed budburst, anthesis and veraison, reduced yield and significantly affected berry composition. The magnitude of these effects increased with the length of the pruning delay. Significance of the Study Delaying hand pruning on pre-pruned grapevines may represent a promising technique to mitigate against some of the deleterious effects of global warming in vineyards.

Spur pruning leads to distinctly different phenolic profiles of base sparkling wines than cane pruning.

Winter pruning is the principal method for regulating yield in viticulture. The aim of this work was to investigate the effectiveness of cane and spur pruning on yield, and on grape and wine composition. Cane and spur pruning were investigated in Vitis vinifera L. 'Pinot noir' and 'Chardonnay' vertically-shoot-positioned vines over three seasons. Effects on vine carbohydrates, yield components, leaf area, grape and base wine composition were determined. The canopies of spur pruned vines established more rapidly than cane pruned vines in the 2009/10 season, for both 'Pinot noir' and 'Chardonnay'. The canopies were denser under spur pruning than cane pruning. Pruning treatment had no effect on total yield for either cultivar in any of the three seasons. Total soluble solids (TSS) and titratable acidity were unaffected by pruning treatment, except in 2012 where TSS and pH were higher for spur pruned 'Chardonnay' vines. Apart from spur pruned 'Pinot noir' vine wood being higher in starch in the winter of 2011, overwintering starch and soluble sugar concentrations were not different between pruning treatments for 'Pinot noir' and 'Chardonnay'. Although not different in yield or basic fruit composition, fruit from spur pruned vines resulted in distinctly different phenolic profiles of base wines, with cane pruning appearing to negatively impact on the low molecular weight phenolics in the wine. The results presented here provide confidence that quality is not lessened, in fact could be improved, by shifting from the industry norm of cane to spur pruning for sparkling wine production in cool climates.

Influence of the pruning system on the growth and productivity of slender spindle apple trees

Slender spindle is currently the most widespread pruning system for apple trees in the Czech Republic. However, further modifications of this pruning system have been developed. In this study, two pruning systems were compared in the years 2012 to 2015: slender spindle and modified slender spindle (characterised by ‘click’ pruning). The pruning systems were validated on three varieties, using either winter pruning or winter pruning supplemented with late summer pruning in August. The studied parameters included the average length of annual shoots, increase of trunk cross-sectional area (ITCA), fruit yield per tree, specific yield, average fruit weight, number of fruits and their size in various parts of the tree crown, the number of interventions by pruning and the total weight of the removed biomass. There were no significant differences in most of the parameters mentioned above. Application of the ‘click’ pruning technique over several years significantly increased the number of cuttings but the total biomass removed was lower compared with traditional slender spindle.

Interactions of personal and occupational risk factors on hand grip strength of winter pruners

BackgroundWinter pruning is an important procedure to sustain the yield and quality of vineyards. Pruning shears are commonly used in this stage. Handling pruning shears may cause work-related musculoskeletal disorders (MSDs). Physical load on pruners at varying intensities and repetitive movements increase the risk of muscle strength and hand-wrist disorders. Grip strength (GS) is well accepted measure of muscle strength. The ambient temperature also affects pruners during winter pruning. PurposeThe purpose of this study was to determine the effects of different type of pruning shears, working ambient temperatures, work experiences of pruners, anthropometric values of the pruners and working hours on the GS values of professional pruners. MethodsThe study was conducted with the participation of professional volunteer pruners during winter pruning in Sultanas’ vineyards. The GS values determined from both hands of pruners in a group of rural workers (n = 18), was evaluated five different times during continuous 18 days of the pruning period. The GS values of pruners were measured using a digital hand dynamometer. The standard anthropometric measurement set was used to determine the anthropometric values of the pruners. ResultsThe average GS values of pruners’ the dominant and non-dominant hands were found to be 363 ± 89 N and 347 ± 86 N, respectively. Except working hours, all other parameters were found r-value and p-value” for correlation with GS. GS decreased with increased age (r = −0.473, p = 0.000). Furthermore, the effect of pruning shears on GS was statistically significant. For dominant hand, the highest GS was observed with the pruning shear with an anvil blade (386 ± 86 N); the lowest GS was observed with the pruning shear with a rotating lower handle (296 ± 55 N). Changes in the temperature of the work environment during a long pruning period had a significant effect on the GS values. The GS values increased with decreasing work environment temperature. ConclusionsGS values of the dominant hand had a greater value than that of the non-dominant hand which is reported in the literature. The study finding for anthropometric dimensions and GS values of pruners was significant. An adverse effect between work ambient temperature and GS values was revealed in winter pruners. GS values were not statistically significant, however, there was found slightly increasing and decreasing effects during the morning and afternoon hours, respectively. The type of the pruning shears affected the GS values. Relevance to industryIt is believed that the findings will inform ergonomists about the potential risk of MSDs during pruning. The results obtained in this study will contribute to ergonomic solutions in a new-product design, in particular choosing the more appropriate equipment to meet the needs of pruners.