Search

Tropical peatlands are carbon-dense ecosystems that are significant sources of atmospheric methane (CH4). Recent work has demonstrated the importance of trees as an emission pathway for CH4 from the peat to the atmosphere. However, there remain questions over the processes of CH4 production in these systems and how they relate to substrate supply. Principally, these questions relate to the relative contribution of recent photosynthetically fixed carbon, released as root exudates, versus carbon substrate supply from the slowly decomposing peat matrix to CH4 emissions within these ecosystems. Here, we examined the role of root inputs in regulating CH4 production inferred from soil emissions using a combination of in situ tree girdling, in situ13C natural abundance labelling via stem injections, and a 13CO2 labelling of transplanted plants of two contrasting plant functional types, a broadleaved evergreen tree, and a canopy palm. Girdling of broadleaved evergreen trees reduced CH4 fluxes by up to 67%. Stem injections of trees and palms with a natural abundance label resulted in significant isotopic enrichment of CH4 fluxes, reinforcing the link between root carbon inputs and peat CH4 fluxes. Ex situ13CO2 labelling of plants resulted in significant 13C enrichment of peat CH4 fluxes. Taken together, our results demonstrate for the first time that plant root exudates make a substantial contribution to CH4 production in tropical peatlands. [ABSTRACT FROM AUTHOR]

Cultivation of acid lime (Citrus aurantifolia (Christm.) swingle) and lemon (Citrus limon L.) holds significant importance in India. Despite its economic importance, propagation faces challenges, primarily due to the recalcitrant nature of seeds, leading to loss of viability and lack of uniformity in seedlings. This necessitates the adoption of vegetative propagation method for producing true-to-type planting materials. Stem cuttings, budding and air layering are the primary methods employed, with stem cuttings being the most suitable for their simplicity and ability to induce precocity in fruit crops. The successful rooting of stem cuttings depends on the maturity of the cuttings, auxins, growing media, nutrition, irrigation water, endogenous food materials, season and microclimatic conditions. The maturity of cuttings influences rooting and uniformity, with virus-free hard, semi-hard, and softwood cuttings being preferred for propagation. The application of Indole Butyric Acid (IBA) significantly influences rooting. Cool season is generally favored for better rooting. Pre-conditioning treatments such as ringing, girdling and wounding influenced rooting. Microclimatic conditions, including temperature, relative humidity and light intensity, are critical for successful rooting. This review is a compilation of up-to-date research and development in stem cuttings of lime and lemon to understand better physiology, the role of auxins, growing media and microclimatic factors. [ABSTRACT FROM AUTHOR]

This research was carried out in 2022 and 2023 to determine the effects of different width and single-double girdling treatments on grape quality in different phenologic periods of 'Yalova Çekirdeksizi' grape variety grown in the 'Table Grape Varieties Application and Research Vineyard' located in the 'ÇOMÜ Dardanos Campus, Faculty of Agriculture, Plant Production Research and Application Unit'. Within the scope of the research, a total of 9 treatments, including the control, were carried out in two different phenologic periods pre-bloom and post-berry set, followed by two different widths of single repeated girdling treatments, and double repeated girdling treatments during the veraison period. As a result; the numeral decrease in yield in the 5 mm girdling treatments (4.33 kg grapevine-1) may be due to the removal of a wider bark+phloem layer, resulting in a later closure of the wound tissues compared to the 3 mm girdling treatments (4.95 kg grapevine-1), and thus a decrease in assimilate products stored in the main root and old parts. Therefore, it was concluded that although 5 mm girdling treatments continue to give positive results in terms of grape quality in many parameters, it is not appropriate to repeat them more than one year in terms of average yield. [ABSTRACT FROM AUTHOR]

Trees allocate carbon below‐ground to fuel the functioning of roots and mycorrhizal fungi, which affect litter decomposition, but the direction and magnitude of this effect are variable. While tree mycorrhizal type is often suggested to mediate this above‐ground–below‐ground linkage, previous studies yield mixed results. In this study, we investigated how absorptive root traits, soil conditions and litter type influence the response of litter decomposition to altered below‐ground carbon allocation, both within and across mycorrhizal types. We girdled transport roots of seven subtropical tree species to eliminate carbon allocation to distal absorptive roots. We monitored leaf and root litter decomposition surrounding girdled and un‐girdled root branches. We found that girdling generally slowed leaf litter decomposition. However, the effect of girdling on root litter decomposition depended on soil moisture, stimulating decomposition in dry soil but suppressing it in moist soil. Absorptive root traits did not influence the girdling effect on either leaf or root litter decomposition. These findings suggest that disturbance in carbon allocation can impact litter decomposition, with the outcome largely contingent on litter type and soil moisture. Synthesis. Our findings highlight the importance of accounting for local soil variability in understanding the relationship between above‐ground and below‐ground carbon dynamics. This study underscores a critical need for comprehensive assessment of below‐ground ecosystem responses to above‐ground disturbances, as it is essential for accurately predicting future forest carbon and nutrient cycles. [ABSTRACT FROM AUTHOR]

Fire damage can significantly impact fruit productivity in orchards. However, the effects of nonlethal fire injuries on the reproductive development of apple trees remain poorly understood. To investigate these effects, we implemented three treatments: trunk girdling to simulate fire injury to xylem, defoliation of a third of the canopy (simulated crown fire injury), and a combined treatment (simulated surface fire injury), alongside a control. The experiment was conducted during the 2021–22 growing season using a randomised block design with four biological replicate plots. Girdling was less effective than crown and surface fire treatments in influencing fruit composition during the current growing season, and flowering and fruiting in the following season. The crown and surface fire treatments induced localised detrimental effects on fruit sugar and titratable acidity while stimulating peel blush. Additionally, these treatments led to reduced starch reserves by harvest, which likely disrupted subsequent flowering and crop load near the previously defoliated sections of the canopy. When surface fires damage leaves near the base of the canopy in addition to the trunk, fruit production in the lower part of the canopy is more likely to be compromised in the following season. Crown fires, which cause leaf loss near the apex of the canopy, appear to be particularly detrimental to tree productivity, as the top defoliation treatment impaired carbohydrate reserves in shoot terminals and roots. In conclusion, fire-induced loss of leaf area during fruit growth alters fruit composition in the current growing season and may lead to lower yields in the subsequent season. [ABSTRACT FROM AUTHOR]

Herbicide flashback is an undesirable response that results in damage or mortality of non-target plants near chemically treated plants. In severe instances, crop trees can be injured resulting in financial loss or inability to capture management objectives. Land managers need to know the potential limitations of using triclopyr acid (50% solution in water) and what quantity can cause damage to non-target trees (trees not aimed at for control via herbicide). Three naturally regenerated (previously clearcut) bottomland hardwood sites, ranging from 14–20 years of age, received partial overstory deadening using Trycera® herbicide. Residual "leave" trees experienced indirect herbicide uptake resulting in some trees either experiencing mortality or partial mortality with top dieback/epicormic branching. An increased probability of damage occurred as tree diameter decreased and the number of treated stems around the non-target stems increased. American sycamore, green ash, and sweetgum were most susceptible to flashback. This study examines the unanticipated chemical effect of deadening adjacent stems surrounding residual leave trees in poorly drained soils. [ABSTRACT FROM AUTHOR]

Manipulation of the source–sink relationship through bark incision is an ancient practice that considerably restricts vegetative growth and subsequently improves fruit production. Girdling intends making an incision of different thickness into the phloem entirely circumscribing the trunk. It inhibits the movement of photosynthates from source to the area below the plant parts from where phloem has been removed. Thereby carbohydrate accumulation and gas exchange are reduced due to feedback inhibition of photosynthesis above the girdled portion. Consequently, plant roots become devoid of photosynthates which results in the reduction of root metabolism that substantially reduces growth and development of both roots and shoots. This methodology is extremely effective controlling vegetative growth, enhancement of fruit yield, and quality attributes in horticultural crops. Duration and time of girdling can have profound effect on plant metabolic reactions, sometimes leading to undesirable outcomes. Additionally, the healing process after girdling plays a crucial role in minimizing any potential damage to the tree and ensuring its recovery. Despite being utilized for many centuries, the precise impact of girdling on plant metabolism still remains unclear. The review provides a concise overview of the girdling procedure, its mechanism, the healing process, and its effect on tree stature, flowering, fruit yield, and quality in temperate fruit crops. [ABSTRACT FROM AUTHOR]

The saguaro is an endemic and emblematic columnar cactus of the Sonoran Desert that offers refuge and food to different species. Climate change and increased ultraviolet exposure are threatening this species. Although reports of an increase in "epidermal browning" in saguaro populations in the United States have been published, to the best of our knowledge, no studies of this or other types of damage to Mexican saguaro populations are available. The present research is the first report of its kind performed in a saguaro population in the El Pinacate and Gran Desierto de Altar Biosphere Reserve (Sonora, Mexico). Seven types of damage were evaluated and classified in saguaro stems: cactus cortical scaling (CCS = epidermal browning), girdling, shell, exposed root, eyelet, termite tubes, and topping cuts. In addition, an anatomical comparison of healthy and CCS‐damaged tissues is presented. Shell was the most frequent type of damage (91% of individuals), followed by CCS (73%). Girdling occurred mainly in small organisms. Shell, exposed root, eyelet, and termite tubes tended to occur more frequently in larger organisms, whereas CCS tended to be more evenly distributed among differently sized individuals. Of all individuals, 3.3% were undamaged, 89.2% were moderately damaged, and 7.5% were highly damaged. CCS damage causes differences in the composition of the tissues, as well as in stomata distribution, thus compromising the photosynthetic function of the stem. The snapshot of the state of the individuals provided in the present study highlights the need for longer‐term studies considering the long life cycle of the saguaro to develop conservation strategies. [ABSTRACT FROM AUTHOR]

Girdling is an important means of improving the yield and quality of jujube trees, but this measure can easily cause injury, or even death, to jujube trees. A technology for increasing yield and improving quality, based on local thermal damage of jujube bark, is proposed to address a series of issues in current jujube-tree-girdling technology. First, we measured the thermophysical parameters of jujube bark and established a heat-transfer model for jujube bark. Then, in order to investigate the impact of local thermal damage on jujube-tree yield and fruit quality, local heating experiments were conducted on jujube-tree bark, using the heat-transfer model. The experimental results indicated that heating the jujube bark at a certain temperature for an appropriate time can effectively improve the yield and quality of jujube fruit. Compared with traditional girdling techniques, this method has less impact on the health of jujube trees and does not form permanent wounds on them. The research results provide new ideas for exploring sustainable yield-increase methods for fruit trees. [ABSTRACT FROM AUTHOR]

【Objective】The production mode of Hainan longan can be divided into natural flowering on-season longan and off-season longan induced by potassium chlorate. Reasonable fruit loading is extremely important to maintain tree vigor and avoid alternate bearing results. The fruit loading regulation modes in the production of on-season and off-season longan are greatly different. The fruit setting amount of on-season longan is great, which seriously affects the tree vigor and fruit quality, while off-season longan fruit abscission before harvest is a common phenomenon, which seriously affects the yield. Therefore, fruit thinning of on-season longan and fruit preserving of off-season longan are equally important in the production.【Method】The main cultivar Shixia longan was used as the test material, and two tests including fruit thinning of on-season longan and fruit preserving of off-season long were set. The fruit thinning effect was studied by treating the longan ears with different fruit thinning agents, and the fruit preserving effect was studied with the treatment of different fruit preserving agents after artificially induced fruit abscission of off-season longan.【Result】By tracking and monitoring the fruit abscission rate and the separation force of the pedicel abscission layer, it was found that IAA and DMTU treatments delayed fruit abscission process for 2 days, 2, 4-D and NAA treatments delayed the fruit abscission process for 3 days in off-season longan, but neither of them could prevent fruit abscission. Treatment of fruit substituted by IAA completely inhibited the pedicel separation in off-season longan. Girdling treatment could induce 100% of on-season longan fruit abscission within 6 days; different concentrations of ethephon, paraquat and 100 g/L urea treatment could induce 11.88%-53.05%, 29.23% and 35.43% of fruit abscission respectively within 10 days. After 10 days, there was very little fruit abscission under urea treatment, while other treatments showed sustained fruit abscission.【Conclusion】The results show that carbohydrate stress, paraquat, ethephon and urea treatment can induce the abscission layer separation of longan pedicel, and these agents have a fruit thinning effect on on-season longan. IAA, 2, 4-D, NAA, DMTU can delay the abscission layer separation of fruit pedicel, which can effectively delay the abscission of off-season longan before harvest. All the treatments that can enhance the IAA signal can play a role in fruit preserving, while all the treatments that reduce the synthesis and transport of IAA and the treatments that enhance the ethylene signal have effects on fruit thinning. Therefore, in terms of production, it is suggested that measures should be taken to thin the fruit of on-season longan as early as possible to reduce the consumption of carbohydrates and then ensure the quality and yield of the fruits. In the middle fruiting period of off-season longan, certain fruit preserving measures should be taken to ensure the accumulation of IAA in the fruit to avoid the abscission of fruits.

AbstractThe species, Schleichera oleosa (Kusum), holds an important place in the livelihood of tribal farmers in eastern region of India. It is getting popular due to its ethnobotanical values and its potential use as host plant for lac production. Its natural population and genetic variability is declining at faster rate due to deforestation and human interventions. Mass production of Kusum seedlings is a major challenge and moreover, auto-generation of heterozygous nature in plants calls for long term experiments for its genetic improvement which require huge monetary investments. Moreover, the factors like low quality and quantity planting materials and the problem of restricted growth in plants raised from seeds hinder the interest of the farmers. Hence, clonal propagation through grafting could be an option. The scientific knowledge on application and standardization of various approaches like girdling of scionstick branches, age of mother plant, rootstocks, etc. of Kusum are extremely limited. Keeping these in view, an experiment was conducted during 2018–2021 to standardize grafting technique in Kusum. The result revealed that grafting methods affected the graft’s success significantly. Cleft grafting was found to be the most successful (72.38% graft) than veneer grafting (64.46%). Moreover, the scions collected from tree aged

Copyright of COMU Journal of Agriculture Faculty / ÇOMÜ Ziraat Fakültesi Dergisi is the property of Canakkale Onsekiz Mart University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Highlights 1. Comparisons between leaves on girdled and non-girdled branches of red maple showed that leaf color change is a coevolutionary phenomenon of maple in response to abiotic stress. 2. C108619.graph_c0 of Pkinase family regulates the color change of A. rubrum leaf by participating in the synthesis of anthocyanins, which has the high homology with c45897.graph_c0 and OsEDR1 of Lagerstroemia indica.

Calcium (Ca) and carbohydrate (CHO) supply in sweet cherry have been associated with fruit quality at harvest and during storage. There is little published information integrating CHO and Ca availability and distribution in sweet cherry and their effects on fruit quality. Accordingly, in the 2019–20 season, vascular restrictions were imposed on the phloem (girdling, G, stopping phloem flow) and xylem (transverse incision, S, cutting 50% of xylem cross–section area) of individual vertical branches of the sweet cherry combination 'Lapins'/Colt trained as Kym Green Bush system to modify mineral and CHO composition in fruit and associate such changes with quality at harvest and storage. The girdling to the phloem was used to induce changes in CHO distribution. The transverse incision to the xylem was a tool to modify Ca distribution. Five treatments (TR) were implemented: TR1–CTL = Control (without vascular restriction), TR2–G, at its base, TR3–G + G: at its base, and G further up at the change of year between the second and the third years of growth TR4––S and TR5–S + G. The vegetative (i.e., shoot and leaf growth), reproductive (i.e., fruit set and yield) development and stomatal conductance were monitored. Each branch was divided into the upper (1–and 2–year–old wood) and the lower (3–and 4–year–old wood) segments of the restriction applied. The quality and mineral composition (Ca, Mg, K, and N) of fruit borne on each segment were measured at harvest. The upper segment of TR3–G + G branches were harvested 10 d before the lower segment. The fruit from the upper segment of TR3–G + G was the largest, the sweetest, and had the higher titratable acidity concentration. However, fruits of this segment were the softest, had the lowest Ca concentrations, and had the highest ratios of N:Ca and K:Ca, compared with the other TRs. TR3–G + G branches developed the highest number of lateral current season shoots including shoots below the second girdling in the lower segment of the branch. This vegetative flow of growth would explain the mineral unbalance produced in the fruit from the upper segment of the branch. TR2–G did not register changes in fruit quality and mineral concentration compared with TR1–CTL. Surprisingly, the fruit from the branches with xylem restriction did not show changes in Ca concentration, suggesting that the xylem stream was enough to supply the fruit in branches without lateral shoot development. Fruit firmness was positively related to fruit Ca concentration and negatively related to the ratios of K:Ca and N:Ca. [ABSTRACT FROM AUTHOR]

Source-sink relationships and the management of carbon partitioning among sinks in plants help us to understand crop physiology and yield limiting issues. The effect of variable leaf fruit ratio alone or in combination with girdling on the yield and fruit quality performance of nectarine peach cv. Silver King was analysed. With increasing leaf fruit ratio alone or in conjunction with girdling, the greatest leaf nutrients, such as N, P, K, Ca, and Mg, decreased. The fruit yield decreased linearly as the leaf fruit ratio increased and the lowest yield was reported with the leaf fruit ratio of 50:1 plus girdling half the bark. However, the fruit quality in terms of fruit size and weight were maximum when the leaf fruit ratio was 40:1 and half the bark was girdled. Other fruit quality indicators such as total soluble solids, total sugars, and sugar acid ratio were highest when the leaf fruit ratio was 50:1 coupled with girdling half the bark. The treatment with the lowest titratable acidity was leaf fruit ratio 40:1 + girdling half the bark, followed by leaf fruit ratio 40:1 + girdling half the bark. When compared to control, all of the leaf fruit ratio treatments alone or in combination with girdling half the bark advanced the harvest date by 1–4 days recording earliest harvest, with leaf fruit ratio 50:1 plus girdling half the bark. Overall, leaf fruit ratios of 40:1 combined with girdling half the bark and leaf fruit ratios of 50:1 combined with girdling half the bark were determined to be acceptable for producing high-quality Silver King nectarine. [ABSTRACT FROM AUTHOR]

Copyright of Guangdong Agricultural Sciences is the property of South China Agricultural University, Guangdong Academy of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Improving the economic benefits of Camellia oleifera is a major problem for C. oleifera growers, and girdling and foliar fertilizer have significant effects on improving the economic benefits of plants. This study explains the effects of girdling, girdling + foliar fertilizer on nutrient distribution, and the economic benefits of C. oleifera at different times. It also explains the N, P, and K contents of roots, leaves, fruits, and flower buds (sampled in March, May, August, and October 2021) and their economic benefits. The results showed girdling promoted the accumulation of N and K in leaves in March 2021 (before spring shoot emergence) but inhibited the accumulation of P, which led to the accumulation of P in roots and that of N in fruits in August 2021 (fruit expansion period). Foliar fertilizer application after girdling replenished the P content of leaves in March 2021, and P continued to accumulate in large quantities at the subsequent sampling time points. The N and P contents of the root system decreased in March. In October (fruit ripening stage), girdled shrubs showed higher contents of N and K in fruits and flower buds, and consequently lower relative contents of N and K in roots and leaves but higher content of P in leaves. Foliar fertilizer application slowed down the effects of girdling on nutrient accumulation in fruits and flower buds. Spraying foliar fertilizer decreased the N:P ratio in the flower buds and fruits of girdled plants. Thus, foliar fertilizer spray weakened the effects of girdling on the nutrient content and economic benefits of C. oleifera. In conclusion, girdling changed the nutrient accumulation pattern in various organs of C. oleifera at different stages, increased leaf N:K ratio before shoot emergence, reduced root K content at the fruit expansion stage and the N:K ratio of mature fruit, and promoted economic benefits. [ABSTRACT FROM AUTHOR]

In this study, the effects of altering carbohydrate supply, carried out through branch girdling, on the carpometric and qualitative characteristics of the Feminello Zagara Bianca variety lemon fruits were evaluated. Four girdling times (70, 100, 130, 160 days) were compared with a control. The results showed important effects of alteration times of the supply of carbohydrates to fruit sinks on many carpometric and qualitative characteristics of lemons. Fruits from trees with early girdled branches (70 and 100 DAFB) showed higher weights and juice contents than those with later girdled branches (130 and 160 DAFB) and from ungirdled trees. The increased availability of carbohydrates for fruit in the initial period of the cell enlargement phase allowed the lemons of the trees girdled at 70 and 100 DAFB to anticipate the degreening process of the peel and pulp and ripening process. The advancement of the ripening process determined that the fruits of trees with early girdled branches had a lower acidity content compared with those harvested after the catabolism of citric acid. The knowledge acquired with this study provides new information on factors affecting the growth and ripening of lemons, the improvement of fruit quality, and the anticipation of harvest time. [ABSTRACT FROM AUTHOR]

Copyright of Ege Üniversitesi Ziraat Fakültesi Dergisi is the property of Ege Universitesi, Ziraat Fakultesi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The color of 'Crimson Seedless' berries is a major constraint in expanding marketing and export potential. The target of this investigation is to enhance the color and quality of 'Crimson Seedless' by using brassinolide (BL) and girdling treatments, individually and in combination, as an alternative to ethephon over two consecutive seasons. The obtained results revealed that the combined treatment BL at 2.0 mg/L and girdling recorded the highest significant yield values (17.78 ± 0.29 and 18.26 ± 0.23 kg/vine) in both seasons, respectively, in contrast to ethephon and girdling treatments which had no significant influence. Besides, BL 2.0 mg/L + girdling presented high levels of physicochemical characteristics of clusters and berries compared to the control. Concerning berry color assessment, ethepon followed by BL at 2.0 mg/L + girdling recorded the highest significant improvement in the red color, as indicated by Color Index of Red Grapes and visual assessment, and had similar and elevated levels of anthocyanin content. On the other hand, flavonoids (3.46 ± 0.03 and 3.66 ± 0.02 mg/100 g FW), and antioxidant capacity (2.37 ± 0.02 and 2.43 ± 0.06 IC50) were obviously increased with BL 2.0 mg/L + girdling, with a slight decrease than ethephon application. As for phenylalanine ammonia-lyase activity, the data show that it increased by ethephon (7.91 ± 0.02 and 8.01 ± 0.02 U mg−1 protein) and BL 2.0 mg/L + girdling (7.77 ± 0.04 and 7.79 ± 0.07 U mg−1 protein), compared to the control (3.69 ± 0.02 and 3.80 ± 0.01 U mg−1 protein) in both seasons, respectively. In terms of polyphenol oxidase activity, the increase in PPO was closely associated with PAL. Moreover, BL 2.0 mg/L + girdling was the most effective treatment for increasing dormant season parameters in both seasons, while ethephon spraying had no influence. All these confirmed that the combined treatment BL 2.0 mg/L + girdling exhibited a synergistic effect in improving the color and quality of 'Crimson Seedless'. [ABSTRACT FROM AUTHOR]

The effects of cane girdling on the berry texture characteristics were studied in three table grape cultivars. The application was carried out at véraison. The total soluble solids (TSS, °Bx) of berry must and berry weight were measured. The berry mechanical properties were investigated by a texture analyser. A double compression test was used to determine berry hardness and its derived parameters. A puncture test was also applied to assess skin hardness, skin elasticity and skin break energy. Skin thickness was also investigated. The sugar concentration of the must and the berry weight after the girdling treatment were significantly higher compared to those of the control. Berry hardness, skin hardness and skin thickness were significantly affected by this technique. The changes in berry mechanical and quality parameters with this application did not show the same pattern as those observed during control ripening. Notably, in our experiment, after the girdling treatments, the higher berry hardness was accompanied with a higher sugar concentration compared to the control. The skin hardness showed lower values as a result of girdling. However, skin thickness was significantly higher in the girdled berries compared to the non-treated vines. [ABSTRACT FROM AUTHOR]

Background: Acer rubrum L. (red maple) is a popular tree with attractive colored leaves, strong physiological adaptability, and a high ornamental value. Changes in leaf color can be an adaptive response to changes in environmental factors, and also a stress response to external disturbances. In this study, we evaluated the effect of girdling on the color expression of A. rubrum leaves. We studied the phenotypic characteristics, physiological and biochemical characteristics, and the transcriptomic and metabolomic profiles of leaves on girdled and non-girdled branches of A. rubrum. Results: Phenotypic studies showed that girdling resulted in earlier formation of red leaves, and a more intense red color in the leaves. Compared with the control branches, the girdled branches produced leaves with significantly different color parameters a*. Physiological and biochemical studies showed that girdling of branches resulted in uneven accumulation of chlorophyll, carotenoids, anthocyanins, and other pigments in leaves above the band. In the transcriptomic and metabolomic analyses, 28,432 unigenes including 1095 up-regulated genes and 708 down-regulated genes were identified, and the differentially expressed genes were mapped to various KEGG (kyoto encyclopedia of genes and genomes) pathways. Six genes encoding key transcription factors related to anthocyanin metabolism were among differentially expressed genes between leaves on girdled and non-girdled branches. Conclusions: Girdling significantly affected the growth and photosynthesis of red maple, and affected the metabolic pathways, biosynthesis of secondary metabolites, and carbon metabolisms in the leaves. This resulted in pigment accumulation in the leaves above the girdling site, leading to marked red color expression in those leaves. A transcriptome analysis revealed six genes encoding anthocyanin-related transcription factors that were up-regulated in the leaves above the girdling site. These transcription factors are known to be involved in the regulation of phenylpropanoid biosynthesis, anthocyanin biosynthesis, and flavonoid biosynthesis. These results suggest that leaf reddening is a complex environmental adaptation strategy to maintain normal metabolism in response to environmental changes. Overall, the results of these comprehensive phenotype, physiological, biochemical, transcriptomic, and metabolomic analyses provide a deeper and more reliable understanding of the coevolution of red maple leaves in response to environmental changes. Highlights: 1. Comparisons between leaves on girdled and non-girdled branches of red maple showed that leaf color change is a coevolutionary phenomenon of maple in response to abiotic stress. 2. C108619.graph_c0 of Pkinase family regulates the color change of A. rubrum leaf by participating in the synthesis of anthocyanins, which has the high homology with c45897.graph_c0 and OsEDR1 of Lagerstroemia indica. [ABSTRACT FROM AUTHOR]

Although the effects of girdling on grape berry development have been widely studied, the underlying mechanisms are poorly understood, especially at the molecular level. This study investigated the effect of trunk girdling on grape (Vitis L.) berry maturation. Girdling was performed on 5-year-old 'Summer Black' grapevines at early veraison, and transcriptional and physiologic analyses were performed. Trunk girdling promoted sugar accumulation and color development in berries and accelerated berry ripening by 25 days. Genes related to sucrose cleavage and polysaccharide degradation were upregulated at the transcriptional level, which was associated with increased monosaccharide accumulation and berry softening. Anthocyanin biosynthesis and accumulation were also enhanced by trunk girdling through the upregulation of anthocyanin biosynthesis genes including phenylalanine ammonia-lyase and UDP-glucose:flavonoid 3-O-glucosyltransferase (UFGT). The increased expression of two VvUFGT genes was accompanied by the upregulation of VvMYBA2 under girdling. The upregulation of genes involved in ethylene biosynthesis and hormone (abscisic acid and brassinosteroid) responses and downregulation of genes involved in indoleacetic acid biosynthesis and response may have also promoted berry ripening in the girdling group. A total of 120 differentially expressed transcription factor genes from 29 gene families including MYB, ERF, and MYB-related were identified in the girdling group, which may participate in the regulation of berry development and ripening. These results provide molecular-level insight into the positive effects of trunk girdling on berry development in grapes. [ABSTRACT FROM AUTHOR]

California voles cause extensive damage to tree crops through girdling of young stems. Recent laboratory trials have indicated substantial repellency (up to 84%) of anthraquinone (a post-ingestive repellent) to voles on treated grain. Given these lab results, we established a field study to test the efficacy of anthraquinone applications to tree stems to reduce girdling damage from voles. We also assessed the impact of vegetation around the base of trees to determine the impact of cover on girdling activity. In Fresno County, CA, during summer 2016 and spring 2017, we established twenty 3.35 × 2.44-m bins (hereafter mesocosms) where we evenly spaced eight 1-yr-old clementine orange trees. Cover crops including various grasses and forbs were planted on randomly-selected halves of each mesocosm. All trees were treated with anthraquinone in half of the mesocosms; trees were left untreated in the remaining half. We captured 40 voles and released two individuals into each mesocosm and tracked girdling damage once weekly for five weeks during summer and six weeks during spring. We observed a significant reduction in girdling damage on anthraquinone-treated trees. The removal of vegetation around the base of trees completely eliminated girdling damage for anthraquinone-treated trees during summer, although vegetation did not significantly impact damage for untreated trees during summer, nor for either anthraquinone-treated or untreated trees during spring. We did not observe an increase in damage over time in anthraquinone-treated mesocosms, indicating that anthraquinone maintained its repellency during the duration of this study. Anthraquinone appears to be highly repellent to voles, and it is worthy of field study in other mammalian species as well.

To investigate the effect of sucrose, yeast and landamineZn spraying and girdling on yield and berry quality of Flame Seedless grapes. Twenty four uniformly vine was selected, as eight treatments with three replications one vine each. The study was carried out during 2019 and 2020 seasons. The experiment set up in a randomized complete block design, where, the study included The obtained results could be summarized as follows; Yield/vine and cluster weight were significantly increased due to spray either sucrose, yeast or landamineZn as well as arm girdling compared to untreated ones (control). Spraying 4 g/L landamineZn was very effective in increasing yield and cluster weight than other treatments. Moreover, all studied treatments significantly improved the berry quality in terms of increasing berry weight, total soluble solids and anthocyanin in skin of berries and decreasing berry firmness and total acidity compared to untreated ones. The greatest results were obtained due to spraying landamineZn at 2 or 4 cm3/L where gave a high yield of good berry quality. No significant differences were obtained due to spray landamineZn at 2 or 4 cm3/L, as well as yeast, sucrose or girdling. It could be concluded that spraying 2 to 4 cm3/L landamineZn to get high yield with good cluster and berry quality of Flame Seedless grapes.

Many commercial vineyards of Malbec, the most cultivated grapevine in Argentina, show unstable yield because of variations in bud fruitfulness and the occurrence of “shatter”, characterised by poor fruit set and fruitlet abscission. Shatter can be due to plant material, growing conditions and meteorological events. Among the parameters that determine fruit set efficiency and vine yield, the availability of carbohydrates (CH) plays an essential role. We previously showed that controlling CH partitioning by removing part of the phloem tissue through an annular incision at the base of the fruit shoots (shoot girdling) reduced shatter in Malbec. The objective of this research was to evaluate the partitioning of CH for the different sink organs of the aerial part of the plant when an interruption of phloem flux from leaves to storage organs is imposed by a girdle. Shoot and trunk girdling trials were conducted during the 2018 and 2019 growing seasons, respectively. At flowering, girdling was performed on different plant lots either at the base of the shoot (Base G), above the distal cluster of the shoot (Top G), to the trunk (Trunk G) or no girdling (Control). Most of the yield components were increased by Base G and Trunk G with no significant impact on vegetative growth or fruit quality. Total shoot biomass was not affected in Base G, while a 39 % reduction was observed in Top G, as compared to Control. The partitioning pattern within the shoot was modified by shoot girdling, and Base G favoured the accumulation of CH towards clusters at the expense of lateral shoots. Shoot girdling increased node diameter, bud fruitfulness and inflorescence dry weight of the shoot. Trunk-girdled vines showed an increase in fruit set and total yield at harvest, with no significant impact on vegetative growth. The restriction of CH flow to the trunk and roots by Base G and Trunk G at flowering increased yield components at harvest without affecting vegetative growth or grape quality. These results reinforce our hypothesis that the root system of the vines under study constitutes a strong sink during the flowering period that competes for CH.

A study was conducted on 6-year-old sweet lime trees on the Mexican lime (Citrus aurantifolia Swingle) rootstock in a randomized complete block design with ten treatments and three replications in southern Fars to determine the appropriate time of plant supplementary feeding to increase flower production and the yield in calcareous soils. In 2016 and 2017, 40 trees that had the same planting and growing conditions, were selected to determine the flower induction time. Ten times (22nd of October, 1st, 11th, and 20th November, December, and January), four branches that had a length of 120 cm and a diameter of half a centimeter were selected on each tree in four geographical directions. At each time, the branches of three trees were ringed at a distance of 120 cm from the tip of the branch, and all the leaves were removed. At the time of flower emergence, the number of flowers was counted. The results showed that the flower induction in these trees was in early December. Based on the results of this experiment and previous research in this field, in September 2017, the 7-year-old trees grafted on the Mexican lime rootstock were treated with the foliar application of nitrogen as urea [CO(NH2)2] and zinc as zinc sulfate (ZnSO4) at three concentrations including 0, 3, and 5 g∙L–1, alone and by combination in two separate pieces in a randomized complete-block factorial design including nine treatments and three replications to increase the yield using elements involved in the flowering. At the harvest time, fruit juice, TSS, TA, vitamin C, average fruit weight, and single tree yield were measured. According to the results, the combination of urea and zinc sulfate at a concentration of 5 g∙L–1 led to an increase in the average fruit weight (58 g) and the yield (68 kg) compared to the control.

A study was conducted on 6-year-old sweet lime trees on the Mexican lime (Citrus aurantifolia Swingle) rootstock in a randomized complete block design with ten treatments and three replications in southern Fars to determine the appropriate time of plant supplementary feeding to increase flower production and the yield in calcareous soils. In 2016 and 2017, 40 trees that had the same planting and growing conditions, were selected to determine the flower induction time. Ten times (22nd of October, 1st, 11th, and 20th November, December, and January), four branches that had a length of 120 cm and a diameter of half a centimeter were selected on each tree in four geographical directions. At each time, the branches of three trees were ringed at a distance of 120 cm from the tip of the branch, and all the leaves were removed. At the time of flower emergence, the number of flowers was counted. The results showed that the flower induction in these trees was in early December. Based on the results of this experiment and previous research in this field, in September 2017, the 7-year-old trees grafted on the Mexican lime rootstock were treated with the foliar application of nitrogen as urea [CO(NH2)2] and zinc as zinc sulfate (ZnSO4) at three concentrations including 0, 3, and 5 g·L-1, alone and by combination in two separate pieces in a randomized complete-block factorial design including nine treatments and three replications to increase the yield using elements involved in the flowering. At the harvest time, fruit juice, TSS, TA, vitamin C, average fruit weight, and single tree yield were measured. According to the results, the combination of urea and zinc sulfate at a concentration of 5 g·L-1 led to an increase in the average fruit weight (58 g) and the yield (68 kg) compared to the control. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Plant Production is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agriculture Science Tokyo is the property of Tokyo University of Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The marketability of table grapes is mainly characterized by berry size, color, taste and texture. Mechanical measurements of table grape berries could provide objective information on the textural qualities of grape berries. In addition, this method might be suitable to study the effects of phytotechnical methods (such as girdling) on table grape quality. The aim of this preliminary work was to demonstrate how instrumental testing could be used to examine the effects of girdling on berry grape texture and define the textural characteristics of table grape berries. Cane girdling was carried out at veraison in two table grape varieties. Texture analysis was performed several times during the maturity. Besides this examination another five varieties were analyzed to assess their berry mechanical properties. Double compression test was used to determine berry hardness and its derived parameters. Puncture test was applied to evaluate skin hardness, skin elasticity and skin break energy. Skin thickness was also investigated. Berry hardness, skin hardness and skin thickness of the girdled grapevines were significantly affected by this technique. Most of the textural parameters showed differences among the seven cultivars. [ABSTRACT FROM AUTHOR]

Growing citrus involves cultural treatments such as girdling and foliar potassium treatment to increase fruit size, yield and quality. The aim of the study was to evaluate the effects of single and double stem girdling, potassium nitrate (KNO3) treatment on leaves and combinations of these treatments on the fruit yield, size and quality characteristics, leaf chlorophyll concentration and leaf nitrogen content, leaf fluorescence (PSII) and leaf sugar content of the ‘Fremont’ mandarin variety. Girdling treatments were applied on the stem by removing 4 mm wide ring of bark at the end of anthesis and after the June fruit drop. Foliar KNO3 applications were applied at a concentration of 4% twice (90 days and 120 days after full anthesis) in the experiment. The single girdling (SG) and double girdling (DG) treatments on stems increased fruit yield (kg · tree−1) by approximately 40% relative to the control (C). Treatments did not significantly affect the internal fruit quality of the ‘Fremont’ mandarin variety except in fruit colour and appearance. The highest impact on fruit size was found in the DG + KNO3 treatment. According to treatments and periods, the SPAD values varied between 62.08 and 70.67, whereas the PSII values varied between 0.698 and 0.756. The treatments significantly increased the leaf nitrogen (N) concentration and the fructose, glucose and sucrose concentrations relative to the control. The highest N concentration content was detected in the foliar potassium treatment, and the highest total sugar content was detected in the SG treatment.

Persea willdenovii is a native species popularly known for its high potential for medicinal use. Due to problems in low seed production and germination, vegetative propagation appears promising. Thus, we seek with this work to evaluate techniques of vegetative rescue and the potential use of shoots obtained in tissue culture. Adult trees of the species were used to apply total and partial girdling treatments and obtain pruned branches as vegetative rescue techniques. Shoot production was monitored over time (90 to 240 days). Sprouts were used for in vitro propagation, and disinfestation treatments were carried out using biocides such as NaClO and Plant Preservative Mixture™ (PPM™), changing the time and concentrations of the products. Multiplication was also tested using doses of 6-benzylaminopurine (BAP) and media and the potential for callogenesis under combinations of BAP and Naphthalene Acetic Acid (ANA). The vegetative rescue by complete or semi-girdling has the potential to produce shoots, though pruned branches proved to be one of the best techniques for rescue. In the micropropagation, the use of biocides such NaOCl for a long period of time (2 % for 20 min) with PPM™ added to the culture medium shows a potential for disinfestation in the in vitro establishment. For in vitro multiplication, the usage of WPM and BAP (2 a 4 g L-1) promotes higher shoot length, shoot number and leaf number. For indirect organogenesis by leaf segments, the cultivation with BAP and ANA was not responsive to the induction of callogenesis. [ABSTRACT FROM AUTHOR]

Aroma is one of the most important indicators of grape quality. Girdling and foliar fertilization with K (K2O) are common agronomic practices applied to improve berry quality in grape production. However, little is known about its effect on the accumulation and biosynthesis of the entire aromatic profile. Our study was aimed to explore the influences of girdling and foliar fertilization with K (alone or in combination) on the general properties, phenolic composition, volatile free aroma compounds, spatial and temporal expression of terpene-related genes and sensory properties in 'Hanxiangmi' table grape. In this study, we found that girdling and foliar fertilization with K (alone or in combination) facilitated fruit enlargement and increased the accumulation of phenolic compounds in skin. The combination treatment of girdling and foliar fertilization with K significantly promoted the concentrations of total soluble solids (TSS) in the pulp and proanthocyanidins in the berry skin, and had a lower titratable acidity (TA) compared to those of the control. In contrast, girdling treatment alone increased the concentrations of titratable acidity. Volatile free aroma composition analysis revealed that the combination treatment increased the volatile compounds and concentrations significantly, most notably in terpenes, such as nerol, citronellol and linalool. Spatial and temporal expression analysis showed that the expression level of VvDXS was significantly correlated with linalool and total terpenes concentrations, as a result of which, we speculated that VvDXS is the candidate gene for the regulation of important grape terpenes. We hope that our results can direct farmers to better apply girdling and foliar fertilization with K in grape production. [ABSTRACT FROM AUTHOR]

Calcium (Ca) and carbohydrate (CHO) supply in sweet cherry have been associated with fruit quality at harvest and during storage. There is little published information integrating CHO and Ca availability and distribution in sweet cherry and their effects on fruit quality. Accordingly, in the 2019–20 season, vascular restrictions were imposed on the phloem (girdling, G, stopping phloem flow) and xylem (transverse incision, S, cutting 50% of xylem cross–section area) of individual vertical branches of the sweet cherry combination ‘Lapins’/Colt trained as Kym Green Bush system to modify mineral and CHO composition in fruit and associate such changes with quality at harvest and storage. The girdling to the phloem was used to induce changes in CHO distribution. The transverse incision to the xylem was a tool to modify Ca distribution. Five treatments (TR) were implemented: TR1–CTL = Control (without vascular restriction), TR2–G, at its base, TR3–G + G: at its base, and G further up at the change of year between the second and the third years of growth TR4––S and TR5–S + G. The vegetative (i.e., shoot and leaf growth), reproductive (i.e., fruit set and yield) development and stomatal conductance were monitored. Each branch was divided into the upper (1–and 2–year–old wood) and the lower (3–and 4–year–old wood) segments of the restriction applied. The quality and mineral composition (Ca, Mg, K, and N) of fruit borne on each segment were measured at harvest. The upper segment of TR3–G + G branches were harvested 10 d before the lower segment. The fruit from the upper segment of TR3–G + G was the largest, the sweetest, and had the higher titratable acidity concentration. However, fruits of this segment were the softest, had the lowest Ca concentrations, and had the highest ratios of N:Ca and K:Ca, compared with the other TRs. TR3–G + G branches developed the highest number of lateral current season shoots including shoots below the second girdling in the lower segment of the branch. This vegetative flow of growth would explain the mineral unbalance produced in the fruit from the upper segment of the branch. TR2–G did not register changes in fruit quality and mineral concentration compared with TR1–CTL. Surprisingly, the fruit from the branches with xylem restriction did not show changes in Ca concentration, suggesting that the xylem stream was enough to supply the fruit in branches without lateral shoot development. Fruit firmness was positively related to fruit Ca concentration and negatively related to the ratios of K:Ca and N:Ca.

Girdling can promote anthocyanin accumulation in grape berries. However, the underlying mechanism is unclear. In this study, we explored the effects of girdling on the accumulation of anthocyanins and the transcript levels of key genes in anthocyanin synthesis in spine grape skins. We also determined the effect of girdling on the contents of vitamin C, titratable acids, soluble sugars, and aroma compounds, and the transcript levels of genes related to sugar transport and aroma compound synthesis. The girdling treatment promoted anthocyanin accumulation in spine grape skins by increasing the transcript levels of genes related to anthocyanin synthesis. Girdling also increased the transcript levels of genes related to sugar transport in leaves, petioles, and flesh, promoted the transport of photosynthetic products to berries, and increased the soluble sugar content in berries. The transcript levels of genes related to aroma compound synthesis and the contents of aroma compounds in flesh were also increased by the girdling treatment. Together, our results show that a girdling treatment can increase the contents of anthocyanins, soluble sugars, vitamin C, and aroma compounds, decrease the titratable acid content, and significantly improve the quality of spine grape berries. [ABSTRACT FROM AUTHOR]

In this study, the effects of altering carbohydrate supply, carried out through branch girdling, on the carpometric and qualitative characteristics of the Feminello Zagara Bianca variety lemon fruits were evaluated. Four girdling times (70, 100, 130, 160 days) were compared with a control. The results showed important effects of alteration times of the supply of carbohydrates to fruit sinks on many carpometric and qualitative characteristics of lemons. Fruits from trees with early girdled branches (70 and 100 DAFB) showed higher weights and juice contents than those with later girdled branches (130 and 160 DAFB) and from ungirdled trees. The increased availability of carbohydrates for fruit in the initial period of the cell enlargement phase allowed the lemons of the trees girdled at 70 and 100 DAFB to anticipate the degreening process of the peel and pulp and ripening process. The advancement of the ripening process determined that the fruits of trees with early girdled branches had a lower acidity content compared with those harvested after the catabolism of citric acid. The knowledge acquired with this study provides new information on factors affecting the growth and ripening of lemons, the improvement of fruit quality, and the anticipation of harvest time.

Key message: Primary growth is less sensitive than secondary growth to water and phloem blockage in maritime pine saplings, with variations in radial growth resulting from tracheid production without altering their size. In plants, primary and secondary growth is regulated by internal and external factors. However, apical and cambial meristems may not respond in the same way. In this study, we disentangle the role of carbon and water availability on stem growth (primary and secondary) and on anatomical tracheid features by investigating the effect of stem girdling (phloem blockage vs. no phloem blockage) and water availability (control vs. drought) in three-year-old Pinus pinaster saplings. We found that primary growth was similar among treatments, while secondary growth was affected by both treatments. Tree ring-width increment in saplings subjected to drought corresponded to half of that on control plants, and phloem blockage enhanced ring width under guidelines soil water conditions. These differences in the radial growth resulted mainly from an increase in tracheid production, which also increased with phloem blockage (above the girdling), regardless the water regime. However, the seasonal pattern of tracheid features was mainly explained by individuals and to a less extent by the water regime and girdling. Contrasting seasonal patterns between treatments were found only on cell wall thickness, showing a faster decrease with increasing water constrains in the drought group than in the control one. The absence of treatment effects on primary growth in P. pinaster saplings suggests a trade-off between the priority in plant development and meristem sensitivity to environmental conditions. [ABSTRACT FROM AUTHOR]

We studied the time-course of stem response for six months following complete girdling in branches of Aquilaria sinensis to determine the potential role of interxylary phloem (IP) in this response. It was found that the vascular cambium, as well as its derivative secondary xylem and phloem, regenerated fully through redifferentiation of IP. We confirmed that vascular cambium regenerated within one month after girdling based on observation of new vessels, IP, and secondary phloem fibers. The time-course study showed that IPs made connections with each other, merged, and became larger through the proliferation of IPs parenchyma cells and the cleaving of secondary xylem in a narrow zone 400 to 1000 μ m deep inside the girdled edge. This led to the formation of a complete circular sheath of vascular cambium, followed by the regeneration of vascular tissue. It is worth noting that the secondary xylem is regenerated always following the formation of a thick belt of wound xylem. [ABSTRACT FROM AUTHOR]