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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.

The research was carried out at University of Belgrade Faculty of Agriculture experimental station “Radmilovac” on table grape Victoria cv with aim to improve grape quality and with consideration the introduction of these ampelographic measures in regular grapevine growing. The research included two treatments of berry thinning (thinning bunch tip - BtT and first lateral wink -BtW), girdling (G) and control (C). Combined effect of berry thinning and girdling were not examined. The following features were examined: fertility and yield, bunch and berry dimensions, bunch and berry structure, sugar content and total acidity. The thinning treatments did not have significant effect on uvometric parameters and grape quality, but they improved the yield by 41.7% (BtW) and 51.4% (BtT) in comparison to the control. It can be explained by bad fruit set influenced by unfavourable meteorological conditions during flowering in control treatment. Berry thinning achieves a better fruit set. Berry thinning should be applied as a regular ampelographic measure according to weather conditions during flowering phonological stage. Results confirm the positive influence of girdling. The yield was increased by 88,34% compared to control, berries had a higher diameter (for about 1mm with respect to control), fruit set and bunch mass were in higher level against other treatments, sugar content (17,00%), total acidity (5,75 g/L) were improved too. Girdling can be introduced as a regular ampelographic measure in the table cultivars vineyards, in order to obtain higher yields and better quality of table grape.

Do tropical trees close to death have a distinct change to their leaf spectral signature? Tree mortality rates have been increasing in tropical forests, reducing the global carbon sink. Upcoming hyperspectral satellites could be used to predict regions close to experiencing extensive tree mortality during periods of stress, such as drought. Here we show, for a tropical rainforest in Borneo, how imminent tropical tree mortality impacts leaf physiological traits and reflectance. We measured leaf reflectance (400–2500 nm), light-saturated photosynthesis (Asat), leaf dark respiration (Rdark), leaf mass area (LMA), and % leaf water across five campaigns in a six-month period during which there were two causes of tree mortality: a major natural drought and a co-incident tree stem girdling treatment. We find that prior to mortality, there were significant (p < 0.05) leaf spectral changes in the red (650–700 nm), the NIR (1,000–1,400 nm), and SWIR bands (2,000–2,400 nm) and significant reductions in the potential carbon balance of the leaves (increased Rdark and reduced Asat). We show that the partial least squares regression technique can predict mortality in tropical trees across different species and functional groups with medium precision but low accuracy (r2 of .65 and RMSE/mean of 0.58). However, most tree death in our study was due to girdling, which is not a natural form of death. More research is needed to determine if this spectroscopy technique can be applied to tropical forests in general.

In arctic ecosystems, climate change has increased plant productivity. As arctic carbon (C) stocks predominantly are located belowground, the effects of greater plant productivity on soil C storage will significantly determine the net sink/source potential of these ecosystems, but vegetation controls on soil CO2 efflux remain poorly resolved. In order to identify the role of canopy‐forming species in belowground C dynamics, we conducted a girdling experiment with plots distributed across 1 km2 of treeline birch (Betula pubescens ) forest and willow (Salix lapponum ) patches in northern Sweden and quantified the contribution of canopy vegetation to soil CO2 fluxes and belowground productivity. Girdling birches reduced total soil CO2 efflux in the peak growing season by 53%, which is double the expected amount, given that trees contribute only half of the total leaf area in the forest. Root and mycorrhizal mycelial production also decreased substantially. At peak season, willow shrubs contributed 38% to soil CO2 efflux in their patches. Our findings indicate that C, recently fixed by trees and tall shrubs, makes a substantial contribution to soil respiration. It is critically important that these processes are taken into consideration in the context of a greening arctic because productivity and ecosystem C sequestration are not synonymous.

In arctic ecosystems, climate change has increased plant productivity. As arctic carbon (C) stocks predominantly are located belowground, the effects of greater plant productivity on soil C storage will significantly determine the net sink/source potential of these ecosystems, but vegetation controls on soil CO2 efflux remain poorly resolved. In order to identify the role of canopy‐forming species in belowground C dynamics, we conducted a girdling experiment with plots distributed across 1 km2 of treeline birch (Betula pubescens ) forest and willow (Salix lapponum ) patches in northern Sweden and quantified the contribution of canopy vegetation to soil CO2 fluxes and belowground productivity. Girdling birches reduced total soil CO2 efflux in the peak growing season by 53%, which is double the expected amount, given that trees contribute only half of the total leaf area in the forest. Root and mycorrhizal mycelial production also decreased substantially. At peak season, willow shrubs contributed 38% to soil CO2 efflux in their patches. Our findings indicate that C, recently fixed by trees and tall shrubs, makes a substantial contribution to soil respiration. It is critically important that these processes are taken into consideration in the context of a greening arctic because productivity and ecosystem C sequestration are not synonymous.

In arctic ecosystems, climate change has increased plant productivity. As arctic carbon (C) stocks predominantly are located belowground, the effects of greater plant productivity on soil C storage will significantly determine the net sink/source potential of these ecosystems, but vegetation controls on soil CO2 efflux remain poorly resolved. In order to identify the role of canopy‐forming species in belowground C dynamics, we conducted a girdling experiment with plots distributed across 1 km2 of treeline birch (Betula pubescens ) forest and willow (Salix lapponum ) patches in northern Sweden and quantified the contribution of canopy vegetation to soil CO2 fluxes and belowground productivity. Girdling birches reduced total soil CO2 efflux in the peak growing season by 53%, which is double the expected amount, given that trees contribute only half of the total leaf area in the forest. Root and mycorrhizal mycelial production also decreased substantially. At peak season, willow shrubs contributed 38% to soil CO2 efflux in their patches. Our findings indicate that C, recently fixed by trees and tall shrubs, makes a substantial contribution to soil respiration. It is critically important that these processes are taken into consideration in the context of a greening arctic because productivity and ecosystem C sequestration are not synonymous.

In arctic ecosystems, climate change has increased plant productivity. As arctic carbon (C) stocks predominantly are located belowground, the effects of greater plant productivity on soil C storage will significantly determine the net sink/source potential of these ecosystems, but vegetation controls on soil CO2 efflux remain poorly resolved. In order to identify the role of canopy‐forming species in belowground C dynamics, we conducted a girdling experiment with plots distributed across 1 km2 of treeline birch (Betula pubescens ) forest and willow (Salix lapponum ) patches in northern Sweden and quantified the contribution of canopy vegetation to soil CO2 fluxes and belowground productivity. Girdling birches reduced total soil CO2 efflux in the peak growing season by 53%, which is double the expected amount, given that trees contribute only half of the total leaf area in the forest. Root and mycorrhizal mycelial production also decreased substantially. At peak season, willow shrubs contributed 38% to soil CO2 efflux in their patches. Our findings indicate that C, recently fixed by trees and tall shrubs, makes a substantial contribution to soil respiration. It is critically important that these processes are taken into consideration in the context of a greening arctic because productivity and ecosystem C sequestration are not synonymous.

In arctic ecosystems, climate change has increased plant productivity. As arctic carbon (C) stocks predominantly are located belowground, the effects of greater plant productivity on soil C storage will significantly determine the net sink/source potential of these ecosystems, but vegetation controls on soil CO2 efflux remain poorly resolved. In order to identify the role of canopy‐forming species in belowground C dynamics, we conducted a girdling experiment with plots distributed across 1 km2 of treeline birch (Betula pubescens ) forest and willow (Salix lapponum ) patches in northern Sweden and quantified the contribution of canopy vegetation to soil CO2 fluxes and belowground productivity. Girdling birches reduced total soil CO2 efflux in the peak growing season by 53%, which is double the expected amount, given that trees contribute only half of the total leaf area in the forest. Root and mycorrhizal mycelial production also decreased substantially. At peak season, willow shrubs contributed 38% to soil CO2 efflux in their patches. Our findings indicate that C, recently fixed by trees and tall shrubs, makes a substantial contribution to soil respiration. It is critically important that these processes are taken into consideration in the context of a greening arctic because productivity and ecosystem C sequestration are not synonymous.

[ES] La mandarina "Orri" es una variedad híbrida obtenida por irradiación de la variedad "Orah" [Temple (Citrus temple Hort ex. Y. Tanaka) × Dancy (Citrus tangerina Hort ex. Tanaka)]. Se caracteriza por presentar maduración tardía y un bajo número de semillas en los frutos, debido a la esterilidad gamética inducida. Pero la irradiación también produce otros efectos no deseados como, en el caso particular de la mandarina "Orri" el bajo cuajado y reducido tamaño del fruto. Los factores endógenos que determinan el cuajado son de tipo nutricional y hormonal. El ovario de la flor de "Orri" es deficiente en la síntesis de giberelinas y presenta una tasa de división celular reducida, que se traducen en desarrollo deficiente. Además, no responde a las aplicaciones de giberelinas y citoquininas para mejorar su transición a fruto en desarrollo. Por otra parte, se desconoce la importancia que los factores nutricionales tienen en el cuajado de esta variedad. Con el fin último de mejorar su producción, el presente TFM plantea el objetivo de determinar la influencia de los factores nutricionales en el cuajado de la mandarina "Orri". Para ello se rayaron y defoliaron ramas, en árboles con diferente capacidad productiva, con la finalidad de estudiar su efecto sobre la producción y los factores fisiológicos responsables del cuajado. El rayado de ramas redujo la expresión del gen B-SNRK1 (indicador de estrés nutricional) y aumento la expresión del gen CYCA1.1 (división celular) y PIN1 (transporte basípeto de auxinas), aumentando la tasa de desarrollo del fruto, el porcentaje de cuajado y la producción. La defoliación provocó el efecto contrario. Pero el aumento de la división celular no se relacionó con la síntesis de GAs, lo que confirma la deficiencia en el metabolismo de esta hormona durante el cuajado de la mandarina "Orri"., [EN] The "Orri" mandarin is a hybrid variety obtained by irradiation of the "Orah" variety [Temple (Citrus temple Hort ex. Y. Tanaka) × Dancy (Citrus tangerina Hort ex. Tanaka)]. It is characterized by presenting late maturation and a low number of seeds in the fruits, due to the induced gametic sterility. But irradiation also produces other unwanted effects such as, in the particular case of the "Orri" mandarin, the low fruit set and reduced size of the fruit. The endogenous factors that determine fruit set are nutritional and hormonal. The ovary of the "Orri" flower is deficient in the synthesis of gibberellins and has a reduced rate of cell division, which results in poor development. Furthermore, it does not respond to the applications of gibberellins and cytokinins to improve its transition to developing fruit. On the other hand, the importance of nutritional factors in the fruit set of this variety is unknown. With the ultimate aim of improving its production, this TFM sets out the objective of determining the influence of nutritional factors in the fruit set of the "Orri" mandarin. For this, branches were girdled and defoliated in order to study their effect on yield. Branch girdling reduced nutritional stress (¿-SNRK1 gene expression) and increased the rate of cell division (CYCA1.1 gene expression) and basipetal transport of auxins (PIN1 gene expression). But the increase in cell division was not related to the synthesis of GAs, which confirms the deficiency in GA-metabolism during "Orri¿ fruit set.

[ES] La mandarina "Orri" es una variedad híbrida obtenida por irradiación de la variedad "Orah" [Temple (Citrus temple Hort ex. Y. Tanaka) × Dancy (Citrus tangerina Hort ex. Tanaka)]. Se caracteriza por presentar maduración tardía y un bajo número de semillas en los frutos, debido a la esterilidad gamética inducida. Pero la irradiación también produce otros efectos no deseados como, en el caso particular de la mandarina "Orri" el bajo cuajado y reducido tamaño del fruto. Los factores endógenos que determinan el cuajado son de tipo nutricional y hormonal. El ovario de la flor de "Orri" es deficiente en la síntesis de giberelinas y presenta una tasa de división celular reducida, que se traducen en desarrollo deficiente. Además, no responde a las aplicaciones de giberelinas y citoquininas para mejorar su transición a fruto en desarrollo. Por otra parte, se desconoce la importancia que los factores nutricionales tienen en el cuajado de esta variedad. Con el fin último de mejorar su producción, el presente TFM plantea el objetivo de determinar la influencia de los factores nutricionales en el cuajado de la mandarina "Orri". Para ello se rayaron y defoliaron ramas, en árboles con diferente capacidad productiva, con la finalidad de estudiar su efecto sobre la producción y los factores fisiológicos responsables del cuajado. El rayado de ramas redujo la expresión del gen B-SNRK1 (indicador de estrés nutricional) y aumento la expresión del gen CYCA1.1 (división celular) y PIN1 (transporte basípeto de auxinas), aumentando la tasa de desarrollo del fruto, el porcentaje de cuajado y la producción. La defoliación provocó el efecto contrario. Pero el aumento de la división celular no se relacionó con la síntesis de GAs, lo que confirma la deficiencia en el metabolismo de esta hormona durante el cuajado de la mandarina "Orri"., [EN] The "Orri" mandarin is a hybrid variety obtained by irradiation of the "Orah" variety [Temple (Citrus temple Hort ex. Y. Tanaka) × Dancy (Citrus tangerina Hort ex. Tanaka)]. It is characterized by presenting late maturation and a low number of seeds in the fruits, due to the induced gametic sterility. But irradiation also produces other unwanted effects such as, in the particular case of the "Orri" mandarin, the low fruit set and reduced size of the fruit. The endogenous factors that determine fruit set are nutritional and hormonal. The ovary of the "Orri" flower is deficient in the synthesis of gibberellins and has a reduced rate of cell division, which results in poor development. Furthermore, it does not respond to the applications of gibberellins and cytokinins to improve its transition to developing fruit. On the other hand, the importance of nutritional factors in the fruit set of this variety is unknown. With the ultimate aim of improving its production, this TFM sets out the objective of determining the influence of nutritional factors in the fruit set of the "Orri" mandarin. For this, branches were girdled and defoliated in order to study their effect on yield. Branch girdling reduced nutritional stress (¿-SNRK1 gene expression) and increased the rate of cell division (CYCA1.1 gene expression) and basipetal transport of auxins (PIN1 gene expression). But the increase in cell division was not related to the synthesis of GAs, which confirms the deficiency in GA-metabolism during "Orri¿ fruit set.

In arctic ecosystems, climate change has increased plant productivity. As arctic carbon (C) stocks predominantly are located belowground, the effects of greater plant productivity on soil C storage will significantly determine the net sink/source potential of these ecosystems, but vegetation controls on soil CO2 efflux remain poorly resolved. In order to identify the role of canopy‐forming species in belowground C dynamics, we conducted a girdling experiment with plots distributed across 1 km2 of treeline birch (Betula pubescens ) forest and willow (Salix lapponum ) patches in northern Sweden and quantified the contribution of canopy vegetation to soil CO2 fluxes and belowground productivity. Girdling birches reduced total soil CO2 efflux in the peak growing season by 53%, which is double the expected amount, given that trees contribute only half of the total leaf area in the forest. Root and mycorrhizal mycelial production also decreased substantially. At peak season, willow shrubs contributed 38% to soil CO2 efflux in their patches. Our findings indicate that C, recently fixed by trees and tall shrubs, makes a substantial contribution to soil respiration. It is critically important that these processes are taken into consideration in the context of a greening arctic because productivity and ecosystem C sequestration are not synonymous.

In arctic ecosystems, climate change has increased plant productivity. As arctic carbon (C) stocks predominantly are located belowground, the effects of greater plant productivity on soil C storage will significantly determine the net sink/source potential of these ecosystems, but vegetation controls on soil CO2 efflux remain poorly resolved. In order to identify the role of canopy‐forming species in belowground C dynamics, we conducted a girdling experiment with plots distributed across 1 km2 of treeline birch (Betula pubescens ) forest and willow (Salix lapponum ) patches in northern Sweden and quantified the contribution of canopy vegetation to soil CO2 fluxes and belowground productivity. Girdling birches reduced total soil CO2 efflux in the peak growing season by 53%, which is double the expected amount, given that trees contribute only half of the total leaf area in the forest. Root and mycorrhizal mycelial production also decreased substantially. At peak season, willow shrubs contributed 38% to soil CO2 efflux in their patches. Our findings indicate that C, recently fixed by trees and tall shrubs, makes a substantial contribution to soil respiration. It is critically important that these processes are taken into consideration in the context of a greening arctic because productivity and ecosystem C sequestration are not synonymous.

In arctic ecosystems, climate change has increased plant productivity. As arctic carbon (C) stocks predominantly are located belowground, the effects of greater plant productivity on soil C storage will significantly determine the net sink/source potential of these ecosystems, but vegetation controls on soil CO2 efflux remain poorly resolved. In order to identify the role of canopy‐forming species in belowground C dynamics, we conducted a girdling experiment with plots distributed across 1 km2 of treeline birch (Betula pubescens ) forest and willow (Salix lapponum ) patches in northern Sweden and quantified the contribution of canopy vegetation to soil CO2 fluxes and belowground productivity. Girdling birches reduced total soil CO2 efflux in the peak growing season by 53%, which is double the expected amount, given that trees contribute only half of the total leaf area in the forest. Root and mycorrhizal mycelial production also decreased substantially. At peak season, willow shrubs contributed 38% to soil CO2 efflux in their patches. Our findings indicate that C, recently fixed by trees and tall shrubs, makes a substantial contribution to soil respiration. It is critically important that these processes are taken into consideration in the context of a greening arctic because productivity and ecosystem C sequestration are not synonymous.

In arctic ecosystems, climate change has increased plant productivity. As arctic carbon (C) stocks predominantly are located belowground, the effects of greater plant productivity on soil C storage will significantly determine the net sink/source potential of these ecosystems, but vegetation controls on soil CO2 efflux remain poorly resolved. In order to identify the role of canopy‐forming species in belowground C dynamics, we conducted a girdling experiment with plots distributed across 1 km2 of treeline birch (Betula pubescens ) forest and willow (Salix lapponum ) patches in northern Sweden and quantified the contribution of canopy vegetation to soil CO2 fluxes and belowground productivity. Girdling birches reduced total soil CO2 efflux in the peak growing season by 53%, which is double the expected amount, given that trees contribute only half of the total leaf area in the forest. Root and mycorrhizal mycelial production also decreased substantially. At peak season, willow shrubs contributed 38% to soil CO2 efflux in their patches. Our findings indicate that C, recently fixed by trees and tall shrubs, makes a substantial contribution to soil respiration. It is critically important that these processes are taken into consideration in the context of a greening arctic because productivity and ecosystem C sequestration are not synonymous.

‘Hass’ avocado fruit changes skin colour from green to purple and then black during ripening. However, markets importing South African avocado fruit have been complaining about the ‘Hass’ skin colour not changing to purple/black during ripening. Thus, the study aimed to investigate the effect of tree girdling, harvest time and ripening temperature on ‘Hass’ avocado fruit skin colour development during ripening. The mature ‘Hass’ avocado fruit were harvested from girdled and non-girdled trees during early (April), mid- (May) and late (June) harvest times. Upon arrival, in the laboratory fruit were cold stored at 5.5°C for 28 days. After storage, fruit were ripened at 25, 21 and 16°C for 8, 6 and 4 days, respectively. After withdrawal from clod storage fruit were evaluated for skin colour development, ripening and physiological disorders (chilling injury). Fruit from girdled trees showed high maturity (low moisture content) when compared with fruit from non-girdled trees during early and mid-harvest. With respect to skin colour development, the results indicate that skin eye colour development of fruit from girdled and non-girdled trees minimally increased from emerald green (1) to olive green (3) across all harvest times, ripening temperature and ripening duration. However, late season fruit from non-girdled trees improved to purple (4) when ripened at 21°C when compared with fruit from girdled trees. In terms of objective colour, lightness, hue angle and chroma decreased for fruit from girdled and non-girdled trees, across all harvest times, ripening temperature and ripening duration. Lightness and hue angle of fruit from girdled trees were slightly reduced when compared with fruit from non-girdled trees, throughout all harvest times, ripening temperature and duration. Early and mid-season fruit harvested from girdled trees showed rapid decrease of chroma when compared with fruit from non-girdled trees, throughout ripening temperature and x duration. In terms of sof

‘Hass’ avocado fruit changes skin colour from green to purple and then black during ripening. However, markets importing South African avocado fruit have been complaining about the ‘Hass’ skin colour not changing to purple/black during ripening. Thus, the study aimed to investigate the effect of tree girdling, harvest time and ripening temperature on ‘Hass’ avocado fruit skin colour development during ripening. The mature ‘Hass’ avocado fruit were harvested from girdled and non-girdled trees during early (April), mid- (May) and late (June) harvest times. Upon arrival, in the laboratory fruit were cold stored at 5.5°C for 28 days. After storage, fruit were ripened at 25, 21 and 16°C for 8, 6 and 4 days, respectively. After withdrawal from clod storage fruit were evaluated for skin colour development, ripening and physiological disorders (chilling injury). Fruit from girdled trees showed high maturity (low moisture content) when compared with fruit from non-girdled trees during early and mid-harvest. With respect to skin colour development, the results indicate that skin eye colour development of fruit from girdled and non-girdled trees minimally increased from emerald green (1) to olive green (3) across all harvest times, ripening temperature and ripening duration. However, late season fruit from non-girdled trees improved to purple (4) when ripened at 21°C when compared with fruit from girdled trees. In terms of objective colour, lightness, hue angle and chroma decreased for fruit from girdled and non-girdled trees, across all harvest times, ripening temperature and ripening duration. Lightness and hue angle of fruit from girdled trees were slightly reduced when compared with fruit from non-girdled trees, throughout all harvest times, ripening temperature and duration. Early and mid-season fruit harvested from girdled trees showed rapid decrease of chroma when compared with fruit from non-girdled trees, throughout ripening temperature and x duration. In terms of sof

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.

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.

Water relations are among the major factors affecting shoot growth and plant vegetative vigor. In many tree crops, dwarfing rootstocks regulate scion vegetative vigor by reducing plant hydraulic conductance. In Prunus spp. reduced xylem vessel size leads to reduced hydraulic conductance, but reduction of annual xylem tissue growth could have similar results. The aim of the present work was to investigate the effects of techniques that allow to manipulate xylem tissue growth on tree vegetative vigor. Two different techniques, early trunk girdling and trunk constriction were applied on peach and on olive trees, respectively. In 2010, at the KAC, Parlier, CA, USA, very early girdling (March 31) and late girdling (April 15) were carried out on 8-year-old ‘Springcrest’/‘Nemaguard’ trees. On peach trees, a deciduous species, early girdling (few weeks after sprouting) caused a significant decrease of early season stem water potential and vegetative growth in comparison with trees in which girdling was carried out later in the season and control trees, respectively. On olive trees a plastic strap was applied in December 2008 to cause a trunk constriction limiting trunk growth during the vegetative season. Three-year-old trees of five cultivars grown in super high-density orchard (1600 tree ha-1) near Perugia, Italy, were used for the experiment. Midday stem water potential was lower in constricted trees than in control trees. At the end of the experiment constricted trees had smaller vegetative growth than control trees. Constriction increased yield efficiency, but severe reduction of vegetative growth triggered alternate bearing in the following year. The results of these experiments underline the role of xylem conductance in regulating tree vegetative growth. Techniques aimed at manipulating trunk/branch xylem growth can be effective in reducing tree vegetative growth in tree horticultural species.

The objective of this study was to evaluate the effect of foliar application of products for fruit set, production and quality of Hass avocado. This research was performed in a terrain that is located in a moderately cold weather, in Antioquia, Colombia. Factors for inducing flowering, types of inflorescence and production alternation were determined. In addition to the aforementioned, simple and combined foliar application of acid 1–naphthaleneacetic (ANA), boron, nitrogen, saccharose as source energy, and girding branches, was performed. For the experiment we used a complete block experimental design, with five replicates per treatment and a single tree as experimental unit, with three evaluations over time (2010, 2011 and 2012). The variables evaluated were initial and final fruit set, quantity, and quality of produced fruit. Results associated with this study indicate that floral induction in this variety occurs in periods of low rainfall and low temperatures, the inflorescences were mostly of an indeterminate type, and a slight alternation of production occurred. Initial fruit and final set increased with girdling branches and with the application of boron and girdling branches in 28% and 33% respectively, but this treatments did not improve the production, instead the production was favored by adding saccharose alone, and in combination with boron, nitrogen and ANA, it presented increments of 14,5, 15.9, 14.9 and 14.4% respectively. Results indicate that the addition of an individual external energy source combined with the foliar application of boron, nitrogen and ANA, improves the quality and quantity of fruit in the Hass avocado., El objetivo de este trabajo fue evaluar el efecto de la aplicación foliar de productos para el amarre, producción y calidad de los frutos de aguacate Hass. Esta investigación se realizó en el departamento de Antioquia, Colombia, en un lote de clima frío moderado. Se determinaron los factores de inducción de la floración, tipos de inflorescencia y alternancia de cosechas. Se realizó el anillado de ramas y aplicaciones foliares simple y combinada de ácido 1–naftalenacético (ANA), boro, nitrógeno y sacarosa como fuente de energía. Se utilizó un diseño de bloques completos con cinco repeticiones y un árbol como unidad experimental, con tres evaluaciones (2010, 2011 y 2012). Se evaluó el amarre inicial y final, la cantidad y la calidad de la fruta producida. Los resultados indicaron que la inducción floral se presentó en periodos de menor precipitación con bajas temperaturas; las inflorescencias fueron en su mayoría indeterminadas, y se presentó una alternancia leve de producción. El amarre inicial del fruto se incrementó con el anillado y la aplicación de boro (28%), mientras que el amarre final se favoreció con el anillado en 33%; estos resultados no mejoraron la producción, característica que se incrementó con la adición de sacarosa sola y en combinación con boro, nitrógeno y ANA en un 14.5, 15.9, 14.9 y 14.4%, respectivamente. La adición de sacarosa individual y combinada con la aplicación foliar de boro, nitrógeno y ANA, mejoraron la calidad y cantidad de fruta en la variedad Hass

The objective of this study was to evaluate the effect of foliar application of products for fruit set, production and quality of Hass avocado. This research was performed in a terrain that is located in a moderately cold weather, in Antioquia, Colombia. Factors for inducing flowering, types of inflorescence and production alternation were determined. In addition to the aforementioned, simple and combined foliar application of acid 1–naphthaleneacetic (ANA), boron, nitrogen, saccharose as source energy, and girding branches, was performed. For the experiment we used a complete block experimental design, with five replicates per treatment and a single tree as experimental unit, with three evaluations over time (2010, 2011 and 2012). The variables evaluated were initial and final fruit set, quantity, and quality of produced fruit. Results associated with this study indicate that floral induction in this variety occurs in periods of low rainfall and low temperatures, the inflorescences were mostly of an indeterminate type, and a slight alternation of production occurred. Initial fruit and final set increased with girdling branches and with the application of boron and girdling branches in 28% and 33% respectively, but this treatments did not improve the production, instead the production was favored by adding saccharose alone, and in combination with boron, nitrogen and ANA, it presented increments of 14,5, 15.9, 14.9 and 14.4% respectively. Results indicate that the addition of an individual external energy source combined with the foliar application of boron, nitrogen and ANA, improves the quality and quantity of fruit in the Hass avocado., El objetivo de este trabajo fue evaluar el efecto de la aplicación foliar de productos para el amarre, producción y calidad de los frutos de aguacate Hass. Esta investigación se realizó en el departamento de Antioquia, Colombia, en un lote de clima frío moderado. Se determinaron los factores de inducción de la floración, tipos de inflorescencia y alternancia de cosechas. Se realizó el anillado de ramas y aplicaciones foliares simple y combinada de ácido 1–naftalenacético (ANA), boro, nitrógeno y sacarosa como fuente de energía. Se utilizó un diseño de bloques completos con cinco repeticiones y un árbol como unidad experimental, con tres evaluaciones (2010, 2011 y 2012). Se evaluó el amarre inicial y final, la cantidad y la calidad de la fruta producida. Los resultados indicaron que la inducción floral se presentó en periodos de menor precipitación con bajas temperaturas; las inflorescencias fueron en su mayoría indeterminadas, y se presentó una alternancia leve de producción. El amarre inicial del fruto se incrementó con el anillado y la aplicación de boro (28%), mientras que el amarre final se favoreció con el anillado en 33%; estos resultados no mejoraron la producción, característica que se incrementó con la adición de sacarosa sola y en combinación con boro, nitrógeno y ANA en un 14.5, 15.9, 14.9 y 14.4%, respectivamente. La adición de sacarosa individual y combinada con la aplicación foliar de boro, nitrógeno y ANA, mejoraron la calidad y cantidad de fruta en la variedad Hass

Autumn senescence is a visually spectacular phenomenon in which trees prepare for the oncoming winter. The mechanism for regulation of autumn senescence in trees has been very hard to pinpoint. In this thesis the main focus is to investigate how autumn senescence is regulated in aspens (Populus tremula). Previous work has established that autumn senescence in aspens is under daylight control, in this thesis the metabolic status and the effect on autumn senescence was investigated. The metabolic status was altered by girdling which leads to accumulation of photosynthates in the canopy. This resulted in an earlier onset of senescence but also the speed of senescence was changed. At the onset of senescence the girdled trees also accumulated or retained anthocyanins. The nitrogen status of aspens during autumn senescence was also investigated, we found that high doses of fertilization could significantly delay the onset of senescence. The effects of various nitrogen forms was investigated by delivering organic and inorganic nitrogen through a precision fertilization delivery system that could inject solutes directly into the xylem of the mature aspens. The study showed that addition of nitrate delayed senescence, addition of arginine did not have any effect on the autumn senescence in aspens, and furthermore the nitrate altered the trees leaf metabolism that was more profound in high dosages of supplied nitrate. Cytokinins are plant hormones believed to delay or block senescence, studies have suggested that the decrease of cytokinins and/or cytokinin signalling may precede senescence in some plants. To investigate how cytokinin regulates autumn senescence in aspens we profiled 34 cytokinin types in a free growing mature aspen. The study begun before autumn senescence was initiated and ended with the shedding of the leaves, and spanned three consecutive years. The study showed that the individual cytokinin profiles varied significantly between the years, this despite th

Autumn senescence is a visually spectacular phenomenon in which trees prepare for the oncoming winter. The mechanism for regulation of autumn senescence in trees has been very hard to pinpoint. In this thesis the main focus is to investigate how autumn senescence is regulated in aspens (Populus tremula). Previous work has established that autumn senescence in aspens is under daylight control, in this thesis the metabolic status and the effect on autumn senescence was investigated. The metabolic status was altered by girdling which leads to accumulation of photosynthates in the canopy. This resulted in an earlier onset of senescence but also the speed of senescence was changed. At the onset of senescence the girdled trees also accumulated or retained anthocyanins. The nitrogen status of aspens during autumn senescence was also investigated, we found that high doses of fertilization could significantly delay the onset of senescence. The effects of various nitrogen forms was investigated by delivering organic and inorganic nitrogen through a precision fertilization delivery system that could inject solutes directly into the xylem of the mature aspens. The study showed that addition of nitrate delayed senescence, addition of arginine did not have any effect on the autumn senescence in aspens, and furthermore the nitrate altered the trees leaf metabolism that was more profound in high dosages of supplied nitrate. Cytokinins are plant hormones believed to delay or block senescence, studies have suggested that the decrease of cytokinins and/or cytokinin signalling may precede senescence in some plants. To investigate how cytokinin regulates autumn senescence in aspens we profiled 34 cytokinin types in a free growing mature aspen. The study begun before autumn senescence was initiated and ended with the shedding of the leaves, and spanned three consecutive years. The study showed that the individual cytokinin profiles varied significantly between the years, this despite th

Autumn senescence is a visually spectacular phenomenon in which trees prepare for the oncoming winter. The mechanism for regulation of autumn senescence in trees has been very hard to pinpoint. In this thesis the main focus is to investigate how autumn senescence is regulated in aspens (Populus tremula). Previous work has established that autumn senescence in aspens is under daylight control, in this thesis the metabolic status and the effect on autumn senescence was investigated. The metabolic status was altered by girdling which leads to accumulation of photosynthates in the canopy. This resulted in an earlier onset of senescence but also the speed of senescence was changed. At the onset of senescence the girdled trees also accumulated or retained anthocyanins. The nitrogen status of aspens during autumn senescence was also investigated, we found that high doses of fertilization could significantly delay the onset of senescence. The effects of various nitrogen forms was investigated by delivering organic and inorganic nitrogen through a precision fertilization delivery system that could inject solutes directly into the xylem of the mature aspens. The study showed that addition of nitrate delayed senescence, addition of arginine did not have any effect on the autumn senescence in aspens, and furthermore the nitrate altered the trees leaf metabolism that was more profound in high dosages of supplied nitrate. Cytokinins are plant hormones believed to delay or block senescence, studies have suggested that the decrease of cytokinins and/or cytokinin signalling may precede senescence in some plants. To investigate how cytokinin regulates autumn senescence in aspens we profiled 34 cytokinin types in a free growing mature aspen. The study begun before autumn senescence was initiated and ended with the shedding of the leaves, and spanned three consecutive years. The study showed that the individual cytokinin profiles varied significantly between the years, this despite th

Autumn senescence is a visually spectacular phenomenon in which trees prepare for the oncoming winter. The mechanism for regulation of autumn senescence in trees has been very hard to pinpoint. In this thesis the main focus is to investigate how autumn senescence is regulated in aspens (Populus tremula). Previous work has established that autumn senescence in aspens is under daylight control, in this thesis the metabolic status and the effect on autumn senescence was investigated. The metabolic status was altered by girdling which leads to accumulation of photosynthates in the canopy. This resulted in an earlier onset of senescence but also the speed of senescence was changed. At the onset of senescence the girdled trees also accumulated or retained anthocyanins. The nitrogen status of aspens during autumn senescence was also investigated, we found that high doses of fertilization could significantly delay the onset of senescence. The effects of various nitrogen forms was investigated by delivering organic and inorganic nitrogen through a precision fertilization delivery system that could inject solutes directly into the xylem of the mature aspens. The study showed that addition of nitrate delayed senescence, addition of arginine did not have any effect on the autumn senescence in aspens, and furthermore the nitrate altered the trees leaf metabolism that was more profound in high dosages of supplied nitrate. Cytokinins are plant hormones believed to delay or block senescence, studies have suggested that the decrease of cytokinins and/or cytokinin signalling may precede senescence in some plants. To investigate how cytokinin regulates autumn senescence in aspens we profiled 34 cytokinin types in a free growing mature aspen. The study begun before autumn senescence was initiated and ended with the shedding of the leaves, and spanned three consecutive years. The study showed that the individual cytokinin profiles varied significantly between the years, this despite th

Autumn senescence is a visually spectacular phenomenon in which trees prepare for the oncoming winter. The mechanism for regulation of autumn senescence in trees has been very hard to pinpoint. In this thesis the main focus is to investigate how autumn senescence is regulated in aspens (Populus tremula). Previous work has established that autumn senescence in aspens is under daylight control, in this thesis the metabolic status and the effect on autumn senescence was investigated. The metabolic status was altered by girdling which leads to accumulation of photosynthates in the canopy. This resulted in an earlier onset of senescence but also the speed of senescence was changed. At the onset of senescence the girdled trees also accumulated or retained anthocyanins. The nitrogen status of aspens during autumn senescence was also investigated, we found that high doses of fertilization could significantly delay the onset of senescence. The effects of various nitrogen forms was investigated by delivering organic and inorganic nitrogen through a precision fertilization delivery system that could inject solutes directly into the xylem of the mature aspens. The study showed that addition of nitrate delayed senescence, addition of arginine did not have any effect on the autumn senescence in aspens, and furthermore the nitrate altered the trees leaf metabolism that was more profound in high dosages of supplied nitrate. Cytokinins are plant hormones believed to delay or block senescence, studies have suggested that the decrease of cytokinins and/or cytokinin signalling may precede senescence in some plants. To investigate how cytokinin regulates autumn senescence in aspens we profiled 34 cytokinin types in a free growing mature aspen. The study begun before autumn senescence was initiated and ended with the shedding of the leaves, and spanned three consecutive years. The study showed that the individual cytokinin profiles varied significantly between the years, this despite th

Stem or trunk girdling is a technique used in physiological studies and in horticultural practice for interrupting carbon flow through the phloem to other parts of the plant without influencing water flow in the xylem. Trunk girdling in peaches is practiced primarily to stimulate fruit growth but it also tends to decrease shoot vigour for a period of time after girdling. Water flow through the trunk or branches of peach trees is thought to be primarily dependent on the most recently formed ring of xylem and vegetative growth is closely related to stem water potential and stem hydraulic conductance. The aim of the present work was to determine whether vigour reduction due to girdling was correlated with a reduction in midday stem water potential during the period of time between girdling and the subsequent healing of stem tissue. 'Springcrest' peach trees were girdled on two different dates. Fruit yield and size, water sprout growth, proleptic shoot growth and stem water potential were measured. Early and late girdled trees yielded larger fruits and fewer and shorter water sprouts in comparison with control trees. Midday stem water potential declined significantly after girdling and gradually recovered until the time of fruit harvest. These results suggest that the vigour reduction of girdled trees is related to a decrease of midday stem water potential caused by girdling. Early tree girdling increased the reduction in midday stem water potential and shoot growth compared with the later girdling treatment. These results point out that even though girdling only removes bark and phloem tissue it can apparently affect water flow in xylem.

To improve fruit quality in grape cv. Flame Seedless, application of Ethephon (400 and 500 ppm) and trunk girdling was done at veraison stage. Cluster thinning was done by retaining 100, 75 and 50% of total number of bunches on the vines, and, the rest were removed immediately after full bloom. Highest yield was obtained in the treatment 100% Crop load + 500ppm Ethephon, followed by 75% Crop load + 500ppm Ethephon. The treatment of 50% Crop load + 500ppm Ethephon resulted in maximum bunch weight, lowest percentage of uneven coloured berries, maximum TSS, minimum acidity and maximum TSS:acid ratio, maximum anthocyanin content, advanced maturity by 9 days and had maximum sensory rating. But, in this treatment, yield was significantly lower than in treatments where either 75% or 100% Crop load was retained. Thus, considering yield as well as quality parameters, the treatment 75% Crop load + 500ppm Ethephon was found to be the best.

To improve fruit quality in grape cv. Flame Seedless, application of Ethephon (400 and 500 ppm) and trunk girdling was done at veraison stage. Cluster thinning was done by retaining 100, 75 and 50% of total number of bunches on the vines, and, the rest were removed immediately after full bloom. Highest yield was obtained in the treatment 100% Crop load + 500ppm Ethephon, followed by 75% Crop load + 500ppm Ethephon. The treatment of 50% Crop load + 500ppm Ethephon resulted in maximum bunch weight, lowest percentage of uneven coloured berries, maximum TSS, minimum acidity and maximum TSS:acid ratio, maximum anthocyanin content, advanced maturity by 9 days and had maximum sensory rating. But, in this treatment, yield was significantly lower than in treatments where either 75% or 100% Crop load was retained. Thus, considering yield as well as quality parameters, the treatment 75% Crop load + 500ppm Ethephon was found to be the best.

The objective of this research was to determine the changes in the levels of endogenous gibberellins GA(1) and GA(4), abscisic acid (ABA), and ethylene during fruit coloring of on-tree fruits of sweet orange. The time course of carbohydrates and nitrogen content in the flavedo prior to fruit color break and during peel ripening were also studied. To identify nutritional and hormonal changes in the fruit, 45 days before fruit color break the peduncles of 15-30 fruits per tree of 'Washington' navel, 'Navelate,' and 'Valencia Delta Seedless' sweet orange, located in single-fruited shoots, were girdled to intercept phloem transport. A set of 15-30 fruits per tree remained intact on the peduncle for control. Girdling significantly delayed fruit coloration for more than 2 months; the delay paralleled higher GA(1) and GA(4) concentrations in the flavedo and retarded the rise of ABA concentration prior to color break. Girdling also reduced carbohydrate concentrations and increased N concentrations in the flavedo compared to control fruits; no ethylene production was detected. Therefore, in sweet orange, fruit changes color by reducing active gibberellin concentrations in the flavedo, which are involved in regulating sugars and ABA accumulation and in reducing N fraction concentration as rind color develops. This was demonstrated in vivo without removing the fruit from the tree. Comparable results were obtained with experiments carried out over four consecutive years in two countries (Spain and Uruguay).

The objective of this research was to determine the changes in the levels of endogenous gibberellins GA(1) and GA(4), abscisic acid (ABA), and ethylene during fruit coloring of on-tree fruits of sweet orange. The time course of carbohydrates and nitrogen content in the flavedo prior to fruit color break and during peel ripening were also studied. To identify nutritional and hormonal changes in the fruit, 45 days before fruit color break the peduncles of 15-30 fruits per tree of 'Washington' navel, 'Navelate,' and 'Valencia Delta Seedless' sweet orange, located in single-fruited shoots, were girdled to intercept phloem transport. A set of 15-30 fruits per tree remained intact on the peduncle for control. Girdling significantly delayed fruit coloration for more than 2 months; the delay paralleled higher GA(1) and GA(4) concentrations in the flavedo and retarded the rise of ABA concentration prior to color break. Girdling also reduced carbohydrate concentrations and increased N concentrations in the flavedo compared to control fruits; no ethylene production was detected. Therefore, in sweet orange, fruit changes color by reducing active gibberellin concentrations in the flavedo, which are involved in regulating sugars and ABA accumulation and in reducing N fraction concentration as rind color develops. This was demonstrated in vivo without removing the fruit from the tree. Comparable results were obtained with experiments carried out over four consecutive years in two countries (Spain and Uruguay).

Photosynthesis down-regulation due to an imbalance between sources and sinks in Citrus leaves could be mediated by excessive accumulation of carbohydrates. However, there is limited understanding of the physiological role of soluble and insoluble carbohydrates in photosynthesis regulation and the elements triggering the down-regulation process. In this work, the role of non-structural carbohydrates in the regulation of photosynthesis under a broad spectrum of source-sink relationships has been investigated in the Salustiana sweet orange. Soluble sugar and starch accumulation in leaves, induced by girdling experiments, did not induce down-regulation of the photosynthetic rate in the presence of sinks (fruits). The leaf-to-fruit ratio did not modulate photosynthesis but allocation of photoassimilates to the fruits. The lack of strong sink activity led to a decrease in the photosynthetic rate and starch accumulation in leaves. However, photosynthesis down-regulation due to an excess of total soluble sugars or starch was discarded because photosynthesis and stomatal conductance reduction occurred prior to any significant accumulation of these carbohydrates. Gas exchange and fluorescence parameters suggested biochemical limitations to photosynthesis. In addition, the expression of carbon metabolism-related genes was altered within 24 h when strong sinks were removed. Sucrose synthesis and export genes were inhibited, whereas the expression of ADP-glucose pyrophosphorylase was increased to cope with the excess of assimilates. In conclusion, changes in starch and soluble sugar turnover, but not sugar content per se, could provide the signal for photosynthesis regulation. In these conditions, non-stomatal limitations strongly inhibited the photosynthetic rate prior to any significant increase in carbohydrate levels. © The Author 2011. Published by Oxford University Press. All rights reserved.

Photosynthesis down-regulation due to an imbalance between sources and sinks in Citrus leaves could be mediated by excessive accumulation of carbohydrates. However, there is limited understanding of the physiological role of soluble and insoluble carbohydrates in photosynthesis regulation and the elements triggering the down-regulation process. In this work, the role of non-structural carbohydrates in the regulation of photosynthesis under a broad spectrum of source-sink relationships has been investigated in the Salustiana sweet orange. Soluble sugar and starch accumulation in leaves, induced by girdling experiments, did not induce down-regulation of the photosynthetic rate in the presence of sinks (fruits). The leaf-to-fruit ratio did not modulate photosynthesis but allocation of photoassimilates to the fruits. The lack of strong sink activity led to a decrease in the photosynthetic rate and starch accumulation in leaves. However, photosynthesis down-regulation due to an excess of total soluble sugars or starch was discarded because photosynthesis and stomatal conductance reduction occurred prior to any significant accumulation of these carbohydrates. Gas exchange and fluorescence parameters suggested biochemical limitations to photosynthesis. In addition, the expression of carbon metabolism-related genes was altered within 24 h when strong sinks were removed. Sucrose synthesis and export genes were inhibited, whereas the expression of ADP-glucose pyrophosphorylase was increased to cope with the excess of assimilates. In conclusion, changes in starch and soluble sugar turnover, but not sugar content per se, could provide the signal for photosynthesis regulation. In these conditions, non-stomatal limitations strongly inhibited the photosynthetic rate prior to any significant increase in carbohydrate levels. © The Author 2011. Published by Oxford University Press. All rights reserved.

In Chile, most avocado orchards have been planted using 'Hass' as the scion variety on seedling rootstocks. This has led to the presence of a large variety of individuals, some of which show, among other characteristics, high productivity and a low degree of biennial bearing cycle in the same growing conditions. The most common method used in other countries to propagate such rootstocks from trees involves severe topping; however, this technique is notably destructive, making it difficult to employ in commercial orchards. With the goal of developing alternate methods for forcing shoot production from the rootstock, we tested two different procedures in July 2002 and March 2003, respectively: wounding in conjunction with the application of 1.1 M or 2.2 M benzylaminopurine (BAP) and the removal of one half of the tree canopy (on a vertical plane) and girdling (at widths of 2 or 5 mm). The results indicate that, by removing the top layer of the soil, wounding and applying the BAP spray (1.1 M in July), it is possible to force the production of epicormic or basal sprouting from the rootstock. Additionally, vigorous shoots were obtained on both evaluation dates through the removal of half of the canopy or through girdling., En Chile, la mayoría de los huertos de palto (Persea americana Mill.) sobre los cuales se encuentra el injerto 'Hass' están sobre portainjertos provenientes de semilla. La influencia de las características propias del portainjerto ha dado como resultado la existencia de una amplia variedad de individuos con distintos niveles de producción y alternancia en iguales condiciones de crecimiento. En otros países, se han desarrollado técnicas como la poda completa del árbol para la clonación de portainjetos, sin embargo esta técnica es altamente destructiva y difícil de implementar en huertos comerciales. Por esta razón se desarrolló una metodología, con el objetivo de obtener brotación de brotes epicórmicos o renuevos basales desde el portainjerto, en dos épocas distintas (julio y marzo, durante los años 2002 y 2003, respectivamente), a través del lesionado y la aplicación de bencilaminopurina (BAP) en dos concentraciones (1,1 y 2,2 M) y rebaje parcial del árbol y anillado (de 2 y 5 mm). Los resultados obtenidos mostraron que mediante el lesionado y aplicación de BAP 1,1 M en julio, se obtuvieron brotes epicórmicos o basales desde la zona del portainjerto; al podar parcialmente el árbol; y que al anillar se logra obtener brotes vigorosos en ambas épocas de evaluación.

Beetles from genus Oncideres, known as twig girdler, have the habit of girdle branches of healthy trees, where they lay their eggs, to establish an appropriate environment to the development of the larvae. This study had the objective of characterize the injuries caused by O. impluviata in Piptadenia gonoacantha, quantify and position the eggs incisions in trees of this forest specie. The results showed that 63.16% of girdled branches were located on the upper third of the trees, with average girdle height above ground of 2.76±0.14 m. The average diameter and height of girdled branches were 1.32±0.04 cm and 1.18±0.03 m, respectively. The average number of incisions per branch was 5.9±1.24, which were located at higher frequency on the lower third of girdled branch. Can be concluded that the twig girdle beetle O. impluviata girdle mostly lateral branches located at the upper third of the tree and lay their eggs mostly on the lower third of the girdled branch, decreasing as advance to the upper third of the twig., Besouros do gênero Oncideres, conhecidos por serradores, possuem o hábito de roletar galhos de árvores em pleno vigor, onde fazem incisões de posturas, para estabelecer, assim, um ambiente adequado para o desenvolvimento da fase jovem. O presente estudo objetivou caracterizar as injúrias causadas por O. impluviata em pau-jacaré (Piptadenia gonoacantha), quantificar e posicionar as incisões de postura em árvores de um plantio dessa essência florestal. Os resultados mostraram que 63,16% dos galhos roletados se encontravam no terço superior das árvores, com altura média dos roletamentos, em relação ao solo, igual a 2,76±0,14 m. O diâmetro e o comprimento médios dos galhos roletados foram iguais a 1,32±0,04 cm e 1,18±0,03 m, respectivamente. O número médio de incisões de postura por galho foi de 5,9±1,24 as quais estavam, com maior freqüência, na parte basal do galho roletado. Diante do exposto, pode-se concluir que o serrador O. impluviata roleta em sua maioria galhos laterais situados no terço superior da árvore e suas incisões de postura são realizadas principalmente no terço inferior do galho roletado diminuindo a medida que avança no sentido apical do galho.

In Chile, most avocado orchards have been planted using 'Hass' as the scion variety on seedling rootstocks. This has led to the presence of a large variety of individuals, some of which show, among other characteristics, high productivity and a low degree of biennial bearing cycle in the same growing conditions. The most common method used in other countries to propagate such rootstocks from trees involves severe topping; however, this technique is notably destructive, making it difficult to employ in commercial orchards. With the goal of developing alternate methods for forcing shoot production from the rootstock, we tested two different procedures in July 2002 and March 2003, respectively: wounding in conjunction with the application of 1.1 M or 2.2 M benzylaminopurine (BAP) and the removal of one half of the tree canopy (on a vertical plane) and girdling (at widths of 2 or 5 mm). The results indicate that, by removing the top layer of the soil, wounding and applying the BAP spray (1.1 M in July), it is possible to force the production of epicormic or basal sprouting from the rootstock. Additionally, vigorous shoots were obtained on both evaluation dates through the removal of half of the canopy or through girdling., En Chile, la mayoría de los huertos de palto (Persea americana Mill.) sobre los cuales se encuentra el injerto 'Hass' están sobre portainjertos provenientes de semilla. La influencia de las características propias del portainjerto ha dado como resultado la existencia de una amplia variedad de individuos con distintos niveles de producción y alternancia en iguales condiciones de crecimiento. En otros países, se han desarrollado técnicas como la poda completa del árbol para la clonación de portainjetos, sin embargo esta técnica es altamente destructiva y difícil de implementar en huertos comerciales. Por esta razón se desarrolló una metodología, con el objetivo de obtener brotación de brotes epicórmicos o renuevos basales desde el portainjerto, en dos épocas distintas (julio y marzo, durante los años 2002 y 2003, respectivamente), a través del lesionado y la aplicación de bencilaminopurina (BAP) en dos concentraciones (1,1 y 2,2 M) y rebaje parcial del árbol y anillado (de 2 y 5 mm). Los resultados obtenidos mostraron que mediante el lesionado y aplicación de BAP 1,1 M en julio, se obtuvieron brotes epicórmicos o basales desde la zona del portainjerto; al podar parcialmente el árbol; y que al anillar se logra obtener brotes vigorosos en ambas épocas de evaluación.

Besouros do gênero Oncideres, conhecidos por serradores, possuem o hábito de roletar galhos de árvores em pleno vigor, onde fazem incisões de posturas, para estabelecer, assim, um ambiente adequado para o desenvolvimento da fase jovem. O presente estudo objetivou caracterizar as injúrias causadas por O. impluviata em pau-jacaré (Piptadenia gonoacantha), quantificar e posicionar as incisões de postura em árvores de um plantio dessa essência florestal. Os resultados mostraram que 63,16% dos galhos roletados se encontravam no terço superior das árvores, com altura média dos roletamentos, em relação ao solo, igual a 2,76±0,14 m. O diâmetro e o comprimento médios dos galhos roletados foram iguais a 1,32±0,04 cm e 1,18±0,03 m, respectivamente. O número médio de incisões de postura por galho foi de 5,9±1,24 as quais estavam, com maior freqüência, na parte basal do galho roletado. Diante do exposto, pode-se concluir que o serrador O. impluviata roleta em sua maioria galhos laterais situados no terço superior da árvore e suas incisões de postura são realizadas principalmente no terço inferior do galho roletado diminuindo a medida que avança no sentido apical do galho., Beetles from genus Oncideres, known as twig girdler, have the habit of girdle branches of healthy trees, where they lay their eggs, to establish an appropriate environment to the development of the larvae. This study had the objective of characterize the injuries caused by O. impluviata in Piptadenia gonoacantha, quantify and position the eggs incisions in trees of this forest specie. The results showed that 63.16% of girdled branches were located on the upper third of the trees, with average girdle height above ground of 2.76±0.14 m. The average diameter and height of girdled branches were 1.32±0.04 cm and 1.18±0.03 m, respectively. The average number of incisions per branch was 5.9±1.24, which were located at higher frequency on the lower third of girdled branch. Can be concluded that the twig girdle beetle O. impluviata girdle mostly lateral branches located at the upper third of the tree and lay their eggs mostly on the lower third of the girdled branch, decreasing as advance to the upper third of the twig.

The effects of two times of branch girdling on fruit properties of three early season peach cultivars: Goldcrest, Royal Gold and Maycrest were studied. The fruits from girdled branches matured three to four days earlier, had higher soluble solids and sugars content and lower acids content in both years. Fruit weight was increased only in the first year while it was decreased in the second year. Girdling at about 30 days after full-bloom gave better results than that during petal-fall., Proučavani su efekti dva termina prstenovanja grana na osobine ploda tri rane sorte breskve: Goldcrest, Royal Gold i Maycrest. Plodovi sa prstenovanih grana sazrevali su ranije za tri do četiri dana, imali su viši sadržaj rastvorljive suve materije i šećera, a niži sadržaj kiselina u obe godine istraživanja. Masa ploda je bila povećana samo u prvoj godini, dok je u drugoj godini bila manja. Prstenovanje u terminu oko mesec dana posle punog cvetanja dalo je bolje rezultate nego ono izvedeno u precvetavanju.

The effects of two times of branch girdling on fruit properties of three early season peach cultivars: Goldcrest, Royal Gold and Maycrest were studied. The fruits from girdled branches matured three to four days earlier, had higher soluble solids and sugars content and lower acids content in both years. Fruit weight was increased only in the first year while it was decreased in the second year. Girdling at about 30 days after full-bloom gave better results than that during petal-fall., Proučavani su efekti dva termina prstenovanja grana na osobine ploda tri rane sorte breskve: Goldcrest, Royal Gold i Maycrest. Plodovi sa prstenovanih grana sazrevali su ranije za tri do četiri dana, imali su viši sadržaj rastvorljive suve materije i šećera, a niži sadržaj kiselina u obe godine istraživanja. Masa ploda je bila povećana samo u prvoj godini, dok je u drugoj godini bila manja. Prstenovanje u terminu oko mesec dana posle punog cvetanja dalo je bolje rezultate nego ono izvedeno u precvetavanju.

There has been an increased interest in characterizing and interpreting ecological heterogeneity over space and time in the past two decades. This is mainly due to the renewed recognition of the significance of heterogeneity in ecological theories. However, studies that have combined both spatial and temporal aspects of heterogeneity have been rare. A unified approach to define and quantify heterogeneity has also been lacking. Designed to overcome these problems, this study was conducted in a 40-year-old Pinus elliottii Engelm. forest at the Savannah River Site near Aiken, SC, USA with the following specific objectives: 1) to characterize the spatial patterns of soil and forest floor variables (moisture, pH, soil available nitrogen and phosphate, forest floor and soil carbon and nitrogen), 2) to examine the dynamics of these spatial patterns in response to two types of disturbance: whole-tree harvesting and girdling, and 3) to evaluate some of the current methods for quantifying ecological heterogeneity. In response to both disturbance treatments, spatial heterogeneity measured by sample variance showed a marked "increase and then decline" temporal pattern in soil moisture, soil available nitrogen and phosphorus. Similar patterns were not found in total soil C and N, and total litter C and N. Harvesting resulted in greater and more drastic changes in the variations of soil nutrients and water than did girdling. Despite the popularity of semivariogram analysis in recent ecological studies, the technique did not provide consistent results on patterns of heterogeneity in our system. A simulation experiment demonstrated that semivariogram analysis may suffer from many problems when it is used to characterize patchiness, one form of heterogeneity. The results from this study have a number of implications. First, spatial patterns of soil resources are high dynamic. The dynamics of patterns in soil resources may partly account for the weak correlation between vegetation an

There has been an increased interest in characterizing and interpreting ecological heterogeneity over space and time in the past two decades. This is mainly due to the renewed recognition of the significance of heterogeneity in ecological theories. However, studies that have combined both spatial and temporal aspects of heterogeneity have been rare. A unified approach to define and quantify heterogeneity has also been lacking. Designed to overcome these problems, this study was conducted in a 40-year-old Pinus elliottii Engelm. forest at the Savannah River Site near Aiken, SC, USA with the following specific objectives: 1) to characterize the spatial patterns of soil and forest floor variables (moisture, pH, soil available nitrogen and phosphate, forest floor and soil carbon and nitrogen), 2) to examine the dynamics of these spatial patterns in response to two types of disturbance: whole-tree harvesting and girdling, and 3) to evaluate some of the current methods for quantifying ecological heterogeneity. In response to both disturbance treatments, spatial heterogeneity measured by sample variance showed a marked "increase and then decline" temporal pattern in soil moisture, soil available nitrogen and phosphorus. Similar patterns were not found in total soil C and N, and total litter C and N. Harvesting resulted in greater and more drastic changes in the variations of soil nutrients and water than did girdling. Despite the popularity of semivariogram analysis in recent ecological studies, the technique did not provide consistent results on patterns of heterogeneity in our system. A simulation experiment demonstrated that semivariogram analysis may suffer from many problems when it is used to characterize patchiness, one form of heterogeneity. The results from this study have a number of implications. First, spatial patterns of soil resources are high dynamic. The dynamics of patterns in soil resources may partly account for the weak correlation between vegetation an

Meadow voles (Microtus pennsylvanicus), pine voles (M. pinetorum), and montane voles (M. montanus) cause significant economic damage in apple orchards throughout the eastern United States and in a few northwestern states where apples are grown commercially. By girdling the bark and roots, these rodents kill trees, reduce yields, and prolong the time for new plantings to come into production. We describe the identification, ecology, and behavior of voles in apple orchards, evaluate the types, extent, and magnitude of losses inflicted by these pests, and describe measures for reducing damage. cost-effective reduction. Proper selection, timing, and application is essential for obtaining best results with rodenticides.

Samples were exposed to higher temperatures, defoliation, partial defoliation and stem girgling. It is concluded that tracheid length is influenced by temperature both directly and indirectly; but that increases in cell length associated with increasing light intensity are not explainable in terms of carbohydrate accumulation. The major determinants of lumen diameter are probably hormonal, but temperature can act directly within this framework. Cell wall thickness is, to a large degree, influenced by carbohydrate availability but hormonal factors may also operate., Samples were exposed to higher temperatures, defoliation, partial defoliation and stem girgling. It is concluded that tracheid length is influenced by temperature both directly and indirectly; but that increases in cell length associated with increasing light intensity are not explainable in terms of carbohydrate accumulation. The major determinants of lumen diameter are probably hormonal, but temperature can act directly within this framework. Cell wall thickness is, to a large degree, influenced by carbohydrate availability but hormonal factors may also operate.