Growth and water relations of field-grown ‘Valencia’ orange trees under long-term partial rootzone drying

Climate, soil water potential (SWP), leaf relative water content (RWC), stem water potential (WPstem), stomatal conductance (g s), trunk, shoot and fruit growth of ‘Valencia’ orange trees were monitored during five consecutive seasons (2007–2012) to study water status and growth responses to irrigation placement or volume. 48 adult trees were exposed to conventional irrigation (CI, 100% of crop evapotranspiration on both sides of the rootzone), partial rootzone drying (PRD, 50% of CI water only on one alternated side of the rootzone) and continuous deficit irrigation (DI, 50% of CI water on both sides of the rootzone). Reducing irrigation volumes by 55% (DI) over CI increased leaf water def…

Dynamics of nitrogen uptake in young 'Nocellara del Belice' olive trees

Carbohydrate metabolism of vegetative and reproductive sinks in the late-maturing peach cultivar ‘Encore’

Activities of NAD(+)-dependent sorbitol dehydrogenase (SDH), sorbitol oxidase (SOX), sucrose synthase (SS), acid invertase (AI), and neutral invertase (NI) in 'Encore' peach (Prunus persica L.) fruits and developing shoot tips were assayed during the growing season to determine whether carbohydrate metabolizing enzymes could serve as indicators of sink strength. In fruit flesh, SS activity was detected during Stage I of growth, when cells were actively dividing, and SDH activity was detected during Stage III, when cells were actively enlarging. Acid invertase activity was detected during Stage I and showed a closer correlation with relative increase in fruit weight during the growing season…

Fruit physical, chemical and aromatic attributes of early, intermediate and late apricot cultivars.

BACKGROUND: In order to reach good fruit quality, apricots require a balance of sugars and acids as well as a strong apricot aroma. In this study, fruit quality of early, intermediate and late apricot cultivars was evaluated by measuring physical, chemical and olfactory attributes. Multivariate analysis of quality and aroma attributes was used to identify groups of similar cultivars and association with ripening season. RESULTS: Physical, chemical and aromatic attributes showed great variation amongcultivars but no relation to ripening season. Aromatic profiles (34 volatiles) of fruit tissues indicated qualitative and quantitative differences among cultivars. Ninfa and Mandorlon were riches…

Huanglongbing modifies quality components and flavonoid content of 'Valencia' oranges.

BACKGROUND: In order to evaluate the effect of citrus greening disease, or Huanglongbing (HLB), on quality components and flavonoid contents of 'Valencia' oranges, fruit from non-infected trees (control), from infected trees but symptom-less (asymptomatic) and from infected trees and showing clear HLB symptoms (symptomatic) were harvested in March and in May, 2013. Fruit peel, pulp and juice were separated, the main quality components were determined, and hesperidin, nobiletin, tangeretin, narirutin and didymin were quantified using liquid chromatography. RESULTS: Peel colour, total soluble solids and citric acid were similar in control and asymptomatic fruits. Symptomatic fruits were small…

Vertical distribution of crop load and fruit quality within vase- and Y-shaped canopies of 'Elegant Lady' peach

Canopy shape and depth may influence crop uniformity of peach trees at harvest. To test this hypothesis we examined yield distribution and fruit quality changes at different canopy levels of peach trees trained to delayed vase (DV) and perpendicular Y (Y). Trees of both training forms were divided vertically into six or seven 50-cm-deep layers and fruit was harvested at commercial ripening from each layer separately. Regardless of training form, number of fruit and yield per layer were highest in the central part of the canopy, but more evenly distributed among canopy layers in Y trees. In DV trees, fruit weight decreased linearly from top to bottom, whereas it remained constant along the t…

Transport and partitioning of 13C-photoassimilate between peach fruiting shoots

We used a non-intrusive method (13CO2 feeding) and a manipulative approach to see whether fruiting shoots in peach trees are autonomous or may import carbon from neighboring shoots under forced conditions, and whether the degree of autonomy is influenced by the source-sink relationship on the shoot. In three experiments, leaf to fruit ratio (L:F) of selected fruiting shoots was moderately (2005 and 2006) or strongly (extreme enforcing 2006) altered to either encourage or discourage movement of carbon from 13C-labeled sending shoots (SFS) to receiving fruiting shoots (RFS), both located on the same main scaffold of V-shaped peach trees. At stage I and III of fruit growth, fruit and shoot tip…

Qualità dei frutti di selezioni di Annurca in ambiente collinare siciliano

Nitrogen dynamics in early and late peach cultivars. VI International Peach Symposium

Effetto del PRD (Partial Rootzone Drying)sulla composizione della frazione volatile di mele ‘Pink Lady’

Monitoraggio in tempo reale dello stress idrico del pesco

La frutticoltura odierna è sempre più caratterizzata dall’utilizzo di nuove tecnologie che si basano sull’utilizzo di molteplici sensori. Una delle grandi sfide della Smart Agriculture (agricoltura intelligente) è quella di integrare le informazioni provenienti da sensori remoti, prossimali e a contatto in modelli informativi in grado di sostenere gli agricoltori, in modo tale da determinare un sostanziale beneficio economico per le aziende. La complessità delle informazioni ottenute scoraggia l’integrazione di dati apparentemente molto diversi, ma allo stesso tempo apre le porte a nuovi modelli d’impresa. In questo lavoro vengono messi in risalto alcuni vantaggi e difficoltà dell’utilizzo …

Fruit quality and volatile fraction of ‘Pink Lady’ apple trees in response to rootstock vigor and partial rootzone drying

BACKGROUND: Partial rootzone drying (PRD) is a novel deficit irrigation technique consisting in the alternated wetting of only one side of the rootzone, which induces partial stomatal closure and increased water use efficiency. The effect of PRD and rootstock vigor on ‘Pink Lady’ apple fruit quality and aroma profile was studied using solid-phase micro-extraction in headspace and gas chromatography/mass spectrometry. RESULTS: PRD irrigation generally did not affect quality attributes, whereas it influenced the aroma of the apple fruit. In particular, PRD improved the aroma of the fruit flesh, while it decreased the volatile fraction in the peel, where most of the compounds are concentrated.…

Evaluation of Late-Maturing Peach and Nectarine Fruit Quality by Chemical, Physical, and Sensory Determinations

In this work, both analytical and sensory determinations were carried out to evaluate the quality of yellow (&lsquo

Relazione tra potenziale idrico e contenuto idrico relativo in alberi adulti di arancio 'Valencia'

Water Deficit Affects the Growth and Leaf Metabolite Composition of Young Loquat Plants

Water scarcity in the Mediterranean area is very common and understanding responses to drought is important for loquat management and production. The objective of this study was to evaluate the effect of drought on the growth and metabolism of loquat. Ninety two-year-old plants of &lsquo

Partitioning of Sorbitol and Sucrose Catabolism within Peach Fruit

The peach (Prunus persica (L.) Batsch (Peach Group)) fruit is a sink organ comprised of different types of tissue, which undergoes three distinct developmental stages during the growth season. The objective of this study was to characterize the activity and partitioning of sorbitol and sucrose catabolism within 'Encore' peach fruit to determine whether the two forms of translocated carbon play different roles in the various fruit tissues and/or stages of development. Sorbitol catabolic activity was defined as the sum of NAD-dependent sorbitol dehydrogenase (SDH) and sorbitol oxidase (SOX) activities, whereas sucrose catabolic activity was defined as the sum of sucrose synthase (SS), soluble…

Foliar fertilization timing in ‘Farmacista Honoraty’ kaki (Diospyros kaki L.) trees

CARATTERIZZAZIONE CLIMATICA E COMPORTAMENTO FENOLOGICO DI GENOTIPI LOCALI DI PESCO NELL’ALTOPIANO DI UDZUNGWA IN TANZANIA

La coltivazione del pesco nell’altopiano di Udzungwa in Tanzania risale agli inizi del XX secolo e ancora oggi rappresenta un'opportunità per aumentare l’apporto nutritivo alla popolazione locale. Questo studio preliminare mira a caratterizzare la climatologia del luogo in rapporto al comportamento fenologico di genotipi locali derivati da vecchie cultivar di pesco europee. Le osservazioni fenologiche sono state condotte nel settembre 2010 e a luglio-agosto 2011 su alberi di pesco appartenenti a un genotipo precoce e a uno tardivo. I dati di temperatura sono stati ricostruiti e utilizzati per stimare l’accumulo di freddo mediante tre modelli fenoclimatici: Utah, Mean Temperature e Dinamico.…

Water-Related Variables for Predicting Yield of Apple under Deficit Irrigation

, it did not reduce yield and gas exchange. In &lsquo

Regular consumption of fresh orange juice increases human skin carotenoid content

Dermal carotenoids are a good indicator of antioxidant status in the body. This study aimed to determine whether regular consumption of orange juice could increase dermal carotenoids. Two types of orange juice, obtained from regularly (CI) and partially (PRD) irrigated trees, were tested to reveal any possible association between juice and dermal carotenoids. Soluble solids, titratable acidity, and total carotenoids were quantified in the juice; skin carotenoid score (SCS) was assessed by Raman spectroscopy. Carotenoid content was 7.3% higher in PRD than in CI juice, inducing no difference in SCS. In a first trial with daily juice intakes for 25 days, SCS increased linearly (10%) in the ind…

Precision Management of Fruit Trees

The aim of the Special Issue “Precision Management of Fruit Trees” was to collect new insights to support the adoption of advanced, efficient, and sustainable management techniques in the fruit production sector. Indeed, this is an opportunity offered by the technological innovations adopted using new-generation sensors and implemented through precise management operations. This Special Issue contains 11 scientific articles contributing to our knowledge on the precision management of fruit trees, indicating the high activity of this sector and possibly leading to the application of new techniques/protocols to overcome global and rapidly changing environmental issues. Scalisi et al. [1], in …

Effect of metabolic promoters on yeld and fruit quality of 'Sanfilippara' and 'Trabia' loquat.

Carbohydrate Metabolism and Source-Sink Relationships in Peach

A growing plant can be viewed as a collection of carbohydrate sinks competing with each other for the available photosynthate supplied by the exporting leaves. Differences in sink strength often result in changes in the ability of various organs to compete for the available food determining final tree growth. A series of experiments have been conducted in peach to study changes and regulation of carbohydrate metabolism in growing organs and get a better understanding of the link between carbohydrate metabolism, sink strength, carbon partitioning and overall tree growth. Along with sucrose, sorbitol represents the major photosynthetic product and the main form of translocated carbon in peach…

Root topology and allocation patterns of Atriplex patula supplied with different nutrient concentrations

To test whether sub-optimal available nutrient concentrations would result in a more herringbone root branching pattern, in lower root diameters, and in greater resource allocation to root growth than to above-ground portions, seedlings of Atriplex patula were grown under optimal (full), intermediate (1/3 full), and low (1/6 full) nutrient treatments. No significant differences were found between the full and 1/3 nutrient treatments for any of the parameters tested. Root topologies did not show conclusive responses to nutrient availability, however roots treated with 1/6 nutrient concentration showed the tendency to grow in a more herringbone pattern. Total dry weights and shoot dry weights…

Effect of drought on sorbitol and sucrose metabolism in sinks and sources of peach

In peach (Prunus persica [L.] Batsch.), sorbitol and sucrose are the two main forms of photosynthetic and translocated carbon and may have different functions depending on the organ of utilization and its developmental stage. The role and interaction of sorbitol and sucrose metabolism was studied in mature leaves (source) and shoot tips (sinks) of'Nemaguard' peach under drought stress. Plants were irrigated daily at rates of 100, 67, and 33% of evapotranspiration (ET). The relative elongation rate (RER) of growing shoots was measured daily. In mature leaves, water potential (ψ w ), osmotic potential (ψ s ), sorbitol-6-phosphate dehydrogenase (S6PDH, EC 1.1.1.200), and sucrose-phosphate synt…

Effect of rootstock vigor and in-row spacing on stem and root growth, conformation, and dry-matter distribution of young apple trees

The effects of M.9 and MM.106 rootstocks and in-row spacing (0.4, 0.7, and 1 m) on the vegetative behavior of three-year-old apple (Malus domestica Borkh) trees were studied. Analysis of digital images was used to estimate canopy and root growth and conformation (shape and size), whereas dry matter distribution was used to determine partitioning to various plant parts. Trees on less vigorous M.9 rootstocks showed reduced stem and root growth as they produced less and/or shorter shoots and less and/or shorter and thinner roots. Canopy spread area (CSA) and volume were similar for trees on both rootstocks and differences in stem length density (stem length per unit canopy volume; SLD) compens…

Fruiting, Morphology, and Architecture of ‘Arbequina’ and ‘Calatina’ Olive Branches

Two different olive cultivars grown under a high-density hedgerow system were studied to compare their fruiting and branch architecture features and to determine the possibility to use ‘Calatina’ olive trees for intensive plantings, as a local alternative to the international reference ‘Arbequina’. Weights of two-year-old branches, fruits and leaves were recorded to estimate the growth partitioning. Growth and architectural parameters, such as shoot length, vector and diameter, branching angle, branch total length, height, width, area, and branching frequency, were determined by digital image analysis. Digital images of the fruits were also used to estimate fruit maturation by peel color an…

Carbohydrate availability affects growth and metabolism in peach fruit

Along with sucrose, sorbitol represents the main photosynthetic product and form of translocated carbon in peach. This study aimed at determining whether peach fruit carbohydrate metabolism is affected by changes in source-sink balance, and specifically whether sorbitol or sucrose availability regulates fruit enzyme activities and growth. In various trials, different levels of assimilate availability to growing fruits were induced in vivo, by varying crop load of entire trees, leaf:fruit ratio (L:F) of fruiting shoots, or by interrupting the phloem stream (girdling) to individual fruits. In vitro, fruit tissue was incubated in presence/absence of sorbitol and sucrose. Relative growth rate (…

Huanglongbing modifies quality components and flavonoid content of ‘Valencia’ oranges

BACKGROUND: In order to evaluate the effect of citrus greening disease, or Huanglongbing (HLB), on quality components and flavonoid contents of ‘Valencia’ oranges, fruit from non-infected trees (control), from infected trees but symptom-less (asymptomatic) and from infected trees and showing clear HLB symptoms (symptomatic) were harvested in March and in May, 2013. Fruit peel, pulp and juice were separated, the main quality components were determined, and hesperidin, nobiletin, tangeretin, narirutin and didymin were quantified using liquid chromatography. RESULTS: Peel colour, total soluble solids and citric acid were similar in control and asymptomatic fruits. Symptomatic fruits were small…

Comparative responses of ‘Gala’ and ‘Fuji’ apple trees to deficit irrigation: Placement versus volume effects

Aims: Climate, soil water potential (SWP), leaf relative water content (RWC), stomatal conductance (gs), fruit and shoot growth, and carbohydrate levels were monitored during the 2008 and 2009 growing seasons to study the responses of 'Gala' and 'Fuji' apple trees to irrigation placement or volume. Methods: Three irrigation treatments were imposed, conventional irrigation (CI), partial root-zone drying (PRD, 50% of CI water on one side of the root-zone, which was alternated periodically), and continuous deficit irrigation (DI, 50% of CI water on both sides of the root-zone). Results: After each irrigation season, DI generated twice the soil water deficit (SWDint) than PRD (average of dry an…

Activities of Sucrose and Sorbitol Metabolizing Enzymes in Vegetative Sinks of Peach and Correlation with Sink Growth Rate

Terminal portions of `Flordaguard' peach roots [Prunus persica (L.) Batsch] were divided into six segments and the activities of NAD+-dependent sorbitol dehydrogenase (SDH), sorbitol oxidase (SOX), sucrose synthase (SS), soluble acid invertase (AI), and soluble neutral invertase (NI) were measured in each segment 10, 15, and 20 days after seed germination. The same type of experiment was conducted with terminal portions of `Flordaguard' and `Nemaguard' peach shoots except that one of the six segments consisted of the leaflets surrounding the apex. Independent of the age of individual roots, activities of SDH and AI were consistently highest in the meristematic portion and decreased with tis…

Responses of apple to partial root-zone drying. A review.

Partial root-zone drying (PRD) is a relatively recent strategy aiming at substantial reduction of irrigation volume. It consists of the alternate irrigation of one portion of the root-zone with volumes reduced to about 40-50% of conventional water. PRD is based on the ability of roots in drying soil to produce hormonal signals, like abscissic acid (ABA), responsible for partial stomatal closure. In turn, partial stomatal closure would improve water use efficiency and increase fruit yield per unit of irrigation water. This technique has been tested on a number of fruit crops, including apple. In addition to climatic conditions, which mainly affect atmospheric water demand, soil properties an…

Water relations and carbohydrate partitioning of four greenhouse-grown olive genotypes under long-term drought

The four olive genotypes exhibited different responses to drought involving leaf drop and g s reductions (broad-leaved genotypes, good leaf hydration); or growth reductions (narrow-leaved genotypes, dehydration tolerance). There was minor effect on carbohydrate levels. Olive plants of broad-leaved ‘Minuta’ (MN) and ‘Nocellara del Belice’ (NB) and narrow-leaved ‘Passulunara’ (PA) and ‘Biancolilla Siracusana’ (BS) were studied to evaluate their responses to drought. In a greenhouse, 2-year-old rooted cuttings were irrigated to field capacity (WW) or with 20% of WW evapotranspiration (DS) for over 3 months. Subsequently, all pots were rewatered to field capacity for 20 days. Gravimetric soil w…

Shoot growth, crop load, and fruit quality within vase-shaped canopies of ‘Fairtime’ peach trees

Position within the canopy and shoot type can affect final fruit quality in peach (Prunus persica (L.) Batsch). In this study we examined the variation of vegetative growth, crop load, and fruit quality within vase-shaped peach canopies. In four adult 'Fairtime' peach trees trained to vase, each shoot was labeled and numbered from the top to the bottom of each branch and consequently also in a centripetal direction with respect to the main axis. The length and diameter of each 1-year-old shoot was measured, and the number of sprouts and fruits was recorded. Fruit weight and soluble solid content (SSC) were measured at commercial harvest to determine fruit quality. Total shoot length, yield,…

Carbohydrate and nutritional responses to stem girdling and drought stress with respect to understanding symptoms of Huanglongbing (HLB) in Citrus

The most important worldwide problem in citrus production is the bacterial disease Huanglongbing (HLB; citrus greening) caused by phloem-limited bacterium Candidatus Liberibacter asiaticus. The earliest visible symptoms of HLB on leaves are vein yellowing and an asymmetrical chlorosis referred to as “blotchy mottle”, thought to be the result of starch accumulation. We tested the hypothesis that such visible symptoms are not unique to HLB by stem girdling 2-yr-old seedlings of two citrus rootstocks with and without drought stress in the greenhouse. After 31 d, girdling had little effect on shoot growth but girdling increased the relative growth rate of shoots in drought stressed trees. Starc…

Possible role of mannitol as an oxygen radical scavenger in olive

Along with mannose and sucrose, olive produces large amounts of mannitol in photosynthesizing leaves. Leaf mannitol shows large variation among olive genotypes and Sicilian cultivars with different leaf mannitol content were used in our trials to see whether mannitol may function as an additional non-enzymatic system to protect cells from oxygen radicals and photosystem damage. In one experiment, entire shoots of 'Passulunara', 'Castriciana', 'Nocellara del Belice', and 'Moresca' olive trees were taken to a greenhouse, and mature leaves were treated with paraquat solution, which generates oxygen radicals in presence of light. After 48 hours leaves were sampled, photographed and percent of n…

Tree Planting Density and Canopy Position Affect ‘Cerasuola’ and ‘Koroneiki’ Olive Oil Quality

To maximize orchard production and tree crop efficiency, optimization of both maximum orchard light interception and radiation distribution within the tree canopy are important strategies. To study the influence of planting density and fruit position within the canopy on oil quality from &lsquo

Use of Leaf and Fruit Morphometric Analysis to Identify and Classify White Mulberry (Morus alba L.) Genotypes

Digital image analysis and multivariate data analysis were used in this study to identify a set of leaf and fruit morphometric traits to discriminate white mulberry (Morus alba L.) cultivars. The trial was conducted using three- to five-year-old potted cuttings of several white mulberry cultivars. 32 leaf morphometric descriptors were recorded in 2011 and 2012 from 11 mulberry cultivars using image analysis of scanned leaves, whereas six fruit descriptors were recorded in 2011 from nine mulberry cultivars. Linear discriminant analysis (LDA) was used to identify a subset of measured variables that could discriminate the cultivars in trial. Biplot analysis, followed by cluster analysis, was p…

Effetto della concimazione fogliare e del diradamento sulla qualità delle uve di cabernet souvignon

Fruit quality of Sicilian, commercially affirmed, and newly selected apple varieties: potential resources for genetic improvement and specialty markets

Several apple varieties are constantly selected for improved quality traits and introduced for cultivation and marketing in addition to a few traditional and affirmed varieties. Recently, specific fruit quality traits like enhanced flavor, crispness and juiciness have been particularly requested by consumers and are gradually replacing more conventional characteristics like fruit size, peel color and sweetness in the breeding programs. Furthermore, some of the newly selected varieties exhibit a relatively low level of plasticity, posing serious problems of adaptation when cultivation is proposed in a wide range of environments. In this most recent perspective, some of the old varieties or l…

Deficit irrigation and maturation stage influence quality and flavonoid composition of ‘Valencia’ orange fruit

Background: Effects of continuous deficit irrigation (DI) and partial rootzone drying (PRD) treatments (50% ETc) in comparison with full irrigation (CI, 100% ETc) were investigated during 'Valencia' orange fruit maturation. Ultra-high-performance liquid chromatography/high-resolution mass spectrometry was used to quantify hesperidin, narirutin, tangeritin, nobiletin, didymin and neoeriocitrin in the fruit juice and peel.; Results: No significant effect of irrigation was found on yield, juice soluble solids or acidity. Juice color was not influenced by irrigation or harvest date, whereas peel color increased during maturation and was more pronounced in CI and PRD fruits. Juice acidity reache…

Physiological and Structural Responses to Prolonged Water Deficit in Young Trees of Two Olive Cultivars

This study aimed to characterize the physiological and structural responses of potted one-year-old olive trees belonging to two olive cultivars—‘Nocellara del Belice’ and ‘Cerasuola’—exposed to prolonged drought under greenhouse conditions. Two irrigation treatments based on evapotranspiration (ET) were imposed for 69 days, i.e., well-watered (WW, 100% ET) and drought-stressed (DS, 10–30% ET). Leaf stomatal conductance (gs), stem water potential (Ψstem), transpiration (E), photosynthetic capacity (Amax), water use efficiency (WUE), stem (Kstem) and root (Kroot) hydraulic conductance, trunk diameter variations (TDV), and leaf patch attenuated pre…

Growth stage and conditions affect sorbitol:sucrose ratio in peach source and sink organs

Along with sucrose, sorbitol represents the major photosynthetic product and the main form of translocated carbon in peach. In leaves, the ability to synthesize and accumulate sorbitol and sucrose increases with leaf age or distance from the apex until full maturity. Also, in the internodes of a growing shoot sorbitol:sucrose ratio (SOR:SUC) increases with distance from the apex. In mature leaves, SOR:SUC increases in response to fruit sink removal and water deficit, due mainly to sorbitol rather than sucrose accumulation. Data from ‘Encore’ peach show that SOR:SUC remains fairly constant around 2:1 from the leaf blade all the way to the fruit peduncle and drops sharply in the fruit flesh a…

Diurnal Regulation of Leaf Water Status in High- and Low-Mannitol Olive Cultivars

The role of mannitol and malic acid in the regulation of diurnal leaf water relations was investigated in ‘Biancolilla’ (high-mannitol) and ‘Cerasuola’ (low-mannitol) olive trees. Photosynthetic photon flux density (PPFD), vapor pressure deficit (VPD), stomatal conductance (gs), transpiration rate (T), relative water content (RWC), mannitol and malic acid were measured in ‘Biancolilla’ and ‘Cerasuola’ leaves during a dry and hot day of summer in Sicily. In general, leaves of ‘Biancolilla’ trees exhibited greater mannitol content, higher gs and T, but lower RWC than leaves of ‘Cerasuola’ trees. Differences in gs and T between the two cultivars were evident mainly in mid to late morning. ‘Bia…

Productive and vegetative responses of 'Gala' and 'Fuji' apple trees under controlled irrigation strategies

We investigated the productive and vegetative responses of ‘Gala’ and 'Fuji' apple (Malus domestica Borkh.) trees to deficit irrigation and partial rootzone drying under the dry climate of central Sicily. Soil water tension (SWT), stomatal conductance, yield, fruit quality, fruit growth, and shoot extension of conventionally irrigated trees (CI), where drip emitters on both sides of each tree were left open, were compared to that of partial rootzone drying (PRD) trees, where only one side of the rootzone was irrigated for the entire season (receiving 50% of the CI irrigation water), and to that of deficit irrigated (DI) trees, where drip emitters on both sides of the rootzone were deliverin…

Association of Marginal Leaf Scorch with Sodium Accumulation in Salt-stressed Peach

The effect of specific ion toxicity during salt stress was tested in the present study. The experiment was repeated twice, in 1996 and 1998, with `Nemaguard' peach seedlings and rooted cuttings grown in hydroponics under two NaCl concentrations (50 and 30 mm). Foliage was separated in symptomatic and symptomless leaves and the amount of sodium (Na+) and chloride (C1–) was determined. Significantly higher Na+ content was found in symptomatic than in symptomless leaves in both experiments, whereas in only two of the six cases was Cl– content higher in symptomatic than in symptomless leaves. The Na+ threshold for leaf scorch was somewhere between 4 and 6 mg·g–1 dry weight. Results indicated th…

Detecting Mild Water Stress in Olive with Multiple Plant-Based Continuous Sensors.

A comprehensive characterization of water stress is needed for the development of automated irrigation protocols aiming to increase olive orchard environmental and economical sustainability. The main aim of this study is to determine whether a combination of continuous leaf turgor, fruit growth, and sap flow responses improves the detection of mild water stress in two olive cultivars characterized by different responses to water stress. The sensitivity of the tested indicators to mild stress depended on the main mechanisms that each cultivar uses to cope with water deficit. One cultivar showed pronounced day to day changes in leaf turgor and fruit relative growth rate in response to water w…

Foliar fertilization and bunch thinning of ‘Cabernet Sauvignon’ grapes

Studies by SPME-GC/MS on aroma compounds of sixteen different apricot (Prunus armeniaca L.) cultivars

Seasonal changes of calcium content in early and late peach cultivars

Effect of Sunred metabolic promoter and deficit irrigation on fruit quality of 'Valencia' oranges

This study evaluated the effect of deficit irrigation and Sunred foliar metabolic promoter on fruit quality of adult 'Valencia' orange trees. Three irrigation strategies were imposed in spring 2011: Irrigation with volumes corresponding to 100% of crop evapotranspiration applied to entire root-zone (CI), partial root-zone drying (PRD) with 50% of CI water applied to one alternated side of the root-zone, and continuous deficit irrigation (DI) with 50% of CI water applied to both sides of the root-zone. Four trees in each irrigation treatment were sprayed 30 and 20 days before harvest with Sunred metabolic promoter containing phenylalanine, methionine, mono-saccharides and oxylipins from plan…

Dynamics of dry matter partitioning in young ‘Nocellara del Belice’ olive trees

Dry matter partitioning of ‘Nocellara del Belice’ olive (Olea europaea L.) trees was assessed during one growing season. Four three-year-old potted trees from rooted cuttings trained to single-trunk free-canopy were destructively harvested at 30-day intervals during the growing season. The average dry matter increase was about 2 kg · year-1 per tree. Total plant dry weight increased linearly over the year, whereas root to shoot ratio followed a quadratic trend with its peak during winter. Dry matter of all canopy parts (trunk, branches, 1-year-old shoots, and leaves) increased linearly and leaves exhibited the fastest growth. Also fine roots accumulated dry matter over the year in a linear …

Efficienza fogliare nell’assorbimento azotato nell’olivo in relazione alla forma somministrata

Studio dei meccanismi di crescita dei frutti di due varietà di mango coltivate in ambiente mediterraneo

Contenuto minerale delle foglie e qualità dei frutti di agrumi per la trasformazione

In the present study, we analyzed leaf mineral contents fruit quality traits of orange, lemon and tangerine varieties grown in Sicily. The purpose of this research was to individuate chemical or physical fruit quality parameters useful to establish the best possible use of the crop, fresh market or processing. Moreover, leaf mineral analyses were conducted in order to characterize nutritional levels of citrus varieties grown in Sicily. In a second study, we evaluated fruit quality of orange trees cv Valencia in response to deficit irrigation.

Tecniche di irrigazione controllata (Prd) per la coltivazione del melo in aree a bassa disponibilità idrica

Soil and Regulated Deficit Irrigation Affect Growth, Yield and Quality of ‘Nero d’Avola’ Grapes in a Semi-Arid Environment

The present work studied the effect of two consecutive years of regulated deficit irrigation (RDI) compared to rain fed management on the vegetative growth, yield, and quality of ‘Nero d’Avola’ grapes. The trial was conducted separately in two soils (vertisol and entisol) located at the top and bottom hillside of the same vineyard. Vertisol was characterized by greater depth, organic matter, exchangeable K20, and total N than entisol. RDI was based on an irrigation volume at 25% of estimated crop evapotranspiration (ETc) up to end of veraison and 10% of estimated ETc up to 15 days before harvest. Predawn water potential (PDWP) was used as indicator of plant water status and irrigation timin…

Performance vegeto-produttiva di alberi di melo 'Pink Lady' innestati su M.9 e MM.106 e sottoposti ad irrigazione di una porzione dell'apparato radicale

Vegetative and reproductive behavior of 'conference' and 'williams' pear trees trained to v-shape system

V-shape systems represent an efficient and popular option to increase yields and fruit quality. Here we present a detailed study on canopy and root system growth and conformation, yields, fruit quality and dry matter partitioning of 'Conference' (C) and 'Williams' (W) pear trees trained to V-shape system. Digital images were used to determine total stem and root length, mean diameter and surface area; canopy and root system spread area, shape index and volume, canopy height and root depth. Dry weights were used to calculate dry matter partitioning. Stems of W trees were longer and thinner than those of C, which resulted in similar stem dry weights for the two cultivars, whereas root dry wei…

Effect of foliar nutrition on olive oil characteristics in cv 'Nocellara del Belice'

Carbohydrate Metabolism and Sink Strength in Peach

Roles of sorbitol and sucrose in growth and respiration of ‘Encore’ peach fruit in the three developmental stages

In peach [Prunus persica (L.) Batsch (Peach Group)], both sorbitol and sucrose are utilized for source to sink carbon (C) transport, yet their specific functions in fruit growth and development remain unclear. Growth rate (GR), respiration rate (R), carbohydrate content, and the activities of sorbitol dehydrogenase (SDH), sorbitol oxidase (SOX), sucrose synthase (SS), acid invertase (AI), and neutral invertase (NI) were determined in ‘Encore’ peach fruit to study the specific functions of sorbitol and sucrose in each phase of fruit development (an early period of rapid cell division, a relatively inactive intermediate stage where endocarp (pit) hardening occurs, and a final swelling due to …

A Rapid and Efficient Method for Determination of Fruit Peel Color

Peel color is a critical index of external fruit quality and consumer appreciation level. Traditional methods for determination of peel color are based on visual analysis or punctual measurements by colorimeter. In this study we present a method based on digital image analysis that integrates the accuracy of an interactive measurement and the efficacy of an image analysis that descibes entire sides of the fruit. A sample of apple, mandarin, grape, and peach fruit was photographed (each fruit on two opposite sides) with a digital camera for determination of peel color. Digital images were converted from RGB to CIE L*a*b* format, and color characteristics were indexed and quantified. The impl…

Fruit Growth Stage Transitions in Two Mango Cultivars Grown in a Mediterranean Environment

Studying mango (Mangifera&nbsp

Fruit physical, chemical and aromatic attributes of early, intermediate and late apricot cultivars

BACKGROUND: In order to reach good fruit quality, apricots require a balance of sugars and acids as well as a strong apricot aroma. In this study, fruit quality of early, intermediate and late apricot cultivars was evaluated by measuring physical, chemical and olfactory attributes. Multivariate analysis of quality and aroma attributes was used to identify groups of similar cultivars and association with ripening season. RESULTS: Physical, chemical and aromatic attributes showed great variation among cultivars but no relation to ripening season. Aromatic profiles (34 volatiles) of fruit tissues indicated qualitative and quantitative differences among cultivars. Ninfa and Mandorlon were riche…

Quantitative evaluation of the phenolic profile in fruits of six avocado (Persea americana) cultivars by ultra-high-performance liquid chromatography-heated electrospray-mass spectrometry

The phenolic profiles of six varieties of avocado (Persea americana) grown in Sicily were investigated. The ultra-high-performance liquid chromatography-heated electrospray-mass spectrometry method was developed to determine qualitative and quantitative changes in fruits at two different ripening stage. Nineteen individual phenolic compounds were detected in avocado pulp extracts. Gallic acid, sinapinic acid, vanillin, p-coumaric acid, and gentisic acid were present only in ripe fruits. On the contrary, epicatechin decreased with fruit ripening, whereas protocatechuic acid, 4-hydroxybenzoic acid, chlorogenic acid, and benzoic acid were relatively stable or exhibited erratic changes with fru…

Low Tree Vigor, Free Palmette Training Form, and High Planting Density Increase Olive and Oil Yield Efficiency in Dry, Sloping Areas of Mediterranean Regions

Exploiting biodiversity must be considered today an effective strategy to improve the sustainability of olive production systems. The evaluation of local cultivars, based on their vegetative and fruiting traits, along with an analysis of product quality, may contribute significantly to the development and diffusion of new olive-growing systems. The aim of this study was to evaluate growth, productivity, and olive oil quality of three Sicilian cultivars with different vigor/growth habit grown in four different combinations of training form and planting density. ‘Abunara’, ‘Calatina’, and ‘Nocellara del Belice’ olive trees were planted in four different int…

Influenze del portinnesto di pompelmo sulla qualità dei frutti di mandarino tardivo di ciaculli.

A simple, rapid extraction and assay procedure for the NAD+-dependent sorbitol dehydrogenase (SDH) in peach

Sorbitol is the major photosynthetic product in peach. In sink tissues, sorbitol is converted to fructose via the NAD+-dependent sorbitol dehydrogenase (SDH). A new procedure is described that allows rapid, simple quantification of SDH activity in growing tissues. The procedure uses only 0.01 to 2.5 grams of fresh tissue per sample, such that a single shoot tip, a single root tip, or about 5 g of fruit flesh can be assayed for SDH activity. Storage of samples at 4 or -20 C° over night resulted in significant loss of enzyme activity. Thus, freshly harvested tissues were ground with sand in buffer at 2°C in a mortar and pestle, and the homogenate centrifuged @ 3000 ´ g to remove particulate m…

Fruit Yield and Quality of ‘Valencia’ Orange Trees under Long-Term Partial Rootzone Drying

Climate, soil and tree water status, fruit yields and quality of &lsquo

Planting Systems for Modern Olive Growing: Strengths and Weaknesses

The objective of fully mechanizing olive harvesting has been pursued since the 1970s to cope with labor shortages and increasing production costs. Only in the last twenty years, after adopting super-intensive planting systems and developing appropriate straddle machines, a solution seems to have been found. The spread of super-intensive plantings, however, raises serious environmental and social concerns, mainly because of the small number of cultivars that are currently used (basically 2), compared to over 100 cultivars today cultivated on a large scale across the world. Olive growing, indeed, insists on over 11 million hectares. Despite its being located mostly in the Mediterranean countr…

Foliar fertilization in ‘Nocellara del Belice’ olive trees

Eight-year-old olive trees of ‘Nocellara del Belice’ grown in central Sicily were treated with five different types/combinations of organic and mineral foliar fertilizers. Floral 20-20-20 (mineral N, P, K, and microelements; FLO), Alga (extract of brown algae; ALG), FLO+ALG, Azomin (organic N, amino acids and peptides; AZO), Supernat93 (organic N and K, distillation residue; SUP), and water (CONTROL) were applied four times during summer and fall 2002. Yield and trunk circumference were measured during fall 2002, whereas other vegetative and reproductive parameters were measured during spring-fall 2003. AZO and SUP trees produced more than CONTROL and ALG ones, whereas only AZO trees showed…

Characterization of Sicilian Olive Genotypes by Multivariate Analysis of Leaf and Fruit Chemical and Morphological Properties

Leaf and fruit size and shape were measured and mannitol, glucose, sucrose and malic acid were quantified in leaf, bark and fruit of 25 Sicilian olive genotypes. Multivariate analysis was used to individuate groups with similar chemical composition and morphological traits suggesting potential for stress tolerance and/or oil yield and quality. Mannitol content varied greatly among genotypes and was the most abundant carbohydrate in leaf and bark, whereas glucose was the most abundant in fruit. Sucrose and malic acid were generally low indicating a marginal role in olive tissues. Mannitol and glucose were directly related in both leaf and fruit tissues. Genotypes also differed for carbohydra…

Cladode growth dynamics in Opuntia ficus-indica under drought

Abstract Cactus pear (Opuntia ficus-indica L. Miller) is a CAM plant with an extraordinary capacity to store water in its succulent stems (cladodes). However, the daily variations of cladode thickness is unknown. Studying cladode thickness fluctuations may be useful for the early prediction of plant dehydration stress. The objective of this study was to determine if age, water availability and temperature influence diel cladode shrinkage and enlargement dynamics in cactus pear. The experiment was conducted in a greenhouse from April to July 2014, using cactus pear plants, equally split into irrigated and unirrigated treatments, and unrooted cladodes detached from mother plants. Soil moistur…

Quality evaluation of extra-virgin olive oils from Sicilian genotypes grown in a high-density system

Studying the sensory profile and chemical composition of monovarietal extra-virgin olive oils (EVOOs) is important to define and manage their quality and uniqueness. Chemical and sensory traits of olive oils from 14 minor Sicilian olive genotypes in comparison with oils from six major Sicilian and three international cultivars were analysed. Oils were extracted in 2015 from fruit of the 23 genotypes grown in an experimental orchard at a planting density of 1140 trees ha−1. Fatty acid composition, phenol composition, carotenoid content and antioxidant power were determined and analysed using univariate and multivariate procedures, in particular Nocellara Etnea along with carotenoid, phenol c…

Carbon autonomy of peach shoots determined by 13C-photoassimilate transport

We used (13)CO(2) tracing and source-sink manipulation to determine if fruiting shoots of peach (Prunus persica (L.) Batsch) trees are autonomous or if they import carbon from neighboring shoots, and if the degree of shoot autonomy is influenced by the source-sink relationship of the shoot. In three experiments, leaf to fruit ratio (L:F) of selected fruiting shoots was moderately (2005 and 2006) or strongly (complete sink removal, 2006) altered to either enhance or inhibit movement of carbon from (13)C-labeled fruiting shoots (LFS) to adjacent non-labeled shoots (NLFS), both located within 10 cm on the same main scaffold of V-shaped peach trees. At Stages I and III of fruit growth, fruit an…

Yield and profitability of modified spanish bush and Y-trellis training systems for peach

Peach trees trained to modified Spanish bush (MSB) and Y-trellis (Y) were evaluated and compared in the Mediterranean settings of Southern Italy. The observations included two peach (Rich May and Summer Rich) and two nectarine (Big Bang and Nectaross) cultivars. In the MSB system, trees were spaced at 4.5 x 2.5 m (888 trees/ha), whereas in the Y system, trees were spaced at 5.5 x 2 m (909 trees/ha). Costs at planting, yield per tree, fruit size grade, unit price of sold peaches for each size grade, amount and cost of materials and labor for cultural management, and grower's profit were quantified throughout all six years from planting and at full crop (year 4-6). Fixed costs of the MSB syst…

Foliar Applications with SUNRED® Biostimulant Advance and Uniform Fruit Ripening in Orange and Olive

This study evaluated the effect of foliar biostimulants on fruit quality of adult 'Valencia' orange and 'Biancolilla' olive trees. Half of the selected orange and olive trees were sprayed twice before harvest with the SUNRED® commercial mix containing phenylalanine, methionine, mono-saccharides and oxylipins from plant extracts as well as potassium salts and urea. Orange and olive yields and fruit quality were measured at harvest, and fruit peel color was determined by digital image analysis. Phenolic and sensory profiles were also determined in the olive oil. In orange, the foliar spray increased TSS:acid ratio and peel color uniformity, while in olive, it increased peel color uniformity, …

Photoassimilate Regulation of Sorbitol and Sucrose Metabolism in Peach Fruit

Along with sucrose, sorbitol represents the major photosynthetic product and the main form of translocated carbon in peach. The objective of the present study was to determine whether in peach fruit, sorbitol and sucrose enzyme activities are source-regulated, and more specifically modulated by sorbitol or sucrose availability. In two separate trials, peach fruit relative growth rate (RGR), enzyme activities, and carbohydrates were measured 1) at cell division stage before and after girdling of the shoot subtending the fruit; and 2) on 14 shoots with different leaf to fruit ratio (L:F) at cell division and cell expansion stages. Fruit RGR and sorbitol dehydrogenase (SDH) activity were signi…

Variazioni Giornaliere Dello Stato Idrico E Del Contenuto Di Mannitolo E Acido Malico In Alberi Di Olivo Delle Cvs 'Biancolilla' E 'Cerasuola'

Carbohydrate and Nutritional Responses to Stem Girdling and Drought Stress with Respect to Understanding Symptoms of Huanglongbing in Citrus

The most important worldwide problem in citrus production is the bacterial disease Huanglongbing (HLB; citrus greening) caused by a phloem-limited bacterium Candidatus Liberibacter asiaticus. The earliest visible symptoms of HLB on leaves are vein yellowing and an asymmetrical chlorosis referred to as “blotchy mottle,” thought to be the result of starch accumulation. We tested the hypothesis that such visible symptoms are not unique to HLB by stem girdling 2-year-old seedlings of two citrus rootstocks with and without drought stress in the greenhouse. After 31 days, girdling had little effect on shoot growth but girdling increased the relative growth rate of shoots in drought-stressed trees…

Fruit and Leaf Sensing for Continuous Detection of Nectarine Water Status

Continuous assessment of plant water status indicators provides the most precise information for irrigation management and automation, as plants represent an interface between soil and atmosphere. This study investigated the relationship of plant water status to continuous fruit diameter (FD) and inverse leaf turgor pressure rates (pp) in nectarine trees [Prunus persica (L.) Batsch] throughout fruit development. The influence of deficit irrigation treatments on stem (Ψstem) and leaf water potential, leaf relative water content, leaf stomatal conductance, and fruit growth was studied across the stages of double-sigmoidal fruit development in ‘September Bright’ nectarines. Fruit relative grow…

Response of transgenic mannitol-producing tobacco plants to water deficit

Transgenic mannitol-producing (+mtlD) and wild type (-mtlD) tobacco plants were exposed to water deficit to test whether mannitol is involved in drought stress protection. Rooted cuttings of -mtlD and +mtlD plants were fully irrigated (100% ET) or received 25% ET for 40 days, followed by 20 days of re-watering. Water deficit reduced RWC of both plant types starting on the 22nd day, total stem length of -mtlD 25% ET already after 11 days, whereas that of +mtlD 25% ET only after 34 days. After 30 days of deficit, a greater percentage of mature foliage was retained by +mtlD 25% ET compared to -mtlD 25% ET. Mannitol-1-phosphate dehydrogenase activity of +mtlD plants was not affected by water de…

Variazione della componente aromatica di mele “Pink Lady” in risposta al vigore del portinnesto e agli apporti idrici.

Technical English for agriculture

As the world goes global, the agricultural business needs to move across frontiers and oceans. Food, raw and processed, is regularly transported across continents. As space is no longer a limit for food trade and human nutrition, language cannot represent a barrier to this continuous exchange. In the last 60 years, English has been taking a foothold as the primary language for world trade and the exchange of agricultural goods is no exception. Agricultural sciences embrace a large number of disciplines, from botany to environmental physiology, from soil science to meteorology, from plant propagation to cultural management, from soil management to pest control, from field crops to animal husb…

Deficit irrigation does not affect alternate bearing of ‘Valencia’ orange trees

This study evaluated the effect of long-term partial rootzone drying and continuous deficit irrigation on the degree of alternate bearing of adult ‘Valencia’ orange trees grown in northern Sicily. Three irrigation strategies were imposed in summer from 2007 to 2011: irrigation with volumes corresponding to 100% of crop evapotranspiration applied to entire rootzone (CI), partial rootzone drying (PRD) with 50% of CI water applied to one alternated side of the rootzone, and continuous deficit irrigation (CDI) with 50% of CI water applied to both sides of the rootzone. The experiment was conducted on 48 adult orange trees arranged according to a randomized block design. Weather and soil paramet…

Fruit quality and aroma of tree ripe and detached, sun-exposed ‘Annurca’ apples

A Cultivar-Sensitive Approach for the Continuous Monitoring of Olive (Olea europaea L.) Tree Water Status by Fruit and Leaf Sensing

Sustainable irrigation is crucial to reduce water use and management costs in modern orchard systems. Continuous plant-based sensing is an innovative approach for the continuous monitoring of plant water status. Olive (Olea europaea L.) genotypes can respond to drought using different leaf and fruit physiological and morphological mechanisms. This study aimed to identify whether fruit and leaf water dynamics of two different olive cultivars were differently affected by water deficit and their response to changes of midday stem water potential (Ψstem), the most common indicator of plant water status. Plant water status indicators such as leaf stomatal conductance (gs) and Ψstem were measured…

Quality evaluation of extra-virgin olive oils from Sicilian genotypes grown in a high-density system

Studying the sensory profile and chemical composition of monovarietal extra-virgin olive oils (EVOOs) is important to define and manage their quality and uniqueness. Chemical and sensory traits of olive oils from 14 minor Sicilian olive genotypes in comparison with oils from six major Sicilian and three international cultivars were analysed. Oils were extracted in 2015 from fruit of the 23 genotypes grown in an experimental orchard at a planting density of 1140 trees ha−1. Fatty acid composition, phenol composition, carotenoid content and antioxidant power were determined and analysed using univariate and multivariate procedures, in particular Nocellara Etnea along with carotenoid, phenol c…