Orange Fruit Quality Research Articles

Genome-wide identification and expression analysis of the MADS gene family in sweet orange (Citrus sinensis) infested with pathogenic bacteria.

The risk of pathogenic bacterial invasion in plantations has increased dramatically due to high environmental climate change and has seriously affected sweet orange fruit quality. MADS genes allow plants to develop increased resistance, but functional genes for resistance associated with pathogen invasion have rarely been reported. MADS gene expression profiles were analyzed in sweet orange leaves and fruits infested with Lecanicillium psalliotae and Penicillium digitatum, respectively. Eighty-two MADS genes were identified from the sweet orange genome, and they were classified into five prime subfamilies concerning the Arabidopsis MADS gene family, of which the MIKC subfamily could be subdivided into 13 minor subfamilies. Protein structure analysis showed that more than 93% of the MADS protein sequences of the same subfamily between sweet orange and Arabidopsis were very similar in tertiary structure, with only CsMADS8 and AG showing significant differences. The variability of MADS genes protein structures between sweet orange and Arabidopsis subgroups was less than the variabilities of protein structures within species. Chromosomal localization and covariance analysis showed that these genes were unevenly distributed on nine chromosomes, with the most genes on chromosome 9 and the least on chromosome 2, with 36 and two, respectively. Four pairs of tandem and 28 fragmented duplicated genes in the 82 MADS gene sequences were found in sweet oranges. GO (Gene Ontology) functional enrichment and expression pattern analysis showed that the functional gene CsMADS46 was strongly downregulated of sweet orange in response to biotic stress adversity. It is also the first report that plants' MADS genes are involved in the biotic stress responses of sweet oranges. For the first time, L. psalliotae was experimentally confirmed to be the causal agent of sweet orange leaf spot disease, which provides a reference for the research and control of pathogenic L. psalliotae.

Effect of different spring and summer fertilization proportions on fruit yield, quality, and nutrient use efficiency of Newhall orange (Citrus sinensis Osbeck) orchard in Ganzhou province

The amount and time of fertilization play an important role in the quality and yield of citrus. Moreover, twice fertilization in the spring (March) and summer (July) are generally applied in citrus orchards, of which the appropriate proportion is unclear, especially in Ganzhou. Therefore, the two-year field experiment containing three proportions (60/40, 80/20, 100/0) of spring and summer fertilization was carried out with a 15-year-old Newhall orange orchard to recommend the optimum fertilization proportion for orchard. Results showed that variations of soil available N, P, K concentrations resulting from different spring and summer fertilization proportion significantly affected orange fruit quality and yield. The soil available nitrogen (N), phosphorus (P), and potassium (K) concentrations fertilized with a proportion of 80/20 spring and summer were higher overall the year. The spring and summer fertilizer application with 80/20 increased fruit yield by 35.14%, and had higher total soluble solids and lower titrated acid. Moreover, the only one-time fertilization exhibited almost the same fruit yield, fruit N, P, K removal, but lower fruit titrated acid content and higher solid acid ratio. The present study results demonstrated that increasing the proportion of spring fertilization particularly the proportion of 80/20 could be a recommended dose for obtaining higher fruit yield and quality.

Using RGB Imaging, Optimized Three-Band Spectral Indices, and a Decision Tree Model to Assess Orange Fruit Quality

Point samples and laboratory testing have historically been used to evaluate fruit quality criteria. Although this method is precise, it is slow, expensive, and destructive, making it unsuitable for large-scale monitoring of these parameters. The main objective of this research was to develop a non-invasive protocol by combining color RGB indices (CIs) and previously published and newly developed three-band spectral reflectance indices (SRIs) with a decision tree (DT) model to evaluate the fruit quality parameters of navel orange. These parameters were brightness (L*), red–green (a*), blue–yellow (b*), chlorophyll meter (Chlm), total soluble solids (TSS), and TSS/acid ratio. The characteristics of fruit quality of navel orange samples were measured at various stages of ripening. The outcomes demonstrated that at various levels of ripening, the fruit quality parameters, RGB imaging indices, and published and newly developed three-band SRIs differed. The newly developed three-band SRIs based on the wavelengths of blue, green, red, red-edge, and NIR are most effective for estimating the six measured parameters in this study. For example, NDI574,592,724, NDI572,584,724, and NDI574,722,590 had the largest R2 value (0.90) with L*, whereas NDI526,664,700 and NDI524,700,664 exhibited the highest R2 value (0.97) with a*. Moreover, integrating CIs and SRIs with the DT model has provided a potentially useful tool for the accurate measurement of the six studied parameters. For instance, the DT-SRIs-CIs-30 model performed better in terms of measuring a* using 30 various indices. The R2 value was 0.98 and RMSE = 1.121 in the cross-validation, while R2 value was 0.964 and RMSE = 2.604 in the test set. Otherwise, based on the fusion of five various indices, the DT-SRIs-CIs-5 model was the most precise for recognizing b* (R2 = 0.957 and 0.929, with RMSE = 1.713 and 3.309 for cross-validation and test set, respectively). Overall, this work proves that integrating the different characteristics of proximal reflectance sensing systems such as color RGB indices and SRIs via the DT model may be considered a reliable instrument for evaluating the quality of different fruits.

An Approach for Detecting Fruit Quality with RBF-SVM Classification Model

For the regular development of rural area especially for the agriculture domain, automation is very important. Currently fruit's quality plays an important factor in their sales and production. Detecting the quality of fruits by using manual methods are not recommended because of the reasons that it cause delay and the results are also not upto the mark. Therefore, machine learning and computer vision is gaining much interest from current researchers to develop fruit quality detection systems. This paper contributes to provide an effective and advanced Orange fruit quality detection system. the proposed scheme is focused on giving an Fuzzy C-Mean based region of interest extracting scheme along with RBF-SVM classification model to improve the classification rate in comparison to existing approaches. The proposed scheme is simulated in MATLAB software and results are evaluated in terms of various performance factors such as Accuracy, Sensitivity, Specificity, Precision, Recall and F-Score. Finally a comparison of the proposed scheme is given that show an improvement of approximately 18% with respect to various state of art techniques. this strengthen the recommendation of proposed scheme for future fruit quality analysis system.

Influences of rootstock and agro-climatic condition on physico-chemical and bioactive compounds of Gunda Gundo orange (Citrus sinensis L. Osbeck) in the Northern Ethiopia

Rootstocks have a significant influence on adaptation to biotic and abiotic stress conditions and quality of fruit. So, choice of rootstock for a specific growing region is an important decision for a grower to make when establishing a commercial citrus orchard. This study was undertaken to assess effects of rootstock and location on quality of orange fruit. The study was conducted over two consecutive years (2017/18 and 2018/19). Scions from the Gunda Gundo orange grove were grafted on rough lemon and sour orange rootstocks and planted in Tigray and Afar, Ethiopia at four sites (Abala, Agulae, Adiha and Rama). The experiment was laid out in Randomized Complete Block Design (RCBD) with four replications. Data on different physico-chemical and bioactive compounds were collected and analyzed using R software (version 4). Compared to sour orange, rough lemon rootstock revealed higher fruit mass (151.96 g, 195.38 g), fruit length (62.27 mm, 68.88 mm) and fruit diameter (65.58 mm, 71.3 mm), in 2017/18, 2018/19, respectively. Among the four locations (Abala, Agulae, Adiha and Rama), higher juice percentage was found in Adiha (43.47% in 2017/18) and Abala (49.87%, in 2018/19). In 2017/18 higher total soluble solid (TSS, 13.87%), TSS/acid ratio (19.18) and fruit rag (32.77%), were obtained at the Rama site. On the one hand, higher vitamin C (826.6 mg·kg−1) and total phenolic content (208 mg·kg−1 GAE) were recorded at Agulae than Abala, Adiha and Rama sites from sour orange rootstock. High TSS, TSS/acid ratio and antioxidant were recorded from orange fruits at Rama site. This was expected to have resulted from hot climate conditions at the site. Besides, at a relatively cooler condition of the Agulae site, high phenolic, reduced ferric power and high vitamin C were recorded. Rough lemon rootstock improved fruit size, while rootstock did not affect the contents of TSS, TSS/acid ratio across the sites in both harvesting years.

Postharvest quality of orange fruit as influenced by salicylic acid, acetic acid, and carboxymethyl cellulose coating

Postharvest quality of orange fruit as influenced by salicylic acid, acetic acid, and carboxymethyl cellulose coating

Tree Age and Harvesting Season Affected Physico-chemical and Bioactive Compounds of Elite Type of Gunda Gundo Orange (Citrus Spp) in the Northern Ethiopia

ABSTRACT Marketability and nutritional content are critical factors that need to be considered when a quality of orange fruit is assessed. Among the many factors affecting orange fruit quality, tree age and harvesting season are crucial once; however, the factors remained unmapped. Thus, this study was aimed to explore quality of orange fruit due to differences in tree age and harvesting season. Three trees age groups (young = 10 to 16, moderate = 20 to 27 and old = greater than 30 years) grown at Gunda Gundo monastery and its surroundings, northern Ethiopia and are harvested in October and December. The physico-chemical and antioxidant contents were characterized during two consecutive years (2017–2018). R software (R version 3.6.2) was used for the analysis. The highest single fruit weight of 218.71 g, peel thickness (3.6 mm) and pH (3.73) were obtained from young tree age in 2017. Total soluble solid of 13.4° Brix was recorded from moderate tree age in 2017, while 13.3° Brix was recorded from older trees of October harvest in 2018. High rag mass of 41.78% in October of 2017 and 38.04% in December of 2018 harvest were obtained from fruits of young trees. High vitamin C (53.95 mg 100 ml−1) and total sugar (11.1%) from the young trees; the highest juice mass (52.04%) from moderate trees age; and the highest phenolic content (9.15 mgGAEg−1), iron-reducing power (54.2 mgAAEg−1), total antioxidant (26.55 mgBHTg−1) and lower DPPH EC50 value (1.5 mg ml−1) from fruits of older tree were obtained. This experimental study results show that old trees age had high antioxidant activity.

The Efficiency of Calcium Boron and Carpox-K Sprays on Fruit Quality of Washington Navel Orange Trees

This research was conducted during seasons 2018 & 2019 on nine-years-old Washington navel orange trees. These trees were grafted on Sour orange rootstock, planted at 5 x 5 meters apart, under surface irrigation conditions, in a private orchard at Manzala village, Toukh region, Qalubia Governorate, Egypt. The seven treatments were used for comparison as follows: T1-100% of chemical NPK (NPK fertilization program adopted at 5, 3 and 1 kg/tree from (NH4)2SO4, superphosphate and K2SO4, respectively) according to the Ministry of Agriculture Recommendation (Control or recommended doses RD). T2-RD+Calcium boron 2 cm3 /L; T3-RD+Calcium boron 3 cm3/L; T4-RD+Carpox-K 1g/L; T5-RD+Carpox-K 1.5g/L; T6-RD+Calcium boron 2 cm3 /L +Carpox-K 1g/L, and T7-RD+Calcium boron 3 cm3/L +Carpox-K 1.5g/L. The main goal of this investigation was directed towards increasing Washington navel orange fruit quality. The obtained data revealed that all investigated treatments increased fruit quality parameters (physical and chemical properties). However, T7- RD + Calcium boron 3 cm3 /L + Carpox-K 1.5g/L was statistically superior. On the contrary, T1- Control or recommended doses (RD) ranked statistically the lowest treatment in this concern. From the obtained results, It can be concluded that the use of RD+ Calcium boron 3 cm3 / L + Carpox-K 1.5g / L or RD+ Calcium boron 2 cm3/ L + Carpox-K 1g / L could be safely recommended under similar environmental and horticultural practises adopted in this experiment.

Role of seaweed (Ulva flexuosa Wulfen) extract in improvement of postharvest quality of Washington navel orange fruits.

Seaweeds are rich sources of bioactive natural products, which have been considered as potential biotic agents. Ulva flexuosa Wulfen is a species of seaweed which is endemic to the Persian Gulf. In this study, the effect of different concentrations of U. flexuosa extract on the antioxidant activity of Washington Navel orange (Citrus sinensis L. cv. Washington Navel) fruits (measured as free radical scavenging activity; FRSA) and postharvest quality of the fruits were evaluated under cold storage (5±1°C) conditions and 85-90% relative humidity up to 60 days. Results indicated that prolonging the storage time increased fruit weight loss, fruit decay and total soluble solids (TSS) contents of the fruits, while prolonging the storage time reduced the percentage of juice and ascorbic acid contents of the fruits. Postharvest quality and antioxidant activity of Washington Navel orange fruit improved significantly when they were immersed in seaweed extracts. The most effective treatment was 3.76 g L-1 concentration of Ulva flexuosa extract, which maximized the improvement of antioxidant capacity, ascorbic acid content and TSS during days of storage (DS). The results of this study indicated that the seaweed extract could be used as a new bioactive agent for maintaining the postharvest quality of orange fruit through enhancing the antioxidant activity.

Effects of postharvest storage conditions on ‘Tarocco’ orange fruit quality

'Tarocco Sant'Alfio' [Citrus sinensis (L.) Osbeck] is a late ripening sweet orange cultivar belonging to the so called “blood oranges”. These fruits are more and more appreciated from consumers for their high nutraceutical value due to the presence of anthocyanins in the flesh. Recently, cold treatment in sweet orange has received more attention due to its usefulness for accomplishing phytosanitary exportation rules, allowing Italian citrus fruit to be sent to Japan and the USA. In addition, cold treatments are useful for increasing pigmentation levels in the fruit. The aim of this work was to define a reliable protocol for postharvest storage of the very-late 'Tarocco Sant'Alfio' blood orange to prolong the availability of this product in the market to be used for fresh squeezed orange juice production. Fruits were subjected to three storage treatments (20 days at 1°C plus 50 days at 4°C; 70 days at 4°C; 70 days at 20°C, as control). The results indicate that cold treatments, in particular at 4°C constantly, can extend 'Tarocco Sant'Alfio' shelf life and might enhance its qualitative value determining an increase of total anthocyanin content in the flesh. The defined protocols allow prolonging market availability of such a high value product till late June with relevant benefits for the citrus industry and advantages for consumers.

THE EFFECTIVENESS OF PREHARVEST FOLIAR SPRAY OF SOME BIOLOGICAL MATERIALS ON KEEPING QUALITY OF VALENCIA ORANGE FRUITS DURING COLD STORAGE

this experiment was conducted during two successive seasons, 2012 and 2013, on 15 years old ″Valencia″ orange trees at a private orchard. Two plant bio stimulants (Lena tonik, Licorice extracts) and GA3 were sprayed during different fruit growth stages. Five separate treatments, GA3 at 100 ppm, Lena tonik at 0.50 and 0.75 cm / L and Licorice extract at 0.2 and 0.4 % plus distilled water as control were applied, monthly from June till September. Fruits were picked at maturity stage and all fruit quality parameters were determined at harvest and at two weeks interval during storage for 6 weeks at 4oC and 90% to 95 % relative humidity. Measured fruit quality parameters included weight loss percentage, firmness; peel color, eating quality, total soluble solids contents, titratable acidity content and Vitamin C content. GA3 treatment caused an obvious delay in fruit ripening processes compared to other treatments and control. Fruits treated with GA3 had the highest value of firmness and TSS content least values of color development at harvest. Moreover, these fruits in addition to those treated with Lena tonik had the lowest weight loss incidence and the less firmness deterioration rate and delaying senescence incidence during cold storage. After 6 weeks of cold storage, Licorice treated fruits had the best taste followed by Lena tonik, while GA3 treatment had the lowest one, but with acceptable note of taste. All treatments of biostimulants proved their usefulness in keeping ″Valencia″ orange fruit quality during cold storage. Licorice extract can be used for its effectiveness in keeping fruit quality and its cheap price in case other materials are unavailable.

Effects of continuous ethylene treatment on ‘Navelina’ orange fruit quality

Effects of continuous ethylene treatment on ‘Navelina’ orange fruit quality

Tree and cold storage influence on incidence of albedo breakdown, textural properties of the rind and fruit quality in ‘Washington Navel’ orange

Introduction . Albedo breakdown (AB) causes serious economic losses to sweet orange growers. The growers practice delayed harvesting (tree storage) to extend the fresh fruit supply to market. We investigated the effects of tree storage and cold storage on AB incidence, textural properties of the rind and fruit quality. Materials and methods. Fruit of ‘Washington Navel’ orange were harvested at the commercial maturity stage (3rd July) and then 31, 62 and 93 days after the harvest. The AB incidence, textural properties of the rind and fruit quality were assessed in one lot of fruit after harvest and a second lot after 31, 62 and 93 days of cold storage (5 °C). Results and discussion. The AB incidence increased from 65% to 89% from the first to the last harvest, respectively. Extended storage periods reduced rind hardness and fruit firmness, and increased the rind tensile force irrespective of the storage type. The rind hardness, tensile force and fruit firmness were higher in cold-stored fruit than fruit stored for 93 days on the tree. The soluble solids concentration: titratable acidity (SSC:TA) ratio in juice increased with the extended storage period in both types of storage. The increase in SSC:TA was more pronounced at 62 and 93 days in cold-stored than tree-stored fruit. The concentrations of fructose and glucose in the juice of fruit stored on the tree for 93 days were higher than in the cold-stored fruit, and sucrose showed the reverse trend. Conclusion. The cold-stored fruit exhibited a higher rind hardness, rind tensile force, firmness and SCC:TA ratio, lower concentrations of citric acid, malic acid, fructose and glucose, and lower AB incidence than the tree-stored fruit. These findings indicate a preference for cold storage over tree storage for the orange fruit quality.

Deficit irrigation for enhancing ‘Tarocco’ orange fruit quality

Deficit irrigation for enhancing ‘Tarocco’ orange fruit quality

RELATIONSHIP BETWEEN SOIL AND LEAF POTASSIUM CONTENT AND 'VALENCIA' ORANGE FRUIT QUALITY

In order to evaluate the relationship between orange fruit quality and potassium concentration in soil and leaves, thirty 20-year-old 'Valencia' orange on 'Cleopatra' mandarin were evaluated in 2006, in Nirgua, Yaracuy State, Venezuela. For each plant 12 samples of 12 fruits each were analysed. The following variables were determined: polar and equatorial diameter of fruit, fresh mass, skin thickness and percentage, juice percentage, total titratable acidity (TA), soluble solids concentration (SSC), and SSC/TA ratio. Fifteen samples of soil and leaves were taken for potassium analysis. A correlation was obtained between soil potassium content and some fruit quality attributes (skin and juice percentages). Leaf potassium had a positive correlation with fruit SSC. It was found that the greater potassium level, minor fresh mass and juice content in the fruits along with higher skin proportion and SSC.

Influence of Different Organic Fertilizers on Quality Parameters and the δ15N, δ13C, δ2H, δ34S, and δ18O Values of Orange Fruit (Citrus sinensis L. Osbeck)

To investigate the influence of different types of fertilizers on quality parameters, N-containing compounds, and the delta(15)N, delta(13)C, delta(2)H, delta (34)S, and delta(18)O values of citrus fruit, a study was performed on the orange fruit cv. 'Valencia late' (Citrus sinensis L. Osbeck), which was harvested in four plots (three organic and one conventional) located on the same farm. The results demonstrated that different types of organic fertilizers containing the same amount of nitrogen did not effect important changes in orange fruit quality parameters. The levels of total N and N-containing compounds such as synephrine in fruit juice were not statistically different among the different treatments. The delta(15)N values of orange fruit grown under fertilizer derived from animal origin as well as from vegetable compost were statistically higher than those grown with mineral fertilizer. Therefore, delta(15)N values can be used as an indicator of citrus fertilization management (organic or conventional), because even when applied organic fertilizers are of different origins, the natural abundance of (15)N in organic citrus fruit remains higher than in conventional ones. These treatments also did not effect differences in the delta(13)C, delta(2)H, delta(34)S, and delta(18)O values of fruit.

Tuning the orchestra: Selective gene regulation and orange fruit quality

Orange fruit quality is highly dependent on time-specific expression of developmental genes in peel tissues, especially those controlling physical structure and synthesis of pigments and aromatic secondary metabolites. Using a custom microarray platform, we examined expression of 366 genes of interest in peel pericarp and endocarp during three developmental stages of Washington Navel orange fruit ( Citrus sinensis L. Osbeck). We examined in detail 28 of these genes that showed strong differential expression over time and across tissues. Genes putatively associated with metabolism of flavonoids, carotenoids, aroma compounds, and ascorbic acid were differentially expressed over time in specific tissues, while genes likely associated with disease resistance, photosynthesis, stress responses, and cell wall synthesis were differentially expressed over both tissue and time. Most highly differentially expressed transcripts within peel likely function to modify the cell wall architecture during growth and to develop color and aroma.

Postharvest characteristics of navel oranges following high humidity and low temperature storage and transport

Fruit moisture loss and the onset of rind disorders in citrus can occur during refrigerated storage and transport, leading to significant economic costs to horticultural industries. High relative humidity (RH) storage obtained by using a modified atmosphere packaging liner in a carton and described as Moisture Control Technology (MCT) was investigated for its effect on navel orange fruit quality in static cold-storage and under commercial export conditions. In static cold-storage, ‘Lanes Late’ navel orange ( Citrus sinensis L. Osbeck) stored with and without MCT for 55 days at ≤5 °C and 21 days at 21 °C lost 3% and 13%, respectively, of their initial weight. Fruit from the MCT treatment were ≥32% firmer and had less chilling injury (1% versus 7%) compared with those without MCT. In the export study, ‘Washington’ navel orange fruit were packed in cartons with and without MCT and sent in a sea shipment consignment (holding conditions: 3 °C, RH 90%) from Adelaide, Australia to San Diego, USA where they were off-loaded into cold storage (5.5 °C, RH 89%). After 3 weeks of cold-storage, fruit with MCT had 83% less moisture loss than those without MCT. Compression damage occurred on fruit without MCT, particularly in the bottom two pallet layers. MCT reduced the incidence of chilling injury by 42% and albedo breakdown by 54% compared with fruit in unlined cartons. Overall, fruit quality was highest in both trials with the use of MCT. Despite the high humidity conditions inside the MCT cartons (≥98%), no mould was detected on fruit at out-turn. This was probably due to the industry standard pre-treatment of fruit with a fungicide dip during pre-pack processing and to the properties of the MCT liner itself.

Effects of Reduced Fall and Winter Irrigation on Citrus Fruit Quality

Earlier work has shown that moderate water deficits imposed on citrus trees can increase fruit Brix without adversely affecting yield. Increased water restrictions have been imposed on citrus growers as Florida's population continues to increase. The objectives of this study were to determine: 1) the effects of no irrigation in the fall and winter on orange fruit quality parameters in Florida; and 2) amount of potential irrigation water savings. Trees were irrigated identically in the spring and summer. A non-irrigation treatment was started on Hamlin and Valencia oranges in September and October, respectively, while controls continued to be irrigated following established irrigation practices. An additional non-irrigated treatment was started at the same time on the Valencias that consisted of a soil covering with a water barrier (Tyvek) to exclude rainfall. Stem water potential was monitored during the fall and winter to estimate differences in water stress among the treatments. Brix and organic acids increased in fruit from non-irrigated treatments when compared to fruit from irrigated trees. Results also demonstrate that reduced irrigation did not affect yield greatly. Amount of irrigation savings was determined for both cultivars that differ in maturity dates.

Analysis of the Major Elements in Orange Leaves Using NIR Spectroscopy

Fertilizers are an essential input for sustained high yields and quality of orange fruit. Monitoring leaf nutrient levels is desirable and procedures for using leaf analysis to make fertilizer recommendations are well established. Wider adoption of leaf analysis would result if more-convenient sampling and analytical techniques were available. Analysis using near-infrared reflectance spectroscopy (NIR) offers many advantages, including accuracy, low cost, and short turnaround time, which should appeal to citrus producers. NIR analysis is currently being used to decide the appropriate fertilizer applications for local cereal producers. Samples were collected from a cross-section (7%) of the orange-producing farms in the Murrumbidgee Irrigation Area (MIA) of New South Wales (lat.35, long.146). This semi-arid, winter-dominant rainfall region is a major citrus-producing area in Australia. Samples comprised the 2nd and 3rd fully expanded leaves from non-fruiting 4-month-old flush shoots of sweet orange trees `Late Valencia' on P. trifoliata rootstock. The microwave-dried and ground samples were analyzed by the traditional techniques, and the samples were then used to develop and verify calibrations for N, P, and K. These calibrations determine nutrients in leaves with error (SEP) values that are close to the errors associated with traditional methods.