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Examining the host range of emerging invasive insects is essential to assess their invasion potential and to anticipate the negative impacts of their spread. The ongoing North American invasion of spotted lanternfly (SLF) [ Lycorma delicatula (White, 1845)] threatens agricultural, urban, and natural areas. The survival and development of SLF nymphs on Washington navel orange [ Citrus sinensis (L.) Osbeck (Sapindales: Rutaceae)] trees were assessed in a quarantine facility. Results indicated that SLF nymphs can develop to at least the third instar by feeding exclusively on Washington navel orange. This finding suggests that, at least up to the third stage of nymphal development, Washington navel orange might be a suitable host for SLF, highlighting the possibility that this invasive pest represents an unrecognized threat to this globally important crop and possibly to other Citrus species. [ABSTRACT FROM AUTHOR]

Progress in non-destructive methods to detect the characteristics of fruits is a new and attractive process for researchers and specialists in this field. On the other hand, these researchers move toward identifying their impacts on their surroundings in line with diagnostic efficiency. One of these essential impacts is the environmental impact of the non-destructive detection process of fruits. Navel oranges are one of the most popular and widely consumed fruits, whose maturity indices such as soluble solids contents (SSC) values and acidity are considered as parameters in determining the quality of this product. This study used the hyperspectral method in the vis-NIR range to evaluate and measure navel oranges' SSC and acidity values. In the following, by applying the life cycle assessment method, the environmental impacts of measuring and evaluating these two parameters of the characteristics of navel oranges were investigated. The Impact2002+ method was used to evaluate the impact of the life cycle list. Based on the findings, the environmental impacts of SSC measurement are about 40, 42, 20, and 18 % higher than those of the environmental impacts of pH measurement from the point of view of endpoint impacts for Human Health, Ecosystem quality, climate change, and resources, respectively. The random forest modeling results showed a suitable and acceptable correlation and relationship (over 90 %) between the wavelengths selected from the feature selection stage and environmental impacts.

The physicochemical and structural properties of water soluble dietary fibres (SDF) extracted from navel orange peel modified by superfine grinding were investigated, as well as the immunomodulatory activity in RAW264.7 cells. Results showed that superfine grinding treatment could significantly enhance the extract yield and reduce the particle size of SDF. And the water-holding capacity, swelling capacity, oil-holding capacity, nitrite adsorption capacity and total antioxidant capacity were consequently improved. Modified SDF could significantly decrease the generation of reactive oxygen species (ROS), and promoted the production of NO and some cytokines (IL-1β, TNF-ɑ, MCP-1, and IL-6) in RAW264.7 cells. The expressions of P-P65 and HO-1 in SDF-M200 and SDF-M500 were significantly up-regulated, suggesting that SDF could mildly induce macrophage activation and enhance the immune activity. These indicated that SDF modified by superfine grinding could serve as a promising candidate of immunomodulatory ingredient for functional foods.

Abstract Background Triple Negative Breast Cancer (TNBC) is a particular type of breast cancer with the highest mortality rate. Essential oils are concerned more and more as potential anti-cancer drugs. Methods TNBC cells were treated with different concentrations of navel orange peel essential oil (NOPEO), and then a variety of experiments were performed to investigate the changes in the growth and progression of TNBC cells. MTT assay was performed to detect the proliferation of TNBC cells. The changes of cell cycle and apoptosis were analyzed by FACS. In order to explored the migration of TNBC cells, scratch wound assay was carried out. Western blotting and qPCR were used to examine the expression of proteins and mRNA of related genes. Furthermore, RNA-seq was used to analyze the altered genes and explored the possible signal pathway. Results NOPEO demonstrated dose- and time-dependent suppression of TNBC cell growth. TNBC cells showed an increased percentage of G2/M-phase cells and the protein levels of CyclinB1 and CyclinD1 were decreased after NOPEO treatment. The apoptotic cells were increased in the NOPEO treated TNBC cells. The migration mobility was significantly inhibited by NOPEO. In total, 1376 genes were found to be up-regulated and 1335 genes were down-regulated after NOPEO treatment. According to KEGG and GO pathways, the differentially expressed genes were related to MAPK, Jak/stat and FoxQ signaling pathways. Conclusion This investigation explored the bio-activity and molecular mechanisms of NOPEO against TNBC cells. These results indicated that NOPEO could suppress TNBC growth and migration perhaps via the MAPK and Jak/stat signaling pathways, which may provide theoretical reference for anticancer drug development. NOPEO may be a potential natural product for the chemotherapeutic of TNBC.

Background: Triple Negative Breast Cancer (TNBC) is a particular type of breast cancer with the highest mortality rate. Essential oils are concerned more and more as potential anti-cancer drugs. Methods: TNBC cells were treated with different concentrations of navel orange peel essential oil (NOPEO), and then a variety of experiments were performed to investigate the changes in the growth and progression of TNBC cells. MTT assay was performed to detect the proliferation of TNBC cells. The changes of cell cycle and apoptosis were analyzed by FACS. In order to explored the migration of TNBC cells, scratch wound assay was carried out. Western blotting and qPCR were used to examine the expression of proteins and mRNA of related genes. Furthermore, RNA-seq was used to analyze the altered genes and explored the possible signal pathway. Results: NOPEO demonstrated dose- and time-dependent suppression of TNBC cell growth. TNBC cells showed an increased percentage of G2/M-phase cells and the protein levels of CyclinB1 and CyclinD1 were decreased after NOPEO treatment. The apoptotic cells were increased in the NOPEO treated TNBC cells. The migration mobility was significantly inhibited by NOPEO. In total, 1376 genes were found to be up-regulated and 1335 genes were down-regulated after NOPEO treatment. According to KEGG and GO pathways, the differentially expressed genes were related to MAPK, Jak/stat and FoxQ signaling pathways. Conclusion: This investigation explored the bio-activity and molecular mechanisms of NOPEO against TNBC cells. These results indicated that NOPEO could suppress TNBC growth and migration perhaps via the MAPK and Jak/stat signaling pathways, which may provide theoretical reference for anticancer drug development. NOPEO may be a potential natural product for the chemotherapeutic of TNBC. [ABSTRACT FROM AUTHOR]

Quantitative descriptive sensory analysis (QDSA), gas chromatography-ion mobility spectrometry (GC-IMS) and Heracles NEO electronic nose (E-nose) combined with chemometrics were used for differential analysis of volatile compounds in essential oils (EOs) extracted from sweet orange peels (blood and navel) using cold pressing (CP), microwave-assisted hydrodistillation (MAHD) or spinning cone column (SCC). The results indicated that significant variations in flavor composition were found among the three EOs. The CP oil had the highest sensory preference with stronger fruity, sweet, and floral aromas. The MAHD oil had stronger fatty, green, and woody aromas, and the SCC oil had a lower aroma intensity. A total of 64 volatile components were identified by GC-IMS, terpenes, alcohols and aldehydes being the major ones, followed by acids, esters and other compounds. The fingerprint indicated that the contents of terpenes in the CP and MAHD oils were significantly higher than that in the SCC oil, whereas the contents of alcohols and aldehydes in the MAHD and SCC oils were significantly higher than those in the CP oil. Based on relative odor activity value (ROAV), β-myrcene and linalool were identified as the major contributors to the flavor of sweet orange EO. Moreover, using GC-IMS combined with partial least square discriminant analysis (PLS-DA) and variable importance in the projection (VIP), 13 differential volatile compounds were identified as aroma markers to distinguish among the 6 oils. Additionally, E-nose combined with principal component analysis (PCA) and discriminant factor analysis (DFA) also successfully distinguished among the 6 EOs according to their volatile compounds.

In this study, the physicochemical properties of plasma‐activated water (PAW) prepared from air, O2 ${{\rm{O}}}_{2}$, Ar $\text{Ar}$, and N2 ${{\rm{N}}}_{2}$ plasma and the trend of the concentration of reactive oxygen and nitrogen species (RONS) with respect to time were investigated and related to the effect of PAW on navel orange mold. The results showed that O2 ${{\rm{O}}}_{2}$ PAW had a strong lethal effect on navel orange mold and could effectively inhibit the mildewing activity of pathogenic spores. In addition, O2 ${{\rm{O}}}_{2}$ PAW is effective in reducing weight loss and decay of navel oranges during storage. This study suggests the potential application of PAW to prevent fungal infections during storage of agricultural products. [ABSTRACT FROM AUTHOR]

The use of chemicals to control land snails can lead to environmental pollution, hazards to humans and toxic residues in agricultural products. Therefore, finding safer alternatives for managing these pests has become a priority. Field experiments were conducted to test different methods for controlling Eobania vermiculata snails infested navel orange trees in Dakahlia Governorate. These methods included ploughing during the egg-laying period in January, planting cabbage traps in February, applying attractive materials in March, using pesticides in April during the activity period, and hand collection during aestivation period in June. The ploughing process significantly (P≤ 0.05) reduced the populations of E. vermiculata. One week after ploughing, the number of snails per sample decreased from 29.22 to 11.76, representing 63.87% reduction. After six weeks, the overall reduction in population was 40.73%. Planting cabbage traps also decreased the snail populations, with a maximum reduction of 68.54% after six weeks. Attractive materials had a significant effect on attracting populations. Sugar-cane syrup and barley powder showed the highest effectiveness, with reductions of 66.05 and 54.12%, respectively. Boiled potatoes had a moderate effect, while vanilla powder was the least effective one, with a reduction of 39.92%. Biocides and plant extracts had a significant effect on the suppression of snail populations. Oikous and clove oil had the highest effect, with 46.05 and 42.56% reduction, respectively. Protecto showed a moderate effect, while eucalyptus oil was the least effective one with 28.21% reduction. The application of pesticides also reduced the snail populations to varying degrees. The molluscicidal efficiency of the tested pesticides could be arranged in descending order after three weeks of application as follows: methomyl < fenamiphos < deltamethrin < oxamyl, with reduction percentages of 60.30, 54.41, 48.81 and 39.03%, respectively. Hand collection during the aestivation period in June also significantly (P≤ 0.05) decreased populations, with a 46.41% reduction as a general mean during the six- week experimental period. Generally, all tested control methods significantly reduced the populations of E. vermiculata in navel orange orchard from January to July. Based on the general means of percent reduction, the tested methods can be arranged in descending order as follows: cabbage traps, pesticides, attractive materials, hand collection, ploughing, and using biocides besides plant extracts. The reduction percentages for the snail species were 51.44, 50.64, 48.93, 46.41, 40.73 and 38.81%, respectively. [ABSTRACT FROM AUTHOR]

Sulfur dioxide (SO2) fumigation was evaluated for efficacy against western flower thrips (Frankliniella occidentalis) and phytotoxicity to four select fresh fruits and vegetables. Western flower thrips were found to be very susceptible to SO2 fumigation. Fumigations with 0.3 and 0.5% SO2 for 60 and 30 min, respectively, at a low temperature of 5 °C achieved 100% thrips mortality. Broccoli, bell peppers, apples, and navel oranges with thrips were subjected to 30 min fumigation with 0.3–0.5% SO2 to verify efficacy and determine potential phytotoxicity. The fumigation resulted in complete control of thrips. Its effects on visual quality of fresh produce varied. The fumigation caused severe discoloration of broccoli. However, the treatment did not have significant effects on the color of other products. No negative impact on visual appearance of bell peppers and navel oranges was observed. However, it caused darkened lenticels on green apples and, therefore, may potentially degrade apple postharvest quality. The lack of phytotoxicity of SO2 fumigation is likely due to well-developed wax layers on those fresh products. The results of the study suggest that SO2 fumigation has good potential to be used safely and effectively against sensitive pests on select fresh fruit and vegetables including peppers and citrus fruits. [ABSTRACT FROM AUTHOR]

Egypt Navel orange planted area reached about 174.6 thousand acres during the average period of 2012-2020. Delta governorates is the major orange’s productive region in Egypt with 97.4% of the total production of the country. 87.2% of orange’s planted area came from only five Delta governorates. The top planted area governorates are El Behera with an acreage area representing about (41.3%), followed by Qalyoubia (16.7%), Ismailia (11.1%), Menufia (9.54%) and Sharqiya (8.52%) of total planted areas during the period 2012-2020. El-Behera is the major Navel orange’s productive governorate in Egypt with (43.9%) of Egyptian total production of Navel orange, followed by Qalyoubia (18.8%), Menufia (9.2%), Ismailia (8.3) and Sharqiya (7.7%) of Navel orange total production during the period 2012-2020. In recent years, small scale farmers have experienced technical, environmental and economic problems. This study will shade light on the economic problems because fruit prices have come to a standstill or even decreased while the production costs have risen continuously. The present study depends on data collected from the private small farm planted with Washington Navel orange trees [Citrus sinensis L.(Osbeck)] since 1968, which is located in Minyat as Siba, Benha-Qalyoubia governorate, Egypt. The result shows that the average values of fertilizers, pests and diseases account for a large proportion of the total costs, representing about 42.57% and 26.47% respectively from the total production costs during 2012-2022. Prices received for Navel oranges fluctuate markedly from year to year. This combined with fluctuations in yields. Over the period 2012 to 2022 farm gate prices of Navel orange averaged 2905 Egyptian pound (LE) per ton, with the minimum of LE 1750 per ton in 2012 and the maximum of LE 4000 per ton in the 2019, 2020 and 2021.

Metabolites changes during fruit growth are currently being studied intensively. In this experiment, Ultra-high performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry was used to identify metabolites during the growing phase of navel oranges. A total of 63 metabolites were identified, and monitored changes in amino acid content. Principal component analysis and Partial least-squares-discriminate analysis were used to construct a cluster analysis model among navel orange metabolites. Among the 19 differential metabolites, flavonoids were the main metabolic markers during the growth of navel oranges. Correlation cluster analysis was used to fit the correlation between the characteristic components, and it was found that many flavonoids were highly correlated. Finally, combined with Kyoto Encyclopedia of Genes and Genomes enrichment analysis, the key metabolic pathway was identified as flavonoid synthesis. The α-glucosidase inhibition experiment showed that with the growth of navel orange, the inhibition rate of the metabolites to α-glucosidase activity decreased continuously. This study provides a necessary basis for exploring the metabolic mechanism of navel orange growth.

A rapid, nondestructive, and online detection of the internal quality of navel orange cannot only reduce the labor intensity, but also improve the economic benefits of the navel orange. In this paper, an online detection and sorting equipment is designed for navel orange. The transmission spectrum data of 1697 navel oranges are divided into the calibration, prediction, and validation sets, with a ratio of 14:3:3. Pre-processing methods such as first derivative (FD), second derivative (SD), standard normal variate transform (SNV), and multiplicative scatter correction (MSC) were chosen to process the spectra. Accordingly, the soluble solids content prediction model for navel oranges is established using standard normal variable transformation (SNV) and partial least squares (PLS). The determination coefficients (R2) of the calibration set, prediction set, and validation set are 0.8476, 0.8326, and 0.8025, respectively. Moreover, the corresponding root mean square errors are 0.5097°Brix, 0.5590°Brix, and 0.6048°Brix, respectively. The residual predictive deviation (RPD) value is 2.4510 (i.e., greater than 2.0), indicating that the model performs accurate predictive simulations, and has high reliability. In addition, two classification methods based on the national standard method and the normal probability graph of the soluble solids content of navel oranges were used to classify navel oranges into three classes for online validation. 185 navel oranges were selected for online validation, in which the classification method based on the normal probability graph of the soluble solids content of navel oranges was more effective and its average sorting accuracy was 81.13 %. Likewise, the mean absolute error (MAE) is 0.4613°Brix. The experimental results show that the online sorting equipment possesses high sorting accuracy and can be practically used for actual postharvest processing. [ABSTRACT FROM AUTHOR]

The sample representativeness, spectral acquisition conditions, and modeling process would affect the practical application value and application range of a model. To establish an applicative online evaluation model for soluble solids content (SSC) of Leibo navel orange, transmittance spectra with the wavelength of 650–950 nm were collected under different sample placement postures and transmission speeds using an online system with four parallel spectrometers. These samples were gathered from three production points at three harvest times and contained four grades with single fruit weight ranging from 133.8 to 645.0 g. Considering the heterogeneity of navel orange and the practical application of online detection, all spectra of the same sample were used to join in modeling, and a series of models for SSC were established. The models by average spectra of four parallel spectrometers got better results than anyone. The accuracy of the model was the best when samples were placed horizontally on the sample tray, followed by stem upward, and stem downward worst. The regression model for SSC by using spectra with horizontal orientation and speed of 0.5 m/s got the best performance in terms of root mean square error of prediction (RMSEP) and residual predictive deviation (RPD), with values of 0.442% and 2.77, respectively. The overall results showed that the research method and system can be applied to the online detection of navel orange quality. [ABSTRACT FROM AUTHOR]

Fifteen compounds including one flavanone hesperitin (1), two cinnamic acid derivatives as (E)-4-hydroxycinnamic acid (2) and (E)-ferulic acid (3), eight polymethoxyflavones (PMFs) (4-11), and four hydroxylated PMFs (12-15) isolated from orange peel were subjected to antibacterial evaluation. Compounds 1-3 exhibited wide-spectrum antibacterial effects against four test strains involving Bacillus subtilis, Staphylococcus aureus, Xanthomonas citri subsp. citri (Xcc), and Meticillin-resistant Staphylococcus aureus (MRSA) with minimum inhibitory concentrations (MICs) ranging from 0.0312 to 0.125 mg/mL. In contrast, all PMFs showed weak antibacterial activity against these four strains with MICs being equal to or more than 0.125 mg/mL. Hydroxylated PMFs demonstrated better antibacterial effect against Xcc relative to PMFs. In addition, the synergistic effect against Xcc was obtained when compounds 1 and 3 were combined. Furthermore, the scanning electron microscopy (SEM) results of Xcc treated with both compounds 2 and 3 showed shrunken and rough surface morphologies, indicative of the cell membrane damage. [ABSTRACT FROM AUTHOR]

The whole‐surface hyperspectral image acquisition of navel orange is particularly important for surface defect detection and quality classification. Because the light intensity at the edge of the navel orange is lower than that in the middle, the defects on the surface of the navel orange cannot be effectively identified. In this paper, a hyperspectral online sorting device for the whole‐surface defects of navel orange is proposed. First of all, the image data of navel orange is collected by online detection sorting equipment and the spectral image of the characteristic wave peak of 1655.72 nm was extracted. Then, the light intensity at the edge of the navel orange is enhanced by nonuniformity correction based on quadratic curve fitting, and the light intensity correction of the navel orange is realized. Finally, the corrected image is segmented by the threshold to obtain surface defects, and the number of surface defect pixels is improved effectively compared with that before light intensity correction. Ultimately, the online sorting test is carried out, and the detection accuracy is 100%. This indicates that this method effectively improves the sensitivity of defect detection. At the same time, the dimensionality reduction of hyperspectral data is also carried out, which is conducive to improving the efficiency of online detection. [ABSTRACT FROM AUTHOR]

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

The aim of this research was to assess the efficacy of some predators worked as a biocontrol tool against the navel orange aphid species (Aphis gossypii (Glover), Aphis citricola (van der Goot), Myzus persicae (Sulzer), and Aphis craccivora Koch.) during a period of two seasons in 2021 and 2022. Aphis gossypii and Aphis citricola are the two main species of aphid discovered on navel orange plants. In the two seasons of the study, there were three abundance peaks of Aphis gossypii. In 2021, the numbers recorded in the third week in April and May, as well as the second week in June were 370, 450 and 454 individuals/40 leaves and recorded 281, 386, and 500 individuals during the first and fourth weeks of April and the fourth week of May in 2022, respectively. Meanwhile, A. citricola had two abundance peaks in both seasons: in 2021 (181 and 98 individuals/40 leaves) and in 2022 (245 and 295 individuals/40 leaves). Coccinella undecimpunctata L., Chrysoperla carnea Steph, C. septempunctata, Metasyrphus corollae Fand Cydonia vicina isis were the most common predators discovered on navel orange trees.. A few number of Paederus alfierii (Koch) and true spiders were the most common predators caught in navel orange trees. On navel orange trees, these predators recorded two peaks in two seasons (73 and 77 predators/40 leaves) during the first season, and (83 and 88 predators/40 leaves) during the second season, respectively. Two predators, C. undecimpunctata and C. carnea, that prey on A. gossypii were researched from a biological perspective at 21±1°C and 65± 5% R.H. C. undecimpunctata and C. carnea took 23.49 ± 1.40 and 25.01 ± 2.63 days, respectively, to develop from egg hatching to adult exclusion. The total consumption rate per C. undecimpunctata and C. carnea larva fed on A. gossypii were 567.50 ± 6.90 and 587.63 ± 9.27 when fed on A. gossypii. During their larval stages, C. undecimpunctata and C. carnea females generally lay around 315.85±5.17 and 321.52±6.19 eggs. [ABSTRACT FROM AUTHOR]

Blue mold caused by Penicillium italicum imposes a serious problem in economically important citrus fruit during the storage period. Traditionally, synthetic chemicals have been widely used to control blue molds; however, this use of chemicals has caused critical environmental problems. This has encouraged scientists to look for safer and readily available alternatives from natural eco-friendly sources such as botanical extracts. In line with that, the present study aims to investigate the antifungal efficiency of twelve methanolic extracts from eight plant species against P. italicum in vitro and to further select the most promising extracts to study their efficacy in vivo on reduction of disease severity and some physiological aspects of 'Washington Navel©' orange fruit under storage conditions. Being the most effective treatment, Sansevieria cylindrica leaf extract was subjected to GC-MS analysis to identify phytochemical components. The results obtained signified the potential efficacy of the tested plant extract to reduce the mycelial growth of P. italicum under in vitro conditions. The most effective extracts were Balanites aegyptiaca fruit, Polianthes tuberosa bulbs, Acacia nilotica fruit and Sansevieria cylindrica leaves at 1000 µg/mL inhibition % of mycelial of 54.3, 42.4, 41.3 and 31.5%, respectively. When compared under storage conditions of orange fruit, the lowest disease incidence and, thus, the highest reduction of disease severity (86.7%) were caused by S. cylindrica leaf extract. These effects were supported by high values of total phenols content (TPC) and total flavonoids content (TFC) in treated fruit, along with elevated activities of antioxidant enzymes: peroxidase (PO) and polyphenol oxidase (PPO). The identified phytochemicals in S. cylindrica leaf extract were dominated by fatty acids and their esters, which, together with the other compounds, have evidence of microbial activity. To sum up, using methanolic extracts of S. cylindrica as a substitute for chemical fungicides may help control P. italicum in 'Washington Navel©' oranges. [ABSTRACT FROM AUTHOR]

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

Sulfur dioxide (SO2) fumigation was evaluated for efficacy against western flower thrips (Frankliniella occidentalis) and phytotoxicity to four select fresh fruits and vegetables. Western flower thrips were found to be very susceptible to SO2 fumigation. Fumigations with 0.3 and 0.5% SO2 for 60 and 30 min, respectively, at a low temperature of 5 °C achieved 100% thrips mortality. Broccoli, bell peppers, apples, and navel oranges with thrips were subjected to 30 min fumigation with 0.3–0.5% SO2 to verify efficacy and determine potential phytotoxicity. The fumigation resulted in complete control of thrips. Its effects on visual quality of fresh produce varied. The fumigation caused severe discoloration of broccoli. However, the treatment did not have significant effects on the color of other products. No negative impact on visual appearance of bell peppers and navel oranges was observed. However, it caused darkened lenticels on green apples and, therefore, may potentially degrade apple postharvest quality. The lack of phytotoxicity of SO2 fumigation is likely due to well-developed wax layers on those fresh products. The results of the study suggest that SO2 fumigation has good potential to be used safely and effectively against sensitive pests on select fresh fruit and vegetables including peppers and citrus fruits.

The present study investigates the chemical composition and antioxidant capacity of juice from the Gannan navel orange, which is harvested at one- to two-week intervals during the ripening period. The total soluble solid (TSS), total polyphenol content (TPC), total flavonoid content (TFC), sucrose and hesperidin contents gradually increase with the ripening of the fruit, followed by slight declines at the late maturity stage. Contrary to these observations, the contents of titratable acid (TA), vitamin C (Vc), and limonin trend downward throughout the ripening period. However, the contents of fructose, glucose, and narirutin fluctuate throughout the harvest time. Three in vitro antioxidant assays consistently indicate that the harvest time exerts no significant influence (P>0.01) on the antioxidant capacity. Furthermore, principal component analysis (PCA) and Pearson's correlation test are performed to provide an overview of the complete dataset. This study provides valuable information for evaluating the fruit quality and determining when to harvest the fruit in order to meet the preferences of consumers. Meanwhile, our observations suggest that the fruits subjected to juice processing should be harvested at the late maturity stage to alleviate the “delayed bitterness” problem without compromising the antioxidant capacity and the flavonoid content in the juice.

Imazalil, a preservative for navel orange in the process of postharvest processing, is easy to seep into the flesh through the peel and produce residues in the flesh, which is vulnerable to cause endanger to human body if it was eaten accidentally. Base on this, a fast detection method of imazalil residues in navel orange peel ,namely surface-enhanced Raman spectroscopy (SERS) was proposed in this study. Firstly, the SERS detection conditions of imazalil residues in navel orange peel were optimized, and the optimal detection conditions were determined as follows: Reaction time of 2 min, gold colloid of 400 µL, NaBr as electrolyte solution, NaBr dosage of 25 µL. Based on the above optimal conditions, 6 groups of spectral data processed by adaptive iterative penalized least squares (air PLS), air PLS combination with normalization, air PLS combination with baseline correction, air PLS combination with first derivative, air PLS combination with standard normal distribution (SNV), air PLS combination with multiplicative scatter correction (MSC) were used to establish support vector regression (SVR) models and compare the models prediction performance. And air PLS method was selected as the spectral pretreatment method, because the value of correlation coefficient computed value of prediction set (RP) is the largest, and the value of root mean square error calculated value of the prediction set (RMSEP) is the smallest. Then, principal component analysis (PCA) was used to extract the features from spectral data, and the first seven principal component scores were selected as the input values of SVR prediction model. SVR, multiple linear regression (MLR) and partial least squares regression (PLSR) were used to analyze and compare the prediction performances. The RP value of prediction set of SVR prediction model could reach 0.9156, the RMSEP value of their prediction set was 4.8407 mg/kg, and the relative standard deviation computation value (RPD) was 2.3103, which indicated that the closer the predicted value of imazalil residue on navel orange surface based on SVR algorithm was to the measured value, the more effective the prediction accuracy of the model could be. The above data indicated that the speedy detection of imazalil residues in navel orange peel could be emploied by SERS coupled with PCA and SVR modeling method.

This study aimed at comparing the physicochemical characteristics, α‐glucosidase inhibitory effect, and hypoglycemic activity of pectins (N‐NOP and H‐NOP) from peels of normal and Huanglongbing (HLB)‐infected Navel oranges. Results indicated the pectins were high methoxy pectins mainly composed of homogalacturonan and rhamnogalacturonan‐I. The pectins exhibited similar functional groups, surface morphology, and particle size, and had no triple‐helical conformation in solution. They exerted fat and glucose absorption capacities and were mixed‐type noncompetitive α‐glucosidase inhibitors with IC50 values of 1.182 and 2.524 mg/ml, respectively. Both N‐NOP and H‐NOP showed hypoglycemic activity in alloxan‐induced diabetic mice. Administration of them could promote the synthesis of hepatic glycogen and/or serum insulin to lower blood glucose levels and enhance antioxidant status to alleviate oxidative stress injury in diabetic mice. Moreover, N‐NOP had higher yield, molecular weight, ζ‐potential, oil holding capacity, α‐glucosidase inhibitory effect and in vivo hypoglycemic activity, whereas H‐NOP possessed higher uronic acid, degree of esterification, thermal stability, water holding capacity, swelling capacity, and fat absorption capacity. It could be concluded that some similarities and differences existed between N‐NOP and H‐NOP in physicochemical characteristics, functional properties, α‐glucosidase inhibitory effects, and hypoglycemic activity. This study provides references for the basic research and application of pectins from peels of normal and HLB‐infected Navel oranges. Practical applications: Pectin has been widely used in the food and pharmaceutical industries for several decades due to its health benefit, gelling, thickening, and emulsification performances. Diabetes mellitus is a worldwide concern in recent years. Pectins (N‐NOP and H‐NOP) from peels of normal and Huanglongbing (HLB)‐infected Navel oranges possessed in vitro and in vivo hypoglycemic activities, indicating they were potential anti‐antidiabetic substitutes of chemical drugs. Moreover, comparative understanding on the physicochemical characteristic, α‐glucosidase inhibitory effect and hypoglycemic activity of pectins from peels of normal and Huanglongbing‐infected Navel oranges was conducive to the recycling and utilization of Navel orange peels. Recently, the biological activity of pectin from peels of normal Navel oranges has been rarely reported, and the information on pectin from peels of Huanglongbing‐infected Navel orange is rare. This study provides references for the basic research and application of pectins from peels of normal and HLB‐infected Navel oranges. [ABSTRACT FROM AUTHOR]

Diet is the main intake source of selenium (Se) in the body. Southern Jiangxi is the largest navel orange-producing area in China, and 25.98% of its arable land is Se-rich. However, studies on the Se-rich characteristics and Se dietary evaluation of navel orange fruits in the natural environment of southern Jiangxi have not been reported. This study was large-scale and in situ samplings (n = 492) of navel oranges in southern Jiangxi with the goal of investigating the coupling relationships among Se, nutritional elements, and quality indicators in fruits and systematically evaluating Se dietary nutrition to the body. The results indicated that the average content of total Se in the flesh was 4.92 mg·kg-1, and the percentage of Se-rich navel oranges (total Se ≤ 10 mg·kg-1 in the flesh) was 7.93%, of which 66.74% of the total Se was distributed in the pericarp and 33.26% in the flesh. The average content of total Se in the flesh of Yudu County was the highest at 5.71 mg·kg-1. There was a significant negative correlation (p < 0.05) between Se, Cu, and Zn in the Se-rich flesh. According to the Se content in the flesh, the Se dietary nutrition evaluation was carried out, and it was found that the Se-enriched navel orange provided a stronger Se nutritional potential for the human body. These findings will help to identify Se enrichment in navel orange fruit in China's largest navel orangeproducing area and guide the selection of Se-rich soils for navel orange production in the future. [ABSTRACT FROM AUTHOR]

Canker is a common disease of navel oranges that is visible before harvest, and penicilliosis is a common disease occurring after harvest and storage. In this research, the typical fruit surface, canker spots, penicillium spore, and hypha of navel oranges were, respectively, identified by hyperspectral imaging. First, the light intensity on the edge of samples in hyperspectral images was improved by spherical correction. Then, independent component images and weight coefficients were obtained using independent component analysis. This approach, combined with use of a genetic algorithm, was used to select six characteristic wavelengths. The method achieved dimension reduction of hyperspectral data, and the testing time was reduced from 46.21 to 1.26 s for a self-developed online detection system. Finally, a deep learning neural network model was established, and the four kinds of surface pixels were identified accurately.

The variation of fruit among batches influences the performance of the portable near infrared spectroscopy (NIRS) instrument and then determines the success or failure for practical application in fruit industry. Model development and update methods were investigated for determining soluble solids contents (SSC) and titrable acidity (TA) of navel orange. The pretreatment and variable selection methods were explored for building partial least square regression (PLSR) models. The best models, developed by the combination of second derivative (2D) and variable sorting for normalization (VSN), could predict SSC but not TA. The root mean square error of prediction (RMSEP), coefficient of determination for prediction (Rp2) and ratio of prediction to deviation (RPD) for SSC were 0.66 °Brix, 0.66 and 1.73. Model maintain methods of model update (MU) and slope and bias correction (SBC) achieved the best results in predicting SSC for two external validation sets with Rp2, RMSEP and RPD of 0.54, 0.83 °Brix, 1.60 and 0.52, 0.83 °Brix, 1.65, respectively. The results suggested model development and update with MU and SBC could improve the robustness of the portable NIRS instrument in predicting SSC of navel orange.

• There is a need for foliar application of boron and molybdenum on navel orange trees under Egyptian conditions due to the alkaline pH of its soil. • Treating navel orange trees with boron and molybdenum improved the productivity and fruit quality. • Foliar application by a combination of 4 % boric acid and 6 % ammonium molybdate improved productivity and fruit quality of navel orange. The majority of Egyptian soil has an alkaline pH of up to 8. As a result, plants have trouble absorbing certain nutrients, and it is necessary to add them via another method. Thus, the current study's objective was to find the ideal combination of molybdenum and boron to produce the highest possible levels of both quantitative and qualitative fruit yield. Molybdenum (ammonium molybdate) concentrations of 2 %, 4 %, and 6 %, were combined with boron in the form of boric acid, with 2 % and 4 %, concentrations of treated foliar applied to navel orange trees. In comparison to the control treatment, which involved spraying the trees with clean water, and other treatments, the results of the study during the two seasons indicated that treating the trees with 6 % ammonium molybdate and 4 % boric acid (T7) resulted in the highest statistical increases in shoot length, canopy volume, leaf intensity of staining green, leaf area, and leaf content of necessary mineral elements. Additionally, the same treatment resulted in a better fruit set and decreased fruit loss, which raised the yield factor as well as the number and weight of fruits produced by each tree. Furthermore, the impact also included enhancing the crop's quality (fruit weight and size), yield efficiency, vitamin C and SSC content, acidity reduction, and improved fruit peel color quality through an increase in carotene and chlorophyll A. In comparison to the control and other treatments, T7 also led to a decrease in the fruits' nitrate and nitrite content. In the current investigation, ammonium molybdate and boric acid were combined with boron in the form of boric acid were enhanced productivity and fruit quality of Navel orange. [ABSTRACT FROM AUTHOR]

Drought stress often occurred in citrus to limit its growth, distribution, and fruit quality. Cuticular waxes play an important role in regulating plant tolerance to drought stress. Plant enoyl-CoA reductase (ECR) is involved in the biosynthesis of cuticular waxes and catalyzes the last step of very long-chain fatty acids (VLCFAs) elongation. In this study, a putative ECR gene, named CsECR, was cloned from "Newhall" navel orange. CsECR protein has high identities with other plant ECR proteins and contained a conserved NADP/NAD-binding motif and three conserved functional sites. The highest expression of CsECR was observed in leaves, followed by stems, flavedos, ovaries, juice sacs, stigmas, stamens, albedos, and petals. Besides, the expression of CsECR was significantly induced by PEG6000 and ABA treatments. Ectopic overexpression of CsECR increased the contents of total waxes and aliphatic wax fractions (n-fatty acids, unsaturated fatty acids, n-alkanes, alkenes, iso-, and anteiso-alkanes) in the leaves and fruits of the transgenic tomato. Furthermore, ectopic overexpression of CsECR reduced the cuticle permeability in the leaves and fruits of the transgenic tomato and increased its tolerance to drought stress. Taken together, our results revealed that CsECR plays an important role in plant response to drought stresses by regulating cuticular wax biosynthesis. [ABSTRACT FROM AUTHOR]

Citrus canker is an important disease caused by Xanthomonas axonopodis pv. citri that affects citrus species. We isolated a bacterium denominated QC-Y with a strong inhibitory effect on citrus canker from navel orange leaves. The isolate was identified as Bacillus amyloliquefaciens based on the morphological, physiological, and biochemical characteristics and the 16S rDNA sequence analysis. The inhibitory activity of the pathogen was significantly affected by environmental factors such as the medium, inoculation amount, media volume, and pH. The biocontrol strain QC-Y effectively colonised on navel orange leaves, and the colonisation gradually decreased with time. Twelve days after inoculation, the isolate maintained a certain population level in the leaves. Mancozeb demonstrated a strong inhibitory effect on the growth of QC-Y; Chlorpyrifos at high concentrations inhibited QC-Y. Thiophanate-methyl, Bordeaux mixture, Kasugamycin, Imidacloprid, amino acid, Difenoconazole, Etoxazole, Alphacypermethrin, Buprofezin, Spirodiclofen, Avermectin, and Pyraclostrobin had no effect on the growth of QC-Y. In the detached leaf assay, compared with the leaves inoculated with the pathogens only, the disease incidence of the leaves treated with QC-Y was reduced by 77.5% and the lesions were smaller. Our findings reveal that Bacillus amyloliquefaciens QC-Y can be used as a potential biocontrol agent against the citrus canker disease.

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Summary: The present study evaluated the effects of 15 μL L‐1 nitric oxide (NO) on the fruit defence response of 'Newhall' navel orange. The decay rate of NO‐treated navel orange fruits was significantly lower than that of control fruits during storage at 20 °C storage (P < 0.05). Treatment with NO suppressed the increase in disease incidence and lesion area in orange fruits inoculated with Penicillium italicum (P. italicum); significantly increased the activities of phenolic metabolism‐associated enzymes and pathogenesis‐related (PR) proteins, including polyphenoloxidase (PPO), phenylalanine ammonia‐lyase (PAL), β‐1,3‐glucanase (GLU) and chitinase (CHT); and enhanced the activities of key enzymes, including 4‐coumarate: CoA ligase (4CL), cinnamate‐4‐hydroxylase (C4H) and chalcone isomerase (CHI) in the phenylpropanoid pathway. The contents of total phenolics, flavonoids and lignin were also higher in NO‐treated fruits than in control fruits. The findings suggest that exogenous NO could induce disease resistance against P. italicum in navel orange fruits. [ABSTRACT FROM AUTHOR]

Previously, we obtained a wax-deficient mutant 'Ganqi 3' (MT) from 'Newhall' navel orange (Citrus sinensis [L.] Osbeck cv. Newhall, WT). The weight loss and postharvest decay in MT fruit were much higher than those in WT fruit after long-term cold storage. To understand the underlying mechanism, the changes in the morphology, chemical composition and gene expression of cuticular waxes between WT and MT fruit were compared during 150 days of storage at 4 °C. The density of epicuticular wax crystals and the contents of most of the aliphatic wax fractions in MT fruit were much lower than those in WT fruit over 90 days of storage. Further research revealed that the differences in the morphology and chemical composition of cuticular waxes might be important causes for the differences of postharvest weight loss and decay rates between WT and MT fruit. Notably, the expression profiles of 16 wax-related genes in WT and MT fruit were consistent with the change trends of corresponding cuticular wax components during cold storage. These results suggest that the morphology and chemical composition of cuticular waxes may be regulated by wax-related genes and play an important role in regulating the postharvest weight loss and the tolerances to postharvest decay in navel orange. • A wax-deficient mutant (MT) originated from navel orange (WT) was used as material. • Wax changes in WT and MT fruit during cold storage were compared in this paper. • Cuticular waxes contribute to postharvest weight loss and decay of WT and MT fruit. • 16 wax-related genes were involved in cuticular wax changes during cold storage. [ABSTRACT FROM AUTHOR]

This study was carried out through two consecutive seasons 2016 and 2017 to investigate the effect of spraying with some antioxidants on vegetative growth, yield, fruit quality and nutritional status of twelve years old Navel orange trees on sour orange rootstock grown in a private orange orchard in Qalubia Governorate, Egypt cultivated in a silty clay loam soil. This experiment involved three antioxidant materials named (salicylic acid, citric acid and folic acid) and each one spraying by three levels of each of with (250, 500 and 1000 ppm) from each salicylic, citric and folic acid plus control treatment so the experiment included ten treatments. Selected trees were spraying three times (at the beginning of the growth cycle in March, just after fruit setting in May and just after June drop in July) by aqueous solution of salicylic acid, citric acid and folic acid until the point of runoff. The highest values of vegetative growth were obtained by spraying 500 ppm salicylic acid, 1000 ppm citric acid and 500 ppm folic acid. Regarding to yield, results pointed out that the foliar spraying with 500 ppm salicylic acid, 500 ppm citric acid and 250 ppm folic acid gave the highest values of yield. Treatments 500 ppm salicylic acid, 250 ppm citric acid and 250 ppm folic acid gave the highest values of physical and chemical fruit properties. In respect to nutrients content, the highest values of macronutrients were obtained by spraying 250 ppm folic acid, while that spraying 1000 ppm salicylic acid and 250 ppm folic acid gave the highest values of micronutrients. Therefore, using treatments 500 ppm salicylic acid, 500 ppm citric acid and 250 ppm folic acid may be recommended from economical point of view and as good treatments for enhancing Navel orange growth, yield, fruit quality and nutritional status especially under old citrus orchards.

Two famous Citrus rootstocks sour orange (C. aurantium.) and volkamer lemon (C. volkamariana.) were tested as interstocks at the stage of transplant production to investigate their mutual effects on the scion growth characteristics, mineral content, carbohydrates, total indols and phenols from side; and rootstock growth traits. nitrogen content, carbohydrates, indols and phenols from the other side. Also the results indicated that Navel orange budded on C. volkamariana grafted on C. volkamariana achieved significantly the highest scion height, root length, leaf number. The highest content of N, P, K, Mg, Fe, Zn, Mn and total phenols in scion stem. Moreover, the mentioned treatment gained the highest significant carbohydrates in roots.

In citrus, post-harvest treatment with ethylene or ethephon in an airtight container frequently resulted in fruit calyx drying, browning and abscission, with a consequent reduction in commercial value. To avoid these problems, pre-harvest degreening with ethepnon was performed on 'CARA CARA' navel orange fruits. An earlier and deeper orange colour development was obtained after treatment, reflecting at higher lightness (L*) and a*/b* ratio. The total carotenoid content in flavedo significantly increased, paralleling with a remarkable decrease in chlorophyll content, while in flesh TSS, TA and Vc were all not affected. A transcriptome analysis revealed that 171 genes in flavedo were involved in ethylene-degreening. These ethylene-responsive genes were involved in photosynthesis, chloroplast biogenesis, sugar metabolism, secondary metabolism, and activation of regulatory processes, including transcription regulation and protein posttranslational modification. In the chlorophyll metabolism, a chlorophyllase gene was strikingly increased, indicating the role of ethylene in promoting chlorophyll degradation. While, the genes related to carotenoid metabolism did not show any significant expression change after ethephon treatments. In conclusion, our data showed that pre-harvest degreening was an effective method to accelerate colour improvement, and meanwhile created a solid foundation for future investigations on the molecular mechanism underlying degreening of orange fruits. [ABSTRACT FROM AUTHOR]

The antioxidant effect of 95% ethanol extract and its three subfractions, PE (petroleum ether), EtOAc (ethyl acetate), and water extracts, from Gannanzao navel orange peel, were evaluated by ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)), DPPH (1,1-diphenyl-2-picryl-hydrazyl) and FRAP (ferric reducing/antioxidant potential) methods for the first time. Furthermore, the TPC (total polyphenol content), TFC (total flavonoid content), and primary individual flavonoids of the four extracts were analyzed and compared. The results indicated that: (1) the EtOAc extract exhibited the best antioxidant potential among these four extracts in all three antioxidant bioassay platforms; (2) Corresponding to the antioxidant potential, the EtOAc extract contained the highest contents of both TPC and TFC; (3) Compared with other extracts, the EtOAc extract was significantly (p < 0.01) rich in the contents of narirutin, sinensetin, nobiletin, 4′,5,6,7-tetramethoxyflavone, and 3,3′,4′,5,6,7-hexamethoxyflavone, which might be the main bioactive compounds responsible for the excellent antioxidant potential of EtOAc extract. [ABSTRACT FROM AUTHOR]

To accurately and efficiently distinguish the stem end and the blossom end of a navel orange from its black spots, we propose a feature skyscraper detector (FSD) with low computational cost, compact architecture and high detection accuracy. The main part of the detector is inspired from small object that the stem (blossom) end is complex and the black spot is densely distributed, so we design the feature skyscraper networks (FSN) based on dense connectivity. In particular, FSN is distinguished from regular feature pyramids, and which provides more intensive detection of high-level features. Then we design the backbone of the FSD based on attention mechanism and dense block for better feature extraction to the FSN. In addition, the architecture of the detector is also added Swish to further improve the accuracy. And we create a dataset in Pascal VOC format annotated three types of detection targets the stem end, the blossom end and the black spot. Experimental results on our orange dataset confirm that the FSD has competitive results to the state-of-the-art one-stage detectors like SSD, DSOD, YOLOv2, YOLOv3, RFB and FSSD, and it achieves 87.479% mAP at 131 FPS with only 5.812M parameters. [ABSTRACT FROM AUTHOR]

High temperature stress can be detrimental to plants, resulting in reduced fruit yield and increased incidences of fruit disorders. One strategy that farmers can use to maintain or increase their yields in the face of a changing climate is to adjust of farm climate by using shade net on the trees. Such, the use of shade netting on Washington navel orange planted on the sandy soil in Al-Nubaria region, Egypt were studied during two successive seasons, either using a permanent shade throughout all the season or using a moveable shade for certain period from the first of March until the end of June for every season. Growth (No. of shoots/one meter branch, No. of leaves/shoot, shoot length and chlorophyll content of the leaves, leaf area and tree canopy), macronutrients (N, P, K, Ca, Mg) and micronutrients (Fe, Zn, Mn, Cu, Na) content in the leaves, fruit characteristics (number, weight, diameter, peel thickness, total soluble solids, total acidity and ascorbic acid), yield and crop efficiency, were determined. It can be concluded that covering Washington navel orange trees grown on sandy soil with shade net especial covering the trees for certain period was very effective at protecting orange trees and led to improve the growth, increase the yield and maintain fruit quality.

This investigation was carried out during two successive seasons 2013 and 2014 on fruits of Washington Navel orange (Citrus sinensis L.). The experiment was conducted to evaluate the influence of some environmentally safe matural products to improve the storability of Navel orange (citrus sinensis) fruits during 2013 and 2014 seasons, Jojoba oil (1,3,5)%, castor oil (0.5, 1,2)%, yeast (1,2,3)%, seaweed (1,2,3)%, hot water (45ᵒC and commercial wax were used for proposed study, After the application of the treatments on the fruits, fruits were stored at a temperature of 5°±1 C and 90%±5 of relative humidity for 60 days, physical characteristics (weight loss%, decay% and the peel's thickness of the crust) and chemical properties (total phenols) were determined. Results indicated that, castor oil (2 and 1)% and jojoba oil 5% reduced the deterioration in weight loss%, decay%, peel thickness, and phenols content, compared to the content was obtained in control. So the results show that, coating orange fruits with castor oil (1, 2)% and jojoba oil (5)% had the most effective in improve the storability of orange fruits Navel Orange (Citrus sinensis L.).

High temperature stress can be detrimental to plants, resulting in reduced fruit yield and increased incidences of fruit disorders. One strategy that farmers can use to maintain or increase their yields in the face of a changing climate is to adjust of farm climate by using shade net on the trees. Such, the use of shade netting on Washington navel orange planted on the sandy soil in Al-Nubaria region, Egypt were studied during two successive seasons, either using a permanent shade throughout all the season or using a moveable shade for certain period from the first of March until the end of June for every season. Growth (No. of shoots/one meter branch, No. of leaves/shoot, shoot length and chlorophyll content of the leaves, leaf area and tree canopy), macronutrients (N, P, K, Ca, Mg) and micronutrients (Fe, Zn, Mn, Cu, Na) content in the leaves, fruit characteristics (number, weight, diameter, peel thickness, total soluble solids, total acidity and ascorbic acid), yield and crop efficiency, were determined. It can be concluded that covering Washington navel orange trees grown on sandy soil with shade net especial covering the trees for certain period was very effective at protecting orange trees and led to improve the growth, increase the yield and maintain fruit quality. [ABSTRACT FROM AUTHOR]

The aroma fraction of fresh fruits is a key factor to evaluate quality and acceptance or resistance of customers. Due to the limited sensitivity of current analytical methods, many important aroma components are unidentified in most studies of fresh fruit. In this work, the aroma compounds in the fresh navel orange were studied by multidimensional gas chromatography quadrupole time-of-flight mass spectrometry which can simultaneously achieve one-dimensional and comprehensive two-dimensional separation on only one instrument, with no need to change columns. As a result, a total of 97 volatile compounds were determined by comprehensive two-dimensional gas chromatography while only 44 compounds were identified by one-dimensional gas chromatography. The identified compounds, which account for 98.30% of the volatile chemicals present in the orange, include 10 aldehydes, 8 ketones, 22 alcohols, 12 esters, 11 hydrocarbons and 34 terpenes. D-limonene was shown to be the predominant compound in fresh navel oranges. The results show that comprehensive two-dimensional gas chromatography provided reliable and comprehensive information on the aroma compounds in fresh navel oranges. [ABSTRACT FROM AUTHOR]

Essential oil (EO) of navel orange (Citrus sinensis) has biological and pharmaceutical properties such as antimicrobial and anticancer. Geographical regions play an important role in physiological processes and accumulation of navel orange EO. The leaves and flowers of navel orange are important parts for EO production. In this investigation the EO isolated from leaves and flowers of navel orange which were collected from different locations (Al-Nubaria, Al-Kalubia, Al-Giza, Baniswef, Al-Minia and Mallawy) in Egypt were investigated. The samples collected from Al-Kalubia region produced the greatest content of leaf and flower EO (%) with the values of 0.4 and 0.3 % respectively. The samples collected from Al-Minia region resulted in the highest values of major components (sabinene, terpinen-4-ol, Δ-3-carene and limonene) of leaf EO. The major constituents of flower EO were sabinene, limonene, cis-sabinene hydrate and linalool. Al-Minia region produced the highest values of sabinene and limonene but the highest values of cis-sabinene hydrate and linalool were obtained from Al-Giza and Baniswef regions, respectively. The identified components of leaf or flower EO were grouped into 4 chemical groups. The major groups were monoterpene hydrocarbons (MHC) and oxygenated monoterpenes (OMHC) while the sesquiterpene hydrocarbons (SHC) and oxygenated sesquiterpenes (OSHC) formed the minor groups. Geographical regions resulted in important statistical changes of all components and chemical groups. [ABSTRACT FROM AUTHOR]

• EPO was recommended for sunlight correction. • Results support use of hand-held NIRS with varying sunlight. • Results support use of hand-held NIRS estimation of optimal harvest date. The models for hand-held near infrared spectroscopy (NIRS) instrument calibrated in the laboratory are prone to failure during orchard application because of measurement conditions change especially on sunlight interference. The models transfer from lab to orchard for assessment of soluble solids content (SSC) of navel orange on tree was investigated with consideration of sunlight influence to the fruit spectra. Chemometrics methods of global model, external parameter orthogonalization (EPO) and generalized least square weighting (GLSW) were attempted to correct the influence of the sunlight. Comparison of global model, both EPO and GLSW improved the predictive ability of partial least square regression (PLSR) models. With few corrected samples requirement, EPO was recommended and validated in predicting the samples in the different harvest date and blocks. The best results of coefficient of determination (R2) of 0.73 and 0.90, root mean square error of prediction (RMSEP) 0.85 and 0.63 % and ratio of standard deviation (SD) to RMSEP of 1.94 and 3.27 in predicting the samples in days after full bloom (DAFB) 237 (block A) and 164 (block B) were obtained. The best model corrected by EPO method was also adopted to estimate the optimal harvest date with a good consistency with destructive analysis. The results suggested that EPO correction aided the model transfer from lab to orchard was feasible for assessment of SSC of navel orange on tree. [ABSTRACT FROM AUTHOR]

• A stereo matching network OrangeStereo is proposed for the 3D surface reconstruction of navel oranges. • The Structural Features Extraction (SFE) module and Attention Weights Generation (AWG) module are utilized to extract stable structural features and suppress redundant information. • An improved loss function is proposed to enhance the matching performance by adding semantic information. • The EPE, RMSE in the navel orange region, and the inference time are 0.60 pixels, 3.53 pixels, and 33 ms, respectively. The RMSE of the depth prediction of navel oranges is 0.81 mm. Three-dimensional (3D) surface reconstruction is crucial to accurately detecting navel orange external qualities such as size and shape, and binocular stereo vision is promising for practical sorting scenarios due to its high frame rates and ease of deployment. For objects with texture-less surface, such as navel oranges, it is very challenging to match the corresponding points using traditional stereo matching algorithms because the detected feature points have high similarity in color as well as structure. Most of the existing deep learning-based stereo matching algorithms focus on the stereo matching performance of the whole image and lack the attention to the matching performance of the main region. Meanwhile, simple background with less texture will bring more uncertainty to the matching of corresponding points, which affects the robustness of the model. The OrangeStereo was proposed based on the GwcNet structure to achieve a better corresponding points matching effect of navel oranges, which can provide more accurate 3D surface information. The Structural Features Extraction (SFE) module was introduced after the initial feature extraction module to extract stable structural features and avoid the limitations of using single convolutional features. The Attention Weights Generation (AWG) module was utilized at matching cost calculation stage to help suppress redundant information and make the network pay more attention to the matching performance of specific regions. The improved loss function assigned a greater weight to the loss of the navel orange region using semantic information from left image to make the network more focused on the matching effect of the navel orange region. An ablation study was conducted to confirm the efficiency of the SFE module, AWG module, and the improved loss function of the algorithm. The ablation study contained five sub-experiments, including the baseline model, adding the SFE and the AWG modules respectively, and whether to add the improved loss function based on the addition of previous two modules. Additionally, PSMNet, GwcNet, RealtimeStereo, and ACVNet, four typical stereo matching methods, were contrasted with the OrangeStereo. The proposed OrangeStereo achieved better performance with EPE, RMSE, bad-1, bad-3, bad-5, and inference time of 0.60 pixels, 3.53 pixels, 2.37 %, 1.83 %, 1.62 %, and 33 ms in the orange region, respectively. The R2 and RMSE for the depth of orange utilizing our method were 0.982 and 0.81 mm, respectively. The proposed algorithm can be employed to obtain accurate depth information of fruits quickly, and it is expected to be used in the 3D reconstruction of fruits in the actual commercial fruit sorting lines to achieve more accurate external quality assessment. [ABSTRACT FROM AUTHOR]

Navel oranges are valued citrus fruits with a strong market presence, and detecting defects is crucial in their sorting due to common diseases and abnormalities during growth and transport. Deep learning, particularly semantic segmentation, is revolutionizing the fruit sorting industry by overcoming the limitations of traditional defect detection and enhancing the accuracy of classifying complex defects in navel oranges. The FastSegFormer network, enabling real-time fruit defect detection, addresses this challenge with our introduced Multi-scale Pyramid (MSP) module for its architecture and a semi-resolution reconstruction branch post-feature fusion. We suggested a multi-resolution knowledge distillation strategy to further increase the network's segmentation accuracy. We developed a navel orange defect segmentation dataset, trained, and evaluated our FastSegFormer-E model, designed for memory-constrained devices. It outperforms ENet by 3.15%, achieving a mIoU of 88.78% on the test set. The FastSegFormer-P model, tailored for high-speed detection, was tested on the mid-range RTX3060 graphics card, surpassing ENet by 3.7% with a mIoU of 89.33% and reaching 108 frames/s. The results demonstrate that the FastSegFormer-E model attains enhanced detection accuracy with reduced memory usage, whereas the FastSegFormer-P model stands out by striking an optimal balance between top-tier detection accuracy and rapid processing speed. Deploying the algorithm system on the same platform as pipeline sorting, 20 frame/s was achieved on a Jetson Nano with very low computational power. The model significantly improves the detection of subtle and intricate edge defects, achieving real-time speeds. Our proposed algorithm enhances the fineness of fruit sorting, resolves the limitation of existing algorithms that apply to a narrow range of fruit sorting scenarios, and provides an efficient and accurate solution for large-scale navel orange defect detection. • Image classification and target detection alone are not suitable for meeting the precise sorting requirements in modern fruit sorting applications. • High-resolution features significantly enhance defect edge differentiation. • During student model training, teacher model enhances performance via knowledge distillation. • Real-time semantic segmentation techniques can be used for large-scale navel orange defect detection. [ABSTRACT FROM AUTHOR]

Iron (Fe) is required for most metabolic processes, including DNA synthesis, respiration, photosynthesis, and chlorophyll biosynthesis; however, Fe deficiency is common in arid regions, necessitating additional research to determine the most efficient form of absorbance. Nano-fertilizers have characteristics that are not found in their traditional equivalents. This research was implemented on Washington navel orange trees (Citrus sinensis L. Osbeck) to investigate the effect of three iron forms—nano (Fe-NPs), sulfate (FeSO4), and chelated (Fe-chelated)—as a foliar spray on the growth, fruiting aspects, and nutritional status of these trees compared to control. The highest values of the tested parameters were reported when the highest Fe-NPs level and the highest Fe-chelated (EDTA) rate were used. Results obtained here showed that the spraying of the Washington navel orange trees grown under similar environmental conditions and horticulture practices adopted in the current experiment with Fe-NPs (nanoform) and/or Fe-chelated (EDTA) at 0.1% is a beneficial application for enhancing vegetative growth, flower set, tree nutritional status, and fruit production and quality. Application of Fe-NPs and Fe-chelated (EDTA, 0.1%) increased yield by 32.0% and 25% and total soluble solids (TSS) by 18.5% and 17.0%, respectively, compared with control. Spraying Washington navel orange trees with nano and chelated iron could be considered a significant way to improve vegetative growth, fruit production, quality, and nutritional status while also being environmentally preferred in the arid regions.