Search

To mitigate problems concerning small-sized spots on apple leaves and the difficulties associated with the accurate detection of spot targets exacerbated by the complex backgrounds of orchards, this research used alternaria leaf spots, rust, brown spots, gray spots, and frog eye leaf spots on apple leaves as the research object and proposed the use of a high-accuracy detection model YOLOv5-Res (YOLOv5-Resblock) and lightweight detection model YOLOv5-Res4 (YOLOv5-Resblock-C4). Firstly, a multiscale feature extraction module, ResBlock (residual block), was designed by combining the Inception multi-branch structure and ResNet residual idea. Secondly, a lightweight feature fusion module C4 (CSP Bottleneck with four convolutions) was designed to reduce the number of model parameters while improving the detection ability of small targets. Finally, a parameter-streamlining strategy based on an optimized model architecture was proposed. The experimental results show that the performance of the YOLOv5-Res model and YOLOv5-Res4 model is significantly improved, with the mAP0.5 values increasing by 2.8% and 2.2% compared to the YOLOv5s model and YOLOv5n model, respectively. The sizes of the YOLOv5-Res model and YOLOv5-Res4 model are only 10.8 MB and 2.4 MB, and the model parameter counts are reduced by 22% and 38.3% compared to the YOLOv5s model and YOLOv5n model. [ABSTRACT FROM AUTHOR]

We used 256 apple germplasm resources for a thorough examination of the genetic diversity associated with 26 phenotypic traits (i.e., genetic diversity analysis, cluster analysis, correlation analysis, principal component analysis, and membership function). The average coefficient of variation for 12 morphological traits was 66.39% (21.10–201.5%). The coefficient of variation was highest and lowest for the fruit arris and the width of the eye basin, respectively. Additionally, the diversity index ranged from 0.54 to 1.33. Moreover, the coefficient of variation for 14 numerical traits varied from 5.37% to 50%. The titratable acid content had the highest coefficient of variation, with a diversity index ranging from 2.01 to 2.08 (average of 2.045). A cluster analysis categorized 256 germplasms into four groups, among which Group I included germplasms with large fruits and the best comprehensive performance. Of the top 10 principal components revealed by the principal component analysis, principal component 1 was mainly related to fruit size and flavor. The top 10 germplasms were selected on the basis of comprehensive scores using the membership function method. Furthermore, a stepwise regression analysis identified 15 key traits for identifying apple germplasms, including the vegetative growth day, fruit weight, and the firmness of the fruit without skin. These results can serve as the foundation for future analyses of the phenotypic diversity of apple germplasms, while also providing a theoretical basis for screening, characterizing, and further improving excellent apple germplasms. [ABSTRACT FROM AUTHOR]

The conducted experiment evaluated the effects of three fungi—Trichoderma atroviride (Ta), Trichoderma harzianum (Th) and Phytium oligandrum (Po)—on the growth of maidens of two apple cultivars, 'Szampion' and 'Topaz', budded on two rootstocks, M.9 and M.26, in the nursery. The evaluation was based on the number of maidens obtained and their height, trunk diameter and number and length of lateral shoots, as well as the fresh weight of the leaves and the whole maiden. For the weaker-growing maidens of the 'Topaz' cultivar, the activity of the photosynthetic apparatus was additionally measured depending on the rootstock and fungal treatments. The number of maidens obtained improved significantly when Th (8.3–9.0%) and Po (8.4–12.8%) were applied, depending on the rootstock and cultivar used. With the best treatment with the Po fungus, on average, for the two cultivars, maiden apple trees budded on the M.9 dwarf rootstock were characterized by a significantly better height of 6% and trunk diameter of 13% compared to the control. In contrast, trees grown on the M.26 rootstock did not have significantly increased growth after the same treatments, with the exception of the Po fungus, which improved the stem diameter by an average of 10%. The use of fungi stimulated an increase in the number and length of the lateral shoots of maidens of the more easily branching 'Szampion' apple tree cultivar. Based on the fluorescence parameters obtained, it can be assumed that the 'Topaz' cultivar on the M.26 rootstock is less susceptible to stress conditions, especially those related to high temperatures and drought. All fungi used had a positive effect on the activity of the photosynthetic apparatus. Significantly worse values of the fluorescence parameters were obtained for the control combination compared to the fungal treatments. [ABSTRACT FROM AUTHOR]

In the realm of automated apple picking operations, the real-time monitoring of apple maturity and diameter characteristics is of paramount importance. Given the constraints associated with feature detection of apples in automated harvesting, this study proposes a machine vision-based methodology for the accurate identification of Fuji apples' maturity and diameter. Firstly, maturity level detection employed an improved YOLOv5s object detection model. The feature fusion section of the YOLOv5s network was optimized by introducing the cross-level partial network module VoVGSCSP and lightweight convolution GSConv. This optimization aimed to improve the model's multiscale feature information fusion ability while accelerating inference speed and reducing parameter count. Within the enhanced feature fusion network, a dual attention mechanism combining channel and spatial attention (GAM) was introduced to refine the color and texture feature information of apples and to increase spatial position feature weights. In terms of diameter determination, the contours of apples are obtained by integrating the dual features of color and depth images within the target boxes acquired using the maturity detection model. Subsequently, the actual area of the apple contour is determined by calculating the conversion relationship between pixel area and real area at the current depth value, thereby obtaining the diameter of the apples. Experimental results showed that the improved YOLOv5s model achieved an average maturity level detection precision of 98.7%. Particularly noteworthy was the detection accuracy for low maturity apples, reaching 97.4%, surpassing Faster R-CNN, Mask R-CNN, YOLOv7, and YOLOv5s models by 6.6%, 5.5%, 10.1%, and 11.0% with a real-time detection frame rate of 155 FPS. Diameter detection achieved a success rate of 93.3% with a real-time detection frame rate of 56 FPS and an average diameter deviation of 0.878 mm for 10 apple targets across three trials. Finally, the proposed method achieved an average precision of 98.7% for online detection of apple maturity level and 93.3% for fruit diameter features. The overall real-time inference speed was approximately 56 frames per second. These findings indicated that the method met the requirements of real-time mechanical harvesting operations, offering practical importance for the advancement of the apple industry. [ABSTRACT FROM AUTHOR]

This study investigates the infestation dynamics of Panonychus ulmi McGregor 1916 and its associated predators in Malus domestica borkh orchards across three towns in Morocco: Midelt, Ait Sebaa, and Imouzzer-Kender, situated in the Fez-Meknes and Draa-Tafilalt regions. Ait Sebaa (Fez-Meknes region), characterized by high temperatures and a lower altitude, exhibited a substantial increase in P. ulmi and its predators. In contrast, Midelt (Draa-Tafilalt region), with the highest altitude, demonstrated lower mite counts. Imouzzer-Kender (Fez-Meknes region), at an intermediate altitude, showed moderate mite levels. Detailed findings reveal a positive correlation between P. ulmi and temperature, as well as with phytoseiid mites. Conversely, a negative correlation exists between P. ulmi and altitude. Additionally, a positive correlation between phytoseiid mites and temperature is identified. Overall, this study provides valuable information on the ecological interactions between mites, temperature, altitude and humidity in distinct Moroccan regions, highlighting the need to take regional specificities into account in pest management strategies. [ABSTRACT FROM AUTHOR]

Iron (Fe) deficiency is one of the most common micronutrient deficiencies limiting crop production globally, especially in arid regions due to decreased availability of Fe in alkaline soils. The ATP sulfurylase (ATPS) gene has been reported to participate in regulating various abiotic stresses. Transcriptome data and qRT-PCR analysis revealed that the ATP sulfurylase gene MhATPS1 was notably induced by Fe-deficiency stress. Consequently, MhATPS1 (103410737) was isolated from Malus halliana, and transgenic tobacco and transgenic apple calli were successfully obtained by genetic transformation. Compared with the wild type (WT), transgenic MhATPS1 lines (transgenic tobacco and transgenic apple calli) displayed stronger resistance to Fe-deficiency treatment. To be specific, transgenic plants exhibited better growth, accumulated more Fe2+ content, had higher ferric chelate reductase (FCR) activity, and a greater active oxygen scavenging capacity. Furthermore, transgenic MhATPS1 lines up-regulated the expression of Fe uptake genes under Fe-deficit stress. Additionally, MhATPS1 transgenic lines secreted more H+ content compared to the WT. In summary, these findings indicate that the MhATPS1 gene may play a positive role in Fe-deficiency stress in both tobacco and apple calli. [ABSTRACT FROM AUTHOR]

Heterogeneous image features are complementary, and feature fusion of heterogeneous images can increase position effectiveness of occluded apple targets. A YOLOfuse apple detection model based on RGB-D heterogeneous image feature fusion is proposed. Combining the CSPDarknet53-Tiny network on the basis of a YOLOv5s backbone network, a two-branch feature extraction network is formed for the extraction task of RGB-D heterogeneous images. The two-branch backbone network is fused to maximize the retention of useful features and reduce the computational effort. A coordinate attention (CA) module is embedded into the backbone network. The Soft-NMS algorithm is introduced, instead of the general NMS algorithm, to reduce the false suppression phenomenon of the algorithm on dense objects and reduce the missed position rate of obscured apples. It indicates that the YOLOfuse model has an AP value of 94.2% and a detection frame rate of 51.761 FPS. Comparing with the YOLOv5 s, m, l, and x4 versions as well as the YOLOv3, YOLOv4, YOLOv4-Tiny, and Faster RCNN on the test set, the results show that the AP value of the proposed model is 0.8, 2.4, 2.5, 2.3, and 2.2 percentage points higher than that of YOLOv5s, YOLOv3, YOLOv4, YOLOv4-Tiny, and Faster RCNN, respectively. Compared with YOLOv5m, YOLOv5l, and YOLOv5x, the speedups of 9.934FPS, 18.45FPS, and 23.159FPS are obtained in the detection frame rate, respectively, and the model are better in both of parameter's number and model size. The YOLOfuse model can effectively fuse RGB-D heterogeneous source image features to efficiently identify apple objects in a natural orchard environment and provide technical support for the vision system of picking robots. [ABSTRACT FROM AUTHOR]

The dynamics of amylose (AM) and total starch content (TSC) have been studied in several apple varieties; however, their responses to environmental variables and rootstocks are less understood in new low-climacteric varieties. In addition, the pertinence of AM and TSC to fruit dry matter content (DMC), fruit quality at harvest, and quality retention after storage is little understood. In this study, we investigated the seasonal changes in AM and TSC of 'Ambrosia' apples grafted onto dwarfing rootstocks Malling 9 (M.9) and Budagovsky 9 (B.9) in two consecutive years, 2016 and 2017, in the Okanagan-Similkameen Valley, British Columbia, Canada. Enzymatic methods with Megazyme® kits were used to analyze the fruit samples collected from four orchards in the growing season. In 2016, the orchard microclimate exhibited cooler nights and greater diurnal temperature ranges (DTRs) compared to 2017. As a result, the AM content and AM portion in TSC were significantly higher in 2016, with levels peaking over 40% compared to the values observed in 2017. However, there were no significant differences in peak values of TSC between the two years. Additionally, the apples grown on the B.9 rootstock consistently showed higher levels of AM and AM percentage compared to those grown on the M.9 rootstock. The study also used Felix 750 Produce Quality Meter, a handheld infrared spectrometer, to assess the dry matter content (DMC) of growing fruit, which showed a strong correlation with AM content (r > 0.8). After being harvested at commercial maturity and stored in controlled atmospheric chambers (CA) for 8 months, fruit quality analysis suggested that the AM level and its percentage in TSC played an important role in determining 'Ambrosia' apple quality after long-term storage. [ABSTRACT FROM AUTHOR]

Sixty-seven apple tree accessions from the Centre for the Conservation of Agricultural Biodiversity of Tenerife (CCBAT) were molecularly characterised for the first time with 13 simple sequence repeats (SSRs). Additionally, previously studied genotypes from the Canary Islands (Tenerife, La Palma and Gran Canaria), Galicia, Asturias and commercial reference varieties were studied to identify possible synonymies and genetic structures, in order to improve the conservation of this genus in the germplasm bank. Thirty-three different genotypes were found in the new accessions analysed (51% clonality): sixteen of them (48%) exclusive to Tenerife, with no genetic coincidence with previous studies, making a total of thirty-three genotypes unique to Tenerife and sixty-five in the whole of the Canary Islands. The analysis of the population structure grouped the apple genotypes into two reconstructed panmictic populations (RPPs), one formed by local varieties or traditional ones ('Peros'), RPP1, from all the regions studied, and the other formed by local and commercial varieties, RPP2. The RPP1 genotypes identified in Tenerife seem to show better adaptation to low chill, with a positive and significant correlation (0.388, p < 0.01), highlighting the importance of local varieties and the need for their conservation. This is the first study reporting significant correlation between genetic structure and chilling requirements. [ABSTRACT FROM AUTHOR]

Apple (Malus domestica Borkh.) is usually produced in the form of a rootstock grafted scion. Rootstocks have important effects on several horticultural attributes. However, the results are not consistent regarding sites and scion–rootstock combinations. The aim of this research was to characterize the horticultural performance of 'Buckeye Gala' apple scion grafted onto ten rootstocks grown in Western Maryland during two harvest seasons. Our results demonstrated that, on average, tree size and yield in G.935, M.26 and G.969 rootstocks were 5–40% higher, but weight per fruit was 2–15% lower than in all other rootstocks. Fruit maturity was significantly delayed with increasingly vigorous rootstocks. There were no crop load differences. Overall, the assessed rootstocks were discriminated into seven significantly distinct clusters characterized by marked differences in vigor, yield, and fruit maturity. Moreover, significant correlations were obtained amongst all assessed variables. Rootstock impact must be considered when making management decisions in 'Buckeye Gala' fruit grown under Western Maryland conditions as they are critical in modulating fruit maturity and quality. [ABSTRACT FROM AUTHOR]

This study attempts to clarify the effect of canopy position on the physico-chemical parameters of apples cv. Braeburn. The experiments were carried out on fruit from the inner and outer part of the canopy in two growing seasons and at two harvest dates. Light measurements revealed that the average value of photo active radiation (PAR) for the inside and outside canopy amounted to 30.3 μmol/m2/s and 133.7 μmol/m2/s, respectively. Production year and canopy position significantly influenced ground color parameters a*, b*, C*, and h°, while the harvest date influenced all color parameters studied. For additional (red blush) coloration, the production year significantly influenced only the L* parameter, harvest date influenced all color parameters, and canopy position influenced L, a*, and C*. Only the fruits of the second harvest date showed more intense additional (red blush) coloration. The production year significantly affected fruit mass, firmness, total soluble solids (SSC), titratable acidity (TA), SSC/TA ratio, DPPH radical scavenging assay (AOP), total phenolic content (TPC), and total flavonoid content (TFC). The harvest date significantly influenced fruit mass, SSC, TA, SSC/TA, AOP, TPC, and TFC. The canopy position significantly influenced SSC, TA, AOP, TPC, and TFC. Regarding mineral content, the production year significantly affected the content of Fe, Ni, Cu, and Ca and the K/Ca ratio. The harvest date significantly affected Fe, Cu, Sr, K and K/Ca. The canopy position affected Fe, Ni, Zn, Sr, Ca, and K/Ca ratio, with a clear significant trend regarding the effect of canopy position only for Ca content (first and second year of the second harvest date) and K/Ca ratio (first year of both harvest dates). PCA analyses identified distinguishing features between apples, with differences defined specifically by AOP, TPC, TFC, Rb, Sr, Ca, and K/Ca on the PC 1 and Mn, Fe, Ni, Cu, and Zn on PC 2. [ABSTRACT FROM AUTHOR]

This study examined the effect of simultaneous fermentations of Saccharomyces cerevisiae and Pichia kluyveri, Lactobacillus plantarum and Oenococcus oeni on the chemical composition of apple cider from two apple varieties—Topaz and Red Topaz. Analytical techniques (HPLC-RID, HPLC-VWD, GC/MS, GC/FID, HPLC-DAD ESI+) were employed to analyze glucides, organic acids, volatile compounds, amino acids and phenolic compounds, respectively. Statistical analysis and and PCA were conducted to assess the correlations among samples based on the compounds identified. In the mixed fermentations, such as Saccharomyces cerevisiae + Lactobacillus plantarum and Saccharomyces cerevisiae + Oenococcus oeni, the amount of lactic acid was higher compared to the other samples, thus proving the effectiveness of malolactic fermentation simultaneous to alcoholic fermentation. The fermentation of Saccharomyces cerevisiae + Pichia kluyveri resulted in the formation of greater amounts of certain volatile compounds. Moreover, the sensory analysis revealed that Saccharomyces cerevisiae + Pichia kluyveri distinguished apple-like, fruity and floral notes. This study suggests that the simultaneous inoculation of Saccharomyces and non-Saccharomyces yeasts results in a more complex-flavored cider. The mixed fermentation of yeast and lactic acid bacteria is a sustainable method given the shortened fermentation duration and can be successfully applied in the cider industry. [ABSTRACT FROM AUTHOR]

The determination of the optimal harvest date is very important to obtain the desired apple quality. This study was aimed at evaluating the impact of the harvest date on selected properties of the following red-fleshed apples: 'Alex Red', 'Trinity', and 'Roxana'. The color parameters of skin and flesh were measured using a portable spectrophotometer. The apple slices were imaged using a digital camera to extract flesh image textures. Then, the contents of chemical compounds, such as sugars, acids, and polyphenols were measured. The greatest significant changes with the delay in the harvest date were observed in the values of parameter a* of red-fleshed apple skin (from 21.57 to 25.42 for 'Alex Red', from 22.65 to 26.81 for 'Trinity', and from 21.82 to 30.00 for 'Roxana') and apple flesh (from 29.06 to 32.80 for 'Alex Red' and from 32.96 to 36.30 for 'Trinity'); image textures (RHMean—from 227.6 to 236.5 for 'Alex Red', from 231.8 to 236.3 for 'Trinity', and from 217.8 to 227.9 for 'Roxana', and SHMean—from 126.0 to 135.6 for 'Alex Red', from 127.4 to 143.4 for 'Trinity', and from 58.4 to 96.0 for 'Roxana'); the total sugar content—from 85.6 to 90.9 g kg−1 for 'Alex Red' and from 112 to 128 g kg−1 for 'Trinity'; total pectin—from 6278 to 6008 mg·100 g−1 for 'Alex Red', from 6196 to 6401 mg·100 g−1 for 'Trinity', and from 5912 to 6807 mg·100 g−1 for 'Roxana'; and total phenolic content—from 536.1 to 501.9 mg kg−1 for 'Alex Red', from 515.5 to 573.3 mg kg−1 for 'Trinity', and from 1121.3 to 1293.3 mg kg−1 for 'Roxana'. The linear relationships with the Pearson's correlation coefficients (R) reaching 0.999 between the image texture from color channel a and color parameter L*, and −0.999 for the image feature from color channel R vs. color parameter a* of the flesh, and image texture from channel X vs. anthocyanins were confirmed. [ABSTRACT FROM AUTHOR]

Apple skin color is essential for market value. Therefore, this study evaluated the efficiency of pneumatic defoliation (PD) on the enhancement of red skin color and anthocyanin pigments in 'Picnic' apples. Three weeks before harvesting, apple trees were treated with PD with low- (0.7 bar) and high- (0.9 bar) air pressure at a tractor driving speed of 2 km/h. Undefoliated trees served as controls. Higher leaf defoliation and leaf damage rates were observed in the high-PD treatment than those in the low-PD treatment. Photosynthetically active radiation inside the canopies was the highest in trees subjected to high-pressure PD than in those that underwent low-pressure PD and the controls. At harvest, the fruit color (a*) value, red-colored area, and anthocyanin content in the fruit skin were the highest in the high-PD treatment, intermediate in the low-PD treatment, and the lowest in the control treatments. Additionally, a higher expression of anthocyanin biosynthetic genes was observed in both defoliation treatments, especially under high PD. However, except for higher flesh firmness under low PD, the L* and b* values and fruit quality indices (fruit weight, starch pattern index, titratable acidity, soluble solids content, and sunburn occurrence) were not significantly affected by either PD treatment. In conclusion, PD can be used to enhance skin coloration and anthocyanin pigments in apples; further PD with high air pressure achieved optimum red skin coloration in 'Picnic' apples. [ABSTRACT FROM AUTHOR]

Changing the harvesting time of apples from the optimum harvest window to delayed harvesting may be applied if it is impossible to harvest apples at the optimal time, but it requires changing other factors, as they influence the quality of fruits and shelf life. The aim of the study was to assess the quality of 'Red Jonaprince' apples during storage after delayed harvesting and 1-methylcyclopropene (1-MCP) preharvest and postharvest treatment for various storage times. Apples were studied within four groups subjected to preharvest and postharvest treatments, as follows: Group 0—no 1-MCP treatment; Group 1—1-MCP preharvest treatment; Group 2—1-MCP postharvest treatment; and Group 3—1-MCP preharvest and postharvest treatment. All apples were subjected to ultra-low oxygen (ULO) storage conducted for 3, 5 or 6 months, while the analyses were conducted directly after ULO storage (simulated shelf life—0 days) and after simulated shelf life (7 days). For firmness, in the case of 1-MCP applied only preharvest (Group 1) and only postharvest (Group 2), before shelf life, the longer ULO storage resulted in obtaining lower values of firmness (p < 0.0001). If 1-MCP was not applied postharvest (Group 0 and Group 1), and short ULO storage was applied (3 and 5 months for Group 0; 3 months for Group 1), after shelf-life lower values of firmness were observed (p < 0.0001). For soluble solids content (SSC), in the case of 1-MCP not applied preharvest (Group 0 and Group 2), before shelf life, and for 1-MCP applied postharvest (Group 2) after shelf life, the longer ULO storage resulted in obtaining lower values of SCC (p < 0.0001). For titratable acidity (TA), in the case of all the studied groups after shelf life, as well as in case of 1-MCP applied only preharvest (Group 1) also before shelf life, the longer ULO storage resulted in obtaining lower values of TA (p < 0.0001). Except for the 1-MCP applied only postharvest (Group 2), in the case of short ULO storage applied (3 and 5 months for Group 0; 5 months for Group 1; 5 months for Group 3), after shelf-life lower values of TA were observed (p < 0.0001). If delayed harvesting must be conducted, applying 1-MCP not only postharvest, but also preharvest, allows obtaining the most stable firmness and SSC, which do not decrease during storage and shelf life. Taking this into account, it may be concluded, that in the case of delayed harvesting, combining 1-MCP applied preharvest and postharvest should be recommended to keep the quality parameters stable during storage and shelf life. [ABSTRACT FROM AUTHOR]

13C discrimination (Δ13C) has been used in research as an indicator of water availability in crops; however, few data are available concerning fruit trees. The aim of this study was to examine the effect of irrigation on the Δ13C values of apple leaves. We assumed that Δ13C would increase with irrigation intensity. The Δ13C of apple trees (Malus domestica) cv. 'Red Jonaprince' was determined in the years 2019–2022. Leaf samples were collected in spring, in June, at the beginning of the irrigation campaign, and in autumn, in September, following the harvest. The irrigation doses were applied to replenish the water consumption, 0% (ET0), 50% (ET50), 75% (ET75), and 100% (ET100), of the calculated evapotranspiration (ET) levels. In November, the leaves collected from different positions on the shoots were sampled, assuming the Δ13C signature would reflect the changes occurring in the water supply during their growth. The irrigation rates had a significant effect on the Δ13C of the leaves when the data for the spring and summer months were pooled. On average, Δ13C increased from 20.77‰ and 20.73‰ for ET0 and ET50, respectively, to 20.80‰ and 20.95‰ for ET75 and ET100, respectively. When the data obtained for the spring and summer months were analysed separately, the effect of irrigation was weak (p < 0.043). The Δ13C value was always higher for treatment ET100 than treatment ET0, for individual experimental years and terms; however, the differences were minor and mostly insignificant. The leaf position had a strong significant effect on Δ13C; the values gradually decreased from the leaves growing from two-years-old branches (22.50‰) to the youngest leaves growing at the top of the current year's shoots (21.07‰). This order was similar for all the experimental years. The results of the experiment suggest that 13C discrimination in apples is affected not only by water availability during growth, but also by the use of C absorbed in previous years. [ABSTRACT FROM AUTHOR]

An apple-picking robot is now the most widely accepted method in the substitution of low-efficiency and high-cost labor-intensive apple harvesting. Although most current research on apple-picking robots works well in the laboratory, most of them are unworkable in an orchard environment due to unsatisfied apple positioning performance. In general, an accurate, fast, and widely used apple positioning method for an apple-picking robot remains lacking. Some positioning methods with detection-based deep learning reached an acceptable performance in some orchards. However, apples occluded by apples, leaves, and branches are ignored in these methods with detection-based deep learning. Therefore, an apple binocular positioning method based on a Mask Region Convolutional Neural Network (Mask R-CNN, an instance segmentation network) was developed to achieve better apple positioning. A binocular camera (Bumblebee XB3) was adapted to capture binocular images of apples. After that, a Mask R-CNN was applied to implement instance segmentation of apple binocular images. Then, template matching with a parallel polar line constraint was applied for the stereo matching of apples. Finally, four feature point pairs of apples from binocular images were selected to calculate disparity and depth. The trained Mask R-CNN reached a detection and segmentation intersection over union (IoU) of 80.11% and 84.39%, respectively. The coefficient of variation (CoV) and positioning accuracy (PA) of binocular positioning were 5.28 mm and 99.49%, respectively. The research developed a new method to fulfill binocular positioning with a segmentation-based neural network. [ABSTRACT FROM AUTHOR]

Apples are susceptible to infection by various pathogens during growth, which induces various leaf diseases and thus affects apple quality and yield. The timely and accurate identification of apple leaf diseases is essential to ensure the high-quality development of the apple industry. In practical applications in orchards, the complex background in which apple leaves are located poses certain difficulties for the identification of leaf diseases. Therefore, this paper suggests a novel approach to identifying and classifying apple leaf diseases in complex backgrounds. First, we used a bilateral filter-based MSRCR algorithm (BF-MSRCR) to pre-process the images, aiming to highlight the color and texture features of leaves and to reduce the difficulty of extracting leaf disease features with subsequent networks. Then, BAM-Net, with ConvNext-T as the backbone network, was designed to achieve an accurate classification of apple leaf diseases. In this network, we used the aggregate coordinate attention mechanism (ACAM) to strengthen the network's attention to disease feature regions and to suppress the interference of redundant background information. Then, the multi-scale feature refinement module (MFRM) was used to further identify deeper disease features and to improve the network's ability to discriminate between similar disease features. In our self-made complex background apple leaf disease dataset, the proposed method achieved 95.64% accuracy, 95.62% precision, 95.89% recall, and a 95.25% F1-score. Compared with existing methods, BAM-Net has higher disease recognition accuracy and classification results. It is worth mentioning that BAM-Net still performs well when applied to the task of the leaf disease identification of other crops in the PlantVillage public dataset. This indicates that BAM-Net has good generalization ability. Therefore, the method proposed in this paper can be helpful for apple disease control in modern agriculture, and it also provides a new reference for the disease identification of other crops. [ABSTRACT FROM AUTHOR]

As a result of worried consumer pressure, European supermarket chains (ESC) have developed very strict rules about the number and concentration of pesticide active substance residues (AS) accepted in fruits. So-called fruit quality toxicological burden indicators were developed. If fruit suppliers do not comply with ESC requirements, their fruit is often rejected. It is becoming increasingly difficult for apple producers to meet all the requirements of the ESC, so they need new residue reduction tools. One of the options to lower the concentrations of residue on apples is a preharvest application of low-risk preparations (LRP) based on potassium bicarbonate (KHCO3) = PBC, coconut di-ethanol amide ((CH3(CH2)nC(=O)N(CH2CH2OH)2) = DEA, hydrogen peroxide (H2O2) = HP, and a mixture of microbes (EM) that have the ability to dissolve or disintegrate the AS residue. Trials were carried out to test the concept mentioned above. The application of LRP during the last four weeks of preharvest significantly reduced the residue concentration of pesticide AS in apples. Reduction rates among 25 active substances ranged from 0 to 100%, depending on the combination of LRP and AS. HP had the highest capacity to accelerate AS degradation, PB was the second most efficient, and DEA and EM displayed a low residue disintegration ability. The application of the tested LRP can enable apple growers to produce fruits with significantly lower residue concentrations and allows them to comply more successfully with strict ESC rules based on the calculations of toxicological burden indicators. [ABSTRACT FROM AUTHOR]

In order to determine the pollinizer success rates between twelve apple cultivars in 2021 and 2022, 671 apple embryos were collected from 19 different orchards in Ullensvang (southwestern Norway) and Svelvik (southeastern Norway). Genomic DNA was extracted from the collected embryos and, afterward, a genetic characterization with 15 polymorphic microsatellite markers was conducted. An identical set of markers was also used on all twelve mother cultivars, as well as on six crabapple pollinizers, which were found in the investigated orchards. The obtained molecular data enabled paternity analyses to be performed with the objective of assigning a male parent to each embryo. The paternity analyses identified pollen donors for all, except for 3% of the embryos. In most cases, it was possible to identify the most successful pollinizers for each cultivar, with 'Aroma' and 'Discovery' being the most efficient pollen donors overall. Tree abundance seems to be a major factor in pollinizer success, while semi-cross-compatible characteristics represent a hindrance. Only 7% of the analyzed embryos were determined to have been fertilized by pollinizers outside the orchard, confirming the significance of pollinizer proximity for efficient pollination. [ABSTRACT FROM AUTHOR]

This study aimed to determine the effect of irrigation amount ( W ), nitrogen ( N ), potassium ( K ), and zinc ( Z n ) on the net photosynthetic rate ( P n ) of closely planted apple trees on dwarf rootstocks in arid areas of Xinjiang. Taking the "Royal Gala" apple as the experimental material, a mathematical model for  P n  was established using the principle of four-factor five-level quadratic regression with a general rotation combination design. The results show that: (1) The regression equations reached significant levels (F = 37.06 > F0.01(11.11) = 4.54). (2) The effect of  W ,  N ,  K ,  Z n  on  P n  is significant with relative importance  W  >  N  >  Z n  >  K . (3) The results of single factor analysis showed that with an increase in W, N, K, and Zn,  P n  exhibits an n-shaped parabolic response. (4) The positive coupling between  W  and  N  is significant, and the positive coupling between  W  and  Z n  is also significant. (5) Analysis of the interaction between sets of three factors revealed that  W ,  N ,  and  Z n  could be combined to best effect, with the maximum value reaching 12.77  μ mol · m − 2 · s − 1 . Compared with  W × K × Z n  and  W × N × K , the combination of  W × N × Z n  reduces  W  by 9.2% and 6.3%, respectively, which indicates its suitability for use in the dry and water deficient planting environment in Xinjiang. (6) Within the 95% confidence level, when  W  is 258–294.75 mm,  N  is 33.44–39.51  kg / hm 2 ,  K  is 53.82–69.39  kg / hm 2 ,  and  Z n  is 6.46–7.84  kg / hm 2 , the net photosynthetic rate reaches 11  μ mol · m − 2 · s − 1 . [ABSTRACT FROM AUTHOR]

Seaweed extracts, which are naturally degradable and environmentally friendly, have become important components of organic fertilizers for fruit. In this study, the effects of seaweed-extract-based organic fertilizers on the levels of mineral elements, sugar–acid components, and hormones in 'Fuji' apples were evaluated. Eleven-year-old 'Fuji' apple ('Yanfu 3'/M9/Malus robusta) trees were sprayed with seaweed-extract-based fertilizers SE1 (contained ≥20 g/L of algal polysaccharides, ≥100 g/L of amino acids, and ≥30 g/L of EDTA-Ca) and SE2 (contained ≥100 g/L of algal polysaccharides, ≥160 g/L of Ca, and ≥10 g/L of Mg) from early May to early October at two-week intervals in 2020. Water spraying was used as a control treatment. The preliminary results showed that SE1 and SE2 significantly increased the net photosynthetic rate, chlorophyll content and Rubisco enzyme activity in 'Fuji' apple leaves. SE1 and SE2 improved the quality of 'Fuji' apples. Compared to the single-fruit weight, soluble solid content (SSC), soluble sugar content, sugar–acid ratio, vitamin C (VC) content, and free amino acid content of control apples, those of SE1-treated and SE2-treated apples increased by 10.74% and 8.94%, 12.16% and 9.76%, 21.96% and 11.90%, 45.12% and 28.55%, 56.12% and 47.96%, and 17.15% and 13.42%, respectively. SE1 and SE2 significantly improved the levels of fructose, glucose, sucrose, and sorbitol, but decreased the levels of malic acid, oxalic acid, and tartaric acid in 'Fuji' apples. Meanwhile, SE1 and SE2 increased the levels of potassium, calcium, magnesium, iron, zinc, and boron in 'Fuji' apples. SE1 and SE2 significantly improved the levels of indole-3-acetic acid, zeatin riboside, and gibberellic acid, but significantly decreased the level of abscisic acid in 'Fuji' apples. In conclusion, spraying seaweed-extract-based foliar fertilizer is beneficial to the nutrient accumulation and flavor development in 'Fuji' apples. [ABSTRACT FROM AUTHOR]

In the past, chemical thinning dominated in fruit orchards. This paper for the special issue outlines alternatives to chemical thinning for crop load management (CLM) and its effect on fruit size, firmness, sugar, starch, and weight, indicating ripeness and fruit quality, yield, and alternate bearing. A total of 450 apple trees (Malus domestica Borkh., cv. 'Roter Boskoop'; six years old) on M9 rootstock were used at the Klein-Altendorf experimental station (50° N) of the University of Bonn, Germany. As the first alternatives, trees were mechanically blossom-thinned at the balloon stage (BBCH 59) with a rotor speed of 320 rpm or 380 rpm at 5 km/h tractor speed or were chemically thinned at the full bloom stage (BBCH 65) with ammonium thiosulfate (ATS), ethephon (ETH), and/or 6-benzyladenine (BA) at 10–12 mm fruit size (BBCH 71) after applying ATS/ETH. Flower clusters and/or cluster leaves (source) were manually removed to determine the optimum sink-source ratio to achieve different ratios of fruitlets (sink) relative to the leaves (source) at fruit set (BBCH 67–69). Un-thinned, adjacent trees served as the control. The majority of CLM methods improved fruit size and weight. Removing cluster leaves at fruit set increased fruit size and weight of the remaining fruit, which has not been observed before. The most effective treatment for fruit size and weight and return bloom was the 75% flower cluster and complete cluster leaf removal. Removal of more than 50% of flower clusters successfully improved return bloom, indicative of alternate bearing. The mechanical blossom thinning had a positive effect on fruit size and weight with a return bloom similar to that of removal of 50% flower clusters. [ABSTRACT FROM AUTHOR]

The impact of low-oxygen (2 kPa) controlled atmosphere storage on the recovery of aroma biosynthesis in 'Golden Delicious' (GD) apple tissues during their subsequent shelf life was investigated. The results showed that the highest ester content was found in skin tissue, followed by Flesh 2 and Flesh 1. The 2 kPa O2 storage of GD apples resulted in a decrease in the emission of volatile esters and alcohols, but an increase in aldehyde emission. Notably, compared with skin tissue, the flesh tissue of 2 kPa O2-stored GD apples had a relatively high recovery capacity of ester biosynthesis but a low recovery capacity of alcohol synthesis for its shelf life. The impact was associated with increased levels in the MdLOX1a and MdAATs (MdAAT1 and MdAAT2) transcripts, as well as a decreased level in the MdHPL transcript in the flesh tissue. In addition, a complex regulatory network of ethylene on fruit aroma biosynthesis in response to low-oxygen conditions was also indicated. Collectively, there was a tissue-specific recovery capability of aroma biosynthesis in GD apples after low-oxygen storage. [ABSTRACT FROM AUTHOR]

Efficient identification of apple leaf diseases (ALDs) can reduce the use of pesticides and increase the quality of apple fruit, which is of significance to smart agriculture. However, existing research into identifying ALDs lacks models/methods that satisfy efficient identification in the wild environment, hindering the application of smart agriculture in the apple industry. Therefore, this paper explores an ACCURATE, LIGHTWEIGHT, and ROBUST convolutional neural network (CNN) called EfficientNet-MG, improving the conventional EfficientNet network by the multistage feature fusion (MSFF) method and gaussian error linear unit (GELU) activation function. The shallow and deep convolutional layers usually contain detailed and semantic information, respectively, but conventional EfficientNets do not fully utilize the different stage convolutional layers. Thus, MSFF was adopted to improve the semantic representation capacity of the last layer of features, and GELU was used to adapt to complicated tasks. Further, a comprehensive ALD dataset called AppleLeaf9 was constructed for the wild environment. The experimental results show that EfficientNet-MG achieves a higher accuracy (99.11%) and fewer parameters (8.42 M) than the five classical CNN models, thus proving that EfficientNet-MG achieves more competitive results on ALD identification. [ABSTRACT FROM AUTHOR]

Apples are one of the most popular crops in the world, grown for fresh consumption, processing, and ornamental purposes. In the present study, the seeds of thirty crab apple (Malus spp.) genotypes were analyzed to evaluate the tocopherol composition and find a crop-specific profile. The mean proportion (%) of tocopherol (T) homologues (α, β, γ, and δ) was as follows: α-T (45.8%), β-T (21.8%), γ-T (24.3%), δ-T (8.1%) with a mean content of 22.41, 10.89, 12.35, and 4.08 mg/100 g dry weight, respectively. The coefficient of variation was higher in γ-T (0.748), δ-T (0.648) and β-T (0.540), and about two times lower for α-T (0.320). The total content of tocopherols varied much less in studied genotypes (coefficient of variation 0.164). α-T was the predominant tocopherol homologue in twenty-four genotypes (33.4–79.0%), while γ-T (36.4–64.9%) was the predominant in the remaining six studied genotypes. Principal component analysis identified six groups based on the tocopherol profile. Variety, purpose (ornamental vs. edible), and species appear to be associated with tocopherol profile. Most Malus sp., M. × prunifolia, and edible genotypes were located in two groups characterized by twice the content of α-T over β-T, and similar content of both (α-T and β-T), respectively. In both cases the sum of α-T and β-T constituted about 80% of total tocopherols. Significant correlations among tocopherol homologues were obtained: positive between α-T vs. β-T and γ-T vs. δ-T, and negative between α-T vs. γ-T, α-T vs. δ-T, and γ-T vs. β-T. These can be explained by the biosynthetic pathway of those lipophilic bioactive compounds. [ABSTRACT FROM AUTHOR]

Fruit tree shoots are potential useful resources that are rich in carbohydrates and inorganic nutrients but that are not typically utilized in sustainable agriculture. Our objective was to evaluate the soil properties and soil quality of an orchard after returning apple shoots in situ and to investigate the contribution rate of apple shoots as an exogenous source of organic carbon for fertility amendment of the apple root domain. One-year-old apple shoots were pruned in spring before budding, chopped into 10 cm sections and placed on the soil surface. Soil samples were collected in the first year and third year after returning the shoots. Principal component analysis, Pearson correlation analysis and soil quality index (SQI) comprehensive analysis methods, combined with fuzzy mathematics, were adopted to evaluate the effects of returning apple shoots on comprehensive soil quality, including the soil fertility indicators, soil exchangeable cations, soil neutral sugar and amino acids. Increases in soil organic carbon (SOC), available potassium (K), and available phosphorus (P) were observed in different layers of the orchard soil with returned shoots over time. The total nitrogen (N) content decreased by 18.75% and 13.79% in the 0–20 cm and 20–40 cm soil layers, respectively, in the first year, but increased significantly in the third year. Significant increases in exchangeable cations (Na+, Ca2+, Mg2+) in the 0–20 cm soil layer were also observed in the third year after returning shoots, compared to the control. In addition, obvious accumulation of glucose and xylose was observed in the 0–20 cm soil layer compared to the controls in the third year after returning shoots. The total water-soluble free amino acid contents in the third year after returning shoots were 1.08- and 1.16-times higher, respectively, than those of the controls in the 0–20 cm and 20–40 cm soil layers. The SQI in the third year was higher than that of the other treatments in the 0–20 cm soil layer. This study suggests that abandoned apple shoots used as a supplementary carbon source for orchards enhanced the soil fertility of different soil layers, regulated the soil micro environment, and improved the overall soil quality. [ABSTRACT FROM AUTHOR]

High salinity and drought seriously limit the production of many crops worldwide, including apple (Malus x. domestica Borkh). Members of the bZIP family of transcription factors play important roles in abiotic stress in various plants, but there have been few studies in perennial tree species. In our previous study, we conducted a genome-wide survey of bZIP family transcription factor genes in apple. Here, we focused on one of these genes, MdbZIP26, which is induced by high salinity, drought, and exogenous abscisic acid (ABA). The MdbZIP26 promoter contains several apparent cis-acting elements associated with abiotic stress response, such as ABRE/G-box, DRE, GT1, and GMSCAM4. The temporal and spatial expression patterns of MdbZIP26 were consistent with a role in abiotic stress response. Arabidopsis thaliana plants expressing MdbZIP26 showed enhanced tolerance to dehydration and salinity, and this was associated with altered expression of ABA/stress-regulated genes. Considered together, these results suggest that MdbZIP26 plays a role in the resistance of drought and high salinity stress in apple via ABA-mediated signaling. [ABSTRACT FROM AUTHOR]

This study was conducted at the Taidong Base of the Shandong Institute of Pomology, Tai'an City, Shandong Province, China, from May to October 2020. The effects of spraying calcium fertilizer on the photosynthetic characteristics, mineral element content, sugar and acid metabolism, and quality of apples were assessed. Fuji Apple Tianhong.2/SH/Malus robusta (M. robusta) was treated with the calcium fertilizers Niucui (Ca ≥ 100 g/L, B: 1–10 g/L) and Naipu 9 (Ca: 90 g/L, Mg: 21 g/L, N: 110 g/L) at the young fruit stage (25 May), the expansion stage (5 July), and the coloring stage (25 September). Water was sprayed as the control application. The results revealed that spraying calcium fertilizer increased the chloroplast pigment content and photosynthetic capacity of the apple leaves. Compared with the control, the net photosynthetic rate of apple leaves sprayed with Niucui increased by 4.3–34.6%, and that of leaves sprayed with Naipu 9 increased by 15.0–57.4%. Spraying calcium fertilizer promoted the accumulation of Ca, Mg, and B mineral elements in leaves and fruits while inhibiting the accumulation of Cu. Spraying calcium fertilizer improved the quality of apple fruit. Compared to the control fruit, the single fruit weight, fruit hardness, soluble solid content, and Vitamin C content of fruit sprayed with Niucui and Naipu 9 increased by 6.5 and 12.1%, 3.6 and 16.1%, 6.3 and 12.0%, and 30.5 and 29.4%, respectively. Spraying calcium fertilizer increased the sugar content and decreased the acid content of the apples. Naipu 9 was more effective at increasing fruit sugar content, especially sucrose and sorbitol, while Niucui was more effective at reducing the acid content, especially malic acid. This was observed because Naipu 9 increased the sugar metabolism enzyme activity, while Niucui increased the acid decomposition-related enzyme activity. In conclusion, according to the nutrition quality and flavor of the fruit, Naipu 9 application was determined to be the best fertilizer for the Fuji apple. [ABSTRACT FROM AUTHOR]

In apple cultivation, dwarf rootstocks are chosen for dense planting and intensive cultivation, which is beneficial to production management. Dwarf rootstocks are widely used in apple production in China. However, the dwarfing mechanisms of dwarf interstock are still unclear. Here, M9 and SH40 were selected as the dwarf interstocks for potted Fuji apples. The key transcription factor MdWRKY24 was screened via transcriptional sequencing. The open reading frame sequence of the MdWRKY24 gene was 657 bp in length, encoded 218 amino acids, and was located on the cell membrane. The MdWRKY24-overexpressing Arabidopsis line showed a dwarf phenotype and delayed flowering. The DELLA protein RGA-like (RGL) gene is a repressor of the gibberellin signaling pathway. Yeast two-hybrid analysis revealed that MdWRKY24 could interact with MdRGL1/2/3. The results indicated that MdWRKY24 might affect plant dwarfing through the synergistic effect of MdRGL1/2/3. The MdWRKY24-MdRGL may be an important pathway underlying the gibberellin-mediated regulation of apple dwarfing. [ABSTRACT FROM AUTHOR]

Apples have long been known for their beneficial effects on human health due to the presence of various bioactive compounds. It is therefore very important to understand the biophysical properties of apple cuticle that dictate apples' storability and quality. The purpose of this work was to determine the roughness, hydrophobicity, surface potential, and color of various autochthonous and new apple cultivars. The surface roughness was measured by optical profilometer, hydrophobicity by tensiometer, zeta potential by electro kinetic analyser, and surface color by chroma meter. Measurements reveal that the new cultivar Elstar has the roughest surface while the autochthonous cultivar Crown Prince Rudolph has the lowest roughness. Under normal physiological conditions, all apple surfaces were negatively charged, with Wax apple having the lowest and Crown Prince Rudolph the highest values; most cultivars had an isoelectric point at around pH = 3. The surfaces of the new cultivars were slightly more hydrophobic than those of the autochthonous. We conclude that autochthonous and new apple cultivars differ in biophysical surface properties, which might impact transpiration, bacterial/fungi adhesion and, consequently, apple storage and shelf life potential. [ABSTRACT FROM AUTHOR]

Sugars Will Eventually be Exported Transporters (SWEETs) play important roles during plant growth and development. Bioinformatics revealed 27 SWEET genes in the apple (Malus × domestica Borkh.) genome and classified them into four clades. These genes are unevenly located on 12 chromosomes, and 8 tandem-repeat genes and 18 fragment-repeat genes are present in the MdSWEET family. PlantCARE-based prediction of cis-acting elements of the MdSWEET promoter suggested that most MdSWEETs may be expressed specifically in the phloem and respond to hormones and stresses. qRT-PCR results showed that expression patterns of MdSWEETs displayed pronounced differences in different tissues/organs and different stages of apple fruit development. MdSWEET5, MdSWEET7, and MdSWEET21 were strongly expressed in mature leaves, MdSWEET2, MdSWEET12, MdSWEET13, MdSWEET14, MdSWEET17, and MdSWEET22 were highly expressed in peduncles, MdSWEET4 was highly expressed in young leaves, MdSWEET3, MdSWEET11, MdSWEET15, MdSWEET16, MdSWEET19, MdSWEET24, and MdSWEET25 were highly expressed in different parts of flowers, and MdSWEET1, MdSWEET6, MdSWEET8, MdSWEET9, MdSWEET10, MdSWEET18, MdSWEET20, MdSWEET23, and MdSWEET26 were strongly expressed in fruits. MdSWEET8 showed higher expression in the early stage of fruit development, MdSWEET1, MdSWEET10, and MdSWEET27 were highly expressed in the middle stage of fruit development, and MdSWEET6, MdSWEET9, MdSWEET18, MdSWEET20, MdSWEET23, and MdSWEET26 were sharply upregulated in the late developmental period. Our study could facilitate SWEET functional analysis in different tissue/organs and in sugar accumulation throughout the development and ripening of apple fruits. These findings provide potential opportunities to increase sugar accumulation in fruit, thereby improving fruit quality and yield. [ABSTRACT FROM AUTHOR]

This study provides insights and best-practice recommendations for marketing managers in the US food retail sector and the horticultural industry. An online survey distributed via a crowdsourcing platform in 2021 aimed to explore the factors that explained the intentions of US consumers to purchase locally grown apples. The Theory of Planned Behavior was used as a conceptual framework to shape the proposed model. The results emphasize the importance of behavioral, normative and control beliefs as important factors towards attitudes. Subjective norms and perceived behavioral control were also found to be key drivers in understanding behavioral intention. All concepts, with the exception of perceived behavioral control, were found to be significant behavioral predictors. [ABSTRACT FROM AUTHOR]

The technology of producing fruits containing an increased amount of elements essential for the health of the human body, including silicon, has become very important in recent years. Due to the popularity of apple tree cultivation in Europe, appropriate research has been undertaken. The aim of the experiment was to determine the advisability of foliar silicon nutrition in apple tree cultivation. Apple cultivars 'Gala Schniga', 'Ligol' and 'Topaz' were studied and treated with three different doses of silicon (100, 200, 300 mg SiO2·L−1). The treatments were performed five times during tree growth in the third year of cultivation from early June to late July. Foliar application of silicon did not improve the evaluated tree growth parameters. It significantly influenced, in the highest analysed concentration, a better fruit yield (12%), a higher yield coefficient, depending on the concentration, from 16 to 18%, a better fruit quality (weight and size) and a more extensive red blush. The considered cultivars differed in the growth and yield of trees in the third year of cultivation. 'Topaz' grew strongest and 'Ligol' yielded the best. The highest yield coefficient was found for the Topaz' cultivar. The fruit of 'Topaz' had the biggest blush and 'Gala Schniga' the biggest sugar content. Macro- and micro-nutrient nutritional status of trees were no better, except for iron and copper in leaves, and at some concentrations of applied silicon also zinc and copper in fruit. [ABSTRACT FROM AUTHOR]

Apples have long been known for their beneficial effects on human health due to the presence of various bioactive compounds. It is therefore very important to understand the biophysical properties of apple cuticle that dictate apples’ storability and quality. The purpose of this work was to determine the roughness, hydrophobicity, surface potential, and color of various autochthonous and new apple cultivars. The surface roughness was measured by optical profilometer, hydrophobicity by tensiometer, zeta potential by electro kinetic analyser, and surface color by chroma meter. Measurements reveal that the new cultivar Elstar has the roughest surface while the autochthonous cultivar Crown Prince Rudolph has the lowest roughness. Under normal physiological conditions, all apple surfaces were negatively charged, with Wax apple having the lowest and Crown Prince Rudolph the highest values; most cultivars had an isoelectric point at around pH = 3. The surfaces of the new cultivars were slightly more hydrophobic than those of the autochthonous. We conclude that autochthonous and new apple cultivars differ in biophysical surface properties, which might impact transpiration, bacterial/fungi adhesion and, consequently, apple storage and shelf life potential.

This study provides insights and best-practice recommendations for marketing managers in the US food retail sector and the horticultural industry. An online survey distributed via a crowdsourcing platform in 2021 aimed to explore the factors that explained the intentions of US consumers to purchase locally grown apples. The Theory of Planned Behavior was used as a conceptual framework to shape the proposed model. The results emphasize the importance of behavioral, normative and control beliefs as important factors towards attitudes. Subjective norms and perceived behavioral control were also found to be key drivers in understanding behavioral intention. All concepts, with the exception of perceived behavioral control, were found to be significant behavioral predictors.

For the years 2012–2018, we investigated the occurrence of storage diseases caused by fungi on four cultivars of apples grown in the central part of Poland. The fruits were picked in orchards managed with Integrated Pest Management (IPM) practices and stored in a cold room for 5–7 months. Depending on the season, apple cultivar and localization of orchard, the incidence of diseases was different. On apple cvs “Gala”, “Ligol” and “Golden Delicious”, bull’s eye rot (Neofabraea spp.) was the most frequently observed disease, whereas on apple cv. “Gloster”, gray mold (Botrytis cinerea) predominated. The blue mold (Penicillium expansum), brown rot (Monilinia spp.) and fungi of Alternaria spp. occurred at significantly lower intensity. We detected the occurrence of the new storage diseases of apples caused by Colletotrichum spp., Neonectria ditissima and Diaporthe eres.

1-Methylcyclopropene (1-MCP), being applied in postharvest treatment of apples as an inhibitor of ethylene perception, contributes to improved quality of apples during 6 weeks of simulated long-distance transportation, but it was not studied if this period may be prolonged. The aim of the present study was to assess the possibility to apply 1-MCP treatment to maintain the quality of Idared apples for long-distance transportation prolonged for 8 weeks. The 1-MCP treatment was applied either alone, or combined with modified atmosphere packaging (MAP) in selected gas permeability bags and was compared with control group. Postharvest, the storage in Ultra Low Oxygen (ULO) chamber was applied (3 periods: 0, 10, or 20 weeks), followed by simulated long distance transportation (storage duration of 8 weeks) and simulated distribution (4 periods: 0, 5, 10, or 15 days). Each studied group (36 groups: 3 postharvest treatments × 3 storage periods × 4 distribution periods) constituted 4 batches with 10 random apples each. After simulated distribution period, each sample was analyzed to assess the differences of firmness, total soluble solids (TSS) and titratable acidity (TA). The applied treatment influenced observed values of firmness, TSS and TA within each applied storage duration and duration of distribution (p < 0.05). For the majority of the studied durations of storage and distribution, the highest values of firmness, TSS and TA were observed for the samples from the group of 1-MCP applied combined with MAP, while only for some of them, the highest values of firmness and TA, but not TSS, were observed for the samples from the group of 1-MCP applied alone. It may be concluded that applying 1-MCP in the case of Idared apples for long-distance transportation allows prolonging it to 8 weeks without decreasing quality of fruits. Applying 1-MCP combined with MAP allows obtaining even better results than 1-MCP alone, after 8 weeks of transportation. It may be recommended to apply 1-MCP combined with MAP in order to slow the ripening process and to maintain the quality of apples during a long-distance transportation.

With the growing demand for quality food in the world, there is a new ambition to produce high-quality apples seeking reduced cultivation costs. The aim of this study was to evaluate the influence of agrotechnological tools on the quality of cv. Rubin apples during the harvest. The apple tree (Malus domestica Borkh.) cv. Rubin was grafted on dwarfing rootstocks P60, planted in single rows spaced 1.25 m between trees and 3.5 m between rows. Six agrotechnological tools were used—hand pruning, mechanical pruning, trunk incision, calcium-prohexadione, summer pruning and mechanical pruning one side, changing sides annually. The agrotechnical tools had no significant effect on accumulation of most sugars and elements, malic, folic and succinic acids in the fruits. Mechanical pruning resulted in significant accumulation of phenolic compounds, antioxidants, ascorbic acid, but reduced the amount of glucose compared to hand pruning. However, the trunk incision or spraying with ca-prohexadione together with mechanical pruning had no significant effect on sugar content but resulted in significantly higher amounts of phenols, antioxidants, ascorbic acid, Fe and Mn and reduced starch and citric acid.

Internal ethylene concentration (IEC) and activities of peroxidase (POX), polyphenol oxidase (PPO), and phenylalanine ammonia-lyase (PAL) were analyzed to evaluate their effects on browning in late-harvested ‘Empire’ apples (Malus × domestica Borkh.), during air storage at 0.5 °C for five months, and for ‘Fuji’ apples treated with 1-methylcyclopropene (1-MCP), stored for seven months. IEC remained higher in the ‘Empire’ apples compared to values observed in the ‘Fuji’ apples for up to three months in storage, although 1-MCP treatment reduced the IEC in both fruit cultivars. Antioxidant enzymes, such as PPO, POX, and PAL, mostly increased in the flesh and core tissues in both 1-MCP-treated apple cultivars, but were slightly higher in the ‘Empire’ apples between one and three months of storage time. Browning developed in the ‘Empire’ apples after three months of storage, with high susceptibility to incidences of browning observed on the 1-MCP-treated fruit.

Essential oils (EOs) are actively investigated as an alternative to numerous synthetic biocide products. Due to their large spectra of biological activities, the impact of EOs on non-target organisms should be characterized for biopesticide development purposes. In this study the potential phytotoxicity of Cinnamomum cassia EO (CEO) on apple trees (Malus domestica) was investigated in terms of oxidative burst (glutathione redox state) and damage (malondialdehyde). At 2%, CEO concentration the reduced glutathione leaf content drops from 269.6 ± 45.8 to 143 ± 28.4 nmol g−1FW, after 30 min, illustrating a rapid and strong oxidative burst. Regarding oxidative damage, malondialdehyde increased significantly 24 h post application to 10.7 ± 3.05 nmol g−1FW. Plant defence induction was previously suspected after trans-cinnamaldehyde (CEO main compound) application. Therefore, the elicitor potential was investigated by qRT-PCR, on the expression level of 29 genes related to major defence pathways (PR protein, secondary metabolism, oxidative stress, parietal modification). Multivariate analysis and increased expression levels suggest induction of systemic resistance. Hence, the present research illustrates the dose–dependent phytotoxicity of CEO in terms of lipid peroxidation. Transcriptional data illustrates the elicitor properties of CEO. These findings can help to design pest management strategies considering both their risks (phytotoxicity) and benefits (defence activation combined with direct biocide properties). [ABSTRACT FROM AUTHOR]

For the years 2012–2018, we investigated the occurrence of storage diseases caused by fungi on four cultivars of apples grown in the central part of Poland. The fruits were picked in orchards managed with Integrated Pest Management (IPM) practices and stored in a cold room for 5–7 months. Depending on the season, apple cultivar and localization of orchard, the incidence of diseases was different. On apple cvs "Gala", "Ligol" and "Golden Delicious", bull's eye rot (Neofabraea spp.) was the most frequently observed disease, whereas on apple cv. "Gloster", gray mold (Botrytis cinerea) predominated. The blue mold (Penicillium expansum), brown rot (Monilinia spp.) and fungi of Alternaria spp. occurred at significantly lower intensity. We detected the occurrence of the new storage diseases of apples caused by Colletotrichum spp., Neonectria ditissima and Diaporthe eres. [ABSTRACT FROM AUTHOR]

Regulatory compliance of experimental releases into the environment of not yet approved genetically modified plants often requires implementation of measures to reduce the dispersal of reproductive material. To study the impact of nets on pollen flow in an experimental field site in Switzerland, non-GM apple varieties 'Ladina' and 'Nicogreen' were planted inside and outside a netted plot, respectively. Seeds harvested from mature fruits were germinated and the paternal variety of the seedlings was determined using simple sequence repeat (SSR) molecular markers. We demonstrate that pollination frequency from trees inside the netted plot to trees outside over a two-year (2018 and 2019) study of 4500 seedlings is 0.6% (26 seedlings). Moreover, these outcrossing events decreased with increasing distance from the pollen donor. Over the study period, we found on average 0.9%, 0.5%, 0.4% and 0.09% of the seedlings derived from apples of 'Nicogreen' trees at 8 m, 15 m, 72 m and 117 m being generated by fertilisations of 'Ladina' pollen, respectively. In comparison, 48.3% (2018 season) and 75.1% (2019 season) of examined 'Ladina' seedlings in the netted plot originated from 'Nicogreen' tree pollen outside the netted plot. The results suggest that insect netting is effective in minimizing egress of apple pollen from an experimental site and that the likelihood of outcrossing is reduced further (<0.1%) when there are no compatible apple trees within a radius of 100 m of the pollen donor. These data are important for biosafety research/regulation to aid understanding of pollen flow in experimental field sites. [ABSTRACT FROM AUTHOR]

Sun damage on apples is attributed to the occurrence of high temperatures, incident radiation, and fruit and plant water parameters, all dependent on climatic conditions and management. The development of new production areas and climate changes increase the interest in studying the behavior of the fruit under different conditions. The effect on sun damage of three nets and two chemical protectants was evaluated in a commercial orchard of 'Granny Smith' in a neotropical climate during the 2012–2016 seasons. We recorded the evolution, incidence and severity of sunburn and sunscald. Fruit surface temperature, fruit size, sprouting and return to flowering was also recorded. Incident radiation and air temperature were considered for the assessment of the crop's microclimate. The transmittance in PAR wavelength and the air temperature variation on netting treatments reached 0.4 and 9 °C, respectively. The fruit surface temperature for the White-Net and Black-Net-50% treatments was always lower than 46 °C. For the sun damaged fruits, the Black-Net-50% treatment showed the highest proportion of slightly sunburned fruits (94%) and the lowest proportion of heavy damages, with a sunscald index equal to or less than 2 (on a scale of 1–4) in all the tested conditions. In a neotropical climate, protectant applications did not reduce the incidence of sunburn, but with the use of nets it was possible to reduce both sunburn and sunscald without affecting growth processes dependent on leaf net assimilation. [ABSTRACT FROM AUTHOR]

In order to meet the growing food demand of the global population and maintain sustainable soil fertility, there is an urgent need to optimize fertilizer application amount in agricultural production practices. Most of the existing studies on the optimal K rates for apple orchards were based on case studies and lack information on optimizing K-fertilizer management on a regional scale. Here, we used the method of combining meta-analysis with the K application rate-yield relationship model to quantify and summarize the optimal K rates of the Loess Plateau and Bohai Bay regions in China. We built a dataset based on 159 observations obtained from 18 peer-reviewed literature studies distributed in 15 different research sites and evaluated the regional-scale optimal K rates for apple production. The results showed that the linear plus platform model was more suitable for estimating the regional-scale optimal K rates, which were 208.33 and 176.61 kg K ha−1 for the Loess Plateau and Bohai Bay regions of China, respectively. Compared with high K application rates, the optimal K rates increased K use efficiency by 45.88–68.57%, with almost no yield losses. The optimal K rates also enhanced the yield by 6.30% compared with the low K application rates. [ABSTRACT FROM AUTHOR]

Apples (Malus domestica Borkh.) represent one of the most produced fruits worldwide, along with citrus and bananas. As high quality is an important trait for the consumer, many studies have focused on the research of new techniques to ensure and preserve the optimal organoleptic characteristics of this fruit. However, despite the huge number of studies on recent technological advances dealing with fruit final quality, less research has focused on the physiological aspects of apple development, including a variety of processes triggered after fertilization, such as photosynthesis, assimilation of carbohydrates, cell division, and cell enlargement, which determine apple final quality. In the present review, we summarize some of the most important changes and mechanisms linked to the primary metabolism of apples, as well as the effect of agronomic practices, such as fruit thinning, as key factors to improve apple quality and meet consumer demands, with the aim of amassing available information and suggesting future directions of research. [ABSTRACT FROM AUTHOR]

This paper presents the history of the introduction and expansion of arboriculture during the 1st millennium BC from the South of the Iberian Peninsula to the South of France. The earliest evidence of arboriculture at the beginning of the 1st millennium hails from the south of the Iberia from where it spread northward along the peninsula's eastern edge. The different fruits (grape, olive, fig, almond, pomegranate and apple/pear) arrived together in certain areas in spite of uneven distribution and acceptance by local communities. Grape was the crop with the greatest diffusion. The greater diversity of crops in the southern half of the peninsula is also noteworthy. Their development paved the way for a commercial agricultural model in some territories where fruits and their derivatives, such as wine and oil, played vital roles. [ABSTRACT FROM AUTHOR]

Crithmum maritimum and Daucus carota subsp. gummifer are two species of the Apiaceae family that share multiple characteristics: both are halophitic, live on cliffs in the same geographic habitats, and are edible. While C. maritimum is rich in essential oils and flavonoids, D. carota is rich in terpenes and a gum producer. In the work presented herein, the biomass of these two wild plants and the bioactive compounds present in their extracts have been studied by elemental and thermal analysis, infrared spectroscopy, and gas chromatography-mass spectroscopy. To explore their bioactivities, both their hydroalcoholic extracts and their major constituents (apiole in C. maritimum and geranyl acetate in D. carota), either alone or in combination with chitosan oligomers, were assayed in vitro against bacterial and fungal pathogens that affect apple trees (Malus domestica) and grapevine (Vitis vinifera). Remarkable inhibition was observed against Erwinia amylovora, the causal agent of fire blight in apple; Xylophilus ampelinus [syn. Erwinia vitivora], the causal agent of bacterial blight of grapevine; and Diplodia seriata, a virulent pathogen of grapevines that also causes canker, leaf spot and fruit rot of apple. In view of their effectiveness against these three phytopathogens, a potential application of these two medicinal plants in organic farming may be envisaged. [ABSTRACT FROM AUTHOR]

The Annurca apple is a typical fruit from Southern Italy that is notable for its high firmness and characteristic flavor, and presents positive effects on human health. The aim of the present study was to improve the agronomic characteristics of Annurca trees and the quality of their fruits by the use of plant biostimulants. We performed the study with three biostimulants (protein hydrolysates, seaweed extracts, and microalgae) to determine their effects on trees and fruits at harvest and during fridge conservation. The measurements in the field concerned the production per plant, the number of fruits, the diameter and fruit weight, the diameter of trunk, the weight of pruning, the first harvest %, and yield efficiency (plant prod./TCSA) for both growing seasons 2018–2019. The analyzed fruit parameters at harvest and during the fridge conservation were: flesh firmness, epicarp color, total soluble solids, pH, and titratable acidity. The results showed positive effects of the biostimulants on the production and the color parameters, especially with microalgae enhancing fruit redness (5-fold) and color index (8.5-fold). In particular, protein hydrolysates and microalgae increased the production (10.4%), diameter of the fruits (7.0%), the first harvest percentage (37.8%), and yield efficiency (6.9%). The tested plant biostimulants showed no significant effect on the measured qualitative parameters. This study represents the first detailed research on the use of different types of biostimulants on Annurca trees and their impact on the quality of its fruits from harvest to storage, and may present a sustainable alternative for the "melaio" processes. [ABSTRACT FROM AUTHOR]