Fruit Hardness Research Articles

The Identification, Separation, and Clamp Function of an Intelligent Flexible Blueberry Picking Robot

Identifying fruit maturity accurately and achieving damage-free harvesting are challenges in designing blueberry-picking robots. This paper presents an intelligent flexible picking system. First, we trained a deep learning-based YOLOv8n network to locate the position of the fruit and determine fruit ripeness. We used a neural network to establish the relationship between fruit hardness and shape parameters, achieving an adaptive gripping force for different fruits. To address the issue of dense clusters in some blueberry varieties, we designed a fruit separation subsystem using a combination of flow field analysis and pressure-sensitive experiments. The results show that the mean average precision can reach 84.62%, the precision is 94.49%, the recall is 83.85%, the F1 score is 88.85%, and the test time is 0.12 s, which can meet the requirements for blueberry fruit recognition accuracy and speed. The spacing between closely packed fruits can increase by 4 mm, and the damage-free picking rate exceeds 92%, achieving stable, damage-free harvesting.

Synergistic antibacterial effect of 405 nm blue light-emitting diodes (LEDs) and gelatin film for inactivation of Escherichia coli O157:H7 and Salmonella Typhimurium on stainless steel and fresh fruit peel

A combined antibacterial effect of 405 nm blue LEDs (BL) and gelatin film (G) was investigated on stainless steel (SUS) and fresh fruit peel for the inactivation of Escherichia coli O157:H7 and Salmonella Typhimurium. On the SUS, the sum of the individual treatments of G for 20 min and BL at 20 J/cm2 was <1 log reduction (log CFU/cm2). In comparison, combination treatment of G and BL (G + BL) at 20 J/cm2 exhibited 2.37 and 3.09 log reduction on E. coli O157:H7 and S. Typhimurium. The G + BL treatment only increased a propidium iodide (PI) uptake, indicating that cell membrane damage occurred. In the G + BL treatment, reactive oxygen species (ROS) scavenging assay confirmed that ROS involved in the bactericidal mechanism. On orange peel, the G + BL treatment at 40 J/cm2 resulted in a 3.05 and 3.17 log reduction on E. coli O157:H7 and S. Typhimurium. In contrast, the individual treatment of G for 40 min led to reductions of 0.63 log CFU/cm2 for E. coli O157:H7 and 0.50 log CFU/cm2 for S. Typhimurium, while the BL treatment at 40 J/cm2 achieved reductions of 0.78 and 0.69 log CFU/cm2, respectively. A synergistic bactericidal effect was similarly observed in the combined treatment groups for both apple and grapefruit peels. In a color and texture analysis, G did not affect hardness, toughness, and visual color of fruit.

Pengaruh Aplikasi Edible Coating Gel Lidah Buaya dan Kitosan terhadap Mutu Buah Stroberi pada Penyimpanan Suhu Ruang dan Suhu Rendah

Strawberries are nonclimateric fruits harvested in the final stages of ripening, so they are highly damaged due to cellular fragility, high respiration rate, and susceptibility to fungal growth. This study aims to test the effectiveness of edible coating of aloe vera gel and chitosan to maintain the quality and shelf life of strawberries. The study was carried out by experimental method with split plot by group random design. Storage temperature treatment as the main plot consists of two treatment levels, namely 25±2o C and 4±1o C, while the concentration of edible coating combination as a plot consists of five treatment levels, namely control without edible coating, aloe vera gel 40%, chitosan 2%, aloe vera gel 40% + chitosan 2%, and aloe vera gel 20% + chitosan 1%. Quality attributes including weight loss, fruit hardness, total dissolved solids, decay index, and shelf life are observed until total deterioration occurs. The results showed that at a storage temperature of 25±2° C, chitosan 2% treatment was more able to maintain the quality attributes of strawberries compared to other treatments. Meanwhile, at a storage temperature of 4±1°C, edible coating treatment of 40% aloe vera gel and 40% aloe vera gel + 2% chitosan which more effectively maintains the quality attributes of strawberries. However, for shelf life parameters, only the temperature factor of the storage room affects the length of shelf life of strawberries. The longest shelf life is achieved at low temperature storage (4±1°C) with edible coating treatment of 40% aloe vera gel + 2% chitosan (13.33 days). However, according to the LSD test at a real level of 5%, this value was not significantly different from other edible coating treatments stored at low temperatures, including the lowest shelf life that occurred in controls without edible coatings (10.67 days).

Assessment of the degree of ripeness of oriental persimmon fruits (Diospyros kaki L.) by tensor stress

The object of the study is persimmon fruits, which occupy an important place among subtropical crops and have a wide development prospect. Since these fruits are difficult to process, they are mainly used fresh. The usefulness of these fruits is associated with their chemical composition. This composition includes biologically active substances, microelements, various mono- and polysaccharides, saturated and unsaturated fatty acids, etc. The complexity of the technological processing of persimmon fruits is associated with its astringent taste, which is determined by the amount of polyphenolic compounds. In general, the strength of raw materials is manifested not only in the degree of ripeness, but also in its technological processing processes, which are the object of the study. From this point of view, the hardness of persimmon fruits acts as a subject of study. Data on the property of fruits and vegetables associated with the stress-hard state is a solution to the problems that arise when expanding the range of finished products. For example, it has been established that at the stage of commercial ripeness, the hardness of persimmon fruits is no more than 12.3 kg/cm2. And this indicator changes downwards over time, i.e. to 1.5÷2.0 kg/cm2. Consequently, the possibility of using fruits for the production of various food products is expanding. The study of raw materials according to the laws of solid state physics is explained by its polymer structure. Therefore, the ripening of raw materials depends on the monomerization of this structure. In such decomposition, a condition is created for the combination of various mono-substances, for example, in persimmon fruits, monophenols combine with monosaccharides, which results in a decrease or disappearance of the tart taste of the raw material. Therefore, determining the degree of raw material ripeness by changes in stress will allow to predict its destruction in advance.

Impact of regulated deficit irrigation on the dynamics of quality changes in processing tomato fruits during ripening

Quality is a key factor restricting the development and economic benefits of the tomato processing industry, and improving the quality of tomatoes has become a hotspot in the development of the tomato processing industry in Xinjiang. Regulated deficit irrigation (RDI) is an abiotic means of crop yield and quality control widely used for crop yield and quality improvement. This study aimed to investigate the impact of RDI on the dynamics of quality changes in processing tomato fruits during ripening via a 2-year (2022–2023) filed experiment with five water irrigation treatments in Xinjiang, China. The results showed that compared with conventional irrigation, regulated deficit irrigation significantly saved 315–1260 m3 ha−1 irrigation water. Mild RDI increased the single fruit weight and fruit hardness by 0.15 % and 3.29 kg cm2, respectively, thus improved the yield and storage and transportation quality of processed tomatoes. Moderate RDI increased the contents of soluble solid, soluble sugar and lycopene in fruit to 0.6 %, 0.56 % and 3.53 μg/g, respectively, therefore significantly improved the nutritional quality and flavor quality of processed tomato. Ultimately, a comprehensive evaluation using a coupled Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) model, taking into account the appearance, nutrition, flavor, and storage and transportation indexes of processed fruits, concluded tha W1 treatment is a sustainable water management approach that balances yield and quality. Therefore, the optimal deficit irrigation model for processing tomato fruits in Xinjiang was recommended to be the W1 treatment, whereas the W2 treatment was considered as an alternate model. The study supported the large-scale development of the tomato processing industry in Xinjiang and the implementation of effective water-saving farming.

A new addition to the toolbox: stone tool use in blonde capuchin monkeys (Sapajus flavius).

The use of tools played a central role in human culture and evolution. Early studies with apes demonstrated the tool use; however, currently the works have focused on Platyrrhine, particularly capuchin monkeys. Blonde capuchin monkeys, Sapajus flavius, have been observed using sticks to fish for termites in the Atlantic Forest, where this species has been extensively studied. In this study, we presented the first evidence of stone tool use by the blonde capuchin monkeys, as well as the dimensions and weight of these tools. We gathered data from three areas of Caatinga dry forest where we discovered this new tool use among the species. The mean weight of the hammers was 475.7g (± 142 SD). The mean height of the anvils was 48.3cm (± 18.7 SD), while the mean surface area of the anvils was 1.2 m2 (± 0.4 SD). We identified fruits and/ornuts from three plant species-Prunus dulces, Cnidoscolus quercifolius, and Syagrus coronate-near the anvils at the study sites. Additionally, we passively observed six instances of stone tool use by blonde capuchin monkeys. Their use of stones to crack encased foods mirrored behaviors previously reported in Sapajus libidinosus, a species well known for using stone tools to exploit hard nuts. Our findings place blonde capuchin monkeys among the list of primates that utilize stones as tools, highlighting the species' adaptability in exploiting resources within the Caatinga. Long-term studies are essentials to comprehend the use pattern of stone tools (across both general and seasonal perspectives) and the influence of variables, such as fruit hardness, distance to watercourses, and fruit availability on the use of this technology by this primate.

Identification of the effect of ripening conditions on the yield of rose hips and their processed products

Wild rose hip fruit, pulp, beverage, nectar, as well as technological methods and tools are taken as the object of research. Rose hips have a, bright red color and a rich chemical composition, which makes it a very important raw material for industry. However, insufficient research slows down this work and makes the use of raw materials inefficient. With this in mind, the aim was to study the mechanical and technological characteristics of the femur, which are considered important for industrial processing. The reflection of ripening conditions on the mechanical, physical and chemical properties of rose hips, as well as the influence of processing methods, especially hot processing, on the quality of the product has been established. Research has shown that the percentage of fruit cultivation in the Dashkasan region was the lowest, and the highest in the Gadabay region, and the Goygol region took an intermediate position. The Latin hardness of fruits grown in Dashkasan region was 6.41 N. Gadabay region with 5.56 N and Goygol region with 5.47 N. This indicator plays an important role in the storage and processing of fruits. As a result of the treatment, the amount of dry matter in fruit, pulp and beverage increased slightly, titratable acids, ascorbic acid and pH decreased. An increase in total phenolic compounds was observed during the initial heat treatment of the raw material and was noted to be much lower in the pulp and beverage. Hot treatment had a reducing effect on the amount of ascorbic acid, which is considered one of the main components of indicators in the thigh. The obtained results can be used in individual family farms and in the food industry

Genotypic Selection Using Quantitative Trait Loci for Better Productivity under High Temperature Stress in Tomato (Solanum lycopersicum L.)

High temperature stress affects tomato production both in tropical and sub-tropical environments worldwide. To explore genetic variation for heat tolerance in tomato, 329 transcontinental tomato genotypes were evaluated at the Ministry of Municipality and Environment (MME) greenhouses near Doha, Qatar, where the average daytime temperature was 38 °C with a big fluctuation during the tomato growth season. A preliminary phenotypic analysis identified a panel of 71 hybrid and pure-line tomato genotypes for more detailed studies. The selected subset was examined in the greenhouse using a randomized complete block design under heat stress. The materials were phenotyped for fruit size, fruit weight, fruit hardness, fruit locules, fruit set, total soluble solids (TSS), and fruit yield. Significant phenotypic differences among genotypes were observed for all the traits assessed. To explore the genetic basis of the variation among the examined genotypes, the subset was genotyped using 104 SNP markers identified in previous heat-tolerance genome-wide association studies (GWAS). Nineteen QTL-associated SNP markers could reliably select heat-tolerant genotypes in terms of better fruit yield, fruit set, and TSS. These markers are located on chromosome 1, 5, 6, 8, 9, and 12. Interestingly, two clusters of markers on chromosome 6 were linked to significant effects on yield, fruit set, and TSS under high temperature. Eighteen out of nineteen SNP markers were mapped within a gene body. Based on the phenotypic and the genotypic analysis, an elite set of five genotypes was selected for approval for heat stress environments in Qatar. The aim of the present work is to provide significant results that are exploitable not only in the Qatar region but also worldwide. Specifically, the 19 molecular markers identified in this study can serve as useful tools for breeders in selecting heat-tolerant material.

Comprehensive Evaluation of Texture Quality of ‘Huizao’ (Ziziphus jujuba Mill. Huizao) and Its Response to Climate Factors in Four Main Production Areas of Southern Xinjiang

A superior cultivar of dried jujube in China is ‘Huizao’ (HZ) jujube. Nonetheless, detailed evaluations of the texture quality of HZ fruit have been the subject of few studies. Texture is a significant indicator of the sensory and processed quality of a fruit. Here, we differentiate and characterize the texture quality of HZ fruit from the four primary producing regions in southern Xinjiang, as well as develop a system for assessing the texture quality of HZ fruit. Correlation investigation indicated strong relationships between the springiness, chewiness, cohesiveness, gumminess, and hardness of HZ fruit. Furthermore, according to the factor molecules, the texture quality of HZ fruit in the four production areas was evaluated as Bazhou (1.24) &gt; Hotan (0.773) &gt; Kashi (−0.577) &gt; Aksu (−0.852). RDA analysis of six texture quality parameters and 24 climate conditions identified higher mean temperature (TEM) and lower relative humidity (RHU) as the primary factors contributing to the improved texture quality of HZ fruit in Xinjiang. This study identified the variations in the texture of HZ fruit in the four primary producing regions of Southern Xinjiang. The HZ fruit in Hotan and Bazhou exhibit superior springiness and stickiness, while the fruit in Aksu and Kashi exhibit greater hardness. The texture of HZ fruit is significantly influenced by springiness, hardness, and adhesiveness, and a comprehensive evaluation model has been established through this research. This will provide a theoretical foundation for optimizing the dominant producing areas and regional production of HZ varieties in Xinjiang.

Pengaruh Jenis Kemasan pada Perubahan Kualitas Salak Pondoh Banjarnegara dalam Bentuk Tandan Selama Transportasi dan Penyimpanan

Salak (Salacca edulis Reinw.) in bunch form can be attractive to consumers because its own unique shape. The use of primary and secondary packaging can maintain fruit quality. This study aims to evaluate quality change of salak in bunches including physical damage, mechanical damage, physiological and microbiological damage. Salak bunches were stored for 22 days, with observations every 3 days to analyze fruit damage, TSS, weight loss, and fruit hardness. The study used a single-factor completely randomized design, involving 3 treatments: wooden crates (K1), cardboard without net foam (K2), and cardboard with net foam (K3). Data were analyzed descriptively, analysis of variance, and DMRT at the 5% level. Primary packaging was effective in reducing mechanical damage to fruit after 13 hours of transportation, with mechanical damage reaching 0 (zero) due to net foam. The type of packaging used had a significant effect on quality change of salak during storage, namely physical, physiological and microbiological damage, weight loss, hardness, and TSS. Cardboard packaging with net foam was the best treatment, showing low physiological and microbiological damage until the 16th day of storage, which amounted to 4.05, as well as a low rate of change in quality for 22 days. Keywords: Salak bunches, storage, packaging, fruit quality, transportation

Edible coating effect on physicochemical properties of banana (Musa sapientum L.) during storage

Abstract Banana (Musa sp.) is very important fruit crops in the tropical world. It is recognized for its potential health benefits and nutritional richness. Banana fruit is semi perishable food that rot quickly. Edible coating is a very useful technique to extend the shelf life of fruit and maintain quality for processing post-harvest fruits. In this research, coating of banana fruit (Musa sapientum L.) was carried out using aloe vera gel as a base material and modified by water extract of sungkai leaves. The aim of this research is to obtain the right composition of coating material to extend the shelf life of bananas. Five formulas (F1, F2, F3, F4, and F5 of coating material were prepared and coated on the Banana fruit. The coated banana fruit was evaluated for physicochemical properties using the Standard Methods at storage times of 0, 3, 6, 9, and 12 days. Banana fruit coating with formula F3 (30% Aloe vera gel, 40% Sungkai leaf extract, 2.0% CMC and 1.0% glycerol) showed the best performance on the days 9 with the weight loss 10.28+0.05%, fruit hardness 10.3+0.05 Newton, total acid titration 0.27+0.01%, Total Soluble Solid 27.67+0.58 °Brix, total antioxidants of 18.84+0.12 mgAAE/gFW and total phenolics 33.27+0.20 mgGAE/gFW compared to other compositions. In conclusion, coating Banana fruit with this coating material can extend the shelf life from 3 to 9 days.

Variability of fruit shelf-life of commercial tomatoes and their hybrids crossing with insensitivity ethylene mutant tomato Sletr1-2

Tomatoes are climacteric fruits that experience a surge in respiration rate and ethylene production. This condition affects the fruits’ physiological deterioration, shortens their shelf-life, and degrades the quality of tomatoes. The study aimed to enhance the shelf-life of commercial tomatoes with different genetic backgrounds by utilizing the Sletr1-2 mutant, which has a lower sensitivity to ethylene. A randomized block design (RBD) was applied to achieve this goal, where 12 different plant genotypes were considered as treatments, and each treatment was replicated four times. The results showed that fruit shelf-life was extended by crossing commercial tomatoes with Sletr1-2 mutant tomatoes. Genetic variability for all shelf-life characteristics were narrow. In contrast, there were broad phenotypic variability for fruit hardness and weight loss characteristics.

Visualization of mitochondrial dynamics in tomato based on green fluorescent protein

This study aimed to visualize the morphological features and dynamic changes of tomato mitochondria to provide a basis for the study of its mitochondrial functions. In this study, transgenic tomatoes expressing mitochondria-localized green fluorescent protein (mitochondria-GFP, Mt-GFP) were obtained by Agrobacterium-mediated genetic transformation. The color, hardness, soluble solids, acidity content, respiration rate, and ethylene production of the transgenic Mt-GFP tomato fruits were determined at the stage of mature green, breaker, and 3, 6, 9 days after breaker, while the wild-type tomato fruits were used as a control. As expected, Mt-GFP recombinant protein did not affect the ripening process, but induced the increased acidity of tomato fruits. The accumulations of Mt-GFP protein in tomato leaves and fruits were successfully verified by Western blotting. The morphological characteristics of mitochondria in flower, leaf and fruit cells as well as the dynamic changes of mitochondria in flower cells were clearly observed and studied under confocal laser microscope. The development of transgenic Mt-GFP tomato plants helps the visualization of tomato mitochondria and provides good research materials for the study of mitochondrial function during tomato development and fruit ripening.

The effect of grafting on vegetative and reproductive traits of tomato

Relevance. Tomato (Solanum lycopersicum L.) is one of the most important vegetables in the world. Every year the number of identified viruses and diseases increases, infection with which causes significant crop losses and significantly worsens the quality of agricultural products, especially in tomatoes. Material and methods. In the present study we compared the growth of the vegetative and reproductive traits of tomato plants ‘Dokia’, ‘TY Red 250’ and ‘Pilabi’ grated onto bacterial wilt (caused by Ralstonia solanacearum) and Fusarium wilt (Fusarium oxysporum) diseases tolerant rootstock “Spider” (Takii seed, Japan). The non-grafted (control - CT) and grafted tomato plants (GR) were transplanted on 4 March of 2021 to the four season (vinyl) greenhouse on substrate perlite (mixture of perlite no. 1 and no. 3) and cultivated until September 20. Results. The results showed that responses of the tomato cultivars to grafting combination was different, where agronomical traits depends on the each cultivar’s features can be ranged. The reduction of the values of stem diameter (SD), leaf length and width (LW), fresh fruit weight (FFW), fruit diameter (FD), fruit pericarp thickness (FPT) and fruit hardness (FH) with aging of plants and rising ambient temperature was detected. However, fruit soluble solids among all cultivars regardless of treatments were slightly increased. The index of fruit yield per truss (FYT) significantly decreased among all cultivars after 10th truss regardless of the treatments when the daily temperature increased from July to August. In grafted tomato ‘TY Red 250’ were identified the highest fruit yield per plants (FYP) than in CT plants, whereas in other tomatoes did not found similar differences between CT and GR plants.

Nondestructive Determination of Epicarp Hardness of Passion Fruit Using Near-Infrared Spectroscopy during Storage.

The hardness of passion fruit is a critical feature to consider when determining maturity during post-harvest storage. The capacity of near-infrared diffuse reflectance spectroscopy (NIRS) for non-destructive detection of outer and inner hardness of passion fruit epicarp was investigated in this work. The passion fruits' spectra were obtained using a near-infrared spectrometer with a wavelength range of 10,000-4000 cm-1. The hardness of passion fruit's outer epicarp (F1) and inner epicarp (F2) was then measured using a texture analyzer. Moving average (MA) and mean-centering (MC) techniques were used to preprocess the collected spectral data. Competitive adaptive reweighted sampling (CARS), successive projection algorithm (SPA), and uninformative variable elimination (UVE) were used to pick feature wavelengths. Grid-search-optimized random forest (Grids-RF) models and genetic-algorithm-optimized support vector regression (GA-SVR) models were created as part of the modeling process. After MC preprocessing and CARS selection, MC-CARS-Grids-RF model with 7 feature wavelengths had the greatest prediction ability for F1. The mean square error of prediction set (RMSEP) was 0.166 gN. Similarly, following MA preprocessing, the MA-Grids-RF model displayed the greatest predictive performance for F2, with an RMSEP of 0.101 gN. When compared to models produced using the original spectra, the R2P for models formed after preprocessing and wavelength selection improved. The findings showed that near-infrared spectroscopy may predict the hardness of passion fruit epicarp, which can be used to identify quality during post-harvest storage.

Effects of Organic Substitution on the Yield and Quality of Apples and Residual Nitrate-N Leaching in Soil

The substitution of chemical nitrogen (N) fertilizer with organic fertilizer (organic substitution, OS) is increasingly applied in crop production, due to its environmentally friendly characteristics, low price, and high crop and soil improvement efficacies. Here, we studied the effects of chemical N fertilizer with organic fertilizer treatment at different proportions (no organic substitution (NOS), 20% (OS-20), 40% (OS-40), 60% (OS-60), 100% (OS-100), and 200% (OS-200, double the organic fertilizer application amount of OS-100) on the yield and quality of apples in the Shanxi Province of China. The results revealed that, compared to the NOS, the total apple yields of OS treatments, especially the OS-60 and OS-100 treatments, decreased. However, all OS treatments, except OS-200, increased the yield of large-sized fruits (transverse diameter ≥ 85 mm) and the mean mass of apple fruits, and significantly decreased yield of small-sized fruits (transverse diameter &lt; 75 mm). All OS treatments, especially OS-40, promoted the total sugar and vitamin C (Vc) contents and fruit hardness of apples, and OS-40, OS-60, and OS-200 resulted in significantly decreased titratable acid contents in apples. The influence of organic substitutions on soil quality was further investigated in a two-year field experiment. The results showed that the influence of organic substitution on soil chemical properties differed between the two years. Notably, 40% OS increased the soil organic carbon (SOC) content and the C/N ratio in the upper 20 cm of the soil in both years. Additionally, OS treatments reduced the residual nitrate (NO3−)-N (RN) content in deep soil layers, suggesting that OS has the potential to alleviate N leaching. Moreover, redundancy analysis (RDA) of the soil, fruit yield, and fruit quality parameters revealed that the SOC content in the 0–20 cm soil layer and the RN content in the 0–100 cm soil layer had the greatest impact on the fruit quality and yield variables, respectively. This study showed that the proper substitution (40%) of chemical N fertilizer with organic fertilizer could improve the yield of large-sized fruits, the mean mass and fruit quality of apples, and soil chemical properties. Our study will provide a basis for rational organic substitution in apple orchards.

Effect of lignite substrate compared to mineral wool and supplementary lighting with HPS and LED on growth, plant photosynthetic activity, yield and fruit quality of greenhouse cucumber

The substrate in hydroponic cultivation is one of the basic factors for proper plant growth, and current environmental trends suggest replacing the previously used mineral wool with organic substrates. Light is also essential for proper plant growth, which is why LEDs (Light Emitting Diode) are increasingly used to provide plants with supplementary light, allowing, among other things, to control the spectral composition. The aim of this study was to determine the effect of lignite substrate and LED supplementary lighting on morphological and physiological parameters as well as quality and yield of cucumber (Cucumis sativus L.) in hydroponic cultivation compared to the cultivation in mineral wool substrate. Lignite mats applied in cultivation with LED supplementary lighting had a beneficial effect on cucumber plant growth and development and plant nutrition in Fe, K, P, Ca, Mg and Zn compared to cultivation in mineral substrate and HPS supplementary lighting. The combination of LED lighting and lignite mats also improved the physiological parameters of the cucumber plants, as well as fruit hardness. Fruits harvested from plants grown in lignite substrate and supplemented with LEDs had the lowest nitrate content and increased TSS value, as well as increased fruit firmness.

Effects of Different Foliar Fertilizer Treatments on Fruit Quality of the Korla Fragrant Pear

Persistent calyx affects the fruit quality of the Korla fragrant pear including increasing fruit hardness. In order to reduce fruit hardness and improve fruit quality, in this study, we used the Korla fragrant pear which has persistent calyx. Korla fragrant pear fruit at different development stages were treated with foliar fertilizers of 101 and calcium–magnesium (Ca–Mg) solutions, and the hardness and pectase, cellulose, lipoxygenase, and amylase activities of persistent calyx fruit were determined and analyzed. We found that the fruit hardness of two foliar fertilizers increased compared with the control after treatment. The fruit hardness of calcium–magnesium foliar fertilizer and 101 foliar fertilizer treatments were increased by 11.7% and 6.8% compared with the control, respectively. Furthermore, the activities of cellulase, pectinase, and lipoxygenase were increased by 30%, 12.7%, and 42% after treatment with calcium–magnesium foliar fertilizer, respectively. The 101 foliar fertilizer inhibited the contents of cellulose and starch. In summary, the internal quality of Korla fragrant pear fruit treated with calcium–magnesium foliar fertilizer was better than 101 foliar fertilizer. It was confirmed that calcium and magnesium foliar fertilizer had a good control effect on the hardness of Korla fragrant pear persistent calyx fruit, and its fruit quality was also improved. This study has great application value in production practice.

Research on the Design Method of Blueberry Automatic Harvesting Clamp Force Based on Neural Networks

Highlights The relationship between fruit size and gripping force was found by BP algorithm. The error between the optimized holding force and the optimal value is not more than 8%, that is, the fruit integrity rate is greater than 92%. The simplified two-parameter method is more suitable for efficient field operation. Abstract. The flourishing development of the blueberry industry has urgently demanded mechanized harvesting, and the rational design of the clamping force of mechanical claws is a challenging aspect for achieving automatic and flexible harvesting. This article proposes a method to predict fruit hardness based on blueberry shape parameters, enabling dynamic adjustment of clamping force. Fruit diameter, height, weight, and rupture pressure data were collected, and using the classical BP neural network algorithm, a mapping relationship between fruit hardness and shape parameters was established. Experimental verification was conducted using an orthogonal table, and the results indicate that the predicted blueberry fruit hardness using this method deviates by less than 8% from the actual values. Further simplification into a two-parameter method was performed to enhance practical field operation efficiency. Although the error slightly increased, it still met the requirements of actual field operations.

Quality improvement of tomato (Solanum lycopersicum L.) ‘Optima’ with amino acid-enriched leaf fertilizer

Tomato quality is influenced by fertilization and matutity level. This study aimed to determine the best dosage of amino acid-enriched leaf fertilizer (Amiboost) and to determine the best nutritional content at several ripeness levels of ‘Optima’ tomatoes. Amiboost is an inorganic foliar fertilizer that is rich in amino acids that can be easily absorbed by plants. The experiment used a factorial (RCBD) with 3 repetitions. The ‘Optima’ tomatoes were grown at Wonosobo and fertilized with 4 levels of Amiboost fertilizer consisting of 0, 1, 2, 4 L ha-1 amino acid fertilizer, and 2 L ha-1 comparison fertilizer (standard fertilizer). The research was conducted at the Horticulture Sub-Laboratory, UGM at 27 °C with a relative humidity of 75%. The tomato quality observed was CO2 concentrations, visual quality rating (VQR), fruit weight percentage, fruit hardness, fruit color, total soluble solids, total titrated acid, vitamin C, carotenoids, lycopene, and flavonoids. The observation was terminated when the score of VQR reached 1 as the shelf life of tomatoes. The best dose of amino acid-enriched leaf fertilizer (Amiboost) is 2 L ha-1 for the lightness (*L) of fruit color, ascorbic acid, and lycopene. The maturity stage of fruit significantly affected vitamin C, flavonoids, total soluble solids, carotenoids, and lycopene.&#x0D; Keywords: Aminoalkanoic; shelf life; leaf fertilizer; tomato quality