Apple Fruit Quality Research Articles

Effects of different interstocks on the growth, yield, and fruit quality of Hanfu apple

A field experiment was conducted using Hanfu apple grafted on 10 dwarfing interstocks to evaluate plant growth, yield, and fruit quality of different apple-interstock combinations in Hulu-dao, Liaoning Province, in order to select the most suitable apple-interstock combinations in the study area. The results showed that tree vigor, yield, and fruit quality were largely affected by the interstocks. Among the interstocks evaluated here, plant height, branch numbers, leaf fresh weight, branch fresh weight, root fresh weight, total root volume, average root diameter and total root tip numbers were the largest on GM256, while the highest trunk diameter, branch length, total root length and total root surface area were observed on CX5, the highest fruit firmness, soluble solids and soluble sugar contents were observed on M26, and the highest fruit vertical diameter, transverse diameter and single fruit weight were observed on GM256. The fuzzy evaluation results showed that the comprehensive character scores decreased in order of GM256, CX5, B9, JM7, CG80, Liaozhen 2, M26, Qingzhen 3, SH38 and MD001. Our results indicated that interstock GM256 and CX5 was better for the cold climate region.

Salicylic and Methyl Salicylic Acid Affect Quality and Phenolic Profile of Apple Fruits Three Weeks before the Harvest.

Effects of spraying over apple trees (Malus domestica; ‘Topaz’) with methyl salicylic acid (MeSA) and SA during fruit maturation were investigated for quality parameters (weight, firmness, hue angle, red blush, yield) and phenolic profile of the peel and pulp (HPLC–mass spectrometry). These treatment effects were also investigated for activities of the phenylpropanoid pathway enzymes phenylalanine ammonia-lyase, chalcone synthase and isomerase (combined), and flavanone-3β-hydroxylase. The MeSA and SA treatments resulted in poor fruit peel coloration, with higher hue angles and 20% and 10% lower red blush, respectively. Anthocyanin levels were also significantly lower (56%) for MeSA treatment. MeSA stimulated activities of phenylalanine ammonia-lyase and chalcone synthase/isomerase, which resulted in higher levels of flavanols (to 34%), flavonols (to 33%), and hydroxycinnamic acids (to 29%), versus control. Therefore, while these salicylate treatments improve levels of some beneficial polyphenols, they also have negative effects on the external quality characteristics of the fruit.

Different eradication effects of latent viruses by combining thermotherapy with shoot tip culture or cryotherapy in four apple cultivars

Virus disease is a serious problem affecting the fruit quality and production of apple, and solutions are being actively and urgently explored. The cultivation of virus-free propagules is an important method to combat virus problems facilitating the propagation of excellent apple cultivars. In this study, the apple cultivars ‘Ruiyang’, ‘Ruixue’, ‘Rui Xianghong’ and ‘Qinyue’ were used as source materials to eradicate the latent viruses (Apple chlorotic leaf spot virus, ACLSV; Apple stem grooving virus, ASGV; Apple stem pitting virus, ASPV), investigated the different virus eradication effects of combining thermotherapy with shoot tip culture (STC) or cryotherapy. Viral status of in vitro shoots of the four apple cultivars was detected using a reverse transcription-polymerase chain reaction before an alternating temperature of 38°C (day) and 30°C (night) were thermo-treated. Results showed that ASGV and ACLSV present from all four cultivars, ‘Rui Xianghong’ and ‘Qinyue’ were additionally infected with ASPV. The shoot survival and regrowth rates of combining thermotherapy with cryotherapy were lower than those of STC, and decreased with the time duration of thermotherapy. The virus eradication in each of the cultivars increased with the time duration of thermotherapy, and virus eradication effect of combining thermotherapy with cryotherapy was better to eradicate the latent viruses than that of STC. Combining 4 weeks of thermotherapy with cryotherapy achieved a 100% eradication of ASPV and ACLSV, and 53% to 92% of ASGV. This study provided the best treatment method for developing new virus-free apple cultivars that will support the propagation and popularization of virus-free plant and sustainability of the apple production industry.

The influence of severity and time of foliar damage on yield and fruit quality in apple (Malus domestica Borkh.)

Leaf damage/defoliation caused by pests or phytotoxic damage following chemical application can result in loss of leaf area at any time during the growing season. Four trials were conducted to examine the impact of severity and time of foliar damage on fruit set and quality in apple. Trees tolerated light to moderate leaf damage throughout the season with no significant effect on fruit set and thus crop load. Where 75% or more of the leaf surface was lost, fruit set was reduced and fruit quality was affected. Complete loss of leaves up to three weeks after full bloom (wAFB) resulted in very low or no fruit set, but from 9 wAFB crop load was not affected by leaf damage. Loss of terminal shoot leaves had no effect on fruit set, but spur leaves were critical early in the season with the impact lessening from 6 wAFB. This study has demonstrated that low levels of foliar damage have little effect on fruit size or quality, but high levels can impact on both set and quality. Fruit quality was reduced following leaf damage during the period 6–12 weeks after full bloom which is the critical period for cell division in the fruit as well as flower initiation for the following year. High levels of leaf damage also reduced fruit size in spite of reduced crop load levels, most likely the result of a reduction in carbohydrate assimilation during the cell division phase of fruit development.

Climate Change Impacts on Temperature and Chill Unit Trends for Apple (Malus domestica) Production in Ceres, South Africa

Climate is an essential part of crop production, determining the suitability of a given region for deciduous fruit products such as apples (Malus domestica). It influences the yield and quality of fruits. There is strong evidence of global and regional-scale climate change since the advent of the industrial era. In South Africa, mean surface temperatures have revealed a warming trend over the last century. This study aimed to assess the impact of climate change on temperature and chill unit trends for apple production in Ceres, South Africa. The daily positive Utah chill units (DPCU) model was used as frequent high temperatures can lead to a high negation volume. Historically observed (1981–2010) and future projected (2011–2100) temperatures were obtained from the South African Weather Service (SAWS) and three ensemble members of the Cubic-Conformal Atmospheric Model (CCAM), respectively. The latter employed the RCP8.5 pathway. Linear trends were calculated for temperature and accumulated PCUs for the historical base period. The probability of accumulating specific threshold PCU values for both historical and future periods was assessed from cumulative distribution functions (CDFs). The historical change in minimum temperatures showed no significant trend. Ceres revealed a warming trend in maximum temperatures over the historical period. By the 2080s, the probability of not exceeding a threshold of 1600 PCUs was exceptionally high for all ensemble members. Future projections showed a decline in the accumulated PCUs of 2–5% by the 2020s, 7–17% by the 2050s, and 20–34% towards the end of the 20th century. Based on these results, it is clear that winter chill units are negatively influenced by climate change. The loss in yield and fruit quality of apples due to climate change can negatively impact the export market, leading to significant economic losses for apple production in the Ceres area.

Effect of some nutrients and growth retardant on fruit quality of Wood apple (Feronia limonia Swingle)

Effect of some nutrients and growth retardant on fruit quality of Wood apple (Feronia limonia Swingle)

A precision management approach to monitor apple fruit growth and quality

A precision management approach to monitor apple fruit growth and quality

The MdMYB16/MdMYB1-miR7125-MdCCR module regulates the homeostasis between anthocyanin and lignin biosynthesis during light induction in apple.

Light induces anthocyanin accumulation and hence decides the coloration of apple fruit. It also plays a key role in regulating the biosynthesis of other secondary metabolites. However, the crosstalk between anthocyanin and lignin metabolism during light induction, which affects the edible quality and visual quality of apple fruit, respectively, have rarely been characterized. In this study, we identified and functionally elucidated the roles of miR7125 and its target, cinnamoyl-coenzyme A reductase gene (CCR), in regulating the homeostasis between anthocyanin and lignin biosynthesis during light induction. Overexpressing miR7125 or inhibiting CCR transiently in apple fruit promoted anthocyanin biosynthesis but reduced lignin production under light-induced conditions. Consistently, opposite results were observed under the background of repressed miR7125 or overexpressed CCR. We found that the repressor MdMYB16 and the activator MdMYB1 bound to the miR7125 promoter. Transient repression of MdMYB16 upregulated miR7125 expression significantly, accompanied by decreased levels of MdCCR transcript, resulting in a reduction in the lignin biosynthesis and an increase in anthocyanin accumulation. However, transient overexpression of MdMYB16 produced the opposite effects to MdMYB16-RNAi. The results reveal a novel mechanism by which the MdMYB16/MdMYB1-miR7125-MdCCR module collaboratively regulates homeostasis between anthocyanin and lignin biosynthesis under light induction in apple.

Productivity Of Intensive Varieties In Apple Trees Depends On Density Of Trees In Orchards

In this article, the productivity of intensive apple varieties was studied, grafting on vegetatively propagated medium-sized stock MM - 106 Golden Delicious and Korey. In a long-term watering experience, it was revealed that in the optimal planting scheme of 6 × 4, the yield of apple fruits increased by 12-15%, the quality of apple fruits improved significantly.

G.213 rootstock – Alternative to apple tree cultivation in different planting areas in southern Brazil

The purpose of this work was to evaluate development, quality, and productivity of Maxi Gala apple fruit grafted on rootstocks G.213, M.9 and Marubakaido with M.9 inter-graft on virgin soil and replanting area conditions, in Vacaria-RS, Brazil. The planting effect was evaluated separately for each set of rootstocks. The experimental areas were prepared in the winter of 2011, spacing of 1.0 × 4.0 m and density of 2500 plants per hectare, with Fuji Suprema as pollinator in 1:4 proportion. The plants were conducted in Tall Spindle system and the evaluations were managed for nine years. We observed that M.9 rootstock has low vigor, high productive efficiency, but low productivity, in both planting soils. The semi-vigorous rootstocks MB/M.9–30 and MB/M.9–20 were characterized by high vigor, high productivity (reduced in replanting area) and low productive efficiency. The G.213 rootstock was characterized by low vigor, high productivity, and high productive efficiency. Except G.213, all rootstocks had high production alternation values, especially when in replanting. In both experiments the rootstocks G.213 and M.9 were efficient in vigor controll, however the rootstock G.213 is more productive and stable over the years, providing greater productive efficiency in Maxi Gala than M.9. It was observed that the fruit quality of Maxi Gala cultivar measured by firmness, ºBrix, diameter and weight are not influenced by the rootstocks evaluated.

Multiomics Analysis Reveals New Insights into the Apple Fruit Quality Decline under High Nitrogen Conditions.

Excessive application of nitrogen (N) fertilizer is common in Chinese apple production. High N reduced the contents of soluble sugar and total flavonoids by 16.05 and 19.01%, respectively, resulting in poor fruit quality. Moreover, high N increased the total N and decreased the total C and C/N ratio of apple fruits. On the basis of the transcriptomic, proteomic, and metabolomic analyses, the global network was revealed. High N inhibited the accumulation of carbohydrates (sucrose, glucose, and trehalose) and flavonoids (rhamnetin-3-O-rutinoside, rutin, and trihydroxyisoflavone-7-O-galactoside) in fruits, and more C skeletons were used to synthesize amino acids and their derivatives (especially low C/N ratio, e.g., arginine) to be transferred to N metabolism. This study revealed new insights into the decline in soluble sugar and flavonoids caused by high N, and hub genes (MD07G1172700, MD05G1222800, MD16G1227200, MD01G1174400, and MD02G1207200) and hub proteins (PFK, gapN, and HK) were obtained.

Peach, Apple, and Pear Fruit Quality: To Peel or Not to Peel?

The nutritional value of the peeled and unpeeled fruit (peel plus flesh tissues) was studied using four peach (Prunus persica L.; Red Heaven, Maria Blanca, Big Top, and Queen Giant), two pear (Pyrus communis L.; Santa Maria, Pyrus pyrifolia N.; Nashi), and three apple (Malus domestica Borkh.; Gala, Granny Smith, and Red Chief) cultivars. Based on principal components analysis (PCA) models, there was a clear differentiation among the cultivars’ and the peeled fruits’ nutritional characteristics in comparison to the unpeeled ones. Increased antioxidant capacity and content of total phenols and flavonoids of peaches (Red Heaven and Maria Blanca) versus nectarines (Big Top and Queen Giant) were recorded. In contrast, nectarines were characterized by higher hydroxycinnamates and dry matter. The apples’ cultivar Granny Smith exhibited a high level of titratable acidity (TA), while the Gala displayed a high level of soluble solids concentration (SSC), carotenoids, dry matter, hydroxycinnamic acids, and flavonols at the unpeeled fruit, whereas the Red Chief by increased anthocyanins, antioxidant capacity, total phenols, and flavonoids. Nashi pears with peel were more beneficial due to the strong skin contribution in the fruits’ beneficial compounds content. The peel of the Granny Smith cultivar was associated with an increased level of P, K, Ca, and Mg, whereas that of Red Chief with increased anthocyanins and Mg content.

INFLUENCE OF FOLIAR APPLICATION OF NOVATEK SOLUB K-MAX FERTILIZER ON THE BIOCHEMICAL COMPOSITION AND COMMERCIAL AND CONSUMER QUALITIES OF APPLE FRUITS

The article presents data on the study of the effect of foliar water-soluble mineral fertilizer NOVATEK Solub K-Max 10-5-30 on the biochemical composition and commercial quality of apple fruits. A rise in vitamin C from the introduction of NOVATEK at a rate of 2.5 kg/ha indicates the effectiveness of this drug for optimizing the content of ascorbic acid in fruits. An increase in the content of monosaccharides and a decrease in disaccharides were found for all the studied rates of consumption of agrochemicals. The use of mineral fertilizer “Novatek Solub K-Max” contributed to increase the dry weight of fruits. The application of this mineral fertilizer is recommended for inclusion in the industry regulations for Apple cultivation as one of the elements of the technology.

Influences of open-central canopy on photosynthetic parameters and fruit quality of apples (Malus × domestica) in the Loess Plateau of China

Although open-central canopy (OCC) is popular in apple (Malus × domestica) orchards in Loess Plateau of China, its relevant photosynthetic mechanisms have not been elucidated. In this study, changes in photosynthetically active radiation (PAR), gas exchange, chlorophyll fluorescence quenching and fruit quality in apple trees were measured in OCC and compared with those in the conventional condensed round and large canopy (RLC). Results showed that light intercepted at different orientations was 44% higher by OCC than that by RLC. The improved light environment within OCC remarkably increased leaf maximum net photosynthetic rate (Pnmax) and significantly decreased stomatal limitation. Under high light, the ratio of photorespiratory rate to gross photosynthetic rate (Pr/Pg) in OCC was higher than that in RLC. Moreover, reversible component in non-photochemical quenching (r(qE)) was increased, while irreversible component (r(qI)) was decreased in OCC than in RLC. As a result, the fruit quality in OCC was greatly boosted as evidenced by the significantly increased single fruit weight, fruit flesh firmness and fruit soluble solid contents and the sharply decreased fruit titratable acid contents. PAR intercepted by the canopy and the fruit soluble solid contents, leaf Pnmax or single fruit weight were positively correlated, while PAR or Pnmax was negatively correlated with the fruit titratable acid contents. Accordingly, the improved crown light environment and the enhanced leaf photosynthetic performance and photoprotective capacity in OCC led to the boosted fruit quality.

Tree Physiology, Fruit Growth and Nutrient Elements of Wax Apple (Syzygium Samarangense) as Affected by Branch Bending Angle

This study was conducted to evaluate the potential effects of branch bending angle on the plant physiological characteristics, mineral nutrients accumulation and fruit quality of wax apple. Different treatments with five replicates each by Randomized Complete Block Design (RCBD) layouts were arranged in this study. All the treatments represent different branch angles which were at 5˚ (control), 20˚, 45˚, 65˚ and 85˚ from vertical axis. Leaf chlorophyll content (SPAD chlorophyll index) was significantly affected by different bending treatments at a budding stage, flowering, fruit development and after harvesting of wax apple. Total soluble solids (TSS) content in the leaves of bent branches increased significantly at before bud development, flowering, fruit ripening and after harvesting stages of wax apple trees. During fruit development and maturation stages, leaf TSS content was decreased in all bent branches. The results showed that 20˚ to 65˚ angle bent branches increase weight and firmness of fruit, fruit diameter and produced dark-coloured fruit compared to control. The results showed that 65˚ bent branches give the highest potassium (K+) and magnesium (Mg2+) content in the fruits. Higher sodium (Na+), iron (Fe2+) and calcium (Ca2+) content in fruits were found in 20˚ bent branches. There was a positive correlation between fruit TSS with Mg2+ (r = 0.70), with Na+ (r = 0.67) and with Ca2+ (0.57) content in the bent branches of wax apple. Fruit TSS content also positively correlated with firmness and peel colour of wax apple fruits. The number of fruit, fruit weight and fruit diameter of wax apple also positively correlated (weak) with leaves TSS content. It can be concluded that 20˚ to 65˚ branch bending angle are promising for enhancing plant physiology, fruit growth and quality of wax apple fruits.

Paclobutrazol regulates hormone and carbon-nitrogen nutrition of autumn branches, improves fruit quality and enhances storage nutrition in ‘Fuji’ apple

Inhibiting the overgrowth of autumn branches during the fruit enlargement stage is one important way to improve the quality of apple fruits. Here, four levels of paclobutrazol (PBZ) (0, 500, 1000, 1500, and 2000 mg·L−1) were applied to the autumn branch leaves of five-year-old ‘Fuji’ apple (Malus × domestica Borkh.) trees at the fruit enlargement stage in 2018 and 2019. The results showed that increasing PBZ levels decreased indole-3-acetic acid (IAA) and gibberellic acid (GA3) contents and increase abscisic acid (ABA) contents in the autumn branch leaves. PBZ also reduced the leaf area, branch length, leaf number, and Rubisco enzyme activity in the autumn branches, but had no significant effect on chlorophyll and net photosynthetic rate. Obvious changes occurred when the concentration of PBZ exceeded 1500 mg·L−1, including the inhibition of autumn branch growth. 13C and 15N isotope labeling results indicated that PBZ coordinated the carbon–nitrogen nutrition of autumn branches in the fruit enlargement stage, reduced the δ13C and nitrogen derived from fertilizer (Ndff) in the leaves of autumn branches. PBZ also coordinated the carbon–nitrogen nutrition of fruits, reduced the accumulation of nitrogen in the fruit and increased the accumulation of carbon in the fruit. PBZ increased the content of soluble sugar, starch, soluble protein, and free amino acids in the roots to varying degrees in early spring the following year (2019 and 2020). These results indicated that a moderate PBZ (1000–1500 mg·L−1) application could reasonably regulate carbon-nitrogen nutrition of autumn branches and fruits, then improve fruit quality and the storage nutrition of apple trees.

Foliar nutritional content and apple fruit quality as affected by organic, conventional, or integrated management

This research aimed to compare two levels (medium and high) and three types of fertilization (organic, chemical, and integrated) in both foliar nutritional content and fruit quality of Golden Delicious apple variety. The foliar concentration of macro and micronutrients was affected neither by fertilization level nor fertilization type, with the exception of potassium which reached their highest concentration in the high level of chemical fertilization (T1-HC). Regarding the fruit quality attributes, results showed no statistical differences in weight, size, firmness, pH, and starch content between the level and type of fertilization. With the high level of organic fertilization, the best apple color was found, while the medium level of organic fertilization showed the highest concentration of both soluble solid content and total phenolic compounds. Thus, fertilization level had greater influence than the fertilization type. Results also showed that under organic fertilization management is possible obtaining a foliar nutritional content and fruits quality attributes similar to those treated with chemical fertilizers. Future studies must be carried out for elucidating the impact of long-term organic fertilization on the fruit quality and foliar nutritional content of other crops.

Classification and Grading of Multiple Varieties of Apple Fruit

Fruit safety plays an important role in the economy of the world for the agriculture field. Recently, it has been noticed that fruits are affected by various diseases. This creates economic failure in the agriculture field across the world. The manual investigation of multiple varieties of an apple fruit is a burdensome task that can be minimized for quality evaluation for fresh and rotten fruits using automatic computerized methods. In this work, a novel method is implemented for multiple varieties of apple fruit quality evaluation. The six different varieties of apples i.e. Fuji, York, Golden Delicious, Red Delicious, Granny Smith, and Jonagold are used for image acquisition. Firstly, images are segmented by the grab-cut method and fuzzy c-means clustering. Secondly, multiple features statistical, textural, geometrical, discrete wavelet transform, a histogram of the oriented gradient, and Laws’ texture energy are extracted and selected by principal component analysis from the feature space. Lastly, the classification of fresh and rotten apples is done by applying k-NN, LR, SRC, and SVM classifiers. The cross-validation technique with distinct values of k is used to validate the performance of the system. The proposed method achieves 92.90% (k = 5), 98.42% (k = 10), and 95.27% (k = 15) accuracy by SVM classifier. It has been seen that the extraction of proper features and selection of features results in upgraded performance. Also, the state of the art techniques are comparable with the proposed algorithm showing the probability to use for multiple fruits.

‘Honeycrisp’ Apple (Malus domestica Borkh.) Fruit Response to Controlled Atmosphere Storage with the Low Oxygen Limit Established by Monitoring Chlorophyll Fluorescence

Postharvest management of apple fruit ripening using controlled atmosphere (CA) storage can be enhanced because CA oxygen concentration is decreased to close to the anaerobic compensation point (ACP). Monitoring fruit chlorophyll fluorescence (CF) is a technology to assess fruit response to low pO2 as fluorescence increases as pO2 reaches a critically low concentration. This type of pO2 management has been referred to as dynamic atmosphere storage (DCA). Use of very low pO2 can enhance post-storage apple fruit quality for many cultivars, allowing better firmness retention and prevention of superficial scald, compared with fruit stored at higher pO2 during CA. ‘Honeycrisp’ is a chilling-sensitive cultivar with little risk of firmness loss or superficial scald during storage; however, other aspects of fruit-quality loss during storage, including soluble solids content (SSC), titratable acidity (TA), peel greasiness, and physiological disorder development may be impacted by pO2. A 2-year study was conducted to identify ‘Honeycrisp’ fruit-quality impacts of CA storage with a low-pO2 setpoint determined by using CF. ‘Honeycrisp’ apples were held 7 days at 10 °C after harvest, then at 3 °C. An additional treatment with 1-methylcyclopropene (1-MCP) was conducted in year two. CA was established 48 hours after transfer to 3 °C. In both years, fruit CF increased when pO2 decreased to ≈0.3 kPa O2 and then decreased after pO2 was increased to 0.5 kPa. Additional CA pO2 concentrations above 0.3 kPa were also maintained for other fruit. Fruit internal disorder incidence increased as pO2 decreased and with 1-MCP use. Changes in SSC, TA, and peel yellowing were inconsistently reduced by storage at lower pO2. Peel greasiness did not develop in either year. CA did not impact the incidence of chilling disorders regardless of pO2. Results indicate some aspects of ‘Honeycrisp’ fruit quality can be enhanced as CA pO2 decreases; however, pO2 above the low pO2 threshold did not prevent internal physiological disorder development.

Exogenous dopamine improves apple fruit quality via increasing flavonoids and soluble sugar contents

Dopamine (DA) acts as a mediator in numerous plant physiological processes. In order to provide a basis for apple fruit quality improvements, we applied dopamine to apple trees via spraying (SDA) and watering (WDA). Five-year-old Changfu 2 (Malus domestica Borkh. cv. Naganofuji No.2) apple trees were treated with SDA or WDA in 0, 50, 100 and 200 μM. Results demonstrate that fruit fructose, sucrose and anthocyanin content, and ethylene production significantly increased for SDA100 and WDA100. Furthermore, the significant upregulation in WDA100 compared to WDA0 was observed for sugar transporter and flavonoid biosynthesis genes. Differential metabolite profiling analysis revealed the ability of flavonoids to distinguish between WDA0 and WDA100. Overexpression of the apple tyrosine decarboxylase gene MdTyDC in apple calli improved the dopamine and soluble content. This study demonstrates the role of dopamine as a regulator of the flavonoids and soluble sugar metabolism in improving apple fruit quality.