Use Of Apple Research Articles

Optimization of lactic acid production from apple and tomato pomaces by thermotolerant bacteria

The production of lactic acid (LA) through biomass fermentation represents a promising alternative to the chemical synthesis. The use of agri-food by-products as fermentable carbohydrate sources can improve process sustainability by reducing waste and valorizing residual biomass. This study assessed the use of apple and tomato pomaces for producing LA through fermentation using thermotolerant bacteria under aerobic and non-sterile conditions. Three bacteria were evaluated and Heyndrickxia coagulans DSM 2314 was selected for its ability to produce LA from hydrolyzates of apple pomace (APH) and tomato pomace (TPH). The fermentation conditions were optimized to maximize LA production from APH, TPH and a mixture of both hydrolyzates. Therefore, LA productions ranged from 36.98 ± 0.41 to 40.72 ± 0.43 g/L, with yields from 0.86 ± 0.02 to 1.01 ± 0.01 g/g. Yeast extract was necessary as a nitrogen source for fermenting APH, while TPH and the mixture of both hydrolyzates did not require any supplementation. Other nitrogen sources, such as wine lees, urea and NH3Cl, were tested for fermenting APH. However, mixing this hydrolyzate with TPH proved to be the most viable alternative. This study demonstrates the potential for valorizing apple and tomato pomaces into LA under feasible fermentation conditions.

Salvaging Cashew Apples Through Processing into Simulated Cashew Meat

Cashew tree (Anacardium occidentale) is a cash crop mainly grown for its nuts. The dried apple is a good source of protein and non-digestible fibre that is essential to prevent many diseases as it helps in bowel movements to remove waste and non-digestible food materials from human system. The dried apple was obtained from extracting juice from the whole apple before drying. The use of apple which is a by-product can be an opportunity for diversifying activities on the farm. The farmers' revenue can increase through various opportunities which, exist for using cashew apples. However, these opportunities are presently not utilised adequately since most farmers are of the peasant status and has no knowledge on how to process the apple. Due to its high rate of perishability, cashew apples will not require to be transported over long distances and need to be processed, if possible, at the farm settlements. Simulated cashew meat was processed by subjecting cashew apple to juice pressing, blanching, salting and different methods of drying. The products obtained were subjected to physiochemical analysis, sensory evaluation and shelf-life studies. The percentage values for pH, moisture, crude protein and crude fiber contents were 4.71, 9.33, 18.31 and 14.32 respectively. The meat-like substance developed from cashew apple was very similar to dry meat. The sensory analysis revealed that there were no significant differences between processed cashew meat when compared with dry meat. The products were stable at room temperature for three months, studies on going to extend the shelf life further. Production of simulated cashew meat as a substitute for both meat consumers and vegetarians had come as a way of adding value to cashew apples that waste away in our cashew farms during peak seasons.

40 years of adding more fructose to high fructose corn syrup than is safe, through the lens of malabsorption and altered gut health–gateways to chronic disease

Labels do not disclose the excess-free-fructose/unpaired-fructose content in foods/beverages. Objective was to estimate excess-free-fructose intake using USDA loss-adjusted-food-availability (LAFA) data (1970–2019) for high fructose corn syrup (HFCS) and apple juice, major sources of excess-free-fructose, for comparison with malabsorption dosages (~ 5 g-children/ ~ 10 g-adults). Unlike sucrose and equimolar fructose/glucose, unpaired-fructose triggers fructose malabsorption and its health consequences. Daily intakes were calculated for HFCS that is generally-recognized-as-safe/ (55% fructose/45% glucose), and variants (65/35, 60/40) with higher fructose-to-glucose ratios (1.9:1, 1.5:1), as measured by independent laboratories. Estimations include consumer-level-loss (CLL) allowances used before (20%), and after, subjective, retroactively-applied increases (34%), as recommended by corn-refiners (~ 2012). No contributions from crystalline-fructose or agave syrup were included due to lack of LAFA data. High-excess-free-fructose-fruits (apples/pears/watermelons/mangoes) were not included. Eaten in moderation they are less likely to trigger malabsorption. Another objective was to identify potential parallel trends between excess-free-fructose intake and the “unexplained” US asthma epidemic. The fructose/gut-dysbiosis/lung axis is well documented, case-study evidence and epidemiological research link HFCS/apple juice intake with asthma, and unlike gut-dysbiosis/gut-fructosylation, childhood asthma prevalence data spans > 40 years.ResultsExcess-free-fructose daily intake for individuals consuming HFCS with an average 1.5:1 fructose-to-glucose ratio, ranged from 0.10 g/d in 1970, to 11.3 g/d in 1999, to 6.5 g/d in 2019, and for those consuming HFCS with an average 1.9:1 ratio, intakes ranged from 0.13 g/d to 16.9 g/d (1999), to 9.7 g/d in 2019, based upon estimates with a 20% CLL allowance. Intake exceeded dosages that trigger malabsorption (~ 5 g) around ~ 1980. By the early 1980’s, tripled apple juice intake had added ~ 0.5 g to average-per-capita excess-free-fructose intake. Contributions were higher (~ 3.8 g /4-oz.) for individuals consuming apple juice consistent with a healthy eating pattern (4-oz. children, 8-oz. adults). The “unexplained” childhood asthma epidemic (1980-present) parallels increasing average-per-capita HFCS/apple juice intake trends and reflects epidemiological research findings.ConclusionDisplacement of sucrose with HFCS, its ubiquitous presence in the US food-supply, the industry practice of adding more fructose to HFCS than generally-recognized-as-safe, and increased use of apple juice/crystalline fructose/agave syrup in foods/beverages has contributed to unprecedented excess-free-fructose intake levels, fructose malabsorption, gut-dysbiosis and gut-fructosylation (immunogen burden)-gateways to chronic disease.

The Effectiveness of Using Apples and Papayas in Reducing the Debris Index Score in Children with Mild Mental Retardation

One of the supporting factors causing dental caries is debris or leftover food around the teeth. The fiber and water content of apples can stimulate the speed of salivary secretion and neutralize acidic substances in the mouth and also have an effect on reducing the debris index. Consumption of fresh fruit rich in vitamins and minerals and water can encourage self-cleaning of the teeth, papaya is a plant source of vitamins, minerals and water. The aim of the study was to determine the effectiveness of using apples and papayas in reducing the debris index score in mildly mentally retarded children at SLBN 2 Jambi City. The type of research used in this study was quasi-experimental while the research design used was two group pre-test and post-test debris index observed twice, namely before treatment and after treatment with a total sample of 32 people with a total sampling technique. Based on the results of the study there was a significant difference in the average debris index between before and after chewing apples p value 0.000 and papayas p value 0.000. There is a significant difference in the average difference in debris index reduction between the use of apples compared to papayas with a p value of 0.000. Keywords: Apple, papayas, debris indeks, mildly mentally retarded

The effect of imposing apple (Malussylvestris Mill) juice on discoloration of nanofiller and nanohybrid composites

Composite resin can undergo discolouration if exposed to dyes. The use of apples can whiten teeth because they contain ma-lic acid. True experiment research with pretest-posttest with control group design using 24 samples divided into 6 treatments, namely sample groups 1 and 2 (nanofiller and nanohybrid composite groups that have been discoloured soaked in apple fruit juice (Malus sylvestris Mill) 80% concentration, groups 3 and 4 (negative control group, discoloured nanofiller and nanohy-brid composites soaked in distilled water) and groups 5 and 6 (positive control group, discoloured nanofiller and nanohybrid composites soaked in 10% carbamide peroxide). The colour change was determined with a shade guide (Vitapan Classical). The results were normally distributed and homogeneous. One-way Anova test showed there was a significant difference in each group. In the independent t-test, there was a significant difference in colour change between nanofiller and nanohybrid composite resins that experienced discoloration in 80% apple juice immersion. It was concluded that nanofiller composite resin had lower discolouration compared to nanohybrid.

Statistic and Network Features of RGB and Hyperspectral Imaging for Determination of Black Root Mold Infection in Apples.

Apples damaged by black root mold (BRM) lose moisture, vitamins, and minerals as well as carry dangerous toxins. Determination of the infection degree can allow for customized use of apples, reduce financial losses, and ensure food safety. In this study, red-green-blue (RGB) imaging and hyperspectral imaging (HSI) are combined to detect the infection degree of BRM in apple fruits. First, RGB and HSI images of healthy, mildly, moderately, and severely infected fruits are measured, and those with effective wavelengths (EWs) are screened from HSI by random frog. Second, the statistic and network features of images are extracted by using color moment and convolutional neural network. Meanwhile, random forest (RF), K-nearest neighbor, and support vector machine are used to construct classification models with the above two features of RGB and HSI images of EWs. Optimal results with the 100% accuracy of training set and 96% accuracy of prediction set are obtained by RF with the statistic and network features of the two images, outperforming the other cases. The proposed method furnishes an accurate and effective solution for determining the BRM infection degree in apples.

The Impact of Integrating an Intelligent Personal Assistant (IPA) on Secondary School Physics Students’ Scientific Inquiry Skills

Intelligent personal assistants (IPAs) carry massive potential in enhancing students’ performance through individualized dynamic scaffolding strategy. Despite IPAs being increasingly recognized among educationists, little is known about their application in the development of students’ scientific inquiry skills, particularly in physics. This study integrated the use of Apple's Siri in physics learning and examined the impact on secondary school student's scientific inquiry skills, and how these interactions affect their learning experiences. This mixed-method study conducted two field quasi-experiments (School A: science boarding school; School B: vocational boarding school) and post-experimental focus group discussions. Each school had two classes that were randomly assigned as experimental and control groups. The quantitative data showed that the experimental groups developed significantly higher scientific inquiry skills in comparison to the control groups (School A: <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</i> = 0.050; School B: <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</i> < 0.001) with moderate ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</i> = 0.62) to large effect size ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</i> = 1.82). The qualitative data further revealed the perceived ability of the IPA to support students’ individualized learning by providing timely scaffolding. This study offers substantial empirical data to support the effectiveness of the IPA in increasing secondary school students’ achievement in physics and scientific inquiry skills.

Design of apple snacks – A study of the impact of calcium impregnation method on physicochemical properties and structure of apple tissues during convective drying

Calcium impregnation methods (at atmospheric pressure, AI, or under vacuum, VI) followed by air drying at 60 °C were used for producing healthy apple snacks. This study compared the effect of the impregnation method on the ultrastructure features and physicochemical properties (desorption isotherm, density, porosity and shrinkage, thermal transitions, rheological behaviour, colour) of fortified apples along convective drying. Calcium concentration in AI and VI dried apples were ≈ 3600 and ≈ 5200 ppm respectively, which implied, considering a portion of dried apple of 50 g, 18% and 26% of the recommended intake for adults. Calcium incorporation did not affect the desorption behaviour but induced browning of apple tissues. Drying resulted in a great increase in porosity of AI samples and a noticeable compaction of the VI tissues. Impregnated tissues at aw ≤ 0.47 exhibited distinctive mechanical properties: AI apples were characterized by very high stiffness and lower resistance to rupture, while VI apples appeared stronger and moderately stiff. Industrial relevance textThis study will help to develop large-scale commercial production of calcium fortified apple snacks with distinctive characteristics. High quality and content of nutrients, easy industrialization and storage and a long shelf life are important aspects of these healthy snacks. They constitute a valuable functional shelf-stable product, that also can help feeding the population during natural disasters and wars, as well as reducing food insecurity in vulnerable groups as part of the diet. On the other hand, the use of apples not meeting the organoleptic requirements for direct consumption, or not processed into juice, drink, or cider as raw material, looks of particular interest for diversifying the production within the framework of sustainable production.

Quality and Microbiological Safety of Poultry Meat Marinated with the Use of Apple and Lemon Juice.

The aim of the study was to evaluate the use of apple juice for the marinating of poultry meat and its effect on the technological as well as sensory characteristics and microbiological safety of the raw product after heat treatment. Broiler chicken breast muscles were marinated for 12 h in apple juice (n = 30), a mixture of apple and lemon juice (n = 30) and compared with those in lemon juice (n = 30). The control group (n = 30) consisted of unmarinated breast muscles. Following the evaluation of the technological parameters (pH, L*, a*, b* colour, cutting force, cooking losses) quantitative and qualitative microbiological evaluations were performed on the raw and roasted products. The microbiological parameters were determined as total Mesophilic aerobic microorganisms, Enterobacteriaceae family, and Pseudomonas count. The bacterial identification was performed using a matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry. The marinating resulted in lower pH value, but increased tenderness of raw and roasted products. Marinating chicken meat in both apple and lemon juices, including their mixtures and in the control sample, resulted in increased yellow saturation (b*). The highest flavour desirability and overall desirability were obtained in products marinated using a mixture of apple and lemon juice, while the most desirable aroma was obtained from products marinated with apple juice. A significant antimicrobial effect was observed in marinated meat products compared to unmarinated, irrespective of the type of marinade used. The lowest microbial reduction was observed in the roasted products. Apple juice can be used as a meat marinade because it promotes interesting sensory properties and improves the microbiological stability of poultry meat while maintaining the product's good technological characteristics. It makes a good combination with the addition of lemon juice.

Evaluate the Capability of Some Local Fungal Isolates to Produce Pectinase Enzyme using Some Fruit Peels

Background: The process of producing enzymes from microorganisms is one of the most current approaches with a bright future. Pectinase is an acidic polysaccharide that is produced by microorganisms, accounts for a large proportion of commercially marketed enzymes and is extremely important because they are used in a variety of industrial, food and medical applications. This study aimed to use the peels of some fruits as a basic material in the production of pectinase enzyme by some fungi isolated from some fruits and vegetables via both solid-state and submerged fermentation methods. Methods: The current study included the isolation and identification of some fungi from fruits and vegetables in the local markets of Al-Diwaniyah City/Iraq, the detection of their capability to produce pectinase enzyme using the standard medium and the possibility of using the peels of some fruits as basic materials. Result: The results indicated the isolation and identification of 178 fungal isolates belonging to 11 genera at different frequency rates and it was found that the isolate P. expansum isolated from Apples was the most efficient isolate in producing pectinase enzyme and the use of Apple peels gave the highest production of the enzyme from the fungal isolate understudy compared to other fruit peels used.

Physical Evaluation of Manalagi Apple Extract Mouthwash

Manalagi apple (Malus Domestica) is one of the local varieties of apples. Apple rind has benefits such as antibacterial, antioxidant, antifungal, and anti-colliferative. The use of apples needs to be developed in the form of mouthwash products. The aim of the research was to determine the organoleptic evaluation of the manalagi apple peel extract mouthwash formulation. The type of this research was experimental research. The sample in this study was the skin of an apple. The stages in this study were making extracts using the maceration method and making mouthwash formulations of apple peel extracts at concentrations of 25%, 30% and 35%, then organoleptic evaluation was carried out for 4 weeks. The results showed that the organoleptic conditions were the same and stable, namely mint and sweet taste, menthol aroma and no precipitate, and brown color. Based on the results of the study, it was concluded that apple peel extract could be formulated as a mouthwash.

Studying the possibility of using fruit wood in the production of Russian Calvados

The traditional technology for obtaining aged Calvados involves the use of oak wood for aging. However, this entails a significant student cost of the product. Based on this, it is of interest to search and study the possibility of using “variegated” wood in the form of chips or staves. The obtained results of the study make it possible to unequivocally assess the prospects for the use of apple, cherry and hazelnut wood.

POSTHARVEST BIOCHEMICAL CHANGES IN APPLE SAMPLES

Apples are seasonal fruits, and it is relevant to prepare them adequately for storage and ensure proper storage conditions. In this study, we used ‘Rubin’ apple cultivar. We studied the qualitative and quantitative composition of phenolic and triterpenic compounds in the apple before placing them in the controlled atmosphere chambers and against at the end of the experiment, eight months later. Different concentrations of oxygen, carbon dioxide and nitrogen, constant temperature, relative humidity, and removal of endogenous ethylene were continually maintained. HPLC analysis showed that in the apple samples stored of variant II (5 % - O2, 1 % - CO2, 94 % - N2) conditions the total amount of triterpenes changed the least, dropped by 20 %. The study showed that the total content of phenolic compounds has increased in apple samples stored under controlled atmospheric conditions. The highest content of phenolic compounds increased in apple samples stored under IV (5 % - O2, 5 % - CO2, 90 % - N2) conditions. Evaluating the optimal storage parameters is useful to providing the consumers with apples that have a known and minimally altered phytochemical composition of phenolic compounds and triterpenes, which estimate the use of apples in the healthy food chain.

An Apple a Day Keeps the Doctor Away: Potential Role of miRNA 146 on Macrophages Treated with Exosomes Derived from Apples.

The constant dialogue between the plant world and the animal world (including man among them) has been known since the time of Adam and Eve, where an apple was the origin of the evils of the world. Apart from Snow White—who might have something to object to when it comes to the use of apples—fruits, plants, and natural extracts have been known for millennia as remedies for human health-related ailments. In the light of such evidence, the aim of the present work was to investigate from a biological point of view the potential role of apple exosomes in inflammatory processes on human cells. To this end we isolated and characterized apple exosomes and treated human cells such as macrophages and NCTC L929 as cancer cells in order to evaluate the tumorigenic and anti-inflammatory effect of apple exomes. Microscopic and molecular biology analyses were conducted to characterize exosomes and to assess cell proliferation, death, and miRNA line, as well as gene expression and the uptake of exosomes by cells. The results confirm the absolute biological safety of exosomes and their anti-inflammatory effect, mediated mainly by miRNA146 production by M2 macrophages.

Impact of Storage Controlled Atmosphere on the Apple Phenolic Acids, Flavonoids, and Anthocyanins and Antioxidant Activity In Vitro.

Apples are seasonal fruits, and it is important to prepare them adequately for storage and ensure proper storage conditions. In this study, we used ten different apple cultivars: ‘Alva’, ‘Auksis’, ‘Connell Red’, ‘Cortland’, ‘Ligol’, ‘Lodel’, ‘Noris’, ‘Rubin’, ‘Sampion’, and ‘Spartan’. We studied the qualitative and quantitative composition of phenolic compounds in the apple and apple extracts antioxidants activity before placing them in the controlled atmosphere chambers and again at the end of the experiment, eight months later. Different concentrations of O2, CO2, and N2, constant temperature, relative humidity, and removal of endogenous ethylene were continually maintained. HPLC analysis showed that the highest amount of 2265.7 ± 152.5 µg/g of chlorogenic acid was found in apple samples of the ‘Auksis’ cultivar stored under variant IV conditions. Different concentrations of gas in the controlled atmosphere chambers caused changes in antioxidant activity in whole apple and apple peel extracts. In our study, we found that the antioxidant activity of apple extracts varied between samples of different apple cultivars and depended on the composition of the controlled atmosphere. Determining the optimal storage conditions is beneficial to providing the consumers with apples that have a known and minimally altered chemical composition of phenolic compounds and the strongest antioxidant activity, which determine the use of apples in the healthy food chain.

&amp;lt;i&amp;gt;Malus domestica&amp;lt;/i&amp;gt; and &amp;lt;i&amp;gt;Solanum lycopersicum&amp;lt;/i&amp;gt; Mixtures for the Synthesis of Graphene Silver and Zinc Oxide Nanocomposites

This study reports on the novel and simple green method involving the use of apple (Malus domestica) and tomato (Solanum lycopersicum) extracts in the synthesis of electroactive layers of silver nanoparticles|graphene oxide (AgNPs|GO) and zinc oxide nanoparticles|graphene oxide (ZnONPs|GO). The surface morphology of the green synthesized nanocomposites was studied using High-Resolution Transmission Electron Microscopy (HRTEM), High-Resolution Scanning Electron Microscopy (HRSEM) while the elemental analysis was studied using Fourier Transform Infrared Spectroscopy (FTIR), Raman spectroscopy and X-Ray diffraction (XRD) and their optical properties were further characterised using Ultraviolet Spectroscopy (UV-vis). The electrochemical studies of these nanocomposites were achieved using cyclic voltammetry (CV) where an increase in electron conductivity of the AgNPs|GO and ZnONPs|GO nanocomposite was observed. Comparatively, the silver nanoparticulate-based platforms were observed to have superior electrochemical properties as opposed to the zinc oxide-based platform. The observed electrochemical activities of the synthesized nanocomposites are a good indication of their suitability as electroactive platforms towards the development of electrochemical sensors. Electrochemical sensors are popular in the Electrochemistry field because they may be developed using different methods in order to suit their intended analytes. As such, the synthesis of a variety of electrochemical platforms provides researchers with a vast range of options to select from for the detection of analytes.

Mobile mindfulness: Predictors of mobile screen time tracking

As individuals spend more time with mobile devices, concerns over screen time have grown, and thus so have efforts to reduce it. Even with mixed evidence for screen time's negative effects, mindfulness about mobile phone use has emerged as a coping mechanism and intervention strategy. This study uses an online survey (N = 405) to investigate whether general mindfulness and perceptions of one's phone use predict the use of Apple's Screen Time feature to track mobile screen time. Based on the Technology Acceptance Model, results indicate that perceived usefulness and perceived ease of use predict positive attitudes toward the feature, intention to use it, and actual use of it. However, mindfulness is a negative predictor of usefulness, indicating that those who are already more mindful find this feature less useful. Perceived time spent on one's phone was not related to perceived usefulness and thus did not predict use of the feature in the overall model. These results provide theoretical implications for the role of mindfulness in communication technology use, for predicting the adoption of screen time tracking tools, and practical implications for how to design these features for users based on their perceptions of their screen time and of screen time tracking.

A High-throughput Color Measurement System for Evaluating Flesh Browning in Apples

The development of new high-quality apple (Malus ×domestica) cultivars that are resistant to flesh browning is needed to expand the use of apples in the food service and catering industry. However, conventional methods for evaluating apple flesh browning can be both time-consuming and costly, thereby rendering such methods unsuitable for breeding programs that must characterize a large number of product samples. Therefore, it is necessary to develop new, simple, and inexpensive methods. The aim was to develop a method for simultaneously measuring the color values of 42 apple samples using a digital camera. The processing time per sample was reduced to less than one-tenth of that of the conventional method. The measurement dispersion [sd of the color difference between two colors ] of this system was less than 0.08, equivalent to the nominal value of a general colorimeter. Time-series analysis of six apple cultivars using this method showed that the calculated browning index values correlated well with the degree of browning judged by human perception. Further, the measurement data showed that the CIE L* a* b* value trends associated with browning in reddish- and watercored-flesh samples, was different from the corresponding trends in yellowish-flesh samples. This work reports the development of a high-throughput analytical system of apple browning and provides cautionary notes for evaluating reddish- and watercored-flesh browning, which should be measured on a different basis from that used for normal-flesh browning.

Using sap flow data to assess variations in water use and water status of apple orchards of varying age groups in the Western Cape Province of South Africa

No accurate quantitative information currently exists on how water use of apple (Malus domestica) orchards varies from planting to full-bearing age, leading to poor irrigation and water allocation decision making. This study sought to address this knowledge gap by investigating how the water use and tree water status vary with canopy cover, cultivar, and climatic conditions in 12 orchards growing in prime apple-producing regions in South Africa. The orchards were planted to the Golden Delicious/Golden Delicious Reinders cultivars which are widely planted in South Africa and the Cripps’ Pink/Cripps’ Red/Rosy Glow which are high-value late-season cultivars. The performance of two transpiration reduction coefficients, one based on sap flow (Ksf) and the other based on soil water depletion (Ks) (FAO approach) were evaluated against the midday stem water potential (MSWP) in all the orchards. While canopy cover had a clear effect on the whole-tree sap flow rates, there were no significant differences in the transpiration per unit leaf area among the cultivars. The daily average sap flux density under unstressed conditions was highest (~284 cm3∙cm-2) in the medium canopy cover orchards (30–44% fractional cover), followed by the mature orchards (~226 cm3∙cm-2), and was lowest in the young orchards (~137 cm3∙cm-2). Canopy cover rather than growing season length had a greater effect on seasonal total water use. Peak daily orchard transpiration ranged from 1.7 mm for young Golden Delicious Reinders trees to 5.0 mm in mature Golden Delicious trees that were maintained with large canopies to reduce sunburn damage to the fruit. For the red cultivars, the peak daily transpiration ranged from 2.0 to 3.9 mm, and the mature trees were maintained with less dense canopies to facilitate the development of the red fruit colour. The less dense canopies on the red cultivars had water-saving benefits since the seasonal total transpiration was lower relative to the Golden Delicious cultivar. The sap flow derived stress coefficient was strongly correlated to the MSWP (R2 ~ 0.60–0.97) in all the orchards while Ks was not able to detect plant stress due to over-irrigation.

Using sap flow data to assess variations in water use and water status of apple orchards of varying age groups in the Western Cape Province of South Africa

No accurate quantitative information currently exists on how water use of apple (Malus domestica) orchards varies from planting to full-bearing age, leading to poor irrigation and water allocation decision making. This study sought to address this knowledge gap by investigating how the water use and tree water status vary with canopy cover, cultivar, and climatic conditions in 12 orchards growing in prime apple-producing regions in South Africa. The orchards were planted to the Golden Delicious/Golden Delicious Reinders cultivars which are widely planted in South Africa and the Cripps’ Pink/Cripps’ Red/Rosy Glow which are high-value late-season cultivars. The performance of two transpiration reduction coefficients, one based on sap flow (Ksf) and the other based on soil water depletion (Ks) (FAO approach) were evaluated against the midday stem water potential (MSWP) in all the orchards. While canopy cover had a clear effect on the whole-tree sap flow rates, there were no significant differences in the transpiration per unit leaf area among the cultivars. The daily average sap flux density under unstressed conditions was highest (~284 cm3∙cm-2) in the medium canopy cover orchards (30–44% fractional cover), followed by the mature orchards (~226 cm3∙cm-2), and was lowest in the young orchards (~137 cm3∙cm-2). Canopy cover rather than growing season length had a greater effect on seasonal total water use. Peak daily orchard transpiration ranged from 1.7 mm for young Golden Delicious Reinders trees to 5.0 mm in mature Golden Delicious trees that were maintained with large canopies to reduce sunburn damage to the fruit. For the red cultivars, the peak daily transpiration ranged from 2.0 to 3.9 mm, and the mature trees were maintained with less dense canopies to facilitate the development of the red fruit colour. The less dense canopies on the red cultivars had water-saving benefits since the seasonal total transpiration was lower relative to the Golden Delicious cultivar. The sap flow derived stress coefficient was strongly correlated to the MSWP (R2 ~ 0.60–0.97) in all the orchards while Ks was not able to detect plant stress due to over-irrigation.