Apple Fruit Production Research Articles

Paecilomyces variotii extracts promote growth and alleviate nutrient deficiency symptoms in apple

It is essential to find environment-friendly agrochemicals to cope with the problems of nutrient imbalance, fruit quality decline, and physiological disorders during apple fruit production, which is beneficial for improving the quality and yield of apple. A natural extract from Paecilomyces variotii (ZNC), an endophytic fungus, has been used widely to enhance crop performance. However, an understanding of the mechanism underlying ZNC-triggered growth and alleviation of nutrient deficiency-associated symptoms in apples remains elusive. Here, the photosynthesis, leaf growth, and fruit quality were enhanced by adding ZNC. In addition, ZNC relieved nutrient deficiency-related symptoms promoted the differentiation of root morphology and vitality, and reduced the accumulation of osmoprotectants and reactive oxygen species, thereby promoting growth under normal and nutrient-deficient conditions. Finally, genome-wide RNA sequencing reveals the ZNC-regulated mechanisms involved in hormone and metal ion pathways. Our study reveals the role of ZNC in promoting growth and improving the quality of apple, providing a new direction for reducing the use of chemical fertilizers and pesticides.

Emerging innovative pre‐ and post‐harvest management practices to mitigate patulin‐linked food safety risks in apple and its products

AbstractPatulin, a toxic secondary metabolite produced by certain molds (Penicillium, Aspergillus, and Byssochlamys), poses a significant health risk when present in apple juice products above permissible levels. Its presence is a major concern for both consumers and regulatory bodies due to its potential carcinogenic and mutagenic effects. Minimizing patulin concentration in apple juice products requires a multifaceted approach involving various stages of apple fruit production, from orchard management to processing and storage. This review explores the pre‐ and postharvest strategies associated with minimizing patulin concentration in apple juice products. It examines the role of good agricultural practices in reducing mold contamination in orchards and discusses the importance of proper postharvest handling, including fruit sorting and washing to remove contaminated apples before processing. During processing, factors such as temperature, pH, and processing time play crucial roles in minimizing patulin levels. Innovative processing technologies, such as pulsed electric fields (PEF), ultraviolet (UV) radiation, high‐pressure processing, enzymatic, and chemical degradation have shown promise in reducing patulin concentration while preserving the sensory and nutritional quality of the juice. Furthermore, effective storage practices, such as maintaining proper temperature and humidity levels, are essential for preventing patulin formation during storage. Continuous monitoring and analytical testing for patulin content throughout the production chain are necessary to ensure compliance with regulatory standards and to guarantee the safety of apple juice products. Despite advancements in technology and production practices, challenges remain in effectively minimizing patulin concentration. These include the need for further research to develop more efficient detection methods, the adoption of sustainable and eco‐friendly practices in orchard management, and the dissemination of knowledge and best practices to stakeholders across the apple juice supply chain. In conclusion, minimizing patulin concentration in apple juice products requires a holistic approach that integrates preventive measures, innovative processing technologies, and stringent quality control measures. By addressing these challenges, the apple juice industry can ensure the production of safe and high‐quality products that meet regulatory standards and consumer expectations.

No wild bees? Don't worry! Non-bee flower visitors are still hard at work: The edge effect, landscape, and local characteristics determine taxonomic and functional diversity in apple orchards

Native pollinators are key to enhancing fruit production in apple orchards and maintaining yield stability through taxonomic and functional diversity. Some studies suggest that the distance to the nearest native forest patch, the edge effect, or apple orchard management, modulate the richness and abundance of pollinators. However, such studies have focused on bees, thereby generating knowledge gaps about non-bee pollinators. This study looks at the taxonomic and functional diversity in central Chile, as well as the abundance of major pollinator groups (native beetles, flies, wild bees, and lepidopterans), and how these are influenced by landscape and apple orchard characteristics. For two seasons, native and managed pollinators were recorded in nine apple orchards with different management approaches (organic vs conventional) and apple varieties (Gala vs Fuji). The taxonomic and functional diversity of major pollinator groups were correlated with distance to the nearest native forest patch. We measured the edge effect on pollinators toward the interior of apple orchards and analyzed the results with one-way ANOVA. Lastly, we associated the diversity and abundance of pollinators with landscape and apple orchards characteristics using GLMM. Excepted managed bees and contrary to the global trend in apple studies, native flies and beetles were the most dominant pollinators, the latter being more abundant at the orchard edge. The distance to the native forest patch was correlated negatively to the functional richness and positively to body temperature, while that same variable influenced the abundance of total native pollinators, beetles, flies, and wild bees. The gala variety was found to attract greater pollinator richness and more wild bees, whereas organic orchards positively influence native flies and conventional orchards attract lepidopterans. Moreover, the number of honey bees influences the abundance of wild bees and lepidopterans. Land intensification practices could decrease the taxonomic and functional diversity of pollinators. Management alternatives like increased landscape heterogeneity or native habitat restoration, could to maintain apple fruit production in space and time.

Aggressiveness and Patulin Production in Penicillium expansum Multidrug Resistant Strains with Different Expression Levels of MFS and ABC Transporters, in the Presence or Absence of Fludioxonil.

Penicillium expansum is the most common postharvest pathogen of apple fruit, causing blue mold disease. Due to the extensive use of fungicides, strains resistant to multiple chemical classes have been selected. A previous study by our group proposed that the overexpression of MFS (major facilitator superfamily) and ABC (ATP binding cassette) transporters constitute an alternative resistance mechanism in Multi Drug resistant (MDR) strains of this pathogen. This study was initiated to determine two main biological fitness parameters of MDR strains: aggressiveness against apple fruit and patulin production. In addition, the expression pattern of efflux transporters and hydroxylase-encoding genes that belong to the patulin biosynthesis pathway, in the presence or absence of fludioxonil and under in vitro and in vivo conditions were investigated. Results showed that the MDR strains produced higher concentrations of patulin but showed a lower pathogenicity compared to the wild-type isolates. Moreover, expression analysis of patC, patM and patH genes indicated that the higher expression levels do not correlate with the detected patulin concentration. The selection of MDR strains in P. expansum populations and the fact that they produce more patulin, constitutes a serious concern not only for successful disease control but also for human health. The above-mentioned data represent the first report of MDR in P. expansum associated with its patulin-production ability and the expression level of patulin biosynthesis pathway genes.

Development of a Knowledge-Based Expert System for Diagnosing Post-Harvest Diseases of Apple

Post-harvest diseases are one of the main causes of economical losses in the apple fruit production sector. Therefore, this paper presents an application of a knowledge-based expert system to diagnose post-harvest diseases of apple. Specifically, we detail the process of domain knowledge elicitation for constructing a Bayesian network reasoning system. We describe the developed expert system, dubbed BN-DSSApple, and the diagnostic mechanism given the evidence provided by the user, as well as a likelihood evidence method, learned from the estimated consensus of users’ and expert’s interactions, to effectively transfer the performance of the model to different cohorts of users. Finally, we detail a novel technique for explaining the provided diagnosis, thus increasing the trust in the system. We evaluate BN-DSSApple with three different types of user studies, involving real diseased apples, where the ground truth of the target instances was established by microbiological and DNA analysis. The experiments demonstrate the performance differences in the knowledge-based reasoning mechanism due to heterogeneous users interacting with the system under various conditions and the capability of the likelihood-based method to improve the diagnostic performance in different environments.

Progress in apple breeding for resistance to fire blight

The paper presents the most important issues concerning the breeding of apple trees resistant to fire blight, which creates great op­portunities to increase the efficiency of apple fruit production without the use of other protection methods, including the chemical treatment. The phenotypic assessment of susceptibility of apple genotypes to the disease is based on observations on the occurrence of symptoms in field and/or closed facilities, e.g. in the greenhouse. Molecular biology methods, including identification of resistance mark­ers, and biotechnology are valuable tools to accelerate the breeding process. Breeding programs conducted in various research centers around the world use wild species of the genus Malus and commercial cultivars of apple. Apple rootstocks with very high resistance to fire blight (USA) and a number of scab-resistant cultivars, also showing high resistance to the disease (Germany, Switzerland) have already been bred. In recent years cultivar Early Szampion and clone No. 69 (J-2003-05) have been bred in Poland. Both genotypes are characterized by a very high resistance, and produce attractive tasty fruit. They have the prospect of being used in breeding programs and commercial plantings.

Resistance of Third and Fifth Instars of Codling Moth, Cydia pomonella (L.) to the Insecticide Deltamethrin in As-Suwayda Governorate, Syria

Bou Hamdan, R., W. Kassis and M. Bufaur. 2023. Resistance of Third and Fifth Instars of Codling Moth, Cydia pomonella (L.) to the Insecticide Deltamethrin in As-Suwayda Governorate, Syria. Arab Journal of Plant Protection, 41(2): 183-189. https://doi.org/10.22268/AJPP-41.2.183189 Codling moth, Cydia pomonella (L.) is a key pest of global importance that affects apple fruit production and its populations have developed resistance to insecticides in many apple production areas. Third-instar larvae of Cydia pomonella has developed a vigor tolerance to deltamethrin in the fields of As-Suwayda Governorate, Syria. The resistance rate (RR) was (5, 5.6, 6.79) after (24, 48, 72) hours after treatment with deltamethrin, respectively, while ultra-vigor tolerance was observed in the non-diapausing fifth-instar larvae of codling moth (males and females), the resistance rate (RR) was (6.42, 7.75, 9.67) for males and (8.49, 9.84, 10.26) for females after (24, 48, 72) hours, 188 مجلة وقاية النبات العربية، مجلد ،41 عدد 2 ) 2023( respectively, It was noted that females of the non-diapausing fifth-instar larvae was more resistant than males. Based on the results, it is recommended to exclude deltamethrin for a while, using it with other insecticides, not re-using it many times or mixing it with one of the synergists. Keywords: Cydia pomonella (L.), non-diapausing larvae, insecticide resistance, resistance rate, deltamethrin

The influence of organo-mineral fertilizers on the growth of evening apple varieties throughout the year

The article describes the research of the apple varieties grown in the areas in the Yangikurgan district of the Namangan region and proper use of apple fruit production and post-harvest activities in the region. "Iskavot" districts "Nazirjon Ilkhomjon Arabboy" farm in the apple orchards of semirenko, golden delicacies, starcrimson, (five stars), local variety (boyken) 4 types, i.e. N120 P100 K30, N50 P30 K10 organic1000, N25 P20 Phenological and biometric evaluations of K5 Organomineral500, Organomineral1000 fertilizers were studied. Apple cultivars were studied at the beginning of vegetation, beginning of flowering, end of flowering, end of branch growth, beginning and end of autumn, the periods of watering the field, the periods of spraying pesticides, the periods of spraying herbicides.

Reduced Sensitivity to Tebuconazole in Botryosphaeria dothidea Isolates Collected from Major Apple Production Areas of China.

China has the largest acreage and is the greatest producer of apples in the world. Apple ring rot (ARR) caused by Botryosphaeria dothidea is one of the major diseases affecting apple fruit production. Tebuconazole, a sterol demethylation-inhibiting (DMI) fungicide, has been increasingly applied to manage ARR in China. Resistance to tebuconazole in field populations of B. dothidea may be selected and accumulate to higher degrees over time. Establishment of tebuconazole sensitivity monitoring programs is critically important for resistance management and effective ARR control. However, the resistance level of B. dothidea to tebuconazole in China remains largely unknown. In this study, invitro mycelial growth assays of B. dothidea in media amended with tebuconazole were conducted, and the sensitivity of B. dothidea to tebuconazole was determined with a set of 390 isolates collected from the major apple production provinces in China between 2006 and 2014. Results showed that the 50% effective concentration (EC50) value ranged from 0.011 to 0.918, 0.040 to 1.621, and 0.052 to 1.925 μg ml-1 with a median value of 0.194, 0.386, and 0.782 μg ml-1 in the isolates collected in 2006, 2010, and 2014, respectively. The frequency distribution of EC50 for tebuconazole was a nonnormal distribution (P < 0.05), suggesting that subpopulations with reduced sensitivity to tebuconazole had emerged in these B. dothidea isolates. The frequency distribution of the B. dothidea isolates collected in 2006 fit a unimodal curve and could be regarded as the baseline sensitivity to tebuconazole. The resistance levels increased over time with the average occurrence frequency of 43.3% and resistance index of 0.38. Positive cross-resistance was observed between tebuconazole and metconazole, which is another DMI fungicide, but multiple resistance was not detected between tebuconazole and non-DMI fungicides. Our results demonstrated that regular long-term resistance monitoring combining with prudent fungicide use should be implemented to prolong the lifespan of tebuconazole in management of ARR in apples.

Optimization of Phlorizin Extraction from Annurca Apple Tree Leaves Using Response Surface Methodology.

Phlorizin is a plant-derived molecule with relevant anti-diabetic activity, making this compound a potential functional component in nutraceutical formulations for the management of glycemia. It is noteworthy that promising sources for the extraction of phlorizin include apple tree leaves, a by-product of apple fruit production. The main aim of this study was to optimize the extraction process of phlorizin from Annurca apple tree leaves (AALs) using response surface methodology (RSM), and to determine the potential nutraceutical application of the obtained extract. The results of the RSM analysis indicate a maximum phlorizin yield of 126.89 ± 7.579 (mg/g DW) obtained under the following optimized conditions: MeOH/H2O, 80:20 + 1% HCOOH as the extraction solvent; 37.7 °C as the extraction temperature; and 170 min as the time of extraction. The HPLC-DAD-HESI-MS/MS analysis performed on the extract obtained under such conditions, named optimized Annurca apple leaves extract (OAALE), led to the identification of twenty-three phenolic molecules, with fifteen of them quantified. To explore the nutraceutical potential of OAALE, the in vitro antioxidant activity was evaluated by DPPH, ABTS, and FRAP assays, resulting in 21.17 ± 2.30, 38.85 ± 0.69, and 34.14 ± 3.8 μmol Trolox equivalent/g of extract, respectively. Moreover, the IC50 of 0.330 mg/mL obtained from the advanced glycation end-product inhibition assay, further supported the antidiabetic potential of OAALE.

Engineering drought-tolerant apple by knocking down six GH3 genes and potential application of transgenic apple as a rootstock.

Drought poses a major threat to apple fruit production and quality. Because of the apple’s long juvenile phase, developing varieties with improved drought tolerance using biotechnology approaches is needed. Here, we used the RNAi approach to knock down six GH3 genes in the apple. Under prolonged drought stress, the MdGH3 RNAi plants performed better than wild-type plants and had stronger root systems, higher root-to-shoot ratio, greater hydraulic conductivity, increased photosynthetic capacity, and increased water use efficiency. Moreover, MdGH3 RNAi plants promoted the drought tolerance of the scion when they were used as rootstock, compared with wild-type and M9-T337 rootstocks. Scions grafted onto MdGH3 RNAi plants showed increased plant height, stem diameter, photosynthetic capacity, specific leaf weight, and water use efficiency. The use of MdGH3 RNAi plants as rootstocks can also increase the C/N ratio of the scion and achieve the same effect as the M9-T337 rootstock in promoting the flowering and fruiting of the scion. Notably, using MdGH3 RNAi plants as rootstocks did not reduce fruit weight and scion quality compared with using M9-T337 rootstock. Our research provides candidate genes and demonstrates a general approach that could be used to improve the drought tolerance of fruit trees without sacrificing the yield and quality of scion fruits.

MdGH3.6 is targeted by MdMYB94 and plays a negative role in apple water-deficit stress tolerance.

Drought significantly limits apple fruit production and quality. Decoding the key genes involved in drought stress tolerance is important for breeding varieties with improved drought resistance. Here, we identified GRETCHEN HAGEN3.6 (GH3.6), an indole-3-acetic acid (IAA) conjugating enzyme, to be a negative regulator of water-deficit stress tolerance in apple. Overexpressing MdGH3.6 reduced IAA content, adventitious root number, root length and water-deficit stress tolerance, whereas knocking down MdGH3.6 and its close paralogs increased IAA content, adventitious root number, root length and water-deficit stress tolerance. Moreover, MdGH3.6 negatively regulated the expression of wax biosynthetic genes under water-deficit stress and thus negatively regulated cuticular wax content. Additionally, MdGH3.6 negatively regulated reactive oxygen species scavengers, including antioxidant enzymes and metabolites involved in the phenylpropanoid and flavonoid pathway in response to water-deficit stress. Further study revealed that the homolog of transcription factor AtMYB94, rather than AtMYB96, could bind to the MdGH3.6 promoter and negatively regulated its expression under water-deficit stress conditions in apple. Overall, our results identify a candidate gene for the improvement of drought resistance in fruit trees.

Intensive apple fruit production in the Caucasian Mountain region

Intensive apple fruit production in the Caucasian Mountain region

Rootstocks with Different Vigor Influenced Scion-Water Relations and Stress Responses in AmbrosiaTM Apple Trees (Malus Domestica var. Ambrosia).

In recent years, awareness has been raised around the benefits of diversifying rootstocks, in order to enhance tree health and sustain apple fruit production under the influence of climate change. However, performances of many rootstocks under stresses remain unclear. This study aimed to set the first step towards a much-needed comprehensive evaluation on water relationships and stress responses of scion–rootstock systems for the popular apple cultivar AmbrosiaTM (Malus domestica var. Ambrosia), because its production and horticultural knowledge had been largely limited to the Malling 9 rootstock (M.9). Five rootstocks were evaluated in a greenhouse water deficit experiment and at the onset of heat stress in a field trial in Summerland, British Columbia, Canada. Multiple stress indicators of leaves and fruits were analyzed to elucidate water use strategies and drought resistance mechanisms. The rootstocks led to differences in scion vigor, and stomatal and photosynthetic characteristics. The largest semi-dwarfing Geneva 202 (G.202) demonstrated more water use and higher stress susceptibility. Large dwarfing Geneva 935 (G.935) and Malling 26 (M.26) showed more stringent stomatal control and reduced water use under stresses, typical of a drought-avoidance strategy. The smallest large dwarfing M.9NIC29® and the small dwarfing Budagovsky 9 (B.9) led to smaller and denser stomata. B.9 demonstrated the most stable water status and drought tolerance. The study suggested that scion stress responses were influenced by rootstock vigor and tree water use strategies. It implied the necessity of vigor-specific irrigation management for alleviating stresses and achieving production goals of different rootstocks.

EVALUATING THE PERFORMANCE OF A SEMI-AUTOMATIC APPLE FRUIT DETECTION IN A HIGH-DENSITY ORCHARD SYSTEM USING LOW-COST DIGITAL RGB IMAGING SENSOR

Abstract: This study investigates the potential use of close-range and low-cost terrestrial RGB imaging sensor for fruit detection in a high-density apple orchard of Fuji Suprema apple fruits (Malus domestica Borkh). The study area is a typical orchard located in a small holder farm in Santa Catarina’s Southern plateau (Brazil). Small holder farms in that state are responsible for more than 50% of Brazil’s apple fruit production. Traditional digital image processing approaches such as RGB color space conversion (e.g., rgb, HSV, CIE L*a*b*, OHTA[I 1 , I 2 , I 3 ]) were applied over several terrestrial RGB images to highlight information presented in the original dataset. Band combinations (e.g., rgb-r, HSV-h, Lab-a, I” 2 , I” 3 ) were also generated as additional parameters (C1, C2 and C3) for the fruit detection. After, optimal image binarization and segmentation, parameters were chosen to detect the fruits efficiently and the results were compared to both visual and in-situ fruit counting. Results show that some bands and combinations allowed hits above 75%, of which the following variables stood out as good predictors: rgb-r, Lab-a, I” 2 , I” 3 , and the combinations C2 and C3. The best band combination resulted from the use of Lab-a band and have identical results of commission, omission, and accuracy, being 5%, 25% and 75%, respectively. Fruit detection rate for Lab-a showed a 0.73 coefficient of determination (R2), and fruit recognition accuracy rate showed 0.96 R2. The proposed approach provides results with great applicability for small holder farms and may support local harvest prediction.

Transcriptome analysis provides insights into the stress response crosstalk in apple (Malus\u2009\xd7\u2009domestica) subjected to drought, cold and high salinity

Drought, cold, and high salinity are three major abiotic stresses effecting apple tree growth and fruit production. Understanding the genetic mechanisms of crosstalk between stress responses signalling networks and identifying the genes involved in apple has potential importance for crop improvement and breeding strategies. Here, the transcriptome profiling analysis of in vitro-grown apple plants subjected to drought, cold and high salinity stress, showed a total of 377 upregulated and 211 downregulated common differentially expressed genes (DEGs) to all 3 stress treatments compared with the control. Gene Ontology (GO) analysis indicated that these common DEGs were enriched in ‘metabolic process’ under the ‘biological process’ category, as well as in ‘binding’ and ‘catalytic activity’ under the ‘molecular function’ category. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that common DEGs were mainly belong to the ‘biological functions’ category and 17 DEGs were identified in ‘environmental information processing’ sub-category which may act as signal transduction components in response crosstalk regulation. Overexpression of 5 upregulated genes individually, out of these 17 common DEGs in apple calli promoted the consistent upregulation of DREB6, CBF1 and ZAT10 and increased the mass weight and antioxidase ability, implying these five common DEGs involved in multiple pathways and improved comprehensive resistance to stress.

Effect of Fruiting and Biennial Bearing Potential on Spur Quality and Leaf Gas Exchange in Apple

Uniform annual apple (Malus ×domestica) fruit production is highly dependent on consistent flower formation from year to year, as inconsistent flowering can lead to the biennial bearing observed in some high-value cultivars. The presence of fruit on a spur has been considered the main cause of the expression of biennial bearing and the inhibition of flower initiation, with a number of theories being introduced to explain the phenomenon. In the current experiment, individual spurs of annual bearing cultivars (Gala, Ruby Jon, and Pink Lady) and biennial bearing cultivars (Honeycrisp, Fuji, and Golden Delicious) were thinned to a single fruit or completely defruited at petal fall. Spurs were sampled at the end of the growing season. Effects of fruiting on spur characteristics such as spur and bourse leaf area, stomatal density, leaf gas exchange, and flower formation were determined. Across all cultivars, the presence of fruit on a spur did not affect spur characteristics or flower formation compared with nonfruiting spurs. Similarly, flowering was unaffected by those factors associated with greater spur carbohydrate status, such as bourse leaf area and assimilation rate. Cultivars with greater transpiration and stomatal conductance (gs) rates had lower rates of flower formation. Future studies should focus on xylem flow and expression of genes regulating flowering and plant growth regulators in annual and biennial bearing cultivars.

An innovative approach to estimate carbon status for improved crop load management in apple

Inconsistent cropping is a major issue in apple fruit production. Consequently, crop load management is critical for growers. Unbalanced crop loads can lead to the establishment of biennial bearing with subsequent high economic losses. An international collaborative project between Australia and Germany was set up to investigate the various aspects of crop load management utilising standard (physiological and molecular) and innovative (image analysis and thinning predictors through modelling) methods. The modelling aspect of the project will investigate a simplified MaluSim model to determine tree carbon status with the aim of providing advice for application of chemical thinners. The focus of the modelling effort will be on early season fruit development as chemical thinners are typically applied up to 80 days after green tip. The first step in evaluating a simplified model is the conversion of key parts of MaluSim into a more flexible format using the software program R. Another aspect of the project is to efficiently measure the physiology of the apple tree through state-of-the-art stereo image reconstruction and improve the accuracy in the carbon balance status. Stereo image reconstruction involves multi-view geometry to detect a number of different variables automatically (including spurs, shoots, flowers, fruit and leaf area) and will considerably reduce manual measurements. This paper will discuss the innovative methods being used and some of the results generated so far.

Target-site mutations (AChE and kdr), and PSMO activity in codling moth (Cydia pomonella (L.) (Lepidoptera: Tortricidae)) populations from Spain

Codling moth, Cydia pomonella (L.) is a key pest of global importance that affects apple fruit production and whose populations have developed resistance to insecticides in many apple production areas. In Spain, enhanced cytochrome P450 polysubstrate monooxygenase (PSMO) activity is the main mechanism involved in insecticide detoxification by codling moth, although acetylcholinesterase (AChE) target site mutations have been described in two populations. However, the extent of AChE and knockdown resistance (kdr) mutations in Spain is unknown. To assess the actual occurrence of AChE and kdr mutations concurrently with the frequency of moths with PSMO enhanced activity (R-PSMO), 32 Spanish field populations from four apple-growing areas of Spain and two susceptible laboratory strains were evaluated. R-PSMO was significantly higher in 23 chemically treated field populations from Extremadura, Catalonia and Aragon, with proportions that varied between 25% and 90%, but no significant differences among strains and the non-chemically treated orchards (organic or abandoned) were observed. The AChE mutation (F290 V) was detected in all field populations from Catalonia (n = 21) and in three field populations from Aragon (n = 5), with resistant phenotype proportions varying from 34.2% to 97.5% and from 7.2% to 65% in Catalonia and Aragon, respectively. In addition, the kdr mutation (L1014F) was detected in twelve Catalonian field populations, at rates of incidence ranging between 2.6% and 56.8%. A positive correlation between R-PSMO and AChE mutation was found. The origin of the mutations and their ability to persist and spread in field populations with different management systems is discussed.

Modern apple fruit production

Modern apple fruit production