Walnut Research Articles

Peer review of the pesticide risk assessment of the active substance aluminium silicate calcined (kaolin calcined).

The conclusions of EFSA following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State Greece and co-rapporteur Member State France for the pesticide active substance aluminium silicate calcined (kaolin calcined) and the considerations as regards the Article 12 MRL review of Regulation (EC) No 396/2005 are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. The conclusions were reached on the basis of the evaluation of the representative uses of aluminium silicate calcined (kaolin calcined) as an insect repellent via broadcast spray application on grapevine, apricot tree, almond tree, cherry tree, hazel tree, walnut tree, peach tree, apple tree, pear tree, quince tree, nashi tree, plum tree, citrus tree, lavender, lavandin and olive tree, as proposed by the applicants. The reliable endpoints, appropriate for use in regulatory risk assessment are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are reported where identified.

Experimental evaluation of the effect of boulders and fines in biodegradable organic materials on the improvement of solar stills

In this research, for the first time, the effect of primary particles (boulders) and secondary particles (fines) in organic mixtures of coffee, black walnut hull, madder, and tea (which are cheap, abundant, and biodegradable) on the improvement of solar stills' daily efficiency is evaluated as an alternative to metal-based nanofluids. A laboratory still simulator is utilised under laboratory conditions to measure the organic mixture's behaviour accurately. Furthermore, the effect of the concentration of organic mixtures and the particle size of organic materials are investigated, as well as the effect of boulders and fines, independently. In addition, two identical solar still systems are used under environmental conditions. The results show that these mixtures increase solar radiation absorption and water production. In most experiments, the maximum amount of produced freshwater belongs to the organic mixtures of the black walnut hull. The highest daily efficiencies of the solar still containing saline water and organic mixtures of black walnut hull and coffee are 44.2% and 40.3%, respectively. Finally, an economic analysis of organic mixtures of black walnut hull and coffee shows that freshwater costs are 0.0107$/L and 0.0112$/L, respectively. Therefore, these organic mixtures seem feasible for solar irradiance absorption and freshwater production.

Mieux

Research Article| November 01 2022 Mieux Oliver Pagani Oliver Pagani Oliver Pagani is a chef and writer focused on the relationship between storytelling and food. He is currently writing a book that marries seasonal recipes with short stories inspired by the history and mythology of the ingredients. Oliver trained under London icons such as Ottolenghi, Bocca Di Lupo, and Dabbous. Search for other works by this author on: This Site PubMed Google Scholar Gastronomica (2022) 22 (4): 93–98. https://doi.org/10.1525/gfc.2022.22.4.93 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation Oliver Pagani; Mieux. Gastronomica 1 November 2022; 22 (4): 93–98. doi: https://doi.org/10.1525/gfc.2022.22.4.93 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentGastronomica Search Those unaccustomed to a nunnery are often overwhelmed upon entering and feel the need to be overly reverential to those who inhabit it rather than directing their reverence to He whom they serve. The men arrived, shuffling in with their caps held low before them. It was also uncommon for us to see the workaday paysans from Oloron enter within our stone walls. We skittered around them and reached for each other’s arms beneath our tunics, subtly, so as not to be noticed and offend. They were here to do what we would not; the grand and ancient walnut tree had stopped yielding fruit, and common practice held that the tree should be beaten to free the new shoots and produce fruits of a finer flavor. The men were speaking to the Abbess. Their leader held his eyes averted from hers, but I saw the others sneaking glances. They had... You do not currently have access to this content.

Identification and Management of Plant Parasitic Nematodes Associated with Walnut (Juglans Regia L.) in Abbottabad

Purpose: Phytonematodes known as the hidden enemies of plants and crops are potential pest of walnut trees in Abbottabad, KP Pakistan. Methods: Soil samples from walnut trees were collected from different localities were processed by using Bearmann funnel techniques. Several nematode species were identified including Meloidogyne incognita, Helicotylenchus dihystera, Psilenchus hilarulus, Tylenchus sp. and Helicotylenchus vulgaris. Findings & Practical implication: Management of plant parasitic nematodes by using castor oil cakes (8kg/tree), cow dung (8 kg/tree) and duck manure (8kg/tree) showed that population was declined after application. Plant growth and yield was also improved. Data plotted in histogram graphs and t-test showed that p values were found significant. Conclusion: The mean and S.D values of initial population, 3 month, 6 month and 12 month for castor oil cakes are 116 ± 1.2, 84 ± 1.0, 60 ± 1.0, 42 ± 0.6, for cow dung 127 ± 5.7, 110 ± 2.4, 87 ± 2.4, 73 ± 1.3 and for duck manure 108 ± 2.4, 92 ± 1.0, 69 ± 0.5, 45 ± 1.0. Keywords: Phytonematodes, walnut, castor oil, cow dung, duck manure.

Morphology and phylogeny of ascomycetes associated with walnut trees (Juglans regia) in Sichuan province, China.

In Sichuan province, walnuts, consisting of Juglans regia, Juglans sigillata, and the hybrid J. regia × J. sigillata, are commercially important edible nuts, and J. regia is the most widespread plant. To date, the diversity and distribution of fungi inhabiting on Juglans have not received enough attention, although there have been studies focusing on pathogens from fruit and stem. In order to update the checklist of fungi associated with Sichuan walnuts, a survey on fungi associated with the three Juglans species from 15 representative regions in Sichuan was conducted. In this article, ten fungi distributed in two classes of Ascomycota (Dothideomycetes and Sordariomycetes) were described based on morpho-molecular analyses, and two novel species, Neofusicoccum sichuanense and Sphaerulina juglandina, a known species of Ophiognomonia leptostyla, and seven new hosts or geographical records of Cladosporium tenuissimum, Diatrypella vulgaris, Helminthosporium juglandinum, Helminthosporium velutinum, Loculosulcatispora hongheensis, Periconia byssoides, and Rhytidhysteron subrufulum were included. Morphological descriptions and illustrations of these fungi are provided.

Phytochemical Screening and Bioactive Properties of Juglans regia L. Pollen.

Pollen is one of the major by-products of the walnut tree, yet it is poorly investigated. Thus, the aim of this study was to investigate the total phenolics, flavonoids, antioxidant, anticancer potential, and polyphenol profile of pollen obtained from male Juglans regia flowers. A total of 24 phenolic compounds were identified in Juglans regia pollen and all of them were reported for the first time for this raw material. The content of polyphenols was 408.03 mg/100 g dry weight (dw) and the most abundant components were quercetin 3-O-sophoroside and 4′,5,7-trihydroxy-3,6-dimethoxyflavone-7-O-beta-D-glucoside. The concentration of these compounds, as well as the total content of polyphenols and flavonoids, strongly determined the antioxidant and cytotoxic activity of Juglans regia pollen. Antioxidant action using the ABTS and CUPRAC methods had the values of 3.35 and 0.32 mmol TE/g dw, respectively. In turn, in the tests of chelating ability of ferrous ion, O2•− and OH− radical scavenging activity, of which the results were expressed as IC50, the values were equal to 335.01, 459.31, and 92.89 µg/mL, respectively. Among the six cancer cell lines, the strongest effect was demonstrated for Caco-2 (140.65 µg/mL) and MCF-7 (140.98 µg/mL) cells. The results provide valuable and previously unpublished data on the polyphenol composition and biological potential of Juglans regia pollen.

Settling Preference of Two Coexisting Aphid Species on the Adaxial and Abaxial Surfaces of Walnut Leaves.

Walnut dusky-veined aphid Panaphis juglandis (Goeze) and walnut green aphid Chromaphis juglandicola (Kaltenbach) cause economic losses and co-occur on walnut trees, but they have separate niche. Panaphis juglandis feeds on the upper (adaxial) surface of leaves while C. juglandicola feeds on the lower (abaxial) surface. Field surveys and controlled experiments in the field and laboratory were conducted to determine microhabitat selection by P. juglandis and C. juglandicola and the factors associated with this behavior. In the field, the two aphid species colonized a leaflet as follows: P. juglandis only, 16.5%; C. juglandicola only, 44.5%; and both species on same leaflet, 39%. C. juglandicola settled on the abaxial surface earlier than P. juglandis settled on the adaxial surface. P. juglandis showed the highest reproduction rate when they were in the erect position on the adaxial surface. C. juglandicola exhibited the highest reproduction rate when they were inverted and on the abaxial surface. Under a light intensity of 50,000 lux, 60.5% of C. juglandicola remained on the illuminated surface, while P. juglandis did not move from the illuminated surface. Through field and laboratory experiments, we found that P. juglandis preferred to settle on the adaxial surface and C. juglandicola preferred to settle on the abaxial surface. Leaf surface, gravity, and light were three physical factors affecting microhabitat selection by the two aphid species but light intensity was the key factor. This information will help to better understand the habitats of two aphid species, which may be helpful for walnut aphids management strategies such as the usage of insecticides option and spraying.

Study of the effect of Estonian and aqueous extract of Persian walnut tree leaf (Juglans regia) on growth indicators in western white shrimp farmed (Litopenaeus vannamei)

Study of the effect of Estonian and aqueous extract of Persian walnut tree leaf (Juglans regia) on growth indicators in western white shrimp farmed (Litopenaeus vannamei)

Crop water use estimation of drip irrigated walnut using ANNs and ANFIS models

Walnut trees, as well as their fruits, represent an important sector of the agricultural industry and their cultivation significantly contributes to the global economy. Irrigation is a key factor in walnut cultivation and the most important problem is related to accurately estimating the need for irrigation water. Walnut water use was estimated in this study through the artificial intelligence methods of Artificial Neural Networks (ANNs) and Adaptive Neuro-Fuzzy Inference System (ANFIS) using meteorological data in western Türkiye, which has semi-arid climatic conditions. Probabilistic scenarios based on maximum, minimum and average temperature, wind speed and sunshine hours over the period 2016-2019 were developed and tested with ANNs and ANFIS models to estimate walnut evapotranspiration. Results indicate that the optimum performance in the training and testing for ANNs and ANFIS models was obtained from the fourth scenario with R = 0.95 and two climate parameters -sunshine duration and mean temperature-. Both ANNs and ANFIS models were able to predict crop water use obtaining high correlation and the minimum number of climatic parameters. Nevertheless, the ANFIS model had a higher predictive capacity, with smaller MSE (0.36 for training and 0.29 for testing) compared to the ANNs model.

4DRoot: Root phenotyping software for temporal 3D scans by X-ray computed tomography.

Currently, plant phenomics is considered the key to reducing the genotype-to-phenotype knowledge gap in plant breeding. In this context, breakthrough imaging technologies have demonstrated high accuracy and reliability. The X-ray computed tomography (CT) technology can noninvasively scan roots in 3D; however, it is urgently required to implement high-throughput phenotyping procedures and analyses to increase the amount of data to measure more complex root phenotypic traits. We have developed a spatial-temporal root architectural modeling software tool based on 4D data from temporal X-ray CT scans. Through a cylinder fitting, we automatically extract significant root architectural traits, distribution, and hierarchy. The open-source software tool is named 4DRoot and implemented in MATLAB. The source code is freely available at https://github.com/TIDOP-USAL/4DRoot. In this research, 3D root scans from the black walnut tree were analyzed, a punctual scan for the spatial study and a weekly time-slot series for the temporal one. 4DRoot provides breeders and root biologists an objective and useful tool to quantify carbon sequestration throw trait extraction. In addition, 4DRoot could help plant breeders to improve plants to meet the food, fuel, and fiber demands in the future, in order to increase crop yield while reducing farming inputs.

Genome-wide association analysis of 101 accessions dissects the genetic basis of shell thickness for genetic improvement in Persian walnut (Juglans regia L.)

BackgroundUnderstanding the underlying genetic mechanisms that drive phenotypic variations is essential for enhancing the efficacy of crop improvement. Persian walnut (Juglans regia L.), which is grown extensively worldwide, is an important economic tree fruit due to its horticultural, medicinal, and material value. The quality of the walnut fruit is related to the selection of traits such as thinner shells, larger filling rates, and better taste, which is very important for breeding in China. The complex quantitative fruit-related traits are influenced by a variety of physiological and environmental factors, which can vary widely between walnut genotypes.ResultsFor this study, a set of 101 Persian walnut accessions were re-sequenced, which generated a total of 906.2 Gb of Illumina sequence data with an average read depth of 13.8× for each accession. We performed the genome-wide association study (GWAS) using 10.9 Mb of high-quality single-nucleotide polymorphisms (SNPs) and 10 agronomic traits to explore the underlying genetic basis of the walnut fruit. Several candidate genes are proposed to be involved in walnut characteristics, including JrPXC1, JrWAKL8, JrGAMYB, and JrFRK1. Specifically, the JrPXC1 gene was confirmed to participate in the regulation of secondary wall cellulose thickening in the walnut shell.ConclusionIn addition to providing considerable available genetic resources for walnut trees, this study revealed the underlying genetic basis involved in important walnut agronomic traits, particularly shell thickness, as well as providing clues for the improvement of genetic breeding and domestication in other perennial economic crops.

Antimicrobial effect of fungal melanin in combination with plant oils for the treatment of wood

Microbial deterioration of wood has gradually destroyed precious historic musical instruments. The Serpentino (English: serpent/little snake) is a wind instrument used for over 400 years and is considered the godfather of modern instruments such as the saxophone and the tuba. Many original instruments have been totally destroyed due to colonization and degradation by bacteria and fungi. Reconstructing the serpent in particular and other ancient instruments in general requires the preservation of wood against bio-deterioration. Conventional chemical preservatives based on copper and boron compounds have been used in the wood processing industry; however, they are not ideal for protecting musical instruments and may pose a negative impact on the health and safety of musicians with direct mouth contact. Non-biocidal preservatives, such as plant oils, have attracted a lot of attention. Herein, we report the antimicrobial efficacy of plant oils, alone and in combination with fungal melanin, for protecting walnut wood that is used to make the serpent, against oral bacteria and wood-decay fungi. Linseed and tea tree oils were found to have a strong antibacterial effect, reducing the survival rate of Streptococcus mutans, a bacterium commonly found in human saliva, to below 1%. Impregnation of wood with plant oils and melanin significantly increased the antibacterial effect when compared to that of the oil(s) alone. A satisfactory antifungal effect was also achieved after 2 weeks as indicated by a reduction (<10%) in the survival rate of Chaetomium globosum on the radial longitudinal wood surface. In addition, the treated wood samples absorbed less water than the untreated wood, and maintained their dimensions at different humidity conditions, highlighting the potential of this approach for wood protection.

Transcriptome-wide identification of walnut PP2C family genes in response to external stimulus

Walnut is an important economic tree species while confronting with global environmental stress, resulting in decline in quality and yield. Therefore, it is urgent to elucidate the molecular mechanism for the regulation of walnut response to adversity. The protein phosphatase 2C (PP2C) gene family participates in cellular processes in eukaryotes through reversible phosphorylation of proteins and signal transduction regulation. However, the stress response function of PP2C genes was far to be clarified. Therefore, to understand the stress response mechanism of walnut tree, in this study, a total of 41 PP2C genes with complete ORFs were identified from Juglans regia, whose basic bio-information and expression patterns in response to multiple stresses and ABA were confirmed. The results showed that the ORFs of JrPP2Cs were 495 ~ 3231 bp in length, the predicted JrPP2C proteins contained 164 to 1076 amino acids and the molecular weights were 18,581.96 ~ 118,853.34 Da, the pI was 4.55 ~ 9.58. These JrPP2C genes were unevenly distributed on 14 chromosomes, among which Chr11 and Chr13 contained the most genes. Phylogenetic analysis found that these JrPP2C proteins were classed into 9 subfamilies, among which group F covered most JrPP2Cs. The JrPP2Cs in the same subfamily exhibited similarities in the composition of conserved domains, amino acid sequences of motifs and exon/intron organization in DNA sequences. Each JrPP2C includes 4 ~ 10 motifs and each motif contained 15 ~ 37 amino acids. Among the motifs, motif1, motif2, motif3 and motif8 were most abundant. Most of the JrPP2C genes diversely response to osmotic, cadmium, and Colletotrichum gloeosporioide stress as well as ABA treatments, among which JrPP2C28, JrPP2C17, JrPP2C09, JrPP2C36 were more obvious and deserves further attention. All these results indicated that JrPP2C genes play potential vital roles in plant response to multiple stimulus, and are possibly involved in ABA-dependent signaling pathway.

The cold-stress responsive gene DREB1A involved in low-temperature tolerance in Xinjiang wild walnut.

BackgroundLow-temperatures have the potential to be a serious problem for plants and can negatively affect the normal growth and development of walnuts. DREB1/CBF (Dehydration Responsive Element Binding Protein 1/C-repeat Binding Factor), one of the most direct transcription factors in response to low-temperature stress, may improve the resistance of plants to low-temperatures by regulating their functional genes. However, few studies have been conducted in walnut. The Xinjiang wild walnut is a rare wild plant found in China, with a large number of excellent trait genes, and is hardier than cultivated walnuts in Xinjiang.MethodsIn this work, we identified all of the DREB1 members from the walnut genome and analyzed their expression levels in different tissues and during low-temperature stress on the Xinjiang wild walnut. The JfDREB1A gene of the Xinjiang wild walnut was cloned and transformed into Arabidopsis thaliana for functional verification.ResultsThere were five DREB1 transcription factors in the walnut genome. Among them, the relative expression level of the DREB1A gene was significantly higher than other members in the different tissues (root, stem, leaf) and was immediately un-regulated under low-temperature stress. The overexpression of the JfDREB1A gene increased the survival rates of transgenic Arabidopsis lines, mainly through maintaining the stability of cell membrane, decreasing the electrical conductivity and increasing the activities of antioxidant enzymes including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). Additionally, the expression levels of cold-inducible genes like AtKIN1, AtERD10, AtRD29A, AtCOR15A and AtCOR47, were significantly increased. These results showed that the JfDREB1A gene may play an important role in the response to cold stress of the Xinjiang wild walnut. This study contributes to our understanding of the molecular mechanism of the Xinjiang wild walnut’s response to low-temperature stress and will be beneficial for developing walnut cultivars with improved cold resistance.

Phenological, morphological and physiological drivers of cereal grain yield in Mediterranean agroforestry systems

Climate change will pose a major threat to food supply worldwide. Agroforestry has been proposed as an effective approach to minimize its effects on crops. However, to design sustainable and productive agroforestry systems, net responses of crops to trees need to be clarified, particularly in regions where competitive interactions will outweigh facilitative ones. The study of plant traits has become a useful approach to select best-adapted plants, yet the sensitivity of yield components to agroforestry and their relationship with plant traits needs investigation. In this experiment, we assess the phenological, morphological and physiological responses of shade-adapted cultivars of winter wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.), growing in an agroforestry system (AF) with walnut trees (Juglans x intermedia Mj209xRa), as compared to cereal monocrops (MC). Agroforestry reduced the light intercepted by crops by 58 %, buffered extreme temperatures at the crop canopy level and increased air relative humidity, advancing plant development for wheat and barley. Major tree effects on crops were observed after walnut budburst. Under trees, crops increased the relative water content (RWC), Photochemical Reflectance Index (PRI) and P content of both wheat and barley leaves, increased Normalized Difference Vegetation Index (NDVI) of barley leaves, and reduced leaf mass area (LMA) in wheat and cell membrane damage in both species. In agroforestry, crops also reduced plant growth, leaf area (LA), leaf area index (LAI) and grain yield in both wheat and barley. Drivers of grain yield differed among agroforestry and open conditions in both species, showing for the first time that the selection of cereal cultivars for specific conditions could be based on plant traits, along with the shade tolerance, to establish successful agroforestry systems.

Phylogeography of walnut pest Atrijuglans hetaohei (Lepidoptera: Gelechioidea) reveals comprehensive influence of geographic barriers and human activities

• The phylogeography of walnut pest Atrijuglans hetaohei were firstly investigated. • The evolutionary patterns of A . hetaohei coincided with its plant hosts walnut trees. • Physical barriers and human activities comprehensively affected its distribution. • A . hetaohei experienced twice population expansion 4000 years ago. Phylogeographic patterns of some extant species have been well documented; however, the evolutionary patterns of plant pests were poorly understood. This study investigated the evolutionary patterns and historical demography of Atrijuglans hetaohei using mitochondrial DNA ( cox1 and cox2 ) and nuclear EF - 1α . Networks and other statistical analyses concordantly revealed four genetic lineages (L1-L4), indicating varying influences of mountains and rivers. Two shared ancestral haplotypes and strong gene flow in refugia (Mt. Qinling and Daba Shan) indicated that the evolutionary patterns of A . hetaohei coincided with its plant hosts, and A . hetaohei experienced long-term vicariance and secondary contact in these areas. The demographic analysis (EBSP) clearly showed that A . hetaohei underwent two sustained population expansions 4000 years ago, and its population size was affected by the size and quality of its plant hosts resulting from human agricultural activities. All the evidence suggests that physical barriers (mountains and rivers) and human agricultural activities have affected this insect’s population structure and distribution to varying degrees. Together, our study contributes to a growing understanding of the origin and population structure of A . hetaohei and provides an important framework for exploring the evolution patterns of the pest and its hosts.

Effects of brassinosteroids on walnut trees fruit set, nut weight and pollen germination

Effects of brassinosteroids on walnut trees fruit set, nut weight and pollen germination

3D-Printed PCL Scaffolds Combined with Juglone for Skin Tissue Engineering

Skin diseases are commonly treated with antihistamines, antibiotics, laser therapy, topical medications, local vitamins, or steroids. Since conventional treatments for wound healing (skin allografts, amnion, xenografts, etc.) have disadvantages such as antigenicity of the donor tissue, risk of infection, or lack of basement membrane, skin tissue engineering has become a popular new approach. The current study presents the design and fabrication of a new wound-dressing material by the addition of Juglone (5-hydroxy-1,4-naphthoquinone) to a 25% Polycaprolactone (PCL) scaffold. Juglone (J) is a significant allelochemical found in walnut trees and, in this study is used as a bioactive material. The effects of different amounts of J (1.25, 2.5, 5, 7.5, and 10 mg) on the biocompatibility, mechanical, chemical, thermal, morphological, and antimicrobial properties of the 3D-printed 25% PCL scaffolds were investigated. The addition of J increased the pore diameter of the 25% PCL scaffold. The maximum pore size (290.72 ± 14 µm) was observed for the highest amount of J (10 mg). The biocompatibility tests on the scaffolds demonstrated biocompatible behavior from the first day of incubation, the 25% PCL/7.5 J scaffold having the highest viability value (118%) among all of the J-loaded scaffolds. Drug release of J into phosphate buffered saline (PBS) at pH 7.4 showed that J was completely released from all 25% PCL/J scaffolds within 7 days of incubation.

Genome-Wide Identification and Characterization of YABBY Gene Family in Juglans regia and Juglans mandshurica

The YABBY gene family is a plant transcription factor that exists in all seed plants. YABBY family members have been studied extensively in various plants and were to play significant roles in plant growth and development. Juglans, especially walnuts, are important economic tree species that are widely distributed worldwide. However, the identification and related research of YABBY in Juglans have not been reported to date. In this study, we identified 19 YABBY genes from two Juglans species, namely, J. regia and J. mandshurica. Ten JrYABBY genes and nine JmYABBY genes were divided into five subfamilies (YAB1/3, YAB2, INO, CRC, and YAB5). Sequence analysis revealed that all encoded YABBY protein sequences had a highly conserved YABBY and C2C2 zinc-finger domains. An analysis of the assumed cis-acting elements revealed that JrYABBY and JmYABBY genes were deeply involved in phytohormone and light responses. Further, gene expression pattern analysis suggested that most walnut YABBY genes were likely involved in peel and flower development and responses to biotic stress. This study not only suppled novel insights into the evolutionary basis of YABBY gene families in Juglans, but also provided clues for the further functional verification and investigation of YABBY genes in other tree species.

Total Soluble Sugars in Root and Stem of Wichita and Western Carya Illinoinensis Varieties in Northern Mexico

Abstract The aim of the current study was to determine the monthly total soluble sugar concentration in the stem and root of the Wichita and Western walnut (Carya illinoinensis) varieties during a productive cycle in northern Mexico. Vegetable samples were obtained using a systematic sampling method, and processed by means of a spectrophotometric assay to determine the total soluble sugars (TSS) concentration in productive walnut trees. Data analysis was performed by means of a 2-way ANOVA. The results of the TSS concentration had differences throughout the months of an annual productive cycle, and were also different between the evaluated walnut varieties. The highest total soluble sugar concentration in stem and root were in the lowest temperature months, and it decreases in both tissues when the environmental temperature rises. The Wichita variety had a higher total soluble sugar concentration than the Western in every month during the productive cycle. Further research is required to assess the effect of other type of factors including environmental or agronomic over the dynamics of the total soluble sugars in productive walnut trees.