Search Results (9)

This study evaluated the effect of soil and foliar fertilization with nitrogen (N), molybdenum (Mo), zinc (Zn), and their combination (Zn-Mo) on nutrition, enzymatic activity, photosynthetic pigments, and productive parameters in the Western Schley pecan tree. An orthogonal Taguchi L16 design was used with differentiated soil and foliar nitrate concentrations, reaching an average of 1557.7 mg kg⁻¹, and increasing up to 1907 mg kg⁻¹ depending on the fertilization dose. Nitrate reductase activity (NRNO₃⁻) significantly increased with N and Mo applications, reaching a maximum of 13.62 µmol. Among photosynthetic pigments, chlorophyll a was the only variable with a significant response, highlighting the role of Mo in its enhancement. Positive effects were also observed on pomological traits such as yield (up to 425 kg ha⁻¹), nut weight, and kernel percentage with increased doses of N and Mo. In conclusion, combined fertilization improved the nutritional status, physiological responses, and productivity of pecan trees, emphasizing the importance of balanced nutrient management to avoid nutritional antagonisms and to optimize both yield and fruit quality. Full article

Pecan is an important nut crop in the United States. It is native to North America and dominantly produced in the southern states in the US. Nitrogen and zinc are two of the most critical nutrients for pecan production. This review provides a comprehensive overview of nitrogen and zinc fertilizer management in pecan orchards, covering key topics such as nitrogen sources, nitrogen application rates, the timing of nitrogen application, nitrogen application of damaged trees, the impact of zinc deficiency, and methods for zinc application. The deficiency of these nutrients causes severe loss in pecan production. However, the cost involving nutrient application and post the effect of excessive application on the soil and environment is of serious discussion. This review summarizes nitrogen and zinc management strategy and explores application methods that can reduce the cost of fertilizer with minimal adverse effect on the soil and environment. Also, this review sheds light on the areas that needs extensive research in nutrient management in pecan production. Full article

Pecan (Carya illinoensis) nuts are delicious and rich in unsaturated fatty acids, which are beneficial for human health. Their yield is closely related to several factors, such as the ratio of female and male flowers. We sampled and paraffin-sectioned female and male flower buds for one year and determined the stages of initial flower bud differentiation, floral primordium formation, and pistil and stamen primordium formation. We then performed transcriptome sequencing on these stages. Our data analysis suggested that FLOWERING LOCUS T (FT) and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 play a role in flower bud differentiation. J3 was highly expressed in the early stage of female flower buds and may play a role in regulating flower bud differentiation and flowering time. Genes such as NF-YA1 and STM were expressed during male flower bud development. NF-YA1 belongs to the NF-Y transcription factor family and may initiate downstream events leading to floral transformation. STM promoted the transformation of leaf buds to flower buds. AP2 may have been involved in the establishment of floral meristem characteristics and the determination of floral organ characteristics. Our results lay a foundation for the control and subsequent regulation of female and male flower bud differentiation and yield improvement. Full article

Walnut tree (Carya illinoensis (Wangenh.) K. Koch) is a plant species showing ecological, social, and economic importance in México. The objective was to determine biomass productivity and to characterize the raw material and biomass briquettes obtained from walnut thinning pruning. The variables evaluated were tree total height (TH), fresh biomass (FB) and dry biomass (DB) per hectare (kg ha⁻¹). Briquettes were made by using the biomass obtained in both orchards. Laboratory tests for original biomass included moisture content (MC), ash content (AC), volatile matter (VM) and fixed carbon (FC), as well as high heating value (HHV). Briquette studies also included diameter (D), weight (W), length (L), volume (V), density (Ds), and HHV. The data were analyzed by using descriptive statistics and analysis of variance (ANOVA) under a completely randomized design with factorial arrangement. Thinning pruning in walnut orchards provides 12 kg tree⁻¹ (998 kg ha⁻¹) of dry biomass, with acceptable levels of AC ≤ 5%, FC (75 to 76%), VM (18.7 to 19.7%) and HHV (16.2 to 16.7 MJ kg⁻¹). The briquette international quality standards were fulfilled: MC≤ 10%, AC ≤ 5% and HHV > 18 MJ kg⁻¹. The integrated use of walnut residues reduces the management problems registered during nut production and the sustainable options to generate bioenergy will be expanded. Full article

The Gly-Asp-Ser-Leu (GDSL)-lipase family is a large subfamily of lipolytic enzymes that plays an important role in plant growth and defense against environmental stress. However, little is known about their function in pecans (Carya illinoensis K. Koch). In this study, 87 CilGDSLs were identified and divided into 2 groups and 12 subgroups using phylogenetic analysis; members of the same sub-branch had conserved gene structure and motif composition. The majority of the genes had four introns and were composed of an α-helix and a β-strand. Subcellular localization analysis revealed that these genes were localized in the extracellular matrix, chloroplasts, cytoplasm, nucleus, vacuole, and endoplasmic reticulum, and were validated by transient expression in tobacco mesophyll cells. Furthermore, the analysis of the promoter cis-elements for the CilGDSLs revealed the presence of plant anaerobic induction regulatory, abscisic acid response, light response elements, jasmonic acid (JA) response elements, etc. The qRT-PCR analysis results in “Pawnee” with salt treatment showed that the CilGDSL42.93 (leaf) and CilGDSL39.88 (root) were highly expressed in different tissues. After salt stress treatment, isobaric tags for relative and absolute quantitation (iTRAQ) analysis revealed the presence of a total of ten GDSL proteins. Moreover, the weighted gene co-expression network analysis (WGCNA) showed that one set of co-expressed genes (module), primarily CilGDSL41.11, CilGDSL39.49, CilGDSL34.85, and CilGDSL41.01, was significantly associated with salt stress in leaf. In short, some of them were shown to be involved in plant defense against salt stress in this study. Full article

As woody oil crop, pecan [Carya illinoinensis (Wangenh.) K. Koch] may be a solution to the shortage of edible oil in the future. In this study, fruit traits, kernel nutrition and fatty acid composition of 10 pecan varieties were determined to assess the potential of pecans for exploitation as edible oil, as well as to further screen varieties that could be used as edible oil resources and to understand their development prospects for cultivation in mountainous hills. The study showed that all the fruit trait indicators measured, including green-fruit weight (mean 28.47 g), nut weight (10.33 g), kernel weight (5.25 g), nut percentage (36.83%) and kernel percentage (50.50%), showed highly significant differences among the 10 varieties. Among the main nutritional indicators of the kernels, the crude fat content was stable (mean 70.01%) with non-significant differences, while protein (67.50 mg·g⁻¹), soluble sugar (10.7 mg·g⁻¹) and tannin (6.07 mg·g⁻¹) showed highly significant differences between varieties. The oil percentage of nuts (kernel percentage * crude fat) averaged 35.36%, with highly significant differences between varieties. The fatty acid composition was dominated by unsaturated fatty acids (mean 91.82%), with unsaturated fatty acids being 11.24 times more abundant than saturated fatty acids. Among the monounsaturated fatty acids, oleic acid was the highest (mean 70.02%), with highly significant differences between varieties, followed by cis-11-eicosanoic acid (0.25%), with non-significant differences between varieties; among the polyunsaturated fatty acids, linoleic acid was the highest (19.58%), followed by linolenic acid (0.97%), both of which showed highly significant differences between varieties; monounsaturated fatty acids were 2.42 times more abundant than polyunsaturated fatty acids. Compared to other oilseed crops, pecan has the potential to produce “nutritious, healthy and stable” edible oil, while its wide habitat and good productivity benefits offer broad prospects for development in the hills and mountains of subtropical China. Full article

Pecan nut (Carya illinoensis) pericarp is usually considered as a waste, with no or low value applications. Its potential as a densified solid biofuel has been evaluated, searching for alternatives to generating quality renewable energy and reducing polluting emissions in the atmosphere, based on particle size, that is an important feedstock property. Therefore, agro-industrial residues from the pecan nut harvest were collected, milled and sieved to four different granulometry: 1.6 mm (N° 12), 0.84 mm (N° 20), 0.42 mm (N° 40), and 0.25 mm (N° 60), used as raw material for biofuel briquette production. The carbon and oxygen functional groups in the base material were investigated by Fourier transform infrared spectroscopy (FTIR) and proximate analyses were performed following international standards, for determining the moisture content, volatile materials, fixed carbon, ash content, and calorific value. For the biofuel briquettes made from base material of different particle sizes, the physical characteristics (density, hardness, swelling, and impact resistance index) and energy potential (calorific value) were determined to define their quality as a biofuel. The physical transformation of the pecan pericarp wastes into briquettes improved its quality as a solid biofuel, with calorific values from around 17.00 MJ/kg for the base material to around 18.00 MJ/kg for briquettes, regardless of particle size. Briquettes from sieve number 40 had the highest density (1.25 g/cm³). Briquettes from sieve number 60 (finest particles) presented the greater hardness (99.85). The greatest susceptibility to swelling (0.31) was registered for briquettes with the largest particle size (sieve number 20). The IRI was 200 for all treatments. Full article

Arbuscular mycorrhizal fungi (AMF) play an important role in the establishment and maintenance of plant communities in forest ecosystems. Most previous studies about AMF have been conducted in natural forests, and little attention has been paid to trees in planted forests. This study investigated AMF associated with tree species and the relationships between edaphic factors and AMF communities in a planted forest of eastern China. We found high total AMF colonization rates in the roots of Carya illinoensis (Wangenh.) K. Koch, Zelkova serrata (Thunb.) Makinoz, Taxodium ‘zhongshansha’, Eucommia ulmoides Oliv., and Elaeagnus pungens Thunb., ranging from 62.07% to 100%, indicating that AMF can establish effective symbiotic relationships with these tree species. The AMF colonization rate was significantly and negatively correlated with soil phosphorus, while AMF colonization intensity was significantly and negatively correlated with soil moisture content, total carbon, and organic matter content. Spore density was in the range of 4.38 to 76.38 spores per g soil. In total, 35 AMF species from 10 genera were identified. Glomus and Acaulospora were the dominant genera. Acaulospora foveata and Septoglomus constrictum were the dominant species. AMF communities differed among the tree species and were closely related to edaphic factors, and AMF diversity was significantly related to soil carbon and pH. Our results revealed the colonization, community, and diversity of AMF associated with tree species, as well as their relationships with edaphic factors, in planted forests. Our findings can be used to provide insight on the utilization and management of AMF to maintain sustainable management of planted forests. Full article

Evidence from observational and intervention studies has shown a high intake of tree nuts is associated with a reduced risk of cardiovascular disease (CVD), mortality from type 2 diabetes (T2DM), and all-cause mortality. However, there is limited data regarding their effects on indicators of cardiometabolic risk other than hypercholesterolemia, and little is known about the demonstrable health benefits of pecans (Carya illinoensis (Wangenh.) K.Koch). We conducted a randomized, controlled feeding trial to compare the effects of a pecan-rich diet with an isocaloric control diet similar in total fat and fiber content, but absent nuts, on biomarkers related to CVD and T2DM risk in healthy middle-aged and older adults who are overweight or obese with central adiposity. After 4 weeks on a pecan-rich diet, changes in serum insulin, insulin resistance (HOMA-IR) and beta cell function (HOMA-β) were significantly greater than after the control diet (p < 0.05). Pecan consumption also lowered the risk of cardiometabolic disease as indicated by a composite score reflecting changes in clinically relevant markers. Thus, compared to the control diet, the pecan intervention had a concurrent and clinically significant effect on several relevant markers of cardiometabolic risk. Full article