Pecan Research Articles

Supplemental Nickel Corrects Mouse Ear Disorder of Bitternut Hickory

Abstract While sought after for use in managed landscapes, bitternut hickory [Carya cordiformis (Wang.) K. Koch] remains underutilized in horticulture due its reputation for difficulty with production and transplanting. After learning of issues experienced by growers and observing deformed leaf development of container-grown stock, we examined effects of supplemental nickel applications on seedlings of bitternut hickory. We hypothesized that, like the closely related species pecan [Carya illinoinensis (Wang.) K. Koch], bitternut hickory would be similarly limited in production by a susceptibility to mouse ear disorder as a function of nickel deficiency. Seedlings cultivated with a soilless substrate in 3.8L (#1) nursery pots were treated with either a substrate drench or foliar spray of Nickel Plus® two weeks after budbreak. After 30 days, plants treated with a drench or foliar spray exhibited increased leaf area and decreased number of leaves per unit shoot extension and leaf greenness compared to nontreated controls. Foliar treatments resulted in an 83.5% increase in shoot extension over nontreated controls. Whereas seedlings provided supplemental nickel displayed healthy foliage after treatment, nontreated seedlings exhibited traditional symptoms of mouse ear disorder. These data indicate bitternut hickory is susceptible to mouse ear disorder, an issue remedied by supplementing nickel. Index words: foliar spray, substrate drench, soilless substrate, nursery production, ornamental plants. Chemicals used in this study: nickel lignosulfonate (Nickel Plus®). Species used in this study: bitternut hickory, Carya cordiformis (Wang.) K. Koch

Pecan (Carya illinoinensis) and Dairy Waste Stream Utilization: Properties and Economics of On-Farm Windrow Systems

Improper management of organic waste can lead to unnecessary carbon dioxide and methane emissions, and groundwater contamination. In this study, organic waste materials from two of New Mexico’s (U.S.A.) top agricultural industries, pecan (Carya illinoinensis) and dairy cattle dairy manure, were used to evaluate the feasibility of an on-farm compost program. Pecan woody residues (P) served as the primary carbon source; regional cattle dairy manure (M) served as the primary nitrogen source. Additional (A) inputs from a compost consulting company (PM/A) and green waste from community landscaping and on-farm harvested legumes (PMG/A) were employed, both of which required additional labor and material inputs. Finished composts were analyzed for selected macro, secondary and micronutrients, pH, sodium adsorption ratio (SAR), electrical conductivity (EC), total carbon (TC) and organic matter (OM) content, bulk density (bd), and microbial biomass. The PM alone treatment showed similar or significantly higher amounts of macro, secondary and micronutrients compared to the PM/A and PMG/A treatments. Total microbial biomass and total salinity were highest for the PM treatment. The total cost of the PM treatment was around 1/6 of the cost of the lowest-cost addition compost production scheme, indicating that simpler, lower-input production methods may be more advantageous for on-farm compost program development.

Soil Type Influences Rhizosphere Bacterial Community Assemblies of Pecan Plantations, a Case Study of Eastern China

The rhizosphere microbiome is closely related to forest health and productivity. However, whether soil type affects pecan (Carya illinoinensis) rhizosphere microbiomes is unclear. We aimed to explore the diversity and structural characteristics of rhizosphere bacteria associated with pecan plantations grown in three soil types (Luvisols, Cambisols, Solonchaks) in Eastern China and analyze their potential functions through high-throughput sequencing. The results showed that the diversity and community structure of rhizosphere bacteria in pecan plantations were significantly affected by soil type and the pH, available phosphorus content, electrical conductivity, soil moisture, and ammonium nitrogen contents were the main factors. At the phylum level, the rhizosphere bacterial community composition was consistent, mainly included Actinobacteria, Proteobacteria, Acidobacteria, and Chloroflexi. At the family level, the pecan plantations formed different rhizosphere enriched biomarkers due to the influence of soil type, with functional characteristics such as plant growth promotion and soil nutrient cycling. In addition, there existed low abundance core species such as Haliangiaceae, Bryobacteraceae, and Steroidobacteraceae. They played important roles in the rhizosphere environments through their functional characteristics and community linkages. Overall, this study provides a basis for the study of the rhizosphere microbiome in different soil types of pecan plantations, and plays an important role in the sustainable management of forest soil.

Comparing the effect of different irrigation water scenarios on arid region pecan orchard using a system dynamics approach

Water scarcity and soil salinization in arid regions have made desalination a competitive alternative source for irrigation. Perceptions of a higher cost and other misconceptions about desalinated water have limited its broader usage in agriculture. In this study, we have focused on understanding the suitability of using desalinated water as a substitute for saline water in the pecan (Carya illinoinensis) orchards of southwest Texas. Pecan is a perennial high-value nut crop that cannot be easily replaced. Therefore, it represents a perfect case study for the application of desalinated water. A recently developed system dynamic model, SMITUV (System Dynamic Modeling of Infiltration, Solute Transport, and Root Water Uptake in Vadose Zone), was modified to assess the effects of irrigation with desalinated water when soil-water salt content increased above pecan tolerance levels. This model simulated five irrigation scenarios with different fractions of river water and saline groundwater. As expected, to sustain the same level of pecan production, a higher amount of desalinated water was needed with increasing amounts of groundwater in the irrigation mix. Soil texture had a significant influence on the amount of desalinated water required. For sandy and silty soils, the 100% river water scenario required no additional desalinated water. Clayey soils could not sustain high production even in a 100% river water scenario. An economic analysis showed that pecan operations might be viable in non-clayey regions for some irrigation mixture even after factoring in the cost of using desalinated water. However, current desalination techniques and associated costs were economically unviable for sustaining pecan in regions with saline groundwater and clayey soils. This study also demonstrated the application of SMITUV and system dynamic modeling as a decision-making tool to assist growers in understanding the farm-scale applicability of desalinated water.

Physicochemical Characteristics of Biofuel Briquettes Made from Pecan (Carya illinoensis) Pericarp Wastes of Different Particle Sizes.

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.

Development of an innovative nougat from honey, blueberries, and pecan nuts

A nougat filling formulation sweetened with honey was optimized using a two-factor design with three levels (3%, 5%, and 7%) for pecans and blueberry powder. Chromatic parameters, water activity, moisture content, and mechanical properties were analyzed using response surface models. According to global desirability criterion, the optimum nougat filling contained 5% pecans and 7% blueberries powder, and it was characterized by: 0.622 N (cutting force), −0.037 N/mm (adhesiveness), 1.03 (elasticity), 0.886 (cohesiveness), 0.664 (water activity), and 18.3% (humidity). Then, the optimum filling was employed to develop a nougat snack, and its storage stability was followed for 35 days. At 25°C the nougat retained its quality properties while at 35°C the fracture stress decreased 3.6 times. Sensory analysis showed very high consumers' interest in the nougat. The results suggest that the product could have a high potential to be launched into the market. Novelty impact statement The novelty of this work stands on the development of a new type of confectionery product following the actual trends to pursue a healthier diet, by increasing fruits and nuts consumption. In this sense, a nougat containing blueberries and pecan nuts was developed, and a sugar/syrup replacement strategy was applied, by using honey as a sweetener in order to attain a sensory acceptable product. Finally, this alternative snack with interesting nutritive input may also be developed from sub-standard blueberries and pecan nuts, adding value to these products.

Genetic Diversity Revealed by Microsatellites in Genus Carya

The genus Carya consists of 17 species divided into 3 sections: Carya or the true hickories, Apocarya or the pecan hickories, and Sinocarya or the Asian hickories. Interspecific hybrids exist and have been used in pecan cultivar development. Nuclear and plastid microsatellite or SSR markers have been useful in distinguishing species, sections, and populations. They provide evidence for hybridity between species and can confirm heredity within crosses. As more sophisticated methods of genomic evaluation are cooperatively developed for use in pecan breeding and selection, the use of these methods will be supplemented and informed by the lessons provided by microsatellite markers, as interpreted across broad germplasm collections. In this study, over 400 Carya accessions from diverse diploid and tetraploid taxa and their interspecific hybrids, maintained at the USDA National Collection of Genetic Resources for Carya (NCGR-Carya), were analyzed using 14 nuclear and 3 plastid microsatellite markers. Principal coordinate analysis showed clear taxonomic classifications at multiple taxonomic levels along with patterns of interspecific hybridity. Evidence was also found for genetic differences associated with geographic distribution. The results indicate that this group of markers is useful in examining and characterizing populations and hybrids in the genus Carya and may help delineate the composition of a core collection to help characterize the NCGR-Carya repository collection for use in its pecan breeding program. The SSR fingerprints of the inventories of the USDA NCGR-Carya repository can also be used as a reference for identifying unknown pecan trees for growers.

A comparative evaluation of physicochemical properties of pecan (Carya illinoinensis (Wangenh.) K. Koch) husk by different drying method

A comparative evaluation of physicochemical properties of pecan (Carya illinoinensis (Wangenh.) K. Koch) husk by different drying method

Effect of thermal annealing and filler ball-milling on the properties of highly filled polylactic acid/pecan nutshell biocomposites

Biodegradable polymer composites reinforced with agri-food lignocellulosic biowaste represent cost-effective and sustainable materials potentially able to replace traditional composites for structural, household, and packaging applications. Herein, the preparation of polylactic acid (PLA)/pecan (Carya illinoinensis) nutshell (PNS) biocomposites at high filler loading (50 wt%) is reported, alongside the effect of two environmentally friendly physical treatments, namely ball-milling of the filler and thermal annealing on biocomposites.PNS enhanced the thermal stability, the viscoelastic response, and the crystallinity of the polymer. Furthermore, filler ball-milling also increased the melt fluidity of the biocomposites, potentially improving melt processing. Finally, the presence of PNS remarkably enhanced the effect of thermal annealing in the compounds. In particular, heat deflection temperature of the biocomposites dramatically increased, up to 60 °C with respect to the non-annealed samples. Overall, these results emphasize the potential of combining natural fillers and environmentally benign physical treatments to tailor the properties of PLA biocomposites, especially for those applications which require a stiff and lightweight material with low deformability.

FUNGOS DA FAMÍLIA BOTRYOSPHAERIACEAE CAUSAM DIFERENTES NÍVEIS DE CANCRO DO TRONCO EM POMARES DE PECAN (Carya illinoinensis) NO BRASIL

ABSTRACT Pecan tree [Carya illinoinensis (Wangenh.) K. Koch] is a widespread species in the southern region of Brazil and commercially important for nut and wood production. Stem cankers in pecan trees negatively impact the orchard, but the biotic causes of cankers are usually not identified. Symptoms of stem canker were observed in about 60% of pecan trees from orchards in the states of Rio Grande do Sul and Paraná. Therefore, this study aimed to analyze the molecular and morphophysiological characteristics of fungi associated with pecan canker in orchards in southern Brazil and to confirm their pathogenicity in pecan seedlings. Samples from symptomatic stems were collected in different municipalities and possible causal agents were isolated. Molecular identification was performed by the Polymerase Chain Reaction technique for amplification of the EF-1α region and subsequent sequencing. The sequencing, followed by morphophysiological aspects of mycelial growth and colony pigmentation, allowed the identification of a species complex included in the Botryosphaeriaceae family. The isolates were classified as Lasiodiplodia theobromae, Pseudofusicoccum kimberleyense and Neofusicoccum parvum. Pathogenicity was tested by inoculating the isolates into pecan seedlings to evaluate the symptoms. All isolates caused canker in the stem, but there was variation in the severity. Therefore, different species of the Botryosphaeriaceae family are responsible for stem canker occurrence in pecan trees in the southern region of Brazil, but at different levels of injury. Thus, it is crucial to identify and understand the behavior of the fungal isolates to best control cankers in pecan orchards.

Cloning and Bioinformatics Analysis of Genes Related to Key Enzymes in Oil Metabolism of <i>Carya illinoensis</i> (Wangech) K Koch

Taking mixed sample of 115 d and 135 d  Carya illinoinensis  ‘Pawnee’ as experimental materials, after RT-PCR amplification, cloning and sequencing, the gene sequences of  CiSAD  gene,  CiFAD2  gene and  CiGPAT  gene related to the key enzymes of oil metabolism in  Carya   illinoinensis  were obtained, and bioinformatics analysis was carried out. The length of  CiSAD  gene was 1 240 bp, containing a complete open reading frame (ORF) of 1 194 bp, encoding 397 amino acids.  CiFAD2  was   1 329 bp, containing an ORF of 1 155 bp, encoding 384 amino acids.  CiGPAT  was   1 671 bp, containing an ORF of 1 626 bp, encoding 541 amino acids. All proteins encoded by the cloned genes have corresponding domains, indicating that the proteins encoded by these genes should have corresponding functions in organisms.

Bending quality of three Brazilian hardwoods modified by different hydrothermal treatments

Background: Boiling, steaming, and microwave radiation treatments were used for softening and then manufacturing curved samples using three Brazilian hardwoods. Solid wood samples from Carya illinoinensis, Luehea divaricata and Platanus x acerifolia were characterized for bending quality, bending defects, minimum radius of bending, spring-back and moisture content. Results: Among the studied woods, Carya illinoinensis wood was the most suitable to conform curved samples since 96.7% of these wood samples reached a perfect curved shape. On the other hand, Luehea divaricata wood presented the worst behaviour, which was marked by only 36.7% of samples achieving a perfect shape. In general, the studied hydrothermal treatments and exposure times induced similar softening behaviours. Conclusion: In this sense, microwave heating seems to be a good option when compared to the other pathways, since it is known that this method require low consumptions of both time and energy.

Proline and Oxidative Metabolism in Young Pecan Trees Associated with Sulphate Accumulation

Pecan [Carya illinoinensis (Wangenh.) K. Koch.] is a deciduous tree whose fruits (nuts) are of high economic value and offer excellent nutritional benefits. However, soils high in sulphates can limit its growth and development. Working with 5-year-old trees of ‘Western Schley’ pecan grown in soils high in sulphates, the levels of proline and oxidative metabolism were recorded in the leaflets. Results showed that different levels of visible leaflet damage (‘sufficiency’, ‘low’, ‘moderate’ or ‘severe’) were associated with different levels of leaflet sulphates (mg kg−1): ‘sufficiency’ (≤40), ‘low’ (41–60), ‘moderate’ (61–80) and ‘severe’ (80–100). ‘Severe’ sulphate damage was associated with significant reductions in chlorophyll (TChl) (17.04 μg g−1), relative water content (RWC) (50%) and leaf area (LA), and with increases in the concentrations of total carotenoids (TC) and proline (Prl). Increases were also observed in the activities of the oxidative metabolism enzymes: superoxide dismutase (SOD) (1.82 units min−1 g−1), catalase (CAT) (2.86 μmol H2O2 min−1 g−1) and antioxidant capacity (AC) (87% DPPH inhibition). However, guaiacol peroxidase (GP) showed a reduction (2.97 nmol GSH min−1 g−1). An inverse relationship was found between the sulphate concentration in the leaflets with respect to the evaluated parameters of TChl, TC, RWC, LA, AC, and GP. Proline synthesis and antioxidant enzymatic activity indicate salt stress in pecan leaflets in orchards irrigated with deep-well water high in sulphates.

Promotores para a melhoria de brotação de cultivares de nogueira-pecã

Abstract The objective of this work was to evaluate the effect of different bud-breaking substances on the budburst of the Barton, Desirable, and Jackson pecan (Carya illinoinensis) cultivars. The experimental design was a randomized complete block with four replicates. The treatments consisted of spraying different rates of commercial bud-break promoters on the trees of these cultivars, in order to induce budburst. The budburst percentage of axillary buds and the budburst heterogeneity index (BHI) were evaluated. Regardless of the used rate, the application of the hydrogen cyanamide product improved the budburst of the tested cultivars and reduced the BHI. In addition, water soluble N + Ca at 6% and water soluble N + organic C soluble in water at 7% significantly improve the budburst and reduce the BHI of the evaluated cultivars, being, therefore, potential alternatives to replace hydrogen cyanamide.

Adsorption of grape pomace (Vitis vinifera) and pecan shell (Carya illinoensis) phenolic compounds to insoluble dietary fiber

Grape pomace (GP) and pecan shell (PS) are agro-industrial by-products rich in healthy bioactives, mainly phenolic compounds (PC) and dietary fiber (DF). Raw GP and PS were chemically characterized, and the adsorption isotherms of their PC-insoluble DF (IDF) complexes were evaluated. GP and PS statistically differed (p < 0.05) in chemical and physicochemical properties. Total PC, total flavonoids, and IDF were higher in GP. Thirteen and eight PC were identified in GP and PS by HPLC-MS/MS chromatography, finding isoquercetin and type B dimer and trimer procyanidins as the most abundant compounds. PC-IDF (phenolic compounds-insoluble dietary fiber) adsorption isotherms were determined by both spectroscopic (Freundlich) and HPLC-MS/MS (Freundlich/Langmuir) techniques, observing that PS IDF presented higher PC adsorption at all tested concentrations. Epicatechin, isoquercetin, and quercetin were the main identified PC in both by-products, and were able to fit to both Langmuir and Freundlich isotherm by HPLC-MS/MS.

Efficient Ultrasonic-assisted Aqueous Enzymatic Method for Pecan Nut Kernel Oil Extraction with Quality Analysis.

In this study, the recovery of pecan nut kernel oil (PNKO) obtained by mechanical pressing (MP) was compared with that obtained by ultrasonic-assisted aqueous enzymatic extraction (UAAEE). At the same time, contents of substances with proven bioactivity, fatty acid compositions, physicochemical properties and antioxidant activities of PNKO were also assessed. Obviously, the oil yield obtained by UAAEE (71.32%) was higher than that obtained by MP (56.81%). Therefore, Plackett-Burman design (PBD), as well as Box-Behnken design (BBD), further optimized the UAAEE process, and the highest oil yield of 78.83% was acquired under the following conditions: incubation time of 2 h, the mixed enzyme (cell ulase+hemicellulase+pectinase+neutrase, w/w/w/w=1/1/1/1) concentration of 2.9%, liquid-solid ratio of 4 mL/g, pH of 4, particle size of 300 μm, ultrasonic time of 20 min, ultrasonic power of 432 W and reaction temperature of 53°C. The PNKO obtained by the two methods possessed similar fatty acid composition, but that obtained by UAAEE had comparatively low acid value and peroxide value. Moreover, rich content of total phenolics, squalene and phytosterols, as well as strong scavenging activities against DPPH and ABTS+ free radicals, were also contained in the PNKO obtained by UAAEE. These results demonstrated that UAAEE was an efficient method to acquire pecan nut kernel oil with excellent quality and high recovery.

Sensory analysis of raw and toasted pecan nuts

Sensory analysis of raw and toasted pecan nuts

Selecting Non-Linear Mixed Effect Model for Growth and Development of Pecan Nut

Selecting Non-Linear Mixed Effect Model for Growth and Development of Pecan Nut

Bazı Pikan Ceviz Çeşitlerinin Meyve Özellikleri İle Biyokimyasal İçeriklerinin Belirlenmesi

This study was carried out to determine some fruit properties and biochemical (total oil, fatty acid composition, protein, total phenolic compounds, total antioxidant capacity, total flavonoids) characteristics of different pecan nut cultivars (Burkett, Choctaw, Mahan, Western, Wichita) grown in the Antalya Region (BATEM). It was determined that some fruit properties and biochemical contents of the cultivars used in the study. In the study, it was determined that the shelled fruit weight varied between 7.78 g (Burkett) and 11.40 g (Mahan), kernel weight between 3.45 g (Burkett) and 5.99 g (Mahan), and kernel percentage between 44.2% (Burkett) and 55.6% (Western). The total oil content of the cultivars ranged from 67.70% (Mahan) to 73.95% (Wichita), protein content from 7.45% (Mahan) to 9.76% (Western), total phenolic compounds from 115.29 mg GAE g-1 (Choctaw) to 176.65 mg GAE/g (Burkett), total antioxidant capacity from 201.36 mg TEAC g-1 (Choctaw) to 487.89 mg TEAC g-1 (Burkett), and total flavonoids from 1.84 mg Catechin g-1 (Western) to 2.24 mg Catechin/g (Mahan). In the study, oleic acid was determined as the major fatty acid, and the lowest ratio of unsaturated fatty acids was found in the Wichita cultivar (90.73%), but the highest ratio was determined in the Western cultivar (91.43%).

Ammonia–Nitrate Mixture Dominated by NH4+–N Promoted Growth, Photosynthesis and Nutrient Accumulation in Pecan (Carya illinoinensis)

Although ammonia–nitrogen (NH4+–N) and nitrate–nitrogen (NO3−–N) are the two main forms of N absorbed and utilized by plants, the preferences of plants for these forms are still unclear. In this study, we analyzed the growth, photosynthesis, and nutrients of pecan under different NH4+:NO3− ratios (0/0, 0/100, 25/75, 50/50, 75/25, 100/0) by indoor aerosol incubation. The results showed that additions of different N forms promoted the growth and development of pecan seedlings. When NO3−–N was used as the sole N source, it significantly promoted the ground diameter growth of pecan and increased the leaf pigment content and photosynthetic rate. The NH4+:NO3− ratio of 75:25 and NH4+–N as the sole N source significantly increased the soluble sugars in stems and roots, starch in leaves, stems and roots, soluble protein in leaves and stems, and soluble phenols in stems and roots. Additionally, the NH4+:NO3− ratio of 75:25 increased plant height, leaf number, root soluble protein, and leaf soluble phenol contents. In conclusion, regarding the physiological aspects of pecan growth, pecans are more inclined to use NH4+–N. Considering that the NH4+–N as the only N source may lead to nutrient imbalance or even toxicity, the NH4+:NO3− ratio of 75:25 was most favorable for the growth and development of pecan seedlings.