Kernel Recovery Research Articles

Determination of the Optimum Moisture Content for the Whole Kernel Recovery During the Cracking Process of Oil Palm Nuts

This study aimed to investigate the effect of moisture content on palm nut cracking and kernel production using a locally fabricated palm nut cracker. Palm nuts of mixed varieties (Dura, Tenera, and Pisifera) were manually cleaned and dried at different moisture content levels ranging from 8.53% to 26.82%. The palm nut cracker is designed with four major units: the in-feed unit, cracking unit, discharge unit and the driving unit. The cracking efficiency was determined by calculating the ratio of completely cracked nuts to the total nuts fed into the hopper. Results show that the whole kernel recovery varies considerably with moisture content and cracking speed. At the lowest moisture content of 8.58%, the whole kernel recovery is generally low across all the cracking speeds. As the moisture content increases, there is a significant improvement in whole kernel recovery at all the cracking speeds. The highest whole kernel recovery was obtained at intermediate moisture contents of around 14% to 18%, and the cracking speeds of 1000 rpm to 1400 rpm. The ANOVA table shows that both the cracking speed and moisture content have a significant effect on whole kernel recovery. Optimizing these parameters could lead to higher whole kernel recovery. However, it is important to note that other factors such as the cultivar of the nut and the equipment used may also affect the whole kernel recovery.

High Outcrossing Levels among Global Macadamia Cultivars: Implications for Nut Quality, Orchard Designs and Pollinator Management

Global fruit and nut yields are affected by shortfalls in pollinator populations, and pollen limitation is most prevalent among tropical, bee-pollinated and self-incompatible plants. Macadamia is a subtropical, bee-pollinated crop in which some cultivars have been found to be highly outcrossing. We aimed to determine the extent of outcrossing and its effects on nut quality across a wide range of international macadamia cultivars in three countries. We sampled fruit from 19 macadamia cultivars across 23 sites in Australia, Brazil and South Africa. We used genotype-by-sequencing and MassARRAY methods to assign paternity to individual fruit and we assessed pollen-parent effects on nut quality. Macadamia was highly outcrossing, producing 80–100% of fruit by cross-pollination, at 17 of the 23 sites. Mixed mating (41–72% outcrossing) was identified at five sites, and low outcrossing (10%) was identified in one cultivar at one site where it was isolated from other flowering macadamia trees. Outcrossed fruit often had significantly better quality than selfed fruit, with 1.61–3.39 g higher nut-in-shell mass, 0.53–1.55 g higher kernel mass, 3.3–6.4% higher kernel recovery, and 3.0–3.5% higher oil concentration. The differences in kernel recovery equated to differences in value of USD 433–841 per ton of nut-in-shell at prices of USD 3000 per ton. In summary, macadamia cultivars were mostly highly outcrossing, and outcrossed nuts often had higher quality than selfed nuts. Growers should consider interplanting different cultivars more closely and distributing bee hives more widely to maximise cross-pollination, produce high yields, and optimise nut quality.

Kernel-, mean-, and noise-marginalized Gaussian processes for exoplanet transits and H0 inference

ABSTRACT Using a fully Bayesian approach, Gaussian process regression is extended to include marginalization over the kernel choice and hyperparameters. In addition, Bayesian model comparison via the evidence enables direct kernel comparison. The calculation of the joint posterior was implemented with a transdimensional sampler which simultaneously samples over the discrete kernel choice and their hyperparameters by embedding these in a higher dimensional space, from which samples are taken using nested sampling. Kernel recovery and mean function inference were explored on synthetic data from exoplanet transit light-curve simulations. Subsequently, the method was extended to marginalization over mean functions and noise models and applied to the inference of the present-day Hubble parameter, H0, from real measurements of the Hubble parameter as a function of redshift, derived from the cosmologically model-independent cosmic chronometer and lambda-cold dark matter-dependent baryon acoustic oscillation observations. The inferred H0 values from the cosmic chronometers, baryon acoustic oscillations, and combined data sets are $H_0= 66 \pm 6,\, 67 \pm 10,\, \mathrm{ and}\,69 \pm 6\,\mathrm{km}\, \mathrm{s}^{-1}\, \mathrm{Mpc}^{-1}$, respectively. The kernel posterior of the cosmic chronometers data set prefers a non-stationary linear kernel. Finally, the data sets are shown to be not in tension with ln R = 12.17 ± 0.02.

WET SEPARATION OF PALM KERNEL AND SHELL MIXTURE USING LATERITE AND ANTHILL SLURRY.

Palm kernel, one of the end products of oil palm fruits processing is recovered by cracking of the palm nuts which is first dried to aid efficient kernel recovery. The possibility of separating oil palm kernel and shell mixture using media other than kaolin in wet separation was investigated in this study. The separation efficiency of laterite was compared with that of anthill. The effect of media type, pH, specific gravity, slurry viscosity on the efficiency of separation were investigated. The media/water percentages of 0, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75 and 80% w/v were prepared in bowls for each media at a time and used to separate the cracked nut (palm kernel and shell mixture). The soil particle size distribution showed that laterite contains 40.3% clay while anthill contains 20.3%. The laterite and anthill slurry shows that the specific gravity and the viscosity increases with increase in media percentage while the pH decreases. Optimum kernel recovery percentages (%Kr) of 99.3 and 99.6% was observed at 30 and 35% ratio respectively for laterite and %Kr of 98.9 and 98.4% at 45 and 50% ratio for the anthill slurry. Among the media used, laterite was found to be comparable to clay at a medium-to-water percentages of 30 and 35% giving optimum efficiency. Thus, it is recommended laterite can be used for wet separation when compared to anthill.

Geographical variation in Canarium indicum (Burseraceae) nut characteristics across Vanuatu

AbstractTropical forests in the Pacific region contain many tree species that bear edible nuts (kernels). Canarium indicum (canarium) is an overstorey tree indigenous to Melanesia that produces commercially valuable kernels due to their pleasant taste and high oil content. This study characterises natural variation in fruit, nut-in-shell (NIS) and kernels of C. indicum across eight islands in Vanuatu. Significant tree-to-tree variation in fruit, NIS and kernel characteristics as well as kernel recovery (kernel:NIS) was found. This variation was largely due to tree-to-tree differences and little of this variation could be attributed to location. There were significant linear correlations among fruit, NIS and kernel traits, including kernel mass with fruit mass (R2 0.57) and kernel mass with NIS mass (R2 0.56). Therefore, trees suitable for cultivation may be screened based on fruit and nut characters before making final selections based on kernel mass. Trees sampled over two fruiting seasons showed that kernel mass and kernel number varied significantly between years for 63.6% and 25.9% of the trees respectively. However, by rank order, those trees that produced larger kernels in the first year of sampling, tended to also produce relatively larger kernels in the subsequent year. The implications of these results for the further domestication of the species for planting in commercial agroforestry systems is explored.

The Comparative Analysis of a Developed Swing Beater and Conventional Beater of a Palm Nut Cracking Machine

Based on high dependent of many processing company on palm kernel oil, high quality palm nut cracking machine is not only necessary but also important to revitalize the production of palm kernel in other to meup with ever increasing industrial demand. Different palm kernel beaters; Swing beater (SB) and the conventional type known as rigid beater (RB) of an existing palm kernel cracker were investigated using the moisture content (7, 17, 26% (db)), five different speeds (970, 1200, 1450,1750, 2430rpm) and three different average nut sizes (14.5, 22.15, 29.43mm) of palm kernel nut. Approximately, six thousand palm nuts of Tenera specie were collected, dried, cleaned and sorted to evaluate the machine. Result shows that, the maximum quality efficiency recorded for Swing beater was 89.5% at 17% moisture content (db), 29.4 mm average nut size and 970 rpm machine speed. Similarly, for the performance of rigid beater, the maximum quality efficiency of 71.5% was recorded at 26% moisture content (db), 29.4 mm average nut size and 970 rpm machine speed. The effect of nut size was however not significant on the quality efficiency however it was generally observed that quality efficiency increased with increase in the nuts size. The machine speed has a significant effect on the quality efficiency. Generally, the quality of the kernel recovered decreased as the machine speed decreased. Beater configuration has significant effect on the quality efficiency of the palm nut cracking machine at 5% significant level. Swing beater can be used instead of conventional beater (rigid beater) to crack palm nut for higher quality of whole kernel recovery.

Cold plasma-assisted buckwheat grain dehulling and farinographical properties of dehulled buckwheat flour

The process of dehulling buckwheat grain should lead to less breaking of the buckwheat grain and improve the whole kernel recovery rate. However, heat treatment-based delhulling is associated with starch gelatinization, protein denaturation, and degradation of flavonoids. This study investigated a cold plasma-based rapid dehulling technology by analyzing the farinographical properties of dehulled buckwheat flour (BF). Cold plasma treatment-mediated etching and dehydration created cracks and pores on the surface of the hull, and the gap between the hull and the kernel increased, resulting in a decrease of the critical damage force of the hull by 58.3%. Compared with heat treatment, significant changes were observed in solubility, swelling power, color, iodine blue values, fatty acid and flavonoid contents, and crystal structure in cold plasma-treated dehulled BF. In conclusion, cold plasma can be used as an ancillary method of dehulling buckwheat for the production of high-quality BF.

Physicochemical quality evaluation and drying characteristics of nutmeg (Myristica fragrans) dried in a solar tunnel dryer with biomass backup

Experiments on drying of nutmeg was performed in a solar tunnel dryer with biomass back up and in a mechanical dryer under three varying temperatures of 45OC, 5OC and 55OC. Drying of nutmeg in solar tunnel dryer was completed in 147 h, while in a mechanical dryer, drying was completed in 105 h, 102 h and 78 h at drying temperatures of 45OC, 50OC and 55OC, respectively. Solar tunnel dried nutmeg had maximum physical quality retention of bulk density (484.88 kg m-3) and kernel recovery (70.63%) whereas dry recovery of nut (61.88%) and shell recovery (31.55%) were maximum in mechanically dried samples at 55OC and 45OC respectively. Secondary metabolites like essential oil (10.67%) and oleoresin (23.25%) were higher in mechanically dried nutmeg at a drying temperature of 45OC. Volatile oil constituents like β-pinene, safrole, terpineol, γ-terpinene, α-thujene, α-terpinene and myristicin content were highest in solar tunnel dried nutmeg.

Analysis Noise Level in Production the Palm Oil: A Case Study

Excessive noise exposure during the manufacturing process is a widespread issue. This research aimed to analyze noise exposure in the kernel recovery station in the manufacturing process of palm oil. We conduct some measurements and calculations for noise exposure analysis to get the Equivalent Noise Level (Leq) value during the daytime for each measurement point. The noise measurement was conducted on four machines, including a depericarper and polishing drum machine, ripple mill machine, silo dryer machine, and clay bath machine. In addition, this research showed noise contour mapping to define the noise distribution. The results of this research are that only the clay bath machine had Ls below the threshold. The clay bath machine workstation has good noise levels. The Depericarper, Polishing Drum, Ripple Mill, and Silo Dryer Machine must be quieter. Thus, this research used the Hierarchy of Control Approach to reduce and control hazardous noise exposure. The stage of HOC includes elimination, substitution, engineering, administrative control, and Personal Protective Equipment (PPE).

Design and development of a circular disc type efficient automatic decorticator for Charoli (Buchanania lanzan)

AbstractThe manual decortication process of charoli seeds by beating the dried seeds on the ground with a hand hammer or stone and, by domestic grinder is a laborious, inefficient, time‐consuming as well as uneconomical process. Therefore, an attempt has been taken toward the automation of the charoli decortication process. The decorticator performance was evaluated at three levels of disc speeds, disc clearances, and different moisture levels of charoli seed viz. 197, 246, and 286 rpm; 6, 7, and 8 mm; and 7.83, 8.57; and 9.04% wb, respectively. The selected input parameters were optimized by using the response surface methodology (RSM). The optimum value of disc speed, disc clearance, and seed moisture content was found to be 197 rpm, 7 mm, and 9.04% (wb), respectively. The corresponding response values in terms of decorticating efficiency, whole kernel, and broken kernel percentage at optimum conditions were recorded as 92.5, 21.6, and 3%, respectively.Novelty impact statementThe decorticating capacity of the developed decorticator was found to be 70 kg per hour which was higher than the existing decorticator. Since the developed machine was automatically operated and each unit operation was sequentially and continuously carried out with no manual intervention, the ideal time in each decortication step was absent and subsequently, higher capacity was achieved. The efficiency of the decorticator was found to be 92.5%. The higher capacity and kernel recovery with no human drudgery and lower cost of decortication imply the significance of the development of the machine.

Boron Effects on Fruit Set, Yield, Quality and Paternity of Macadamia

Many tree crops experience sub-optimal yields and low fruit quality due to inadequate pollination, low fruit set, and poor crop nutrition. Boron (B) is a critical crop nutrient for fruit set because B levels affect pollen germination and pollen tube growth. However, the relationship between floral B concentration and fruit set is not well understood. The aim of this study was to determine the effect of B applications on the initial fruit set, yield, quality, and paternity of macadamia (Macadamia integrifolia). Cultivar ‘816’ trees received one of three treatments: (a) 0 g, (b) 15 g, or (c) 30 g B per tree prior to flowering. Boron application increased the B concentration of macadamia flowers. Application of 15 g B increased fruit set at 3 weeks after peak anthesis, but this higher initial fruit set was not translated into higher fruit set at 6 or 10 weeks after peak anthesis or higher yield. Boron application increased B concentrations in kernels but did not affect nut-in-shell (NIS) mass, kernel mass, kernel recovery, kernel oil concentration or incidence of whole kernels. Cultivar ‘816’ was highly outcrossing, with 97–98% cross-paternity among kernels from all treatments. Our results indicate that higher B concentration in macadamia flowers can be associated with an increased initial fruit set. However, high B levels did not affect yield, nut quality, or the proportion of self-pollinated fruit at maturity. The heavy dependence on outcrossing highlights the importance of inter-planting different cultivars and managing bee hives to sustain the productivity of macadamia orchards.

Fast calculation of spatial sensitivity kernels for scattered waves in arbitrary heterogeneous media using graph theory

SUMMARYP-to-S and S-to-P receiver functions are widely used to constrain the seismic discontinuity structures of the Earth. Typically, receiver functions are projected to the depth and location of conversion assuming a 1-D layered Earth structure. Receiver function finite frequency sensitivity kernels have the potential to increase resolution. Here we present a method for rapidly calculating the P- and S-wave receiver function sensitivity kernels, based upon the shortest path method and Dijkstra's algorithm to calculate the traveltime fields, and accounting for geometrical spreading in heterogeneous media. The validity of the approach is evaluated by comparing with amplitudes derived from a finite difference elastic full waveform simulation in a complex subduction zone geometry. We show P-to-S and S-to-P kernels calculated using our method for three examples cases: a half space, a layer with topography, and a sinusoidal discontinuity. We also demonstrate the kernel recovery of discontinuities with these topographies by inverting synthetic data from SPECFEM2D. We find that P-to-S kernels recover the structure of strong topography better than S-to-P kernels, although S-to-P kernels may be useful in some situations. P-to-S kernels also show better recovery of the amplitude of the discontinuities in comparison to S-to-P, although both typically achieve values within a few percent of the input model. The computational cost of our approach for improved kernel calculation in heterogeneous media is up to a few tens of seconds per station for typical regional scale models on the scale of several 100s of kilometres.

Genetic variability and correlation for nut and yield characters in arecanut (Areca catechu L.) germplasm

A study on genetic variability and correlation for nut and yield characters was carried out among 25 arecanut accessions of diverse geographic origins. High GCV and PCV values were observed for the number of female flowers/inflorescence/palm/year, the number of nut/inflorescence, the number of nuts/palm/year, dry weight of husk, fresh fruit weight, dry weight of nut, dry weight of kernel and fresh nut yield. High estimates of heritability coupled with high genetic advance as per cent mean (GAM) were observed for stem girth above the fixed mark, the number of female flowers/inflorescence/palm/year, fruit length, fruit breadth, fresh fruit weight, kernel length, kernel breadth, dry weight of nuts, dry weight of kernel, fresh nut yield, dry kernel yield and kernel recovery indicating amenability for phenotypic selection of these characters in early generations. The observations revealed that the palm height, kernel breadth and dry weight of kernel can be considered for improvement of arecanut as these characters had high positive direct effects on the dry weight of kernel. Key words: Genetic variability, Arecanut, Heritability, Genetic advance, Germplasm.

The genome of the endangered Macadamia jansenii displays little diversity but represents an important genetic resource for plant breeding.

Macadamia, a recently domesticated expanding nut crop in the tropical and subtropical regions of the world, is one of the most economically important genera in the diverse and widely adapted Proteaceae family. All four species of Macadamia are rare in the wild with the most recently discovered, M. jansenii, being endangered. The M. jansenii genome has been used as a model for testing sequencing methods using a wide range of long read sequencing techniques. Here, we report a chromosome level genome assembly, generated using a combination of Pacific Biosciences sequencing and Hi‐C, comprising 14 pseudo‐molecules, with a N50 of 52 Mb and a total genome assembly size of 758 Mb of which 56% is repetitive. Completeness assessment revealed that the assembly covered −97.1% of the conserved single copy genes. Annotation predicted 31,591 protein coding genes and allowed the characterization of genes encoding biosynthesis of cyanogenic glycosides, fatty acid metabolism, and anti‐microbial proteins. Re‐sequencing of seven other genotypes confirmed low diversity and low heterozygosity within this endangered species. Important morphological characteristics of this species such as small tree size and high kernel recovery suggest that M. jansenii is an important source of these commercial traits for breeding. As a member of a small group of families that are sister to the core eudicots, this high‐quality genome also provides a key resource for evolutionary and comparative genomics studies.

Pollen limitation and xenia effects in a cultivated mass-flowering tree, Macadamia integrifolia (Proteaceae).

Pollen limitation is most prevalent among bee-pollinated plants, self-incompatible plants and tropical plants. However, we have very little understanding of the extent to which pollen limitation affects fruit set in mass-flowering trees despite tree crops accounting for at least 600 million tons of the 9200 million tons of annual global food production. We determined the extent of pollen limitation in a bee-pollinated, partially self-incompatible, subtropical tree by hand cross-pollinating the majority of flowers on mass-flowering macadamia (Macadamia integrifolia) trees that produce about 200 000-400 000 flowers. We measured tree yield and kernel quality and estimated final fruit set. We genotyped individual kernels by MassARRAY to determine levels of outcrossing in orchards and assess paternity effects on nut quality. Macadamia trees were pollen-limited. Supplementary cross-pollination increased nut-in-shell yield, kernel yield and fruit set by as much as 97, 109 and 92 %, respectively. The extent of pollen limitation depended upon the proximity of experimental trees to trees of another cultivar because macadamia trees were highly outcrossing. Between 84 and 100 % of fruit arose from cross-pollination, even at 200 m (25 rows) from orchard blocks of another cultivar. Large variations in nut-in-shell mass, kernel mass, kernel recovery and kernel oil concentration were related to differences in fruit paternity, including between self-pollinated and cross-pollinated fruit, thus demonstrating pollen-parent effects on fruit quality (i.e. xenia). This study is the first to demonstrate pollen limitation in a mass-flowering tree. Improved pollination led to increased kernel yield of 0.31-0.59 tons ha-1, which equates currently to higher farm-gate income of approximately $US3720-$US7080 ha-1. The heavy reliance of macadamia flowers on cross-pollination and the strong xenia effects on kernel mass demonstrate the high value that pollination services can provide to food production.

Phenotypic Characterisation for Growth and Nut Characteristics Revealed the Extent of Genetic Diversity in Wild Macadamia Germplasm

Macadamia is a recently domesticated Australian native nut crop, and a large proportion of its wild germplasm is unexploited. Aiming to explore the existing diversity, 247 wild accessions from four species and inter-specific hybrids were phenotyped. A wide range of variation was found in growth and nut traits. Broad-sense heritability of traits were moderate (0.43–0.64), which suggested that both genetic and environmental factors are equally important for the variability of the traits. Correlations among the growth traits were significantly positive (0.49–0.76). There were significant positive correlations among the nut traits except for kernel recovery. The association between kernel recovery and shell thickness was highly significant and negative. Principal component analysis of the traits separated representative species groups. Accessions from Macadamia integrifolia Maiden and Betche, M. tetraphylla L.A.S. Johnson, and admixtures were clustered into one group and those of M. ternifolia F. Muell were separated into another group. In both M. integrifolia and M. tetraphylla groups, variation within site was greater than across sites, which suggested that the conservation strategies should concentrate on increased sampling within sites to capture wide genetic diversity. This study provides a background on the utilisation of wild germplasm as a genetic resource to be used in breeding programs and the direction for gene pool conservation.

Development and Assessment of Cracking and Sorting Processes of Palm Kernel Nut Machine

This paper presents a research on the Development and Assessment of the cracking and sorting processes of palm kernels nuts in a mechanical cracking machine. The palm kernel oil is an important agricultural produce, it has a wide range of usage aside from cooking. In attempt to reduce energy exploitation, in conjunction with the regular high rate of demand for products been extracted from palm kernel nut, the need to improve on the manual method of cracking and sorting became eminent. The mechanical cracker was made up of two units: the cracking and sorting unit. Experimental studies of properties of machine components were considered with the purpose of avoiding fatigue failure and fracture on the palm nuts during the processing duration. The mechanical cracker was designed, fabricated and performance evaluation carried out using locally sourced materials. It was developed with a 5hp electric motor to drive the machine coupled with belts and pulleys. The average data assessment shows a 2.01% of un-cracked nuts, 2.36% of partially cracked nuts, 93.58% of un-cracked nut and 2.05% broken nuts. The cracking-sorting efficiency was estimated at 94% and throughput capacity was determined to be 80kg/h while the overall palm kernel recovery efficiency was 85%. These suggest that the machine is very suitable for separating the palm kernel nuts from the cracked shells clearly and completely.

Development and Assessment of Cracking and Sorting Processes of Palm Kernel Nut Machine

This paper presents a research on the Development and Assessment of the cracking and sorting processes of palm kernels nuts in a mechanical cracking machine. The palm kernel oil is an important agricultural produce, it has a wide range of usage aside from cooking. In attempt to reduce energy exploitation, in conjunction with the regular high rate of demand for products been extracted from palm kernel nut, the need to improve on the manual method of cracking and sorting became eminent. The mechanical cracker was made up of two units: the cracking and sorting unit. Experimental studies of properties of machine components were considered with the purpose of avoiding fatigue failure and fracture on the palm nuts during the processing duration. The mechanical cracker was designed, fabricated and performance evaluation carried out using locally sourced materials. It was developed with a 5hp electric motor to drive the machine coupled with belts and pulleys. The average data assessment shows a 2.01% of un-cracked nuts, 2.36% of partially cracked nuts, 93.58% of un-cracked nut and 2.05% broken nuts. The cracking-sorting efficiency was estimated at 94% and throughput capacity was determined to be 80kg/h while the overall palm kernel recovery efficiency was 85%. These suggest that the machine is very suitable for separating the palm kernel nuts from the cracked shells clearly and completely.

Development of a decorticator for Buchanania lanzan nuts and its process optimization

AbstractThe study was aimed to develop a decorticator and to standardize the process for separation kernels from nuts. The developed machine was optimized using independent parameters, that is, cold water soaking, steaming, and sand roasting, different moisture levels (7 and 9%), cylinder speed (150 and 300 rpm), and concave clearances (7.5 and 8 mm). The optimum performance of a developed decorticator was obtained when sand roasted nuts (7% moisture content) fed at a cylinder speed of 300 rpm and a concave clearance of 8 mm. At this condition, decortication efficiency, capacity, and whole kernel recovery were 96.10, 64.15, and 12.60%, respectively. The decorticator produced 126 g whole kernels (56.71%) from 1 kg of nuts. The independent process parameters have significant effect on response variables. The machine had low labor requirement, high efficiency, and ease to operate; thus, the results will be useful for processing of nuts and in other studies.Practical applicationsThe chironji nut decorticator has application to decorticate nuts to produce kernel at manufacturing site of food, flavor, cosmetic, and pharmaceutical industries. The kernels have very short shelf‐life because they are very soft and susceptible to mechanical damage and spoilage. The available decorticators have very limited efficiency and more breakage thus the results can be utilized to fill existing gap to obtain increased efficiency and less damage. The results of different treatments to nuts will assist future studies as well.

Genetic variability, correlation and path-coefficient studies among Persian walnut (Juglans regia) genotypes

The present study was conducted during 2015 and 2016 at ICAR-CITH, Rangreth, Srinagar to corroborate genetic variability among walnut genotypes and determine the potential traits for selection of superior genotypes. Genetic variability in any crop is a pre-requisite to initiate the breeding programme for the selection of superior entries over the existing cultivars. The efficiency of selection largely depends upon the magnitude of the genetic variability present in the plant population. Thus, large genetic variability offers better scope for the crop improvement. The experimental material comprised 136 walnut genotypes. Nut samples of each genotype were collected randomly in five replications and each replication consisted of five nuts. Quantitative traits were recorded as per walnut descriptors developed by IPGRI. The highly significant differences (P = 0.01) existed between genotypes for the nut and kernel traits studied. The range of some economically important traits varied widely for nut weight (6.08–24.23 g), kernel weight (3.30–11.16 g), and kernel recovery (36.27–60.19 %). The estimates of GCV and PCV were very high for nut weight (25.07, 26.05 respectively) and kernel weight (23.59, 25.35 respectively) indicating the importance of these traits in selection of superior genotypes. Trait association analysis also revealed mutual relationships and degree of interrelationships among all the nut and kernel traits. Thus, ample genetic variability observed among the studied genotypes for nut and kernel traits indicated effectiveness of direct selection for improvement of these commercially important traits.