Kernel Size Distribution Research Articles

Discrete Element Method Simulation of Wheat Bulk Density as Affected by Grain Drop Height and Kernel Size Distribution

HighlightsThe predicted bulk density of two wheat varieties varied with drop height, similar to the experiments.The percentage composition of three kernel size fractions in the wheat varieties affected the bulk density.Accurate particle shape representation simulated the heap profile better but required longer computational time.The single-sphere model is more practical to use because of its higher accuracy and lower computational cost.Abstract. Grain bulk density varies widely depending on kernel properties and handling practices. The discrete element method (DEM) can model such behavior at the particle level, including wide-ranging interactions with equipment. The objective of this study was to develop a DEM model to predict wheat bulk density as affected by grain drop height and kernel size distribution. The bulk density of two wheat varieties was measured experimentally for a range of drop heights with a modified test weight per bushel apparatus and was simulated in EDEM v2018.1 using single-sphere and five-sphere particle models that accounted for three kernel size fractions. For both particle models, simulations matched the observed behavior, showing a bulk density increase with increasing drop height and bulk density differences between varieties due to different kernel size fractions. The single-sphere particle model predicted the bulk density with higher accuracy than the five-sphere particle model, while the five-sphere model, which more accurately represented the shape of wheat kernels, allowed better simulation of the heap profile at the cost of longer computation time. These particle models can be used to simulate bulk density of wheat under compaction and to improve prediction models of grain pack factor for wheat. Keywords: Bulk density, DEM, Drop height, Size distribution, Wheat.

Inter-Relationships between Test Weight, Thousand Kernel Weight, Kernel Size Distribution and Their Effects on Durum Wheat Milling, Semolina Composition and Pasta Processing Quality.

Although most of the durum wheat produced in the Canadian prairies in 2017 and 2018 met the test weight (TW) requirements for the top grades of Canada Western Amber Durum (CWAD), some samples of top grades were inferior in milling quality. To understand the abnormality, this study was conducted to investigate TW, thousand kernel weight (TKW) and kernel size distribution (KSD) in relation to durum milling potential, semolina composition and pasta quality. With reduction of kernel size, semolina and total milling yields decreased progressively, and kernels passing through no.6 slotted sieve had detrimental impact on milling. The overall relationship between TW and milling yields appeared to be genotype dependent. At similar TW, variety showed lower milling yields had greater proportion of smaller kernels. By account for the difference in KSD, greater relationships (R2 > 0.91, p < 0.001) were found for TKW and proportion of kernels passing No.6 slotted sieve with milling yields than TW (R2 = 0.75, p < 0.001). This infers potential use of small kernels (passing No.6 slotted sieve) as a new objective grading factor for rapid prediction of milling quality of CWAD. Although small kernels exhibited much higher yellow pigment than the larger ones, pasta made from small kernels was duller, redder and less yellow, likely due to the higher semolina ash and protein contents, which adversely affected pasta color.

Wheat Flour Milling Yield Estimation Based on Wheat Kernel Physical Properties Using Artificial Neural Networks

Wheat is a stable food raw material for the majority of people around the world as wheat-based products provide an important part of the daily energy intake in many countries. Wheat is generally milled into flour prior to use in the bakery industry. Flour yield is one of the major quality criteria in wheat milling. Flout yield detection requires large amount of sample, costly machinery, longer time of tempering and milling practices requiring substantial workload. In this study, artificial neural network (ANN) approach has been employed to predict flour milling yield. The ANN was designed in the MATLAB software using such wheat physical properties as hectoliter weight, thousand-kernel weight, kernel size distribution, and grain hardness. Flour yields and four different kernel physical features (hectoliter weight, thousand-kernel weight, kernel size distribution, and grain hardness) were first collected from 2400 wheat samples through the conventional methods. The ANN was trained using 85% of 2400 flour yield data and tested with 15% of the remaining data. In the training of the ANN, various models have been investigated to find the best ANN structure. Additionally, two data sets with and without grain hardness have been employed to determine the effect of grain hardness on the prediction performance of the ANN model. It was found that grain hardness which reduced the MAE values from 2.3333 to 2.2611 and RMSE values from 3.0775 to 2.9146 gave better result. The results proved that the developed ANN model can be used to estimate flour yield using wheat kernel physical properties.

The Alteration of Physicochemical and Thermal Characteristics of Peanut by Salting-Roasting Process

Peanut as nutritious food containing high protein, high fat, carbohydrate, and bioactive substance is usually processed in order to enhance palatability and consumer preference. One of the thermal processes, a traditional salting-roasting process used by BIMARAM SME in Gunungkidul to add the value of peanut, was predicted to be able to alter the properties of peanut, i.e., physicochemical and thermal characteristics. This research investigated the alteration, and the comparison of salted-roasted peanut and raw peanut properties was essentially needed to be conducted. Physicochemical characteristics were represented by parameters such as moisture content, ash content, fat content, protein content, antioxidant activity, color, mean geometric peanut kernel diameter, kernel size distribution, hardness, and fracture parameter. Meanwhile, thermogravimetric analysis (TGA) result described thermal characteristic. The salting-roasting process produced the decreasing of moisture, protein, fat, antioxidant activity expressed by antiradical power, and CIE Lab color values (lightness (L*), redness (a*), and yellowness (b*)), compared with that of raw peanut. Meanwhile, the ash content of the peanut was increased by the process. All of the changes were significant (p<0.05) statistically. The process reduced the mean geometric peanut kernel diameter (p<0.05) and yielded a narrower kernel size distribution. According to TGA result, the roasted peanut was more stable thermally, which was shown by the shifting of endothermic peak to the higher temperature. The enhancing of palatability of peanut by salting-roasting was proven by hardness decreasing (p<0.05), although the fracture was insignificantly increased (p>0.05).

Influence of Kernel Shape and Size on the Packing Ratio and Compressibility of Hard Red Winter Wheat

Abstract. Grain compaction occurs during bin storage, and its determination is important for the grain mass estimation needed for inventory and auditing. The degree of compaction is dependent on grain type, bin type, moisture content, amount of grain, initial grain bulk density, coefficients of friction, lateral-to-vertical pressure coefficient, and variation in kernel size. Previous studies have correlated several of these parameters, such as bulk density and grain packing, with moisture content. This study investigated the influence of wheat kernel shape and size distribution on packing ratio and compressibility. Two dockage-free hard red winter (HRW) wheat samples, with no shrunken or broken kernels, were sieved using U.S. Tyler sieves #6, #7, #8, and #10, and the kernels retained on the sieves were used in the experiments. The kernel dimensional parameters and bulk sample parameters were measured, and additional derived parameters were calculated for each size fraction and variety. Packing ratio and compressibility of the size fractions and of binary and ternary mixtures of the size fractions were also determined for each variety. Packing ratio increased with larger kernel size, while compressibility decreased. Sphericity and flatness shape factor had strong positive linear relationships with packing ratio and strong negative relationships with compressibility, while elongation shape factor behaved the opposite way with packing ratio and compressibility. The higher the percentage mass of the larger kernel fraction in a mixture, the higher was its packing ratio and the lower its compressibility. The two tested varieties of wheat did not significantly differ in packing ratio and compressibility. These findings can be used in developing models for more accurate estimation of grain pack factor and to determine the mass of grain inside bins and other storage structures. Keywords: Compressibility, Packing, Shape, Size, Wheat.

Peanut Response to Crop Rotation, Drip Tube Lateral Spacing, and Irrigation Rates with Deep Subsurface Drip Irrigation

ABSTRACTLong term crop yield with various crop rotations irrigated with subsurface drip irrigation (SSDI) is not known for US southeast. A SSDI system was installed in 1998 on Tifton loamy sand soil with five crop rotations, two drip tube lateral spacings, and three irrigation levels. Crop rotations ranged from continuous peanut (Arachis hypogaea L) to four years between peanut. Laterals were installed beneath each crop row (0.91-m) and alternate row middles (1.83-m). Crops were irrigated daily at 100, 75 and 50% of estimated crop water use. Laterals spaced at 1.83 m had the same yield as laterals spaced at 0.91-m in nine out of ten years. The 50, 75, and 100% irrigation treatments averaged 3263, 3468, and 3497 kg/ha, respectively. There was no yield difference between the 75 and 100% irrigation treatments implying 25% water savings. Crop rotation affected peanut yield seven out of eight years and continuous peanut had lowest yield across all years. As time between peanut crops increased peanut yield increased. Irrigation treatment had no effect on total sound mature kernels (TSMK). Lateral spacing affected TSMK 20% of the time and crop rotation affected TSMK 90% of the time. Continuous peanut rotation had the lowest TSMK with higher TSMK occurring as time between peanut crops increased. There was no evidence of any one crop rotation negatively affecting kernel size distribution except for continuous peanut. When using SSDI, it is possible to save 25% irrigation water, install drip laterals in alternate row middles, and rotate with peanut every three years without negatively affecting peanut yield or grade.

Genome mapping of kernel characteristics in hard red spring wheat breeding lines

Kernel characteristics, particularly kernel weight, kernel size, and grain protein content, are important components of grain yield and quality in wheat. Development of high performing wheat cultivars, with high grain yield and quality, is a major focus in wheat breeding programs worldwide. Here, we report chromosome regions harboring genes that influence kernel weight, kernel diameter, kernel size distribution, grain protein content, and grain yield in hard red spring wheat breeding lines adapted to the Upper Midwest region of the United States. A genetic linkage map composed of 531 SSR and DArT marker loci spanned a distance of 2,505 cM, covering all 21 chromosomes of wheat. Stable QTL clusters influencing kernel weight, kernel diameter, and kernel size distribution were identified on chromosomes 2A, 5B, and 7A. Phenotypic variation explained by individual QTL at these clusters varied from 5 to 20% depending on the trait. A QTL region on chromosome 2B confers an undesirable pleiotropic effect or a repulsion linkage between grain yield (LOD = 6.7; R (2) = 18%) and grain protein content (LOD = 6.2; R (2) = 13.3%). However, several grain protein and grain yield QTL independent of each other were also identified. Because some of the QTL identified in this study were consistent across environments, DNA markers will provide an opportunity for increasing the frequency of desirable alleles through marker-assisted selection.

Properties of field-sprouted sorghum and its performance in ethanol production

The objective of this research was to investigate physicochemical and biochemical characteristics of field-sprouted grain sorghum and its fermentation performance in ethanol production. Five field-sprouted grain sorghum varieties, which received abnormally high rainfall during harvest, were used in this study. Enzyme activities, microstructure, flour pasting properties, kernel hardness, kernel weight, kernel size, flour size and particle distribution of field-sprouted grain sorghum were analyzed. The effect of germination (i.e., sprouting) on conversion of grain sorghum to ethanol was determined by using a laboratory dry-grind ethanol fermentation procedure. Sprouted sorghum had increased α-amylase activity; degraded starch granules and endosperm cell walls; decreased kernel hardness, kernel weight, kernel size, and particle size; and decreased pasting temperature and peak and final viscosities compared with non-sprouted grain sorghum. The major finding is that the time required for sprouted sorghum to complete fermentation was only about half that of non-sprouted sorghum. Also, ethanol yield from sprouted sorghum was higher (416–423 L/ton) than that from non-sprouted sorghum (409 L/ton) on a 14% moisture basis.

Corroborative Study on Maize Quality, Dry-Milling and Wet-Milling Properties of Selected Maize Hybrids

A corroborative study was conducted on the maize quality properties of test weight, pycnometer density, tangential abrasive dehulling device (TADD), time-to-grind on the Stenvert hardness tester (SHT), 100-kernel weight, kernel size distribution, and proximate composition as well as maize dry- and wet-millability by six participating laboratories. Suggested operating procedures were given to compare their measurements and provide the variance structure within and between laboratories and hybrids. Partial correlation coefficient among maize quality properties varied among laboratories. The repeatability and reproducibility precision values were acceptably low for the physical quality tests, except for TADD and SHT time-to-grind measurements. The yields of dry- and wet-milled products and their correlation with maize quality properties were dependent on the collaborating laboratory. This paper highlights the importance of laboratory variation when considering which maize hybrids are best suited for dry-milling and wet-milling.

Peanut Response to Row Pattern and Seed Density when Irrigated with Subsurface Drip Irrigation

A two year study (2001 and 2002) was conducted at Sasser and Shellman, GA to determine the effects of planting pattern and plant population on the pod yield, market grade, and market value of peanut (Arachis hypogaea L.) when irrigated with subsurface drip irrigation (SDI). Soils were a Tifton loamy sand (fine-loamy, kaolinitic, thermic Plinthic Kandiudults) and Greenville sandy loam (fine, kaolinitic, thermic Rhodic Kandiudults) with 1% slope. Seeds were planted at recommended (20 seeds/m; 1.0R) and half the recommended rate (10 seeds/m; 0.5R) in a single and twin-row pattern. Plots were irrigated daily to replace estimated daily evapotranspiration (ETa). This study showed that twin-row plant pattern had 490 kg/ha higher pod yield compared with single-row pattern when irrigated using subsurface drip irrigation. The twin-row pattern also had a one percentage point increase in grade value (TSMK) compared with the single-row pattern. There was no difference in kernel size distribution with planting pattern. Twin-row planting had a $213/ha higher market value compared with single-row. There was no difference in yield on market value for seeding rate. This implies that it may be possible for a grower to plant in a twin-row pattern at half the recommended seeding rate without sacrificing net market value but may increase the risk of yield due to TSWV damage.

Durum wheat quality I: some physical and chemical characteristics of Syrian durum wheat genotypes

SummarySome physical and chemical characteristics of nine Syrian durum wheat genotypes were determined in order to investigate the relationships among individual kernel components and kernel quality. All genotypes were grown on fully irrigated plots in Syria. Test weight, 1000‐kernel weight, kernel size distribution, hardness and semolina extraction rates were determined along with the chemical characteristics of the kernel (ash, moisture, protein, wet gluten, starch content and falling number). All tested genotypes had high test weight (83.1–85.9 kg hl−1) and 1000‐kernel weight (42.5–55.5 g) indicating high milling yield potential. Additionally, all the wheat genotypes demonstrated high falling numbers (433–597 s). Correlation coefficients among the quality properties showed that moisture content did not demonstrate any strong correlations with the studied quality parameters. Protein content exhibited a positive correlation with vitreousness (r = 0.78), and a negative correlation with ash content (r = −0.57). Test weight exhibited a negative correlation with 1000‐kernel weight (r = −0.66), and a positive correlation was observed between test weight and starch content of the kernel (r = 0.78). The results illustrate the commonality between Syrian durum wheat genotypes and US and Canadian durum wheat genotypes reported by researchers previously.

IMPROVING PEANUT YIELD AND GRADE WITH SURFACE DRIP IRRIGATION IN UNDULATING FIELDS

A surface drip irrigation system was developed to irrigate peanut in two experimental fields: one with very littletopographic variation on Greenville fine sandy loam soil, and one with undulating terrain containing 2.4% slope on Facevillefine sandy loam soil. Pod yield, kernel size distribution, and total sound mature kernels (TSMK) were evaluated with twopeanut varieties, two planting patterns, and two drip tape lateral spacings. Test results were compared with the adjacentnon-irrigated area planted with the same varieties of peanut. Soil temperature and volumetric water content were measuredat different locations to monitor soil temperature and water movement from drip tapes. Maximum soil temperature in theirrigated area was substantially lower than in the non-irrigated area. For both 13 and 25 mm irrigations, about 16 h wererequired for water to move laterally 46 cm to reach the peak water content level. No significant difference (p < 0.05) wasobserved in yields between 0.9 m and 1.8 m drip tape lateral spacings. Peanut yields with drip irrigation were 1.4 times thoseof the non-irrigated yield. The irrigation water use efficiency from surface drip irrigation was 10 kg/ha-mm during the twogrowing seasons. Yields tended to slightly decrease as the land elevation decreased for both irrigated and non-irrigated zones.Compared to the non-irrigated areas, the drip-irrigated area produced a greater portion of larger kernels than smallerkernels. In the undulating area, the average TSMK was 73.7% and 64.9% for drip-irrigated and non-irrigated treatments,respectively. Average gross revenue was $2,093 per ha with drip irrigation and $1,253 per ha with no irrigation.

Row Orientation and Seeding Rate on Yield, Grade, and Stem Rot Incidence of Peanut with Subsurface Drip Irrigation1

Abstract A 2-yr study was conducted on a Tifton loamy sand (fine-loamy, kaolinitic, thermic Plinthic Kandiudults) soil near Sasser, GA during the 2001 and 2002 growing seasons to determine the effects of three plant row orientations (single, twin, and multi-row) and two plant populations on the pod yield, market grade, and stem rot disease incidence of peanut when irrigated with subsurface drip irrigation (SDI). Seeds were planted at the recommended rate [20 seeds/m; 1.0R (recommended rate)] and half the recommended rate (10 seeds/m; 0.5R). Plots were irrigated daily to replace estimated daily evapotranspiration (ETa). Twin row orientation had the highest pod yield with 5407 kg/ha compared with the other row orientations, which averaged 4897 kg/ha. Market grade (total sound mature kernels, TSMK) for the twin and diamond row orientation was 1% point higher (74.7%) compared with the single row orientation. Pod yield was 8.5% greater for the 1.0R seeding rate compared with the 0.5R seeding rate. Stem rot incidence was highest in the single row orientation and lowest in the diamond row orientation. Within the three row orientations, kernel size distribution characteristics showed jumbo kernels had mixed percentages, with medium and ones showing no differences. The 1.0R plant population did have 4.4 % more jumbo kernels than the 0.5R plant population. This study indicates that twin row orientation and planted at the recommended rate (1.0R) had the best pod yield and market grade compared with single row orientation when irrigated with SDI.

POD YIELD AND KERNEL SIZE DISTRIBUTION OF PEANUT PRODUCED USING SUBSURFACE DRIP IRRIGATION

Longterm yield data are essential to determine the economic feasibility of installing a subsurface drip irrigation(SDI) system for crop production. However, first year yields and associated economic returns are vital for system paymentthe first year. Vegetable and row crop production has been successful with SDI, but pod yield and kernel size distribution dataon peanut (Arachis hypogaea L.) are limited especially during the installation year. Site 1 was established in 1997 on aFaceville sandy loam soil (fine, kaolinitic, thermic Typic Kandiudults) converted from native grass pasture. Site 2 wasestablished in 1998 on a Tifton sandy loam soil (fineloamy, kaolinitic, thermic Plinthic Kandiudults) following two yearsof cotton. These SDI systems include two lateral spacings (0.91 and 1.83 m) buried at 0.3 m soil depth. Site 1 had two emitterspacings (46 and 61 cm) and two irrigation levels. Site 2 had one emitter spacing (46 cm) and three irrigation levels. Anonirrigated (NI) control was included at each site. Irrigation water was applied daily based on estimated ETo whereirrigation level one (IL1) was ETo *Kc, and IL2 and IL3 were 75 and 50% of IL1, respectively. Pod yield increased 38% withSDI (5433 kg ha 1 ) compared to NI peanut (3937 kg ha 1 ). When compared to the state average (3012 kg ha 1 ), SDI showeda 81% pod yield increase. The percentage of jumbo kernels increased 39% at Site 1 and 81% at Site 2 compared with NI. SDIpeanut had lower quantity (75% less) of number one sized peanut kernels than NI. Overall, during the installation year, SDIhad higher pod yields and larger kernel size than NI treatments. These yield data can be useful when projecting the economicfeasibility of installing a SDI system and making the first year payment.

Relationship of Test Weight and Kernel Properties to Milling and Baking Quality in Soft Red Winter Wheat

Although test weight is used as a grading criterion and an indication of quality in wheat (Triticum aestivum L.), its relationship to specific quality parameters in soft wheat is not well documented. Seed characteristics, flour yield, and baking quality were studied in 24 soft red winter wheat (SRWW) genotypes grown in six environments to determine their relationship to test weight. Flour yield, flour protein, alkaline water retention capacity (AWRC), and softness equivalent (SEQ) were evaluated by the micro‐procedures of the USDA‐ARS soft wheat early‐generation milling and baking quality evaluation program. Despite removal of shriveled kernels prior to evaluation, environmental effects had a significant impact on quality parameters, ranging from 68% of total variability (SEQ) to 5% (AWRC). Test weight was correlated with flour yield, but was significantly correlated with flour protein content (r = 0.54, P &lt; 0.05) as was kernel density (r = 0.49). Thousand‐kernel weight, diversity of seed size, proportion of large seed, and average kernel length and width were not correlated with flour yield or other quality parameters. Test weight did not predict flour yield in SRWW when shriveling was absent, but it was related to flour protein content, which is associated with baking quality. Kernel size or size distribution did not affect end‐use quality. The best predictive model based on the characters above explained little of the total variation in flour yield (R2 = 0.22).

Shrinkage of Farmers Stock Peanuts During Storage1

Abstract A3-yr study was conducted during crop years 1989–91 to determine the value loss (shrinkage) experienced during long-term storage of farmers stock peanuts. Typical warehouses used to store each of the three major peanut market types were selected in each of the peanut production regions of the United States. Peanuts were purchased and stored according to conventional operating procedures for at least 60 d, unloaded, and hauled to the shelling plant (regrade). The loan value of the peanuts was determined using the 1990 Peanut Loan Schedule based on official grades and weights at load-in, bailout, and the shelling plant. Data from samples shelled at the National Peanut Research Laboratory Pilot Shelling Plant were used to determine the difference between outturns estimated from the official grade and the actual shelling outturns after storage. The 3-yr average change in value from load-in to regrade for runner peanuts was −2.04%; Spanish peanuts was −2.81%; and Virginia peanuts was −4.17%. Increases in foreign material and loose shelled kernels due to handling during loading and unloading, and changes in the kernel size distribution contributed equally to the value loss for the runner peanuts. Moisture loss to levels below 7% was responsible for approximately 20% of the value loss in both the Spanish and Virginia peanuts. Redistribution of kernel size, primarily the increase in split kernels, resulted in approximately 25% of the loss experienced in virginia-type peanuts. An increase in foreign material percentage accounted for approximately 50% of the Virginia peanut value loss. Increased foreign material and loose shelled kernels accounted for approximately 66% of the loss experienced in the Spanish peanuts. The total kernel weight obtained when the peanuts were shelled averaged 1.5% less than that estimated from the official grades at the time of original purchase. All market types had decreased outturn of whole edible kernels and increased split kernels. A net decrease in edible kernel outturns of 1.3% was observed.

Maize ( Zea mays L.) response to a severe soil water-deficit during grain-filling

Factors which reduce the rate or duration of grain-filling usually are detrimental to grain-yield. The effects of a severe soil water-deficit during the grain-filling period were studied for two commercial maize hybrids grown under field conditions utilizing a rain shelter. Two planting dates provided a range in the developmental stage at which deficits were imposed. Objectives were to compare the influence of the water-deficit on biomass accumulation, rate and duration of kernel-filling, kernel numbers, kernel size distribution, and final yield against an irrigated control. Deficit plants had less green leaf area during grain-filling due to early senescence. Above-ground biomass at the end of the growing season was 23–36% less for deficit plants than for irrigated control plants. Yield reductions ranged from 21% to 40% for the water-deficit treatments, with kernel weight being the most affected component. Individual kernel samples indicated that duration of the linear kernel-filling phase was shortened by as much as 8 days, whereas rate of single kernel-filling was not significantly reduced by the water shortages. There was a larger percentage of kernels weighing less than 100 mg for deficit plants, which reflected the abbreviated kernel-filling period.

Sink Manipulation in Wheat: Compensatory Changes in Kernel Size

Kernel size (KS), an important yield component of wheat (Triticum aestivum L.), depends on assimilate availability and the capacity of the kernel to use assimilates. The objective of this study was to evaluate the response of wheat cultivars with different KS (20 to 43 mg kernel −1,) to sink manipulation. Twenty cultivars grown at two locations were partially degrained by removal of all spikelets from one side of only one spike per plant. Control spikes were left intact. Partial degraining decreased kernel number (KN) by 51%. Relative compensatory kernel growth tended to increase with decreasing KS. However, the KS of five cultivars was unaffected by partial degraining, and the relative growth response of one small‐ and one large‐kernel cultivar each deviated markedly from the predicted response. Partial degralning enhanced kernel N of all cultivars, with an estimated 19 to 80% of the increase in KS attributed to greater accumulation of N compounds. For selected caltivars, the KS distribution and flag‐leaf abscisic acid (ABA) were determined to evaluate the relationship of sink size to these traits. Partial degraining altered KS distributions; for all but one of seven cultivars evaluated, partially degrained cultivars had the largest 5% of kernels and the single largest kernel. Compensatory kernel growth was unrelated to flag‐leaf ABA, indicating partial degraining had no adverse effects on assimilate supply related to excessive ABA levels in the flag leaf. These results demonstrate variable cultivar response to partial degraining; apparently, kernel growth of some cultivars is source limited, while other cultivars are at their capacity to accumulate assimilates.