FRICTIONAL PROPERTIES OF SELECTED SEEDS

K e y w o r d s: physical attributes, coefficient of external friction, relation. A b s t r a c t The thickness, width, length and weight of five seed species (buckwheat, vetch, pea, lupine and faba bean) and their external friction angle were determined on two types of surfaces -steel and rubber. The experiment was performed with the use of a an inclined plane with an adjustable angle of inclination that measures the angle of external friction and the time taken by seeds to travel a given distance, which supports the determination of the coefficient of kinetic friction. The measured parameters were used to calculate arithmetic and geometric mean diameter, aspect ratio and sphericity index. The dimensions, weight and the calculated indicators of the examined seeds did not significantly affect their coefficients of static and kinetic friction or their coefficients of rolling resistance and rolling friction. The studied parameters were largely influenced by the type of friction surface, and significantly lower average values were reported for steel than rubber. In the studied seed species, the static friction coefficient was determined in the range of 0.187 to 0.582, kinetic friction coefficient -0.134 to 0.479, rolling resistance coefficient -0.148 to 0.529 and rolling friction coefficient -0.29 to 1.80 mm. Symbols: D a -arithmetic mean diameter, mm, D g -geometric mean diameter, mm, m -seed weight, mg f 1 , f 2 -coefficient of rolling friction of seeds on steel and rubber, respectively, mm, r -radius of a rolling seed, mm, R -aspect ratio, %, S -travel distance of the particle, m, t -time required by the particle to travel distance, s, T, W, L -seeds thickness, width and length, mm, x, SD -average value and standard deviation of trait, x min , x max -minimum and maximum value of trait, α -angle of external friction of seeds, o , α s1 , α s2 -angle of static friction of seeds on steel and rubber, respectively, o , α t1 , α t2 -angle of rolling friction of seeds on steel and rubber, respectively, o , μ -coefficient of external friction of seeds, Correspondence: Zdzisław Kaliniewicz, Katedra Maszyn Roboczych i Metodologii Badań, Uniwersytet Warmińsko-Mazurski, ul. Oczapowskiego 11/B112, 10-719 Olsztyn, phone: +48 89 523 39 34, e-mail: [email protected] μ k1 , μ k2 -coefficient of kinetic friction of seeds on steel and rubber, respectively, μ s1 , μ s2 -coefficient of static friction of seeds on steel and rubber, respectively, μ t1 , μ t2 -coefficient of rolling resistance of seeds on steel and rubber, respectively. Φ -sphericity index, %

Influence of Scarification on the Germination Capacity of Acorns Harvested from Uneven-Aged Stands of Pedunculate Oak (Quercus robur L.)

Scarification involves the partial removal of the seed coat on the side of the hilum, opposite the radicle, to speed up germination in acorns. The aim of this study was to determine the influence of scarification on the germination capacity of pedunculate oak acorns, selected and prepared for sowing. The diameter, length and mass of acorns were measured before and after scarification in four batches of acorns harvested from uneven-aged trees (76, 91, 131 and 161 years). The measured parameters were used to determine the correlations between acorn dimensions and mass, and to calculate the dimensional scarification index and the mass scarification index in acorns. Individual complete and scarified acorns from every batch were germinated on sand and peat substrate for 28 days. The analyzed acorns were characterized by average size and mass. Scarification decreased acorn mass by around 22% and acorn length by around 31% on average. Scarification and the elimination of infected acorns increased germination capacity from around 64% to around 81% on average. Acorns can be divided into size groups before scarification to obtain seed material with varied germination capacity. Larger acorns with higher germination capacity can be used for sowing in container nurseries, whereas smaller acorns with lower germination capacity can be sown in open-field nurseries

Influence of Steel Plate Roughness on the Frictional Properties of Cereal Kernels

The aim of this study was to determine the correlation between the external friction angle of cereal kernels and the roughness of a steel friction plate. The experiment was performed on the kernels of five principal cereals: wheat, rye, barley, oats, and triticale. Flat seed units composed of three spaced kernels joined by adhesive tape were analyzed in each experimental variant. The external friction angle of flat seed units was determined on nine steel friction plates with different roughness. Measurements were performed in three replications with a photosensor device which registered the external friction angle of cereal kernels. On friction plates with surface roughness Ra = 0.36 to Ra = 6.72, the average values of the angle of external friction ranged from 17.56° in rye kernels to 34.01° in oat kernels. The greatest similarities in the angle of external friction were observed between wheat and triticale kernels, whereas the greatest differences were noted between barley and oat kernels and between barley and triticale kernels. Friction plates made of ST3S steel should be characterized by the lowest surface roughness to minimize energy consumption during grain processing. The optimal surface roughness of steel friction plates was determined at Ra = 0.9

Physical Properties of Seeds of Eleven Spruce Species

Information about the variations and correlations between the physical properties of seeds is essential for designing and modeling seed processing operations. The aim of this study was to determine the variations in the basic physical properties of seeds of selected spruce species and to identify the correlations between these attributes for the needs of the seed sorting processes. Terminal velocity, thickness, width, length, mass, and the angle of external friction were determined in the seeds of 11 spruce species. The measured parameters were used to calculate three aspect ratios (geometric mean diameter, sphericity index, and specific mass) of each seed. The average values of the basic physical properties of the analyzed seeds were determined in the following range: terminal velocity—5.25 to 8.34 m s−1, thickness—1.10 to 2.32 mm, width—1.43 to 3.19 mm, length—2.76 to 5.52 mm, the angle of external friction—23.1 to 30.0°, and mass—2.29 to 18.57 mg. The seeds of Jezo spruce and Meyer’s spruce were most similar to the seeds of other spruce species, whereas oriental spruce seeds differed most considerably from the remaining seeds. Our findings indicate that spruce seeds should be sorted primarily with the use of mesh sieves with longitudinal openings to obtain fractions with similar seed mass and to promote even germination

An analysis of variations and correlations between the physical properties of samaras of 11 maple species

Kluczem do projektowania i modelowania wielu procesów związanych ze zbiorem, obróbką i siewem nasion jest zdobycie informacji o zakresie zmienności ich cech fizycznych oraz występujących między tymi cechami współzależności. Dlatego też celem pracy jest wyznaczenie zakresu zmienności podstawowych cech fizycznych skrzydlaków wybranych ich gatunków oraz określenie współzależności między tymi cechami w aspekcie wykorzystania tych danych przy sortowaniu nasion. Z tego względu dokonano pomiarów prędkości krytycznej unoszenia, grubości, szerokości, długości i masy skrzydlaków jedenastu gatunków klonów oraz grubości i masy owocni każdego skrzydlaka po usunięciu skrzydełka. Na ich podstawie obliczono wskaźniki proporcji poszczególnych wymiarów i mas skrzydlaków. Dane z pomiarów i obliczeń opracowano statystycznie, wykorzystując analizę wariancji oraz analizę korelacji i regresji. Średnia prędkość krytyczna unoszenia skrzydlaków analizowanych gatunków klonów zawiera się w przedziale od 3,71 do 8,65 m·s–1, ich średnia grubość – od 0,28 do 0,61 mm, średnia szerokość – od 5,91 do 13,00 mm, średnia długość – od 21,59 do 45,60 mm, średnia masa – od 15,6 do 136,1 mg, średnia grubość owocni – od 1,31 do 6,38 mm oraz średnia masa owocni – od 12,4 do 110,6 mg. Pod względem masy skrzydlaki klonów są uszeregowane rosnąco wg następującej kolejności: tatarski, Henry’ego, Dawida, zielonokory, palmowy, jesionolistny, polny, jawor, kosmaty, okrągłolistny i pospolity. W procesie uszlachetniania materiału nasiennego klonów należy stosować separatory pneumatyczne i/lub separatory sitowe z sitami o otworach podłużnych, co zapewni większe wyrównanie uzyskanych frakcji pod względem masy skrzydlaków, a przy osobnym ich wysiewaniu może prowadzić do większego ujednolicenia terminu wschodów roślin.Information about the range of variation in the basic physical attributes of seeds and the presence of correlations between these attributes is essential for designing and modeling seed harvesting, processing and sowing operations. The aim of this study was to determine the range of variation in the basic physical properties of samaras of selected maple species and to identify correlations between these attributes for the needs of the seed sorting process. The terminal velocity, thickness, width, length and mass of samaras of 11 maple species and the thickness and mass of pericarps without wings were measured. The measured parameters were used to calculate the relative dimensions and the mass of samaras. The results were processed statistically by analysis of variance, correlation analysis and regression analysis. The average values of the evaluated parameters were determined in the following ranges: terminal velocity of samaras – from 3.71 to 8.65 m s–1, thickness of samaras – from 0.28 to 0.61 mm, width of samaras – from 5.91 to 13.00 mm, length of samaras – from 21.59 to 45.60 mm, mass of samaras – from 15.6 to 136.1 mg, pericarp thickness – from 1.31 to 6.38 mm, and pericarp mass – from 12.4 to 110.6 mg. The samaras of the analyzed maple species can be arranged in the following ascending order based on their mass: Tatarian maple, Henry’s maple, Père David’s maple, East Asian stripe maple, palmate maple, ash-leaved maple, field maple, sycamore maple, devil maple, vine maple and Norway maple. Maple seeds should be separated with the use of pneumatic separators and/or mesh sieves with longitudinal openings to produce fractions with similar samara mass and to promote germination uniformity

Effect of Biostimulants on the Yield and Quality of Selected Herbs

The aim of this study was to determine the effect of amino acid biopreparations on the yield of summer savory, marjoram, and lemon balm, and the concentrations of selected biochemical and mineral compounds in their herbage. The first experimental factor was plant species: summer savory (Satureja hortensis L.) var. Saturn, marjoram (Origanum majorana L.) var. Miraż, and lemon balm (Melissa officinalis L.). The second experimental factor was the effect exerted by two biopreparations, Calleaf Aminovital and Maximus Amino Protect, on herbage yield and quality. In the control treatment, plants were sprayed with water. The analyzed herb species differed considerably in yield and the concentrations of selected biochemical compounds and minerals. Lemon balm was characterized by the highest yield (1.73 kg m−2). Marjoram var. Miraż was characterized by the highest concentrations of reducing sugars (0.89 g 100 g−1 FM) and L-ascorbic acid (39.7 mg 100 g−1 FM). Summer savory was most abundant in total N, K, and Ca. The tested biostimulants contributed to a decrease in nitrate concentrations in the studied plants. The interaction between the experimental factors significantly affected the content of nitrates and mineral compounds and total N, P, K, and Ca in the herbage of the analyzed plant species

No Effect of Biostimulants on the Growth, Yield and Nutritional Value of Shallots Grown for Bunch Harvest

Shallots (Allium cepa L. Aggregatum group) are cultivated on small areas, mostly to harvest mature bulbs with dry scales. Due to their exceptional taste and nutritional value, and a short growing season, they can also be grown for early bunch harvest. New shallot cultivation strategies are being sought to meet consumers’ growing expectations regarding the quality of vegetables, and their increasing awareness of global food safety. Therefore, the aim of this study was to evaluate the effect of selected biostimulants on the biometric parameters, yield and nutritional value of shallot bulbs and leaves. The experimental factors were as follows: two biostimulant types—Effective Microorganisms (EM) and Goëmar Goteo (GG), two shallot cultivars—Bonilla F1 and Matador F1, grown for bunch harvest, and year of the study. Shallot leaves had a higher content of L-ascorbic acid, reducing sugars and nitrates than bulbs. Young bulbs had a higher content of DM and total sugars than leaves. The leaves and bulbs of shallot plants treated with EM accumulated the highest amounts of minerals. Macronutrient ratios were closer to optimal in shallot leaves than bulbs. The nitrate content of bulbs was inversely proportional to the nitrate content of leaves. Therefore, an increase in the nitrate content of leaves by around 330% led to an approximately 40% decrease in the nitrate content of bulbs. The correlations between the parameters of the chemical composition of shallots and shallot leaves show that the increase in the dry matter content of the bulbs (by approx. 60%) was accompanied by an increase in the L-ascorbic acid content in the leaves (by approx. 240%). The use of biostimulants in the cultivation of A. cepa L. Aggregatum group contributed to the reduction of L-ascorbic acid content in bulbs and had no positive effect on the leaves. Moreover, no positive effect of biostimulants on the reduction of nitrate content in shallot leaves and bulbs was observed, which is undesirable from the consumer’s point of view. After the use of biopreparations, the yield of shallots was lower than that of the control—by approx. 14% (EM) and approx. 4% (GG). Therefore, the measurable benefits of biostimulants in the cultivation of shallots grown for early bunch harvest do not balance the costs of their purchase and use

Effect of Biostimulants on the Yield and Quality of Selected Herbs

The aim of this study was to determine the effect of amino acid biopreparations on the yield of summer savory, marjoram, and lemon balm, and the concentrations of selected biochemical and mineral compounds in their herbage. The first experimental factor was plant species: summer savory (Satureja hortensis L.) var. Saturn, marjoram (Origanum majorana L.) var. Miraż, and lemon balm (Melissa officinalis L.). The second experimental factor was the effect exerted by two biopreparations, Calleaf Aminovital and Maximus Amino Protect, on herbage yield and quality. In the control treatment, plants were sprayed with water. The analyzed herb species differed considerably in yield and the concentrations of selected biochemical compounds and minerals. Lemon balm was characterized by the highest yield (1.73 kg m−2). Marjoram var. Miraż was characterized by the highest concentrations of reducing sugars (0.89 g 100 g−1 FM) and L-ascorbic acid (39.7 mg 100 g−1 FM). Summer savory was most abundant in total N, K, and Ca. The tested biostimulants contributed to a decrease in nitrate concentrations in the studied plants. The interaction between the experimental factors significantly affected the content of nitrates and mineral compounds and total N, P, K, and Ca in the herbage of the analyzed plant species

Numerical modeling of agricultural products with the use of reverse engineering – the example of cucumber fruits®

Celem pracy przedstawionej w artykule było zbudowanie za pomocą skanera 3D modeli numerycznych owoców ogórka siewnego odmiany Śremski oraz wykorzystanie tych modeli do analizy wybranych cech geometrycznych. Do budowy modeli oraz wykonania pomiarów zastosowano programy komputerowe ScanStudio HD PRO firmy NextEngine, MeshLab oraz Solid Edge v. 20. Dokładność pomiarów wynosiła d = 0.01 mm. Zmierzono pole powierzchni, objętość, pole powierzchni wybranych przekrojów, podstawowe wymiary owoców oraz współczynniki kształtu. Badanie wyników pomiarów przeprowadzono za pomocą testu t, przyjmując poziom istotności a = 0.05. Różnica między polem powierzchni określonym za pomocą skanera 3D a polem powierzchni obliczonym na podstawie formuły zaproponowanej przez McCabe i in. w 1986 jest istotna, natomiast różnica między objętością owocu ogórka określoną z modelu 3D a objętością ogórka określoną na podstawie formuły przedstawionej przez Gaston’a i in. w 2002 jest nieistotna. Model numeryczny opisujący szczegółowo geometrię owoców wraz z określoną masą i gęstością pozwala na efektywne wykorzystanie go w pracach badawczych i projektowych.Numerical models of cucumbers cv. Śremski were developed with the use of a 3D scanner, and the results were used to analyze selected geometric parameters of cucumber fruits. NextEngine ScanStudio HD PRO, MeshLab and Solid Edge v. 20 programs were used to develop the models and perform measurements. Geometric parameters were measured within an accuracy of d = 0.01 mm. The surface area, volume, selected cross-sectional areas, basic dimensions and aspect ratios of cucumbers were determined. The results were analyzed by a t-test at a significance level of a = 0.05. The difference between the surface area determined in the 3D scanner and the surface area calculated based on the formula proposed by McCabe et al. (1986) was statistically significant, whereas the difference between cucumber volume determined from the 3D model and the volume calculated based on the formula proposed by Gaston et al. (2002) was not statistically significant. Numerical models that describe the geometric properties, mass and density of fruit can be effectively used in research and design

An Evaluation of the Physical and Chemical Parameters in <i>Brassica</i> Seedlings Grown on Various Organic Substrates

Horticultural substrates should promote seed germination and seedling emergence. The value of the SPAD index was significantly influenced by the type of substrate. The substrates had a beneficial effect on plant height in comparison with the control substrate. Brassica plants grown on the substrates used in the experiment had a compact growth habit, which is a desirable trait in seedling production. In general, macronutrient uptake differed in Brassica plants grown on various substrates. Significant differences in this parameter were observed mainly in broccoli (increase of approx. 14%) and white cabbage (decrease of approx. 30%) grown on PRO2, and in all plants grown on PRO3 (increase of approx. 9% in broccoli, decrease of approx. 33% in white cabbage, and decrease of approx. 15% in cauliflowers). The substrates decreased the total micronutrient concentrations in broccoli leaves by around 15% (PRO1) to around 40% (PRO3) relative to the control substrate. In comparison with the control treatment, micronutrient levels in cauliflower leaves increased by around 12% on PRO1 to around 35% on PRO3. In white cabbage, the total micronutrient content of leaves increased by around 24% on PRO1, and decreased by around 20% and 35% on PRO2 and PRO3, respectively, relative to the control treatment