Physical Properties of Seeds of Eleven Fir Species

Abstract

Research Highlights: The correlations between seed mass and the remaining physical properties were determined in selected fir species, and a method for seed sorting was proposed to promote uniform germination and emergence. Background and Objectives: Information about the variation and correlations between the physical properties of seeds is essential for designing and modeling seed processing operations such as seed separation. The aim of this study was to determine the range of variation in the physical properties of seeds in eleven fir species, and to analyze the correlations between these parameters to improve the seed sorting process. Materials and Methods: Terminal velocity, thickness, width, length, the angle of external friction and mass were determined in the seeds of 11 fir species. The measured parameters were used to calculate the geometric mean diameter, three aspect ratios, sphericity index and the specific mass of each seed. Results: The seeds of Sierra white fir where most similar, whereas the seeds of balsam fir differed most considerably from the seeds of the remaining fir species. In the majority of the analyzed fir species, seed mass was most strongly correlated with terminal velocity, followed by thickness. Conclusions: Fir seeds should be sorted primarily with the use of mesh sieves with longitudinal openings to obtain fractions with similar seed mass and to eliminate the need for dewinging.

Analysis of the physical properties of spindle seeds for seed sorting operations

“…A comparison of variations in seed mass in different size fractions revealed that the optimal ratio of coefficients of variation (9:6) was obtained by dividing seeds into three fractions based on seed thickness. These findings indicate that similarly to common beech seeds 59 , seeds of selected spruce species 60 and fir seeds 37 , and hemp seeds 62 , spindle seeds should be sorted with the use of mesh screens with slotted apertures.…”

“…The studied spindle species differed significantly in seed mass and geometric mean diameter. In terms of mass, European spindle seeds are similar to field maple and small-leaved lime seeds 56 and the seeds of selected wheat cultivars 43 , 44 ; broadleaf spindle seeds most closely resemble European ash seeds 56 and grand fir seeds 37 ; large-winged spindle seeds are similar to glossy buckthorn seeds 56 ; Hamilton’s spindle seeds resemble common ivy seeds 56 , European black pine seeds 34 and Japanese fir seeds 37 ; and winged spindle seeds are similar to corkbark fir seeds 37 .…”

“…Broadleaf spindle seeds are similar to pedunculate oak seeds 57 in terms of the T/L aspect ratio, and to African star apple seeds 58 in terms of the W/L aspect ratio. As regards the W/L aspect ratio, Hamilton’s seeds resemble balsam and Korean fir seeds 37 , and European spindle seeds are similar to common hornbeam and black locust seeds 59 . Winged spindle seeds and cowpea seeds 39 are characterized by similar values of the sphericity index.…”

“…Specific seed mass was determined in the range of 5.3 g m −1 (winged spindle) to 8.3 g m −1 (European spindle), and the analyzed species differed significantly in this trait. In terms of specific mass, broadleaf spindle seeds are highly similar to Forrest’s fir seeds 37 ; European spindle seeds closely resemble silver and white fir seeds 37 ; Hamilton’s spindle seeds are similar to small-leaved lime seeds 59 and Sierra white fir seeds 37 ; and winged spindle seeds resemble Morinda spruce seeds 60 and European black pine seeds 34 .…”

“…Seeds that differ in both mass and dimensions cannot be accurately sorted into fractions. Therefore, the relationships between seed mass and other physical properties have to be analyzed to effectively plan and perform seed cleaning and sorting operations 34 – 37 . There is a general scarcity of published data on the distribution of basic physical properties of seeds belonging to different spindle species.…”