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The alfalfa seeds intended for marketing must not contain any seeds of the dodder (Cuscuta spp.), because it is a quarantine weed in Serbia and the world. Cuscuta spp. are frequently found in natural alfalfa seeds; nevertheless and because of this, the seed must be processed, i.e. cleaned of weeds. The paper presents a study of seed size variability of Cuscuta spp. of four seed lots of natural alfalfa seeds originating from Banat, Serbia. From each of the four examined seed lots of natural alfalfa seeds, a difference in seed size was determined for 30 seeds of Cuscuta spp. per lot. The difference in seed length of Cuscuta spp. was 371 µm, and the difference in seed width was 330 µm. The coefficient of variation varied from CV=8.356% to 12.00% for seed width; and from CV=9.383% to 10.69% for seed length. Seed size of Cuscuta spp. did not significantly affect the efficiency of magnetic separator work in extracting Cuscuta spp. seeds from natural alfalfa seeds. [ABSTRACT FROM AUTHOR]

Seed processing and dormancy break treatments are recommended for rendering seeds restoration-ready. Conversely, fruit structures and seed coats may protect seeds from environmental harm in the field. We evaluated the effects of seed processing (by either keeping fruit structures or extracting seeds) and/or scarification (of physically dormant seeds) on the seedling emergence and establishment of 10 legume tree species from tropical forests and savannas of Central Brazil. We sowed seeds in a greenhouse for reference and in a field experiment conducted in tilled ready-to-seed sites. We monitored seedling emergence and survival for a year. We calculated the costs of harvesting, processing, and pretreating seeds, and considered the final cost of a 1-year-old seedling. Seed extraction resulted in lower emergence for most species in the greenhouse and in the field. It also accelerated emergence of three and four species in the greenhouse and the field, respectively. Scarification resulted in lower seedling emergence in the field for half of the species, while it increased emergence of three species in the greenhouse. Most species presented accelerated emergence both in the greenhouse and the field. The seedling cost was 1.6 to 74.6 times higher when seeds were processed, and 1.3 to 6.0 times when seeds were scarified, except for one species. Keeping fruit structures and seed coats reduced the costs of seeds and increased the success of direct seeding. [ABSTRACT FROM AUTHOR]

The use of larger seeds may improve the initial development, plant stand, and mass productivity in forage crops. The present study aimed to evaluate the effect of the size of seeds of Sudan grass (Sorghum sudanense L.), standardized on density, on parameters of physiological quality and crop productivity. Seeds were processed in a gravitational table in order to become uniform in terms of density and then submitted to sieves with apertures of 1.75 or 2.00 mm. Three different treatments (seeds without size classification, seeds with diameter between 1.75 mm and 1.99 mm, and seeds with diameter above 2.00 mm) were compared. This study consisted of a laboratory stage for the analysis of physiological variables of seed, and a stage in field plots under a randomized block design and 3 replicates. Larger seeds presented better physiological and productive performance and had a higher germination rate, seedling growth, and forage yield at the first cut. Both the sieve with opening of 1.75 mm and that of 2 mm were suitable for processing of seeds of this species. [ABSTRACT FROM AUTHOR]

Direct native seed planting is a cost-effective and popular approach for restoring degraded terrestrial ecosystems. However, the handling and precision seeding of multispecies mixes with diverse seed sizes, and shapes is logistically complex, requires highly customised equipment and often results in poor seedling establishment. This issue is accentuated in small-seeded species, where handling difficulties and a lack of precision placement result in seed wastage. The agricultural seed sector relies on the application of external material to small seeds to improve handling via seed pelleting. Yet this method has been rarely tested on small-seeded native species for ecological restoration. We pelleted the seeds of 15 small-seeded Myrtaceae species commonly used for seed-based restoration programs and recorded a range of physical traits. Prior to pelleting, each seed batch was tested for purity and viability and processed to improve quality (Pure Live Seed, PLS%). Seedling emergence from pelleted and control seeds was tested in controlled laboratory conditions and at two field sites in Western Australia. We linked seedling's emergence outcomes to the degree of physical modification achieved via pelleting to understand which trait would be responsible for a potential decrease or delay in emergence. Seed processing improved the average quality (PLS%) across all species from 23.4 ± 4.8% to 83.6 ± 2.3%. Seed pelleting, on average, resulted in a 27-fold increase in volume, a 30-fold increase in weight, and a 26% increase in bulk density. Seedling emergence response to pelleting varied among species, but on average, emergence speed was 3.1 days faster (p < 0.001) for pelleted seeds, while final emergence was not significantly different (p = 0.217). The results show that a combination of seed processing and pelleting can be used to increase and standardise seed physical properties for improved handling and precision seeding, with limited consequences on seedling emergence and faster emergence. This novel approach could enable the use of large-scale agricultural seeding equipment for rapid and cost-effective delivery of multispecies native seed mixes in biodiverse global restoration programs. • Seed quality of small-seeded Myrtaceae species is improved by seed processing • Seed pelleting greatly increased the size and volume of individual seeds. • The physical properties of pelleted seeds are more homogenous across species, improving handling of multi-species mixes. • Seed pelleting had limited effect on final seedling emergence but increased emergence speed. [ABSTRACT FROM AUTHOR]

The seed pelleting is one of the most perspective way of the presowing processing of seeds. It covers seeds with a shell of organomineral materials, polymer binders and target additives and helps to smooth their surface, provide seedlings in the early phases of development with the necessary elements of mineral nutrition, protecting them from pests and diseases. At present, this technique is used in agriculture for seeding small seeds. The studies presented in this article are aimed at optimizing the technological process of seed pelleting of coniferous tree species, namely, Scots pine (Pinus silvestris L.) and Korean pine cedar (Pinus koraiensis Siebold et Zucc.). Experimental studies were performed using an electromechanical seed drazhirator. The organomineral mixture was used in a ratio of 0.48 kg per 1 kg of seeds. At the end of the process, the bonding strength of the filler to the seeds was determined. The dynamics of formation of the layer thickness was determined on the cross sections of the treated seeds using an optical microscope. As a result, the dependence of the thickness of the layer on the time and repetition of the seed pelleting was established. The article presents diagrams of experimental information with its subsequent equalization by a theoretical law having a high agreement on a given time interval. The thickness of the first layer formed around the seeds of Scotch pine was 0,3 mm - 0,4 mm and Korean pine cedar - 0,5 - 0,7 mm. The seeder does not destroy this shell. When increasing the coating layer for 1 stage, the optimum thickness is reached within 7-8 minutes. When it is planned to increase the thickness of the layer, the draining process is expediently divided into 2 stages. The time of pelleting at stage 1 is 2 minutes, on the second - 6 minutes. When the thickness of the limiting layer is reached and the pelleting is continued, it is possible to reduce time. [ABSTRACT FROM AUTHOR]

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Seed processing machines remove viable seeds from non-viable seeds and inert materials based on physical characteristics. The objective of this study was to assess the effect of each processing machine alone on the physical and physiological qualities of the soybean seeds. Seed samples of two soybean cultivars - BMX Potência RR and NK 7059 RR - were collected from five machines separately: air-screen machine, spiral separator, size grader and gravity separator. The experimental design was a completely randomized factorial, varying with the equipment, with 20 replications. Samples were assessed by germination test, accelerated aging, viability and vigor by tetrazolium test (TZ), weathering damages (TZ class 3), mechanical damages (TZ 1-8) and (TZ 6-8), stink bug damages (TZ 1-8) and weight of one thousand seeds. The air-screen machine and the spiral separator did not contribute to improve physiological quality of seeds; the size grader concentrated mechanical damages in larger sizes and stink bug damages in smaller sizes. Gravity separators showed higher quality seeds at the upper part of the machine compared to intermediate and lower parts. Mechanical damages and stink bug damages can be reduced by gravity separator and weathering damages are not eliminated by any of the machines. [ABSTRACT FROM AUTHOR]

Coffea arabica L. is highly homozygotic and caffeine content in most cultivars is reported to be similar (approximately 1%). The caffeine content was analysed using individual seeds of cultivars Catuaí Vermelho, Mundo Novo and Bourbon Vermelho, and varieties Mokka and Laurina of C. arabica. Seeds were cut transversely in half, a thin slice from each was extracted in a mixture of chloroform and methanol, and caffeine was measured by high performance liquid chromatography. The extraction procedure was validated by comparison with two conventional methods less suited for analysing large numbers of seeds. The results revealed an unexpectedly large variation [Catuaí Vermelho: 3.72-25.9mgg-1 (seeds); Mundo Novo: 5.06-18.59mg g-1; Bourbon Vermelho: 6.76-16.59mgg-1] even in types naturally low in caffeine such as Laurina (1.17-9.97mg g-1) and Mokka (2.01-9.64mgg-1). The mean values for all cultivars were always in the range of the caffeine content found in the literature. Several studies showed that C. arabica has approximately 10% cross-pollination, but the variation observed in caffeine content in individual seeds was too large to be explained by cross-pollination. [ABSTRACT FROM AUTHOR]

The 2007 growing conditions were not farourable for corn production. Soil drought was present in a larger part of the growing seeson. The drought was combined with exception ally high temperatures, which caused pollen deterioration and reduced pollination. In spite of the unfavourable conditions, some growers obtained satisfactory yields of seed corn, which were close to yields obtaned in commercial production. Evidently, these growers adhered to the recommended cultivation practices and their schedule. Harvest and drying, two important operations, were well-organized and they were completed al ready by the beginning of October. Despite the poor production conditions and low yields, seed quality was good, which vouchsafes a safe and profitable commercial production. [ABSTRACT FROM AUTHOR]