Seed Size Distribution, Germination, and Emergence of 6 Switchgrass Cultivars

Abstract

Sdtchgrass (Punicum virgatum L.) has potential as a forage and biomass crop, but difficult establishment has limited its use. Germination and emergence were studied for 6 eultivars of suitchgrass ('Alamo', 'Blac~~ell', 'Cave-in-Rock', 'Kanlow', 'Pathfinder', and 'Trailblazer'). Germination studies Tvere conducted to determine the effect of light on germination and coleoFfile length, and to determine the effect of seed size (40,50, 63, 700, and SO" air valve settings for a South Dakota seed blower) an germination. A greenhouse study was also conducted to examine the effect of seed size, planting depth, (5,10, and 20 mm), and soil type (sand and 2 silt loams) on emergence. Germination of unsized seed increased linearly as duration in the germination chamber increased from 7 to 21 days for all cultivars. Although presence of light did not affect germination, coleoptile length under continuous darkness averaged 4.1 cm and was greater than the 1.9 cm measured for those v.ith daily light exposure of 16 hours. Both germination and emergence increased nonlinearly as seed size increased. For both silt-loam soils, emergence was low acd not affected by planting depth. A nonlinear decline in emergence with increased planting depth uas detected in sand 7 days after pIant&, but not after 14 and 21 days. Results of the study indicate that seed size and soil texture had a greater effect on emergence than did planting depth dolm to a depth of 20 mm.

Enhancement of Switchgrass (Panicum virgatum L.) Biomass Production under Drought Conditions by the Ectomycorrhizal Fungus Sebacina vermifera

“…The cocultivated plants consistently produced higher levels of root biomass than control plants, suggesting a greater potential to sequester carbon and hold soils, both highly desired properties in a crop grown under low-input conditions. As with many warm-season perennial grasses, switchgrass can be difficult or slow to establish (1,20), and this is a major impediment to its implementation as a primary bioenergy crop (5). Therefore, both the shoot-and root-growth-promoting effects of S. vermifera, particularly at early points in plant development, are likely to improve competitiveness of switchgrass seedlings, especially during the establishment process.…”

Does Seed Size Affect Water Stress Tolerance in Quercus leucotrichophora A. Camus at Germination and Early Seedling Growth Stage?

“…4 The seed size variation has been shown to have several important ecological implications. It may affect seed germination, 5 emergence, 6 seedling establishment, 7 growth rate and plant size, 8 survivorship, 9 competitive ability and reproductive ability of adult plant. 10 Several studies carried out on weeds and crops have revealed that seedling size is usually directly related with food reserves and energy content of seeds which increases with seed weight.…”

Technical Note: Early harvest of squirreltail seed

“…In both 1995 and 1996, weight of seeds became significantly heavier for seeds collected later in the growing season (Table 2). Heavier seeds within a seed lot have been shown to exhibit higher germination amounts and better seedling emergence characteristics than lighter seeds (Aiken and Springer 1995, Limbach and Call 1996, Hou and Romo 1998. Seeds collected later in the process of seed head maturation also exhibit greater seed germination amounts (Phaneendranath et al 1978).…”