Factors Affecting Germination of Dogfennel (Eupatorium capillifolium) and Yankeeweed (Eupatorium compositifolium)

Abstract

Laboratory studies were conducted to determine the effect of various factors on germination of dogfennel and yankeeweed. Dogfennel seed were found to be strongly photoblastic with no germination in the dark. Yankeeweed seed were moderately photoblastic, with 12% germination occurring in the absence of light Germination for both species increased in response to red light (650 nm), indicating phytochrome regulation. At the soil surface, dogfennel and yankeeweed emergence was 40 and 48%, respectively, but declined rapidly with increasing soil depths where dogfennel germination was lower than that of yankeeweed. Yankeeweed germination was 60 to 75% from 10 to 30 C while dogfennel germination was 45 to 70% between 15 to 30 C. Both species germinated over a broad range of pH (6 to 10) with the highest germination occurring at pH 8. Yankeeweed and dogfennel were moderately tolerant to water stress, but yankeeweed tolerated higher water stress than dogfennel. Both species germinated over a wide range of conditions, possibly enhancing adaptation to many diverse environments.

Light, Temperature, Seed Burial, and Mulch Effects on Mulberry Weed (Fatoua villosa) Seed Germination1

“…On the basis of the regression equations in Figures 1 and 2, a planting depth of Ն 1.8 cm or mulching to a depth of Ն 3.7 cm will provide Ն 90% mulberry weed control. This emergence response is typical of many small-seeded species (Baird and Dickens 1991;Billeaud and Zajicek 1989;Biswas et al 1975;MacDonald et al 1992;Smith et al 1998;Soteres and Murray 1981). MacDonald et al (1992) reported that dogfennel did not emerge from greater than 0.75-cm depth.…”

“…3 Knowledge of weed biology, particularly germination requirements, is important when developing effective integrated management programs (Bhowmik 1997). Light stimulates seed germination of many weed species (Biswas et al 1975;MacDonald et al 1992). Therefore, cultural controls such as mulching may be used to reduce emergence of weeds that require light for germination (Buhler et al 1997;Zimdahl 1999).…”

Effects of Environmental Factors on Germination and Emergence of Swallowwort

“…and milkweed vine, is also sensitive to extremes in hydrogen ion activity (Baird and Dickens 1991; Singh and Achhireddy 1984;Wilson 1979). Germination under a variety of soil conditions enhances the ability of a plant to invade diverse habitats (MacDonald et al 1992). Based of the results of this study, a broad pH range for germination indicates that pH should not be a limiting factor for swallowwort seed invasion in most soils.…”

Rainfall interception and redistribution by a common North American understory and pasture forb, <i>Eupatorium capillifolium</i> (Lam. dogfennel)

“…Dogfen-D. A. R. Gordon et al: Rainfall interception and redistribution by a common North American understory nel is a forb of the Asteraceae family that is native to (and widespread across) North America (Van Deelen, 1991;Wunderlin and Hansen, 2003). Although dogfennel behaves as an annual plant throughout much of its North American range, it can behave as a perennial in the southern US by overwintering as a rosette, typically from January to March, before regrowing from a taproot in the spring, typically in April (Macdonald et al, 1992(Macdonald et al, , 1994. Dogfennel can be abundant in disturbed forest understories, particularly pine forests (Brockway et al, 1998) and pastures (Fig.…”