Crossability of naturalized and cultivated Lythrum taxa

1994 ◽  
Vol 72 (3) ◽  
pp. 337-341 ◽  
Author(s):  
Kimberly A. Ottenbreit ◽  
Richard J. Staniforth
Keyword(s):  
Key Words ◽  
Wild Population ◽  
Lythrum Salicaria ◽  
Purple Loosestrife ◽  
Wild Plants ◽  
High Fertility ◽  
Viable Seed ◽  
Viable Seeds ◽  
Pollination And Fertilization

Lythrum cultivars Morden Pink, Morden Gleam, and Dropmore Purple, and a wild population of Lythrum salicaria from Lockport, Manitoba were artificially self- and cross-pollinated. Success of pollination and fertilization was measured in terms of the percentage of resulting capsules and the average numbers of viable seeds per capsule. Germination tests were used to measure the viability of seeds produced as a result of successful crosses. Cultivars rarely produced seeds as a result of selfing but many crosses with wild plants or with other cultivars were fertile. As expected, legitimate (i.e., different style morphs) wild crosses were highly fertile, but other crosses gave high fertility, especially those in which 'Morden Gleam' was the provider of pollen or ovules. Although some sterility was indicated in 'Dropmore Purple' and perhaps 'Morden Pink', neither are sufficiently sterile to be considered safe for ornamental flower gardens. Most illegitimate crosses yielded greatly reduced seed outputs in comparison to legitimate crosses, but there were some exceptions. Germinability of ripe seeds from any cross was high and averaged 98%. Cultivars of Lythrum are capable of contributing viable seed and (or) pollen to the spread of purple loosestrife. The sale of cultivars, regardless of parentage, should be prohibited. Key words: purple loosestrife, Lythrum spp., interfertility, hybridization.

Effect ofGalerucellaspp. on survival of purple loosestrife (Lythrum salicaria) roots and crowns

Weed Science ◽  
1999 ◽  
Vol 47 (3) ◽  
pp. 360-365 ◽  
Author(s):  
Elizabeth J. Stamm Katovich ◽  
Roger L. Becker ◽  
David W. Ragsdale
Keyword(s):  
Plant Stress ◽  
Growing Season ◽  
Lythrum Salicaria ◽  
Purple Loosestrife ◽  
Biological Control Agents ◽  
Plant Mortality ◽  
Galerucella Calmariensis ◽  
Galerucella Pusilla ◽  
Crown Tissue ◽  
Severe Leaf

Starch levels, used as a measure of plant stress, were not consistently reduced in root or crown tissue of purple loosestrife plants after 2 yr of severeGalerucella calmariensisorGalerucella pusilla(Coleoptera: Chrysomelidae) defoliation. Early in the season, defoliation fromGalerucellaspp. approached 100%, but the majority ofLythrum salicariaplants regrew by the end of August, resulting in an average reduction of 81% of the aboveground biomass compared to the control. The stress imposed byGalerucellaspp. defoliation was less than that achieved from more severe stress imposed by mechanical shoot clipping at 2- or 4-wk intervals from June to October. Both shoot-clipping treatments killed the majority of plants after one growing season.Galerucellaspp. feeding reduced plant stature, which may reduce competitiveness. However, considering the extensive carbohydrate reserves present in the large woody crowns ofLythrum salicaria, it will require in excess of 2 yr of consistent, severe leaf defoliation to cause plant mortality. A combination of stresses, such as winter crown injury, or other biological control agents in addition toGalerucellaleaf defoliation may be required for plant mortality.

Influence of Nontarget Neighbors and Spray Volume on Retention and Efficacy of Triclopyr in Purple Loosestrife (Lythrum salicaria)

Weed Science ◽  
1996 ◽  
Vol 44 (1) ◽  
pp. 143-147 ◽  
Author(s):  
Elizabeth J. Stamm Katovich ◽  
Roger L. Becker ◽  
Brad D. Kinkaid
Keyword(s):  
Plant Density ◽  
Spray Deposition ◽  
Soil Surface ◽  
Lythrum Salicaria ◽  
Purple Loosestrife ◽  
Central Target ◽  
Basal Portion ◽  
Spray Volume ◽  
Vegetative Propagules ◽  
Target Plant

Greenhouse studies were conducted to determine the influence of plant density and spray volume on the retention, spray deposition, efficacy, and translocation of the amine salt of triclopyr in purple loosestrife. More spray solution was retained on leaves at 935 Lha−1than at 94 Lha−1at populations of 0, 4, or 8 nontarget neighbors. Spray coverage decreased with decreasing height within the plant canopy when spray cards were placed in the top, middle, and soil surface adjacent to the central target plant. Within a population, spray card coverage generally increased as spray volume increased. Regrowth from the crown was affected by spray volume, and uniform spray coverage of the plant was required for adequate control of vegetative regrowth and was achieved with spray volumes of 374 and 935 L ha−1spray volume. Regrowth of purple loosestrife was greater at 94 Lha−1at all three plant populations indicating that less herbicide penetrated the canopy to reach the basal portion of the plant. A laboratory experiment was conducted to investigate the translocation of radiolabelled triclopyr to roots and crowns of purple loosestrife. Only 0.3 to 1.4% of absorbed14C-labelled material was translocated to roots and crowns. Low spray volumes and dense stands of purple loosestrife would likely result in poor control because inadequate amounts of triclopyr reach the basal portion of the plant and translocate to vegetative propagules.

Viable seed populations by soil depth and potential site recolonization after disturbance

1977 ◽  
Vol 55 (18) ◽  
pp. 2408-2412 ◽  
Author(s):  
Janice M. Moore ◽  
Ross W. Wein
Keyword(s):  
Soil Depth ◽  
Seedling Emergence ◽  
Mineral Soil ◽  
Organic Soil ◽  
Viable Seed ◽  
Soil Layers ◽  
Forest Experiment Station ◽  
Viable Seeds ◽  
Study Sites ◽  
Germination Experiment

Seedling emergence from organic and mineral soil layers was measured for nine study sites at the Acadia Forest Experiment Station near Fredericton, New Brunswick. The number of viable seeds showed a decrease from deciduous-dominated forest, to conifer-dominated forest, to organic soil study sites. Viable seed number varied from 3400/m2 for a deciduous-dominated forest study site to zero for a bog study site. Most seeds germinated from the upper organic soil layers of all study sites and were predominantly Rubus strigosus Michx. After the germination experiment, ungerminated seeds, which showed no viability by the tetrazolium test, were separated from the soil. These seeds were almost entirely Betula spp. and seed numbers were as high as 4200–9400/m2 for a deciduous-dominated forest. The applicability of the results to differing types of postdisturbance revegetation is discussed.

Winter survival of late emerging purple loosestrife (Lythrum salicaria) seedlings

Weed Science ◽  
2003 ◽  
Vol 51 (4) ◽  
pp. 565-568 ◽  
Author(s):  
Elizabeth J. Stamm Katovich ◽  
Roger L. Becker ◽  
Jane L. Byron
Keyword(s):  
Lythrum Salicaria ◽  
Winter Survival ◽  
Purple Loosestrife

Isozyme characterization of genetic diversity in Minnesota populations of purple loosestrife,Lythrum salicaria(lythraceae)

1996 ◽  
Vol 83 (3) ◽  
pp. 265-273 ◽  
Author(s):  
Mark S. Strefeler ◽  
Elizabeth Darmo ◽  
Roger L. Becker ◽  
Elizabeth J. Katovich
Keyword(s):  
Genetic Diversity ◽  
Lythrum Salicaria ◽  
Purple Loosestrife

The Biology and Management of Purple Loosestrife (Lythrum salicaria)

1998 ◽  
Vol 12 (2) ◽  
pp. 397-401 ◽  
Author(s):  
Barbra H. Mullin
Keyword(s):  
Large Scale ◽  
Management Practices ◽  
Habitat Degradation ◽  
Control Measure ◽  
Management Strategies ◽  
Lythrum Salicaria ◽  
Wildlife Habitat ◽  
Purple Loosestrife ◽  
Riparian Areas ◽  
Wetland Ecosystems

Purple loosestrife is an invasive, introduced plant that is usually associated with wetland, marshy, or riparian sites. It is found across the northern tier states and provinces in North America. Purple loosestrife affects the diversity of native wetland ecosystems. Infestations lead to severe wildlife habitat degradation, loss of species diversity, and displacement of wildlife-supporting native vegetation, such as cattails and bulrushes. The plant spreads effectively along waterways, and the thick, matted root system can rapidly clog irrigation ditches, resulting in decreased water flow and increased maintenance. Effective management of purple loosestrife along waterways and in riparian areas requires integrating management strategies to prevent further introductions, detecting and eradicating new infestations, and containing and controlling large-scale infestations. Management practices that aid in the control of purple loosestrife include herbicide, physical, and biological practices. Each infestation site should be individually evaluated to determine the appropriate control measure. Factors to be considered include the proximity and type of vegetation on the site, whether the water is flowing or still, and the utilization of the site and the water (domestic, irrigation, recreation, or scenic value).

Desiccation of alfalfa for seed production with diquat and glufosinate

1996 ◽  
Vol 76 (3) ◽  
pp. 435-439 ◽  
Author(s):  
J. R. Moyer ◽  
S. N. Acharya ◽  
J. Fraser ◽  
K. W. Richards ◽  
N. Foroud
Keyword(s):  
Key Words ◽  
Seed Production ◽  
Seed Yield ◽  
Seed Weight ◽  
Viable Seed ◽  
Hard Seed ◽  
Alfalfa Seed ◽  
Percent Germination ◽  
Medicago Sativa L ◽  
Seed Yields

Recommendations for desiccation of alfalfa do not clearly define the stage at which desiccants should be applied. To obtain this information, diquat and glufosinate were applied to alfalfa (Medicago sativa L) from 1991 to 1994 at various stages of maturity to determine the effect of desiccant and stage of maturity at desiccation on seed yield 1000-seed weight and seed germinability. Alfalfa seed yields, 1000-seed weights, percent germination and percent viable seed were similar after desiccation with diquat and glufosinate. Desiccation when 60–75% of the alfalfa seed pods were brown permitted maximum seed yields. Percent germination increased slightly in seeds that were exposed to weathering under normal conditions until all pods turned brown. Both desiccants adequately desiccated alfalfa for harvesting but desiccation with glufosinate took 2 or 3 d longer than diquat. Desiccants did not reduce alfalfa growth in the spring after application. Key words: Germination, yield, hard seed, seed weight, stage

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