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.

scholarly journals First Report of White Mold Caused by Sclerotinia sclerotiorum on Common Sage (Salvia officinalis) in Italy

Plant Disease ◽  
2004 ◽  
Vol 88 (9) ◽  
pp. 1044-1044
Author(s):  
A. Garibaldi ◽  
A. Minuto ◽  
M. L. Gullino
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Plant Density ◽  
Soil Surface ◽  
Salvia Officinalis ◽  
White Mold ◽  
Rooted Cuttings ◽  
First Report ◽  
Streptomycin Sulfate ◽  
High Plant Density ◽  
White Mycelium

Salvia officinalis L. is cultivated as an aromatic ornamental plant in Italy. In the spring of 2003, rooted cuttings grown in containers in commercial farms near Albenga (northern Italy) had soft and watery stem tissue covered with whitish mycelium at the soil level. Leaves and stems showed necrotic areas of irregular shape and size. As necrosis progressed, infected plants wilted and died. Wilt occurred within a few days on young plants. Because of high plant density, the pathogen spread rapidly within and across containers to infect many rooted cuttings. Sclerotinia sclerotiorum (Lib.) de Bary (2) was consistently recovered from infected stem pieces of Salvia officinalis that were disinfested for 1 min in 1% NaOCl and plated on potato dextrose agar (PDA) amended with 100 ppm of streptomycin sulfate. Sclerotia produced on PDA were ellipsoid and measured 1.4 to 4.2 × 1.1 to 2.1 (average 2.1 × 1.5) mm. Pathogenicity of three isolates obtained from infected plants was confirmed by inoculating 30-day-old plants grown in pots (14-cm diameter). Inoculum of each isolate was 14-day-old cultures of mycelium and sclerotia grown on sterile wheat kernels (300 g) and deionized water (320 ml) in a 1-liter flask at 20 to 25°C. Inoculum (10 g) of each isolate was placed on the soil surface around the base of 10 plants. Ten noninoculated plants served as controls. The inoculation trial was repeated once. All plants were kept in a screenhouse at temperatures ranging between 8 and 31°C and watered as needed. Inoculated plants developed symptoms of leaf yellowing, followed by the appearance of white mycelium within 7 days, and eventually wilted within 12 to 15 days. Control plants remained symptomless. White mycelium and sclerotia developed on infected tissues, and S. sclerotiorum was reisolated from inoculated plants on PDA amended with 100 ppm of streptomycin sulfate. To our knowledge, this is the first report of white mold of Salvia officinalis caused by S. sclerotiorum in Italy. The disease has been observed in Canada (1) as well as Tasmania and New Zealand. References: (1) G. J. Bolland and R. Hall. Can. J. Plant Pathol. 16:93, 1994. (2) N. F. Buchwald. Den. Kgl. Veterin.er-og Landbohojskoles Aarsskrift, 1949.

The influence of floral morph ratios and low plant density on mating and fertility in a tristylous colonizing species

Botany ◽  
2018 ◽  
Vol 96 (8) ◽  
pp. 533-545 ◽  
Author(s):  
Christopher M. Balogh ◽  
Spencer C.H. Barrett
Keyword(s):  
Field Experiment ◽  
Seed Set ◽  
Plant Density ◽  
Pollen Limitation ◽  
Lythrum Salicaria ◽  
Long Distance ◽  
Experimental Conditions ◽  
Wide Range ◽  
Morph Ratios ◽  
Floral Morph

Sexual reproduction in heterostylous populations may be vulnerable to demographic conditions because of the small number of mating types in populations. Here, we investigate mating and fertility under natural and experimental conditions in tristylous Lythrum salicaria L., an invasive species that exhibits a wide range of floral morph ratios and demographic contexts. We grew 147 open-pollinated seed families from six populations with different morph structures to estimate intermorph mating (d). In a field experiment, we used progeny ratios from 47 spatially isolated individuals to estimate d, and measured the intensity of pollen limitation experienced by the morphs. The M- and S-morphs experienced high rates of d, regardless of population size or morph ratio. Estimates for the L-morph revealed low levels of intramorph mating in three dimorphic and two trimorphic populations, but near complete intramorph mating in a monomorphic population. Despite high levels of intermorph mating in the field experiment, the morphs experienced significant pollen limitation of fruit and seed set, but this did not differ in intensity among the morphs. Our field experiment demonstrates that although plant isolation was associated with pollen limitation of seed set, “long-distance” bee-mediated pollen flow served to maintain intermorph mating. Tristyly in L. salicaria is remarkably robust to the demographic variation associated with colonization.

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.

scholarly journals Control of a Sharpshooter with Exp 80698A and Karate, 1997

1998 ◽  
Vol 23 (1) ◽  
pp. 273-273
Author(s):  
M. O. Way ◽  
R. G. Wallace
Keyword(s):  
Relative Humidity ◽  
Plant Density ◽  
Agricultural Research ◽  
Experimental Unit ◽  
Seeding Rate ◽  
Plastic Cylinder ◽  
Spray Volume ◽  
Extension Center ◽  
Sweep Net

Abstract The experiment was conducted in a greenhouse at the TAMU Agricultural Research and Extension Center at Beaumont and was designed as a RCB with 6 treatments and 4 replications. The greenhouse was maintained at 31° C, 70% relative humidity, and 12 h light:12 h dark. Each experimental unit was a pot (6 inch diam X 6 inch deep) filled with sifted League soil. On 30 Sep, selected pots were planted with 8 untreated or EXP 80698A 75 FS-treated seeds. Seeds were treated at the rates shown in the table using the “Le Sak” method developed by Rhone-Poulenc Ag Company. On the same day, selected pots were sprayed with EXP 80698A 75 FS at the rates shown in the table using a 4 nozzle (800067 tip size, 50 mesh screens), hand-held spray rig pressurized with CO2. Final spray volume was 9.0 gpa. On the same day, pots were fertilized with urea at 51 lb nitrogen/acre. Immediately following planting, and spraying, soil in each pot was “raked” with forceps to simulate incorporation. On 5 Oct, rice emerged through soil. On 21 Oct, selected pots were treated with Karate at the rate shown in the table using the same spray rig and final spray volume as before. Immediately after spraying Karate, a plastic cylinder was placed over 2 plants in each pot. Cylinders were 3 inch in diam so that the plant density within a cylinder was equal to a seeding rate of 90 lb/acre, given 100% emergence and survival of seeds. The cylinders were ventilated with screen windows and tops. After securing the cylinders, which served as cages, each was infested on 21 (Oct 17 d after emergence of rice through soil) with 5 adult sharpshooters. Insects were collected from untreated rice using a sweep net. Two d later, cages were inspected for live and dead sharpshooters. Data were expressed as % mortality which was transformed using arcsine. Transformed data were then analyzed by 2-way ANOVA and means separated by DMRT.

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).

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