A Flexible Ropewick Applicator for Use on Uneven Terrain

Weed Science ◽  
1985 ◽  
Vol 33 (5) ◽  
pp. 724-726 ◽  
Author(s):  
Russell S. Moomaw ◽  
Alex R. Martin
Keyword(s):  
Leafy Spurge ◽  
Euphorbia Esula ◽  
Weed Species ◽  
Flexible Pipe ◽  
Uneven Terrain

A 4.6-m-long, segmented, flexible-pipe ropewick applicator was constructed to apply picloram (4-amino-3,5,6-trichloropicolinic acid) to leafy spurge (Euphorbia esulaL. ♯ EPHES) and other weed species. Gauge wheels on each ropewick applicator segment permit height adjustments, and a loose, independent, vertical flexing action permits the segments to effectively traverse depressed or raised areas. The applicator was designed for use in pastures with rough, uneven terrain where it is difficult to uniformly wipe herbicide solution on plants with a rigid-pipe ropewick. The applicator was found to be durable and effective in applying picloram to leafy spurge.

scholarly journals Population Modeling Approach for Evaluating Leafy Spurge (Euphorbia esula) Development and Control

1988 ◽  
Vol 2 (2) ◽  
pp. 132-138 ◽  
Author(s):  
Bruce D. Maxwell ◽  
Mark V. Wilson ◽  
Steven R. Radosevich
Keyword(s):  
Control Strategies ◽  
Model Development ◽  
Research Priorities ◽  
Leafy Spurge ◽  
Population Models ◽  
Euphorbia Esula ◽  
Generation Model ◽  
Weed Species ◽  
Weed Population ◽  
Modeling Approach

Weed population models can serve as a framework to organize weed biology information and to develop weed control strategies. Models help to identify information gaps, to set research priorities, to develop hypotheses pertinent to weed population regulation, and to suggest control strategies. A population simulation model of leafy spurge (Euphorbia esulaL. # EPHES) was used to demonstrate the applicability of population models to weed science. Sensitivity analysis of an existing leafy spurge model indicated that transition from basal buds to vegetative shoots, survival of vegetative shoots, and survival of basal buds over winter were important transition parameters influencing population growth of this weed species. Possible mechanisms (intraspecific competition and environmental factors) that influence the transition from basal buds to vegetative shoots were shown. Intraspecific density effects on basal bud transition and production were included to show model refinement and second-generation model development. Four control strategies were simulated and were compared to field studies to show the predictive and management potential of the modeling approach. Simulations of population response to foliage feeding herbivores was highly correlated (r = 0.98) with field data for sheep grazing on leafy spurge. Simulation of picloram (4-amino-3,5,6-trichloro-2-pyridinecarboxylic acid) applied to leafy spurge also was correlated (r = 0.97) with field results.

Comparison of Aminocyclopyrachlor Absorption and Translocation in Leafy Spurge (Euphorbia esula) and Yellow Toadflax (Linaria vulgaris)

Weed Science ◽  
2014 ◽  
Vol 62 (2) ◽  
pp. 321-325 ◽  
Author(s):  
Rodney G. Lym
Keyword(s):  
Leafy Spurge ◽  
Euphorbia Esula ◽  
Perennial Species ◽  
Weed Species ◽  
Perennial Weed ◽  
Plant Parts ◽  
Yellow Toadflax ◽  
Excellent Control ◽  
Rapid Regrowth

Aminocyclopyrachlor has provided excellent control of many perennial weed species including leafy spurge, but control of yellow toadflax has been inconsistent.14C-aminocyclopyrachlor absorption was rapid in both leafy spurge and yellow toadflax and averaged 72% 48 h after treatment (HAT). However, translocation within the plant differed by species. More14C translocated to the aboveground portion of yellow toadflax (28% of applied) compared to leafy spurge (16.5% of applied). There was rapid translocation of14C-label to the roots of both species but more reached the belowground portion of leafy spurge than yellow toadflax. Over 12% of applied14C translocated into leafy spurge roots within 24 HAT but declined to 2% by 192 HAT. In comparison, only 2% of applied14C was found in yellow toadflax roots 24 HAT, and just 0.15% remained in belowground plant parts by 192 HAT. The inconsistent long-term control of yellow toadflax with aminocyclopyrachlor is likely due to poor translocation to the root system, which would allow for rapid regrowth in this hard to control perennial species.

scholarly journals Release of Postsenescent Dormancy in Leafy Spurge (Euphorbia esula) by Chilling

Weed Science ◽  
1988 ◽  
Vol 36 (6) ◽  
pp. 784-786 ◽  
Author(s):  
Stephen J. Harvey ◽  
Robert M. Nowierski
Keyword(s):  
Growth Rate ◽  
North America ◽  
Growth And Development ◽  
Leafy Spurge ◽  
Climatic Conditions ◽  
Euphorbia Esula ◽  
Flower Buds ◽  
Significant Growth ◽  
Number Of Stems

The growth and development of leafy spurge (Euphorbia esulaL. #3EPHES) collected during postsenescent dormancy and grown in the greenhouse was increasingly stimulated by chilling treatments longer than 14 days duration at 0 to 6 C. Production of stems with flower buds, primary flowers, and secondary flowers was greater in plants chilled for 42 days or more. The effects of chilling on total number of stems, number of strictly vegetative stems, or number of stems with vegetative branching were not significant. The height of the tallest stem per pot was influenced by chilling longer than 42 days. Growth rate also increased as a function of chilling duration. Based on our findings, we believe that there is little possibility that any significant growth can occur in the postsenescent period because of the prevailing climatic conditions found in areas of leafy spurge distribution in North America.

A Note on the Sugars and Amino Acids of Leafy Spurge, Euphorbia esula

Weeds ◽  
1956 ◽  
Vol 4 (3) ◽  
pp. 275 ◽  
Author(s):  
Duane Le Tourneau
Keyword(s):  
Amino Acids ◽  
Leafy Spurge ◽  
Euphorbia Esula

Cattle Foraging Behavior in Leafy Spurge (Euphorbia esula)-Infested Rangeland

1987 ◽  
Vol 1 (4) ◽  
pp. 314-318 ◽  
Author(s):  
Rodney G. Lym ◽  
Donald R. Kirby
Keyword(s):  
Warm Season ◽  
Economic Loss ◽  
Leafy Spurge ◽  
High Density ◽  
Euphorbia Esula ◽  
Low Density ◽  
Forage Production ◽  
Grazing Season ◽  
Grazing Cattle ◽  
Early Fall

Leafy spurge causes economic loss by reducing both herbage production and use. Herbage use by grazing cattle in various densities of leafy spurge (Euphorbia esulaL. #3EPHES) was evaluated over a 3-yr period in North Dakota. Forage production and disappearance were estimated in four density classes of leafy spurge. Use of cool- and warm-season graminoids, forbs, and leafy spurge was estimated during the middle and the end of each grazing season. Cattle used 20 and 2% of the herbage in the zero and low density infestations, respectively, by mid-season. Moderate and high density infestations were avoided until the milky latex in leafy spurge disappeared in early fall, and herbage availability in zero and low density infestations declined. Herbage use in moderate and high density infestations increased to an average of 46% by the end of the grazing season compared to 61% in zero and low density infestations. An annual herbage loss of at least 35% occurred in pasture infested with 50% density or more of leafy spurge.

Change in Leafy Spurge (Euphorbia esula) Density and Soil Seedbank Composition 10 Years following Release of Aphthona spp. Biological Control Agents

2013 ◽  
Vol 6 (1) ◽  
pp. 147-160 ◽  
Author(s):  
Cassandra M. Setter ◽  
Rodney G. Lym
Keyword(s):  
Native Species ◽  
Kentucky Bluegrass ◽  
Leafy Spurge ◽  
Euphorbia Esula ◽  
Stem Density ◽  
Ecological Sites ◽  
Western North Dakota ◽  
Soil Seedbank ◽  
Weedy Species ◽  
Native Species Richness

AbstractFlea beetles (Aphthona spp.) were released in the Little Missouri National Grasslands (LMNG) in western North Dakota in 1999 to control leafy spurge. The changes in leafy spurge density and soil seedbank composition were evaluated on two ecological sites 10 yr (2009) after Aphthona spp. release to monitor the effectiveness of the insects on weed control and the associated changes in plant communities. In 2009, leafy spurge stem density averaged 2 and 9 stems m−2 (0.19 to 0.84 ft−2) in the loamy overflow and loamy sites, respectively, compared with 110 and 78 stems m−2, respectively, in 1999. Leafy spurge constituted nearly 67% of the loamy overflow seedbank in 1999, compared with 2% in 2009. In the loamy seedbank, the weed represented nearly 70% in 1999, compared with approximately 15% in 2009. As leafy spurge abundance was reduced, native species richness and seed count increased 10 yr after Aphthona spp. release. Late seral species represented 17% of the loamy overflow seedbank in 2009, an increase from 5% in 1999. However, Kentucky bluegrass, a nontarget weedy species, increased more than 250% in the loamy overflow seedbank. Late seral species were 38% of the loamy seedbank in 2009, compared with 13% in 1999. The number of native species increased from 31 in 1999 to 39 in 2009 in the loamy overflow seedbank, but only changed from 32 to 34 species in the loamy site during the same period. The reestablishment of native species has been slow, but seedbank analysis indicates the number and type of species found before the leafy spurge infestation have increased. Planting native species in selected areas may have reduced the lag time in these species return to the seedbank and reduced invasion from other nondesirable species, such as Kentucky bluegrass.

Cytogenetic studies of leafy spurge, Euphorbia esula, and its allies (Euphorbiaceae)

1988 ◽  
Vol 66 (11) ◽  
pp. 2247-2257 ◽  
Author(s):  
A. E. Stahevitch ◽  
C. W. Crompton ◽  
W. A. Wojtas
Keyword(s):  
Seed Germination ◽  
Chromosome Number ◽  
Natural Populations ◽  
Leafy Spurge ◽  
Euphorbia Esula ◽  
Meiotic Abnormalities ◽  
Stability Studies ◽  
Polymorphic Species ◽  
Cytogenetic Studies ◽  
Euphorbia Cyparissias

Cytological and cytogenetic studies were carried out on populations of leafy spurge (Euphorbia esula L. s.l.) and its allies primarily from North America but also from Europe. Chromosome numbers were determined for 126 samples of E. esula, 11 of E. cyparissias L., 1 of the hybrid (E. ×pseudoesula Schur) between these two species, and 1 of E. agraria Bieb. All plants of E. esula were hexaploid. Of the total, 125 leafy spurge accessions had a chromosome number of n = 30; 1 of n = 25++. Very few meiotic abnormalities were observed. Euphorbia cyparissias was primarily tetraploid (n = 20), although occasional diploids (n = 10) were encountered. Tetraploids were fertile; diploids were sterile. The hybrid between the two foregoing species had a chromosome number of n = 25, indicating that the E. cyparissias parent was a tetraploid; meiosis in the hybrid was abnormal. Euphorbia agraria was found to have a gametic number of n = 20, which is the first chromosome number determination for this species; meiosis was normal. Artificial crosses were made successfully between 31 accessions of leafy spurge. Seed germination of the F1 progeny slightly exceeded that reported for natural populations, and meiosis was normal. Pollen stability studies were carried out on herbarium material. Stainability was 100% for most of the samples studied. Extensive pollen size polymorphism was found. It is suggested that this phenomenon supports the hypothesis that E. esula is of allopolyploid origin. No cytological or cytogenetic basis was found for considering the leafy spurge accessions examined in this study as other than as a single, albeit somewhat polymorphic, species.

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