11,741 research outputs found
Response of St. Augustinegrass to Fluridone in Irrigation Water
Research has shown that aquatic weeds, particularly hydrilla
(
Hydrilla verticillata
, (L.F.) Royle), can be controlled with
exposure of 8 to 12 weeks with concentrations of 10 to 15
ppb of fluridone (1-methyl-3-phenyl-5-[3-trifluoromethyl)
phenyl]-4(1
H
)- pyridinone) (Haller et al. 1990 and Fox et
al. 1994). Fluridone label recommendations restrict the use
of the treated waters for irrigation of turf or newly seeded
crops and seed beds for 30 days following the last application
of the herbicide. The objective of this
research was to determine the effects of 10 weeks of irrigation
with fluridone containing water on a common Florida
residential turfgrass
Carfentrazone-ethyl Pond Dissipation and Efficacy on Floating Plants
Carfentrazone-ethyl (CE) is a reduced risk herbicide that
is currently being evaluated for the control of aquatic weeds.
Greenhouse trials were conducted to determine efficacy of
CE on water hyacinth (
Eichhornia crassipes
(Mart.) Solms-
Laub.), water lettuce (
Pistia stratiotes
L.), salvinia (
Salvinia
minima
Baker) and landoltia
(Landoltia punctata
(G. Mey.)
Les & D. J. Crawford
)
. CE controlled water lettuce, water hyacinth
and salvinia at rates less than the maximum proposed
use rate of 224 g ha
-1
. Water lettuce was the most susceptible
to CE with an EC
90
of 26.9 and 33.0 g ha
-1
in two separate trials.
Water hyacinth EC
90
values were calculated to be 86.2 to
116.3 g ha
-1
, and salvinia had a similar susceptibility to water
hyacinth with an EC
90
of 79.1 g ha
-1
. Landoltia was not adequately
controlled at the rates evaluated. In addition, CE was
applied to one-half of a 0.08 ha pond located in North Central,
Florida to determine dissipation rates in water and hydrosoil
when applied at an equivalent rate of 224 g ha
-1
. The
half-life of CE plus the primary metabolite, CE-chloropropionic
acid, was calculated to be 83.0 h from the whole pond,
and no residues were detected in water above the limit of
quantification (5 μg L
-1
) 168 h after treatment. CE dissipated
rapidly from the water column, did not occur in the sediment
above the levels of quantification, and in greenhouse
studies effectively controlled three species of aquatic weeds
at relatively low rates.(PDF contains 6 pages.
Selectivity of Metsulfuron Methyl to Six Common Littoral Species in Florida
Many Central Florida lakes, particularly those in the Kissimmee
River watershed, are maintained 0.5 to 1.0 m lower than historic (pre-1960) levels during the summer hurricane
season for flood control purposes. These lower water levels
have allowed proliferation and formation of dense monotypic
populations of pickerelweed (
Pontederia cordata
L.) and
other broadleaf species that out compete more desirable native
grasses (Hulon, pers. comm., 2002). Due to the limited
availability of data on the effects of metsulfuron methyl on
wetland plants, particularly in Florida, the present study was
carried out with the objective of testing its phytotoxicity on
six wetland species, to determine the feasibility of its use for
primary pickerelweed control
Supersonic STOVL ejector aircraft from a propulsion point of view
A baseline supersonic STOVL ejector aircraft, its propulsion and typical operating modes is described, and important propulsion parameters are identified. Then a number of propulsion system changes are evaluated for improvement of the lift-off performance aft deflection of the ejector jet and heating of the ejector primary air either by burning or using the hot engine core flow. The possibility for cooling the footprint is illustrated for mixing or interchanging the fan and core flows, and in use of a core flow ejector. The application of a new engine concept the turbine bypass engine plus a turbocompressor to supply the ejector primary air, and thrust during takeoff combat are presented
Surface Derivatized Silica-Sol Particles as Immunospecific Markers for High Resolution Electron Microscopy
Thanks to methods developed in the forties and early fifties, highly concentrated,
extremely stable silica sols are produced in tonnage quantities and
are incorporated into such everyday products as floor waxes, textiles and
plastics1-s
Mineralocorticoid receptor blockade during a rat's first violent encounter inhibits its subsequent propensity for violence.
In individuals naive to serious conflict in an unfamiliar environment, violence has long-lasting effects on subsequent aggressive behavior. This effect of the stressful experience of a first violent conflict occurs in victims as well as offenders. The authors study in the male rat as offender the role of a rapid corticosterone signal mediated by brain mineralocorticoid receptors (MR) in adjusting the threshold of aggressive responses. For this purpose, the authors have applied electrical stimulation of the brain's aggression circuit via the hypothalamic attack area or HAA. Using this paradigm, they found that in inexperienced rats, retesting of the animals on subsequent days facilitated aggression. Hypothalamic attack thresholds decreased to about 50% of their initial level. However, blocking the MR once with the mineralocorticoid antagonist spironolactone, during the very first evoked attacks, permanently prevented attack facilitation in subsequent conflicts in that same environment. The MR-mediated effect blocked by the antagonist occurred within an hour following the start of the first aggression tests only. A later MR blockade was not effective. These findings suggest that the corticosterone stress response during a very first serious conflict initializes an enhanced propensity for violent aggression through the brain MR
Within the States\u27 Jurisdiction: Metropolitan, Northeast Bancorp, and the Equal Protection Clause
2007-01-15, Roger to Mother
https://digitalcommons.chapman.edu/rwhaller_collection/1000/thumbnail.jp
Efficacy and Residue Comparisons between Two Slow-release Formulations of Fluridone
Residue profiles and efficacy of Avast and Sonar, two slow
release pellet formulations of fluridone {1-methyl-3-phenyl-5-
[3-(trifluoromethyl)phenly]-4(1H)-pyridinone}, were compared
in outdoor tanks. Hydrilla (Hydrilla verticillata (L.f.)
Royle) and southern naiad (Najas guadalupensis (Sprengel)
Magnus) were treated with a split application of 6, 12, 18 and
24 μg/l a.i. fluridone and the concentrations of both formulations
compared over a 134-day period. Both pellet formulations
exhibited very similar residues over time for each
respective treatment, resulted in peak concentrations of fluridone
40 to 50 days after application, and effectively and
similarly controlled southern naiad and hydrilla at all rates
tested by 92 days after initial application. (PDF contains 3 pages.
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