Academic literature on the topic 'Flupropanate'

Hyparrhenia hirta (L.) Stapf (Coolatai or Tambookie grass) has invaded roadside areas, travelling stock routes and grazing lands in northern New South Wales and southern Queensland. In these situations it is regarded as an undesirable species. There are no herbicides registered for use on this grass and little information is available on the long-term effectiveness of chemical control. Plots consisted of: 3 treatments imposed before herbicide application (untreated, mown and burnt); 5 herbicides [glyphosate, flupropanate (formerly tetrapion), 2,2-DPA, mixtures of glyphosatel flupropanate, and an untreated control]; 3 application rates for each herbicide; and 2 times of herbicide application (spring 1990 and autumn 1991). Herbicide effectiveness on Coolatai grass was measured by comparing reductions in dry matter and phytotoxicity up to 20 months after application. Six months after the spring application, yields were depressed (P<0.05) by herbicides (flupropanate applied at 4.4 kg a.i./ha and 2,2-DPA at 14.8 kg a.i./ha) and preapplication treatments (burnt plots sprayed with flupropanate at 1.1 and 2.2 kg a.i./ha), but their overall interaction was not significant. Ten months after autumn application, Coolatai grass yields were reduced (P<0.05) by herbicide, pre-application treatment and their interaction. Mowing and burning reduced (P<0.05) yields to 40 % of those in undefoliated plots. Yields were lowest (P<0,05) in mown (flupropanate 4.4 kg a.i./ha) and burnt (glyphosate, 2.16 and 4.32 kg a.i./ha, and flupropanate, 4.4 kg a.i./ha) treatments, where mean yields were <30% of the control. Seventeen and 20 months after application, none of the herbicide treatments gave 100% control of Coolatai grass. Glyphosate applied at 2.16 and 4.32 kg a.i./ha in autumn and flupropanate applied at 4.4 kg a.i./ha in autumn or spring were the most effective in the long term, reducing Coolatai grass dry matter yields by 70-80%.

Flupropanate (sodium 2,2,3,3 tetrafluoropropanate), a slow-acting lipid bio- synthesis-inhibiting herbicide, was recently registered in New Zealand as Taskforce (745 g/L flupropanate as the sodium salt) for the selective and long-term control of Nassella trichotoma (nassella tussock) in pastures. In five dose-response experiments in permanent hill pastures in Canterbury, conducted between 2012 and 2016, we measured the efficacy of the herbicide against established plants of N. trichotoma and its residual activity against recruiting seedlings. Mortality, as an average across the five sites, was 93% 1.5 years after applying 1.49 kg flupropanate/ha (the label-recommended rate), and 100% at 2.98 kg/ha. This indicates that an application rate higher than the label rate will be necessary for complete control of a N. trichotoma infestation. The presence of 1,000 and 6,250 visible seedlings of N. trichotoma/ha in the autumn 3.2 and 2.1 years after applying 1.49 kg flupropanate/ha (at a Greta Valley and Scargill site respectively) indicates that the herbicide’s soil residues had decayed within 12 months to a concentration lower than necessary to kill the germinating seedlings of N. trichotoma.

Flupropanate a soilactive herbicide that inhibits lipid biosynthesis has become available in New Zealand for the selective control of the stipoid grasses Nassella neesiana and N trichotoma in pasture In commercial spray operations and field trials the selectivity of the herbicide has been extremely variable As a first step towards identifying pasture species that could be safely sown following application of the herbicide the in vitro doseresponse of 33 species and cultivars (grasses and dicotyledons) was determined Ranking the cultivars based on the slopes of linear regressions fitted to their radicle lengths (relative to untreated control) against the logarithm of flupropanate dose suggested that ryegrass and Nassella spp are among the most sensitive whilst plantain chicory and some legumes including lucerne are relatively tolerant The rankings from this study will be subjected to validation in a field trial using a subset of the species

Nassella trichotoma (serrated tussock) is a hardy perennial grass weed that rapidly invades disturbed areas. Pasture competition is an important component of an integrated weed-management system for native pastures. This paper reports on a field experiment to ascertain the level of competition from native grasses for adult N. trichotoma plants. Native grasses prevented N. trichotoma plants from increasing in biomass and basal area when rotationally grazed or when grazing was removed and fertiliser was withheld. Smaller N. trichotoma plants (<500 mm2) were more likely to vary in size with very little change in larger plants. Flupropanate efficiently killed all N. trichotoma plants but caused considerable damage to perennial native species, resulting in an uncompetitive pasture dominated by broadleaf weeds.

Native perennial grass competition can substantially reduce the invasion of Nassella trichotoma (serrated tussock), a major perennial grass weed problem in south-eastern Australia. This paper reports on a field experiment that investigated the recruitment of N. trichotoma seedlings, and determined what level of native grass competition was needed to prevent establishment in the central-west of NSW. Grasslands that maintained >2 t dry matter (DM)/ha and 100% ground cover (measured in spring) prevented N. trichotoma seedling recruitment. Relatively small amounts of perennial grass (>0.5 t DM/ha measured in spring) resulted in mortality of N. trichotoma seedlings that had recruited earlier in the year, through the next summer. Flupropanate also markedly reduced native perennial grasses and substantially increased N. trichotoma seedling establishment 12 months after application. Rotational grazing to maintain adequate levels of DM was an important management tactic that prevented N. trichotoma establishment and survival.

Coolatai Grass Hyparrhenia hirta is an exotic perennial grass and environmental weed that is spreading rapidly in parts of southeastern Australia. This study examined the effects of Coolatai Grass invasion on the composition of ground strata vegetation within Kwiambal National Park in northern New South Wales. Plots that were heavily infested with Coolatai Grass together with matching control plots were surveyed. Coolatai Grass infestation reduced the richness of native ground strata plants and their projected groundcover, but did not affect the number of exotic species in plots. The control plots varied markedly in floristic composition, but infested sites were more homogenous, with Coolatai Grass clearly dominating the ground strata vegetation. Coolatai Grass appears to increase in abundance following fire; it persists under heavy grazing and is resistant to many herbicides. Spot spraying small swards and isolated tussocks with glyphosate or flupropanate provides prospects of control on a small scale, but there are no suitable methods for largescale control. Changes to roadside management practices could help to reduce the spread of Coolatai Grass, but research into seed bank dynamics and appropriate control techniques is required, as well as increased awareness of the threat to native vegetation posed by the species.

Serrated tussock (Nassella trichotoma) and Giant Parramatta Grass (Sporobolus fertilis) are among the most noxious weeds in Australia. Both cause problems in pasture and there are limited control measures relying heavily on the herbicide flupropanate. With the recent confirmation of flupropanate resistance in serrated tussock and the report of suspected flupropanate resistance in Giant Parramatta Grass (GPG), this option appeared to be under threat.The aims of this thesis were to determine the extent of flupropanate resistance in serrated tussock and GPG in Australia and to understand the genetics of flupropanate resistance in serrated tussock. This thesis also documents the GPG resistance to 2,2-DPA and investigates a fungal pathogen, Nigrospora oryzae, as a potential biocontrol agent for GPG. A local paddock survey determined the spread and extent of flupropanate resistance in serrated tussock within 5 km of the original resistant site. The pot-dose method of assessing resistance identified plants resistant to flupropanate up to 3.5 km from the original site found in Victoria. Seeds from these plants showed 0-100% resistance, with sensitive plants often having a low („T5%) level of resistant seed. These results indicate the movement of flupropanate resistance through seeds or pollen and shows that its spread occurred within one year of detection. A national mail survey confirmed the massive impacts of serrated tussock across Australia, with annual serrated tussock costs ranging from $15,000 to $16,000 per year per respondent. This survey also identified the widespread infestation of this weed in a variety of land use patterns, from pasture to native grasslands, and the decrease in the value of farmland as a result. Heritability studies using controlled breeding experiments indicated a strong involvement of a maternal component in the inheritance of flupropanate resistance in serrated tussock, with a minor proportion of resistance heritable through pollen. GPG plants and seedlings were tested for flupropanate and 2,2-DPA resistance.Seedlings tested for flupropanate resistance were highly resistant (tolerating 33-39 times more than sensitive biotypes). With 2,2-DPA, resistant GPG plants did not die even at 14 times the field rate and resistant seedlings also showed 5-6 times more resistance than the sensitive biotype. The study has confirmed that flupropanate and 2,2-DPA resistance now exists in GPG.The potential of Nigrospora oryzae, a pathogenic fungus, as a biocontrol agent for GPG was determined. Mature plants and seedlings of GPG were inoculated with conidia of N. oryzae using three treatments (run-off, crown, and spray). Inoculated plants were smaller, with greater proportions of dead leaves (70% with the run-off a nd crown treatments and 53% with the spray treatment) than the control plants. GPG seedlings inoculated with N. oryzae were stunted and showed greater proportions of necrotic leaves in all the treatments than the control. There is potential to develop N. oryzae as a mycoherbicide to control GPG and further testing is warranted.