Use of herbicides for selective removal of Eragrostis curvula (Schrad.) Nees from a Phalaris aquatica pasture

1985 ◽  
Vol 25 (3) ◽  
pp. 665 ◽  
Author(s):  
MH Campbell ◽  
JJ Dellow ◽  
MJ Keys ◽  
AR Gilmour

In the main experiment, the effectiveness of tetrapion, glyphosate and 2,2-DPA in selectively removing Eragrostis curvula from a Phalaris aquatica pasture was determined by applying each at three rates in July 1980, September 1980, December 1980 and March 1981 near Braidwood, New South Wales. Auxiliary experiments were conducted from April 1981 to April 1983 to determine the reliability of herbicide effect on E. curvula. Tetrapion (2.25 and 3.375 kg/ha a.i.) was the most effective herbicide in killing E. curvula and promoting P. aquatica and Trifolium subterraneum. It was more selective when applied in September 1980 and December 1980 than when applied in July 1980 or March 198 1. Re-infestation by E. curvula seedlings in the 3 years after spraying with tetrapion amounted to a maximum of 3% of ground cover. In the auxiliary experiments, tetrapion was effective on all nine occasions of application, which demonstrated its reliability and effectiveness at any time of the year. Glyphosate (1.08 and 1.62 kg/ha a.i.) was effective in killing E. curvula in March 1981 but this result could not be repeated in March 1982 or March 1983 or in nine other applications at other times in these years. 2,2-DPA (maximum rate 22.2 kg/ha a.i.) was ineffective in killing E. curvula at four times of application. Recovery of the P. aquatica pasture after treatment declined in the order: tetrapion >2,2-DPA>glyphosate.


1986 ◽  
Vol 26 (3) ◽  
pp. 331 ◽  
Author(s):  
MH Campbell ◽  
MJ Keys ◽  
RD Murison ◽  
JJ Dellow

The effects of time and rate of application of glyphosate, 2,2-DPA and tetrapion on Poa labillardieri and Themeda australis were measured in seven experiments carried out 55 km south of Braidwood, on the southern tablelands of New South Wales between 1980 and 1982. In an eighth experiment (1981) and in a 35-ha demonstration (1983), at the same site, the effects of applying herbicides (before and after the autumn break) and surface-sowing Phalaris aquatica, Festuca arundinacea and Trifiolium repens with fertiliser on the control of P. labillardieri were ascertained. All three herbicides proved effective in reducing the ground cover of P. labillardieri from applications at any time of the year. For T. australis, tetrapion proved effective when applied at any time of the year, while glyphosate and 2,2-DPA were effective in all seasons except winter. Glyphosate at rates between 0.72 and 1.44 kg/ha a.i. was more cost effective than 2,2-DPA (11.1 kg/ha a.i.) and tetrapion (3.75 kg/ha a.i.). Best establishment and development of sown grasses and legumes was attained by applying herbicides after the autumn break but before heavy frosts, and then surface-sowing 1-3 months later. Control of P. labillardieri was best where P. aquatica and F. arundinacea established most densely.



2005 ◽  
Vol 45 (4) ◽  
pp. 401 ◽  
Author(s):  
W. H. Johnston ◽  
P. S. Cornish ◽  
V. F. Shoemark

A grazing experiment conducted in Wagga Wagga (New South Wales) from September 1993 to September 1998 compared the productivity of pastures containing 3 palatable types of summer-active Eragrostis curvula complex, with pastures containing either Medicago sativa or Phalaris aquatica. Issues relating to the management of E. curvula pastures were also investigated. Herbage growth rates of the P. aquatica and M. sativa pastures were highest in winter and spring; E. curvula pastures were most productive in summer and autumn. Stocking rates equivalent to 30–40 dry sheep were carried by the pastures during their growing seasons. Throughout the study, the pastures were dominated by their respective sown perennial species, however, a suite of desirable and undesirable annual grasses and annual legumes usually contributed >20% of total herbage mass in spring. The P. aquatica pasture contained a higher proportion of weedy species than the other pastures, especially C4 grasses and broadleafed species, and towards the end of the experiment it was also invaded by several native perennial grasses. Overall, the wool yield from the M. sativa pasture was 0.5–1.0 kg/animal.year higher than the other pastures. Management to minimise herbage accumulation on the E. curvula pastures was a key issue, and provided that pastures were grazed heavily, this was achieved by the rotational grazing strategy used in the experiment. It was concluded that palatable varieties of E. curvula have a useful and complementary role as perennial pastures in southern Australia. By increasing herbage availability in summer and autumn, E. curvula may improve management flexibility for a wide range of pastures that are commonly grown on farms.



2005 ◽  
Vol 45 (10) ◽  
pp. 1255 ◽  
Author(s):  
W. H. Johnston ◽  
P. S. Cornish ◽  
T. B. Koen ◽  
V. F. Shoemark

The productivity, carrying capacity and liveweight performance of wether sheep grazing pastures of Eragrostis curvula cv. Consol and Medicago sativa cv. Nova, which were also sown with annual grasses and Trifolium subterraneum, were compared under an intensive 4-paddock rotational grazing regime in a ‘put-and-take’ grazing experiment at Wagga Wagga, New South Wales from November 1993 to August 1996. The productivity of the pastures was broadly similar, with production peaks of >1000 kg/ha in winter and >3000 kg/ha in spring and summer in paddocks that had been spelled for 6 weeks. Although annual species contributed a high proportion of the total herbage mass in spring, over the remainder of the year, both pastures were dominated by their respective perennials. E. curvula maintained an average plant density of approximately 20 plants/m2. The density of M. sativa declined noticeably during the 3 years, and at the end of the experiment M. sativa plants in 1 replicate of the experiment were killed by rising groundwater and dryland salinity. The long-term average stocking rate of E. curvula and M. sativa pastures were similar (12.1 v. 12.5 sheep/ha) and both pastures were capable of sustaining high stocking rates for lengthy periods in spring and summer. Sheep grazing M. sativa tended to be heavier than animals grazing E. curvula, and they produced, on average, 1.1 kg (or 21%) more wool. However, M. sativa was more difficult to establish and its costs for weed and insect control were higher. Therefore, although it was more productive, it might not have been the most economically viable of the 2 pastures. The implications of the findings were discussed within a whole-farm context and it was concluded that E. curvula has a complimentary role to M. sativa for sowing on landscapes and in situations to which M. sativa is poorly adapted.



1987 ◽  
Vol 27 (3) ◽  
pp. 359
Author(s):  
MH Campbell ◽  
HW Kemp ◽  
RD Murison ◽  
JJ Dellow ◽  
H Ridings

In 3 experiments near Candelo, New South Wales, the effectiveness of tetrapion, glyphosate and 2,2-DPA in selectively removing Eragrostis curvula (agronomic type Tall Chloromelas) from a Pennisetum clandestinurn pasture was determined by applying each at various rates in each season of the year in 1981-82 (experiments 1 and 2) and in 1983 (experiment 3). Experiment 4 examined the effect of the herbicides on 3 cultivars of P. clandestinum when applied in each season in 1983-84. Tetrapion (2.25 and 3.00 kg/ha a.i.) was the most effective herbicide in killing E. curvula and promoting P. clandestinum in experiments 1 and 2, but, in experiment 3, glyphosate and 2,2-DPA were equally effective in killing E, curvula at 3 (glyphosate) and 2 (2,2-DPA) of the 4 application times. The differences between the results of the experiments were attributed to the herbicide being leached faster by the higher rainfall and being immobilised by the greater amounts of dead foliage of E. curvula in experiment 3. Despite occasional success in killing E. curvula, glyphosate and 2,2-DPA could not be considered for selective use as both were much more phytotoxic to P. clandestinum than tetrapion (experiment 4). Time of application had little influence on the selectivity of tetrapion, the least effective being May-June. In experiments 1 and 2, E. curvula was still well controlled by P. clandestinurn 5 years after the application of tetrapion. Pennisetum clandestinum cv. Crofts was more tolerant of tetrapion than were cvv. Whittet or Common.



1987 ◽  
Vol 14 (2) ◽  
pp. 163 ◽  
Author(s):  
D. Lunney ◽  
B. Cullis ◽  
P. Eby

This study of the effects of logging on small mammals in Mumbulla State Forest on the south coast of New South Wales included the effects of a fire in November 1980 and a drought throughout the study period from June 1980 to June 1983. Rattus fuscipes was sensitive to change: logging had a significant impact on its numbers, response to ground cover, and recapture rate; fire had a more severe effect, and drought retarded the post-fire recovery of the population. The three species of dasyurid marsupials differed markedly in their response to ground cover, canopy cover, logging and fire. Antechinus stuartii was distributed evenly through all habitats and was not affected by logging, but fire had an immediate and adverse effect which was sustained by the intense drought. A. swainsonii markedly preferred the regenerating forest, and was not seen again after the fire, the failure of the population being attributed to its dependence on dense ground cover. Sminthopsis leucopus was found in low numbers, appeared to prefer forest with sparse ground cover, and showed no immediate response to logging or fire; its disappearance by the third year post-fire suggests that regenerating forest is inimical to the survival of this species. Mus musculus showed no response to logging. In the first year following the fire its numbers were still very low, but in the next year there was a short-lived plague which coincided with the only respite in the 3-year drought and, importantly, occurred in the intensely burnt parts of the forest. The options for managing this forest for the conservation of small mammals include minimising fire, retaining unlogged forest, extending the time over which alternate coupes are logged and minimising disturbance from heavy machinery.



1994 ◽  
Vol 34 (1) ◽  
pp. 33 ◽  
Author(s):  
GM Lodge

Burrs were collected from paddocks on 3 properties in northern New South Wales where the age of the Trifolium subterraneum var. brachycalycinum cv. Clare swards varied from 19 to 28 years. At 1 site burrs were also sampled from swards sown 2 and 10 years previously. Twenty seedlings from these burrs and 20 plants of certified cv. Clare were grown as spaced plants in a nursery. These were assessed for vegetative and floral characters, flowering time, number of seeds per burr, seed weight, and percentage hardseed after storage at 25/25�C for 6 months and 25/45�C for a further 6 months. For most plants the mean number of days from sowing to first flower was similar to that of Clare. Compared with the naturalised strains, Clare had the lowest (P<0.05) mean number of seeds per burr: about 25% below the mean of the strains (2.7 seeds per burr). While the lowest mean seed weights of the strains were not significantly different from those of Clare, the seed weights of plants from 3 sites were higher (P<0.05) than those of Clare. After storage for either 6 or 12 months, hardseed levels were also lowest (P<0.05) for Clare. Plants from the 2-year-old sward had the same median number of seeds per burr (2.0) as Clare. As sward age increased, the median number of seeds per burr increased to 2.8. Hardseed percentages were lowest for plants of Clare and for those from the 2-year-old sward after 6 months, and for Clare after 12 months. These studies indicated the presence of divergent strains in old swards of Clare in a summer rainfall environment. Natural selection among variability within Clare is the most likely reason for the development of these strains in an environment marginal for the long-term persistence of this softseeded cultivar. Although strains had the same vegetative and floral markings as Clare, differences in ecologically important characters such as number of seeds per burr, seed weight, and hardseededness may result in plants that are better adapted to the environment in which they evolved. From these studies 23 plants of T. subterraneum var. brachycalycinum were selected for further evaluation.



2001 ◽  
Vol 41 (2) ◽  
pp. 187 ◽  
Author(s):  
R. Aldaoud ◽  
W. Guppy ◽  
L. Callinan ◽  
S. F. Flett ◽  
K. A. Wratten ◽  
...  

In 1995–96, a survey of soil samples from subterranean clover (Trifolium subterraneum L.) paddocks was conducted across Victoria, South Australia, New South Wales and Western Australia, to determine the distribution and the prevalence of races of Phytophthora clandestina (as determined by the development of root rot on differential cultivars), and the association of its occurrence with paddock variables. In all states, there was a weak but significant association between P. clandestina detected in soil samples and subsequent root rot susceptibility of differential cultivars grown in these soil samples. Phytophthora clandestina was found in 38% of the sampled sites, with a significantly lower prevalence in South Australia (27%). There were significant positive associations between P. clandestina detection and increased soil salinity (Western Australia), early growth stages of subterranean clover (Victoria), mature subterranean clover (South Australia), recently sown subterranean clover (South Australia), paddocks with higher subterranean clover content (Victoria), where herbicides were not applied (South Australia), irrigation (New South Wales and Victoria), cattle grazing (South Australia and Victoria), early sampling dates (Victoria and New South Wales), sampling shortly after the autumn break or first irrigation (Victoria), shorter soil storage time (Victoria) and farmer’s perception of root rot being present (Victoria and New South Wales). Only 29% of P. clandestina isolates could be classified under the 5 known races. Some of the unknown races were virulent on cv. Seaton Park LF (most resistant) and others were avirulent on cv. Woogenellup (most susceptible). Race 1 was significantly less prevalent in South Australia than Victoria and race 0 was significantly less prevalent in New South Wales than in South Australia and Western Australia. This study revealed extremely wide variation in the virulence of P. clandestina. The potential importance of the results on programs to breed for resistance to root rot are discussed. in South Australia.



1988 ◽  
Vol 28 (1) ◽  
pp. 53 ◽  
Author(s):  
WH Johnston

The palatability of 20 accessions of E. curvula collected from naturalised populations in New South Wales was compared on 7 occasions with 2 selected accessions previously found to be highly palatable. The experiment was conducted at Wagga Wagga, N.S.W., between January 198 1 and July 1983. The relative palatability of most accessions was substantially similar from rating to rating, despite differences in the extent to which the trial was grazed. Palatability was related to the agronomic group to which the accessions belonged. For the naturalised taxa, Curvula was ranked equal to Tall Chloromelas. but both were more palatable than Short Chloromelas. The naturalised accessions were all less palatable than the selected accessions. It was concluded that the selected accessions were sufficiently palatable to be well utilised in pastures by stock grazing at commercial stocking rates.



2002 ◽  
Vol 42 (5) ◽  
pp. 571 ◽  
Author(s):  
W. M. Kelman ◽  
G. M. Lodge ◽  
R. A. Culvenor

Successful seedling recruitment events in sparse stands of the grass Phalaris aquatica (phalaris) are rare. A major contributing factor to this situation is the seed-harvesting activity of ants. In recently developed cultivars of phalaris, the seed is retained within the glumes of the floret and is shed in a seed-retaining panicle fragment. We tested the hypothesis that seed contained in panicle fragments was less likely to be harvested by ants than naked seed and that this would be reflected in increased seedling recruitment. Observations of ant seed-harvesting activity and records of seedling recruitment following dispersal of seed and panicle fragments onto field plots were made at Canberra, Australian Capital Territory, and Tamworth, New South Wales, over 2 years. In the second year, the effects of 2 pasture renovation treatments (sheep-grazing and shallow-discing) on seedling recruitment from seed and panicle fragments were examined. Averaged over the 2 localities, 4% of large-sized (>10�florets), 13% of medium-sized (5-10 florets) and 27% of the small-sized (2 or 3 florets) panicle fragments were harvested in a 24 h period by ants (mainly Pheidole spp.), compared with 83% of the naked phalaris seed. The effects of panicle fragment size on recruitment were variable depending on site in the first year and the interaction of site and renovation treatments in the second year, but contrary to expectation, recruitment often was not higher in panicle fragment treatments than in seeded treatments. Seedling recruitment at Canberra (a hardsetting sandy loam) was lower (22 plants/m2 from naked seed and 15 plants/m2 from seed in panicle fragments) because of the competition from existing vegetation and germination of subterranean clover from the seedbank, than at Tamworth (a self-mulching red chromosol; 179 plants/m2 from naked seed and 118 plants/m2 from seed in panicle fragments), where seedling recruitment was also significantly increased by the sheep-grazing renovation treatment. At Tamworth, a larger seedbank was recovered from plots of oversown panicle fragments compared with plots oversown with naked phalaris seed. This suggested that protection of seeds in panicle fragments over the summer months on the Tablelands of New South Wales would increase the time over which phalaris seeds are available for recruitment. Further work is needed to test seedling recruitment in panicle shattering v. non-shattering phalaris populations and to define the conditions under which the seedbank contained in the panicle fragments can be exploited to improve stand persistence.



1966 ◽  
Vol 6 (20) ◽  
pp. 17 ◽  
Author(s):  
F McMullen

A factorial glasshouse pot trial was used to examine the supply of phosphorus, boron, zinc, copper, cobalt, magnesium, molybdenum, potassium, and manganese, to the Dwalganup strain of Trifolium subterraneum L. growing in virgin granite soils from Bendemeer, New South Wales. Calcium sulphate was applied as a basal nutrient. Significant dry matter responses were obtained on all four virgin soils to the application of phosphorus, molybdenum, and potassium; to copper on two soils; and to boron and cobalt on one soil. Phosphorus was so deficient that responses to other plant nutrients did not occur in its absence. On all soils, significant first order interactions were recorded between phosphorus and other deficient elements. In addition, significant interactions were recorded between molybdenum and magnesium, copper and molybdenum, boron and molybdenum, copper and cobalt, and potassium and molybdenum.



Sign in / Sign up

Export Citation Format

Share Document