Replacement series studies of competition between tropical perennial and annual grasses and perennial grass mixtures in northern New South Wales

2009 ◽  
Vol 60 (6) ◽  
pp. 526 ◽  
Author(s):  
G. M. Lodge ◽  
S. P. Boschma ◽  
S. Harden
Keyword(s):  
Perennial Grass ◽  
Maximum Likelihood Estimates ◽  
Separate Experiment ◽  
Replacement Series ◽  
Rhodes Grass ◽  
Barnyard Grass ◽  
Tropical Grasses ◽  
South Wales ◽  
Digitaria Eriantha ◽  
Annual Grasses

Seedlings of three perennial tropical grasses, Chloris gayana cv. Katambora (Rhodes grass), Panicum coloratum var. makarikariense cv. Bambatsi (panic grass), and Digitaria eriantha ssp. eriantha cv. Premier (digit grass), were each grown in replacement series mixtures with seedlings of the annual summer-growing grass weeds Urochloa panicoides (liverseed grass) and Echinochloa colona (awnless barnyard grass). A separate experiment examined the competitiveness of seedlings of the three perennial tropical grasses when two species were sown together. Plants were sown 50 mm apart in boxes at a density of 307 plants/m2. Maximum likelihood estimates were used to derive parameters of a non-linear competition model using the dry weights of perennial and annual grasses. Seedlings of the summer-growing annual liverseed grass competed aggressively with those of the tropical perennial Katambora Rhodes grass. However, Bambatsi panic seedlings were equally competitive with those of awnless barnyard grass, while those in a Premier digit-barnyard grass mixture were inhibited by the presence of each other. In the perennial grass mixtures study, the performance of both Premier digit and Bambatsi panic was adversely affected by the presence of Katambora Rhodes grass.

Effects of depth and time of sowing and over-wintering on tropical perennial grass seedling emergence in northern New South Wales

2009 ◽  
Vol 60 (10) ◽  
pp. 954 ◽  
Author(s):  
G. M. Lodge ◽  
S. Harden
Keyword(s):  
Seedling Emergence ◽  
Perennial Grass ◽  
Soil Surface ◽  
Perennial Grasses ◽  
Sowing Time ◽  
Rhodes Grass ◽  
Factors Affecting ◽  
Nylon Mesh ◽  
South Wales ◽  
Digitaria Eriantha

Two studies were conducted in northern NSW to examine some of the factors affecting the successful emergence of seedlings of five species of tropical perennial grasses [Panicum coloratum var. makarikariense cv. Bambatsi (panic), Digitaria eriantha ssp. eriantha cv. Premier (digit), Chloris gayana cv. Katambora (Rhodes grass), Dichanthium aristatum cv. Floren (bluegrass), and Bothriochloa bladhii ssp. glabra cv. Swann (forest bluegrass)]. The first experiment investigated the effects of depth and time (month) of sowing on tropical perennial grass seedling emergence, while a second series of studies examined the effects of contact of dispersal/sowing units with the soil, particularly over winter, on subsequent seed germination and seedling emergence. No seedling emergence of any species occurred in September 2006 and June–August 2007. From October 2006 to May 2007 there were significant effects (P < 0.001) of species, sowing time, depth, and their interaction on predicted emergence. From December to March, predicted emergence was always lower for surface-sown caryopses compared with those sown at 10 and 25 mm depth, and Bambatsi was the only species that had >50% emergence from a depth of 50 mm. Recovery of intact caryopses from 300 μm nylon mesh bags stored in the soil for 6 and 12 months was low for all species. Similarly, predicted germination of caryopses from field soil surface and buried locations (2007 and 2008) and those from florets and coated seeds (2008) was low, indicating that these species had a poor ability to over-winter in moist soil.

Competition among seedlings of perennial grasses, subterranean clover, white clover, and annual ryegrass in replacement series mixtures

2000 ◽  
Vol 51 (3) ◽  
pp. 377 ◽  
Author(s):  
G. M. Lodge
Keyword(s):  
White Clover ◽  
Plant Competition ◽  
Perennial Grass ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Perennial Grasses ◽  
Maximum Likelihood Estimates ◽  
Annual Ryegrass ◽  
Replacement Series ◽  
Successful Establishment

Seedlings of 3 perennial grasses, Danthonia linkii Kunthcv. Bunderra, D. richardsonii Cashmore cv. Taranna(wallaby grasses), and Phalaris aquatica L. cv. Sirosa,were each grown in replacement series mixtures with seedlings ofTrifolium repens L. (white clover),Trifolium subterraneum L. var. brachycalycinum (Katzn.et Morley) Zorahy & Heller cv. Clare (subterraneanclover), and Lolium rigidum L. (annual ryegrass). Plantswere sown 5 cm apart in boxes (45 by 29 by 20 cm) at a density of 307plants/m2. Maximum likelihood estimates were usedto derive parameters of a non-linear competition model using the dry matterweights of perennial grasses and competitors at 3 harvests, approximately 168,216, and 271 days after sowing. Intra-plant competition was examined inmonocultures of each species, grown at plant spacings of 2, 5, and 8 cm apartwith plants harvested at the above times.Competition occurred in all perennial grass–competitor mixtures, exceptin those of each perennial grass with white clover and thephalaris–subterranean clover mixture (Harvest 1) and those withD. richardsonii and phalaris grown with white clover(Harvest 2). For D. richardsonii (Harvests 1 and 2) andD. linkii (Harvest 1 only) grown with white clover andthe phalaris–subterranean clover (Harvest 1), the two species in themixture were not competing. In the phalaris–white clover mixture, eachspecies was equally competitive (Harvests 1 and 2). These differences incompetition and aggressiveness reflected differences in individual plantweights in monocultures where there was an effect (P < 0.05) of species ondry matter weight per box, but no significant effect of plant spacing.These data indicated that for successful establishment,D. richardsonii and D. linkiishould not be sown in swards with either subterranean clover or white clover,or where populations of annual ryegrass seedlings are likely to be high.Phalaris was more compatible with both white clover and subterranean clover,but aggressively competed with by annual ryegrass.

Temperatures for seedling emergence of tropical perennial grasses

2017 ◽  
Vol 68 (5) ◽  
pp. 493
Author(s):  
M. K. Egan ◽  
S. P. Boschma ◽  
S. Harden ◽  
C. A. Harris ◽  
C. Edwards
Keyword(s):  
Seedling Emergence ◽  
Perennial Grasses ◽  
Sowing Time ◽  
Rhodes Grass ◽  
Temperature Range ◽  
South Wales ◽  
Optimal Temperature Range ◽  
Digitaria Eriantha ◽  
Chloris Gayana ◽  
Rainfall Region

A growth-cabinet study was conducted to determine the optimum temperature range for seedling emergence of seven tropical grasses commonly sown in the frost-prone, summer-dominant rainfall region of inland northern New South Wales. The grasses were Bothriochloa bladhii subsp. glabra (forest bluegrass) cv. Swann, Bothriochloa insculpta (creeping bluegrass) cv. Bisset, Chloris gayana (Rhodes grass) cv. Katambora, Digitaria eriantha (digit grass) cv. Premier, Panicum coloratum var. makarikariense (makarikari grass) cv. Bambatsi, and Megathyrsus maximus (panic) cvv. Gatton and Megamax 059. Six constant temperatures were used, ranging from 10°C to 35°C in 5°C increments. Katambora Rhodes grass was the only grass to emerge at 10°C; seedlings of all grasses emerged at temperatures >10°C. Optimal temperature range for emergence varied between species, falling into three groups: low (Bisset creeping bluegrass 16−22°C); intermediate (Premier digit grass 21−32°C, Swann forest bluegrass 23−31°C, Megamax 059 panic 23−35°C, Gatton panic 24−32°C); and high (Bambatsi makarikari grass 24−35°C, Katambora Rhodes grass 24−35°C). The temperature range at which 50% of optimum emergence occurred was 12−14°C for Katambora Rhodes grass, Bisset creeping blue and Premier digit, and 17−18°C for the panic grasses, Swann forest bluegrass and Bambatsi makarikari grass. These temperatures provide options for sowing earlier in spring or later in summer–autumn and may assist development of sowing time options in new environments and provide insight into competition between species.

Perennial Grass Response to Seasonal Rests in Naturalised Pastures of Central New South Wales.

1996 ◽  
Vol 18 (2) ◽  
pp. 309 ◽  
Author(s):  
PM Dowling ◽  
DR Kemp ◽  
DL Michalk ◽  
TA Klein ◽  
GD Millar
Keyword(s):  
New South ◽  
Perennial Grass ◽  
New South Wales ◽  
Perennial Grasses ◽  
Stocking Rate ◽  
Herbicide Application ◽  
Active Growth ◽  
South Wales ◽  
Continuous Grazing ◽  
Annual Grasses

The influence of grazing management, herbicide and fertiliser on botanical change in two perennial grass based pastures was assessed over six years at two sites in central New South Wales. Ten treatments at both sites compared continuous grazing, three seasonal rests from grazing (autumn, winter, summer), and herbicide application for seedling grass control, each at two levels of fertiliser addition (nil, recommended). These treatments were designed to screen options for management rather than devise complete systems. In a degraded perennial pasture dominated by annual grasses, the proportion of perennial grasses and forbs increased with summer rests, especially at the recommended fertiliser level. Legumes increased with herbicide application, and annual grasses remained high in the continuously grazed control and other treatments. There were no significant effects on composition from autumn or winter rests. On the summer rest treatment at the recommended fertiliser level, perennial grasses (mostly cocksfoot) increased from 11% to 30% compared with the control where perennial grass declined below 5%. The increase was due to both recruitment and increase in size of existing plants, as a consequence of resting the perennial grasses when actively growing, flowering and setting seed, in favourable seasons. In contrast, on the better quality perennial pasture dominated by phalaris, there were limited management effects and perennial grasses increased on all treatments over time. The absence of a response at this site was attributed to a lenient stocking rate, dominant perennial grasses and limited rainfall during periods when active growth might be expected. Summer rests in this case also led to a small increase in forbs. The data suggest that perennial grasses can be encouraged with a conservative stocking policy that maintains the available feed-on-offer above 1 t DM/ha through seasons of active growth.

Seedling competition of lucerne in mixtures with temperate and tropical pasture species

2010 ◽  
Vol 61 (5) ◽  
pp. 411 ◽  
Author(s):  
S. P. Boschma ◽  
G. M. Lodge ◽  
S. Harden
Keyword(s):  
Tall Fescue ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Tropical Species ◽  
Replacement Series ◽  
Temporal Separation ◽  
Rhodes Grass ◽  
Digitaria Eriantha ◽  
Cutting Height ◽  
Tropical Grass

Two replacement series studies were conducted to quantify the competitive ability of seedlings of Medicago sativa (lucerne) sown in mixtures with temperate and tropical species. A temperate mixtures study (Expt 1) consisted of lucerne cv. Genesis sown with each of Phalaris aquatica (phalaris) cv. Atlas PG, Lolium arundinaceum (tall fescue) cv. Resolute MaxP, Cichorium intybus (chicory) cv. Puna, Trifolium subterraneum (subterranean clover) cv. Clare, Austrodanthonia richardsonii (wallaby grass) cv. Taranna and Avena sativa (forage oats) cv. Eurrabie. There was also an additional mixture of chicory and subterranean clover. A tropical grass mixtures study (Expt 2) included Genesis lucerne sown with each of Panicum coloratum var. makarikariense cv. Bambatsi, Dicanthium aristatum cv. Floren, Chloris gayana (Rhodes grass) cv. Katambora, Digitaria eriantha subsp. eriantha cv. Premier and Bothriochloa bladii subsp. glabra cv. Swann. In Expt 1, lucerne-phalaris mixtures were equally competitive, whereas lucerne-tall fescue mixtures over-yielded. Chicory was aggressive in mixtures with lucerne and subterranean clover; similarly forage oats was more competitive than lucerne. Subterranean clover was competitive against lucerne at harvest 1, but by harvest 2 the low cutting height had reduced its competitiveness. Lucerne was more aggressive than wallaby grass. In Expt 2, all tropical grass-lucerne mixtures over-yielded; however, lucerne was generally more competitive than the grasses, except for Rhodes grass at harvest 1. While our study indicated that mixtures of lucerne seedlings with phalaris or tall fescue may be compatible, mixtures with tropical grasses were more likely to result in lucerne seedling dominance. This competitiveness may be overcome by either spatial or temporal separation and we discuss the concept of using mixtures to exploit environmental niches.

Satellite derived maps of pasture growth status: association of classification with botanical composition

1997 ◽  
Vol 37 (5) ◽  
pp. 547 ◽  
Author(s):  
P. J. Vickery ◽  
M. J. Hill ◽  
G. E. Donald
Keyword(s):  
Near Infrared ◽  
Perennial Grass ◽  
Vegetation Indices ◽  
Fast Growth ◽  
Perennial Grasses ◽  
Bayesian Probability ◽  
Cumulative Probability ◽  
Botanical Composition ◽  
South Wales ◽  
Native Pastures

Summary. Spectral data from the green, red and near-infrared bands of Landsat MSS and Landsat TM satellite imagery acquired in mid-spring were classified into 3 and 6 pasture growth classes respectively. The classifications were compared with a site database of botanical composition for the Northern Tablelands of New South Wales to examine the association between spectral growth class and pasture composition. Pastures ranged in composition from unimproved native perennial grasses through semi-improved mixtures of native and naturalised grasses and legumes to highly improved temperate perennial grasses and legumes. For 3 years of MSS data, the fast growth class had a mean botanical composition of about 80% improved perennial grass and 0% native; medium growth class averaged 46% improved perennial grass and 14% native; while the slow growth class had about 60% native and 1% improved perennial grass when averaged over 3 years of MSS data. For the 6 class TM data from a single year, a predictive logistic regression of cumulative probability was developed for percentage of ‘very fast’ growth pixels and ordered 10 percentile categories of improved perennial grass or native grass. Differences in patch characteristics between classes with MSS disappeared with TM reclassified to the same 3 class level. Most probable pasture type was inferred from 3 class MSS and TM data using Bayesian probability analysis. The resulting maps were similar in general appearance but detail was better with the TM data. The pasture growth classification identified highly improved perennial grass pastures and native pastures but sensitivity to intermediate pasture types was poor. Future improvement will come from direct measurement of biophysical characteristics using vegetation indices or inversion of reflectance models.

Persistence and tolerance to soil acidity of phalaris and cocksfoot in north-eastern Victoria

1992 ◽  
Vol 32 (8) ◽  
pp. 1069 ◽  
Author(s):  
AM Ridley ◽  
SM Windsor
Keyword(s):  
Root System ◽  
Plant Density ◽  
Perennial Grass ◽  
Relative Sensitivity ◽  
Solution Culture ◽  
Acidic Soils ◽  
Drought Tolerant ◽  
South Wales ◽  
Plant Densities ◽  
Lime Application

Persistence of Phalaris aquatica L. cv. Sirosa (phalaris) and Dactylis glomerata cv. Porto (cocksfoot) was evaluated for 5 pH treatments at 2 field sites on acidic soils. At one site (Beechworth) the soil was strongly acidic [pH(CaCl2) 14.21 to depth (80 cm) and contained concentrations of CaCl2-extractable aluminium (Al) >11 �g/g. At the other site (Lake Rowan) the soil pH (0-10 cm) was 5.0 and A1 concentrations were 4 �g/g. At Beechworth, lime incorporated at 5.5 t/ha improved establishment of phalaris but plant density declined, and by 30 months after sowing, phalaris plant densities were similar to treatments receiving no lime. Establishment of cocksfoot was less affected by lime application than phalaris, and plant densities were similar to those of phalaris by 26 months after sowing. However, there were no differences between pasture species where no lime was applied. Considerable re-establishment of cocksfoot seedlings occurred regardless of soil treatment. Despite the reported relative sensitivity of phalaris to Al in solution culture experiments, at Beechworth phalaris had more root development at depth than cocksfoot or annual pasture. Although concentrations of Al in the subsoil were high, the perennial deep root system of phalaris may give it an advantage over cocksfoot in terms of survival over summer. A larger root system at depth may give phalaris greater potential than cocksfoot for reducing nitrate leaching and soil acidification. On less acidic soils at the Lake Rowan site, lime application did not affect establishment of either phalaris or cocksfoot. Phalaris had greater persistence than cocksfoot at Lake Rowan. Dry summer conditions at Lake Rowan were the likely cause of poor persistence of cocksfoot. More drought-tolerant cocksfoot cultivars are required if this species is to be a useful perennial grass for pastures in ley cropping areas of Victoria and southern New South Wales.

Correlations between environmental factors, the biomass of exotic annual grasses and the frequency of native perennial grasses

2006 ◽  
Vol 54 (7) ◽  
pp. 655 ◽  
Author(s):  
Tanja I. Lenz ◽  
José M. Facelli
Keyword(s):  
Species Composition ◽  
Soil Fertility ◽  
Perennial Grass ◽  
Perennial Grasses ◽  
Annual Rainfall ◽  
Grass Species ◽  
Soil Factors ◽  
Annual Grasses ◽  
Exotic Annual Grasses ◽  
Native Perennial Grass

The species composition of temperate grasslands in the mid-north of South Australia has been radically altered from a system dominated by native perennial grasses to a system dominated by Mediterranean annual grasses. This study investigated the importance of chemical and physical soil characteristics, topographical features and climatic variables on the abundance of native and exotic grass species in nine ungrazed grasslands. Overall, climatic and other abiotic factors were highly variable. In addition, past management practices and original species composition are generally unknown, leading to further unexplained variation in the data. On a large spatial scale (among sites), the abundance of exotic annual grasses was positively correlated with mean annual rainfall, and on any scale, with finer soil textures and higher soil organic carbon levels. The most abundant annual grass, Avena barbata (Pott ex Link), was generally associated with soil factors denoting higher soil fertility. The abundance of native perennial grass species was not correlated with any environmental variables at any scale. The various native perennial grass species did not show clear associations with soil factors, although they tended to be associated with factors denoting lower soil fertility. However, at small spatial scales (within some sites) and among sites, the abundances of exotic annual and native perennial grasses were strongly negatively correlated. The results suggest that at the present time, rainfall and soil properties are important variables determining the abundance of annual grasses. The driving variables for the abundance of perennial grasses are less clear. They may be controlled by other factors or extreme rainfall events, which were not surveyed. In addition, they are likely to be controlled by competitive interactions with the annual grasses.

Evaluation of three herbicides for the control of grasses in rices

1966 ◽  
Vol 6 (21) ◽  
pp. 219 ◽  
Author(s):  
BB Fischer ◽  
DJ Swain ◽  
EB Boerema
Keyword(s):  
Rice Yield ◽  
New South ◽  
Effective Control ◽  
Rice Seed ◽  
Rice Seedlings ◽  
Barnyard Grass ◽  
Treated Soil ◽  
Stage Of Development ◽  
South Wales ◽  
Excellent Control

Increased rice yield was obtained when the predominant grasses infesting rice fields in the Murrumbidgee irrigation areas of New South Wales were effectively controlled. Ordram (ethyl hexahydro-1 H-azepine-1-carbothioate) applied at pre-sowing and at post-emergence of the rice and grass, gave excellent control of grasses. Propanil, applied to vigorously growing barnyard grass in its 2-3 leaf stage of development, also gave very effective control. Ordram, applied at pre-sowing at less than two inches from the germinating rice seed in the soil of applied at pre-emergence in the water when the plumule of the germinating seed had to grow through the herbicide treated soil, reduced the density of the stand or the vigour of the rice seedlings.

A survey of native grasses in the Goulburn District and factors influencing their abundance.

1991 ◽  
Vol 13 (2) ◽  
pp. 118 ◽  
Author(s):  
DJ Munnich ◽  
PC Simpson ◽  
HI Nicol
Keyword(s):  
Species Differences ◽  
New South ◽  
Acid Tolerance ◽  
Trifolium Subterraneum ◽  
Common Species ◽  
Native Grasses ◽  
South Wales ◽  
Cent Increase ◽  
Annual Grasses ◽  
Microlaena Stipoides

A survey of natural and improved paddocks on 34 farms was conducted over winter within a 60 km radius of Goulburn on the Southern Tablelands of New South Wales. Seventeen of the properties which were found to have significant (greater than 10 per cent) proportions of potentially useful native grasses were resurveyed in the subsequent summer to identify specific Danthonia spp. The survey revealed that useful native yearlong green species such as Microlaena stipoides and Danthonia spp. were relatively abundant in natural paddocks surveyed over winter (16 per cent and 10 per cent respectively), Danthonia being represented by four common species. These natural paddocks, most of which contained Trifolium subterraneum and had some superphosphate input, carried 80 per cent as many stock as their improved counterparts in terms of average DSE/ha. Factors such as cultivation and the presence of naturalized or sown species influenced the abundance of these species, but species differences were apparent. Cultivation reduced the abundance of Danthonia spp. but did not affect the abundance of M. stipoides, which was thus more prevalent than Danthonia spp. in improved pastures. Microlaena stipoides was also more prevalent in uncleared than cleared paddocks. The frequency of Danthonia spp. was negatively associated with high percentage frequencies of annual grasses (principally Vulpia spp.), declining by approximately 2.5 per cent for each 10 per cent increase in annual grasses over winter. The proportion of M. stipoides observed in paddocks appeared to be more influenced by sown pasture species, with lowest percentages recorded where species such as Phalaris aquatica had been sown and highest percentages where no exotic species had been introduced. The abundance of M. stipoides was affected by pH, with percentage frequency increasing as pH declined (down to pH 4 (Cacl~)), indicating the possible acid tolerance of this species. Species' percentages recorded changed with season. For example, Danthonia percentages recorded were considerably greater over summer when flowering heads were obvious than those recorded in winter. This aspect highlights the importance of recording different species during specific seasons to increase the accuracy of frequency estimates.

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