Phalaris Aquatica Research Articles

The role of introduced grasses other thanLolium perenne, Dactylis glomerata, Phalaris aquatica, andFestuca arundinaceain the pastoral systems of temperate Australia

Abstract Pasture improvement throughout temperate Australia has been, with a few noted exceptions, confined to the use of only four species i.e. Dactylis glomerata, Festuca arundinacea, Lolium perenne, and Phalaris aquatica. However, there are large areas where the above are clearly not adapted e.g., deep acidic sands in South Australia, salt‐affected lands in Victoria, and the low‐fertility tablelands of New South Wales. Further plant introduction has identified a limited number of species that have been able to perform in specific environmental niches, but often with limited animal production under commercial grazing conditions. It is argued that further grass introduction must take place if pasture improvement is to continue, not only for increased livestock production but also to restore those lands that are in the process of degradation. A number of the other temperate perennial grass species exhibiting potential for trial and further selection, particularly from the genus Bromus, are listed and discussed.

Genetic resources for temperate perennial grass improvement programmes in Australia

Abstract The dependence of Australia on exotic species for temperate pasture improvement is likely to continue into the foreseeable future. The principal species are Dactylis glomerata, Festuca arundinacea, Lolium perenne, and Phalaris aquatica. Germplasm from Western Europe is well represented in the major collections; however, further collections are still required from the Mediterranean region and adjacent semi‐arid areas. Several specific geographic areas known to contain ecotypes of the four species under threat of genetic erosion and as yet not collected, have been identified. The germplasm available for study and evaluation of the remaining temperate grass genera and/or species, likely to be of value in Australia, is extremely limited. Suggested areas for further exploration are listed and three species with high potential are described.

Toxins in temperate grasses—implications and solutions

Abstract The toxicity of several important temperate grass species is reviewed. Identification of N‐methyltyramine in Phalaris aquatica cultivars provides a possible new etiology for the sudden death syndrome associated with this pasture species. The spread of the plant‐pathogenic, toxigenic bacterium Clavibacter toxicus to new grass species and recent episodes of poisoning in livestock grazing C. toxicus‐infected grasses raise the possibility that this poisoning disease may affect a wider range of pastures in the future. While livestock, especially ruminants, are well adapted to detoxifying poisons they ingest, there are examples of secondary poisoning of humans through the consumption of animal products. The issue of transfer of poisonous plant components to animal products for human consumption needs to be investigated where a real risk to human health is perceived. Elimination of toxins from pasture species provides the best solution to poisoning. Where this is impracticable, vaccination and enhanced ...

Phalaris improvement in Australia

Abstract The genetic improvement of Phalaris aquatica L. and its scientific basis are reviewed. The few accessions made in the 1890s gave rise to cv. Australian. Trumble selected ‘Gb81’ within ‘Australian’. Major collections in 1951 and 1954 gave cultivars Sirocco and El Golea through selection within Moroccan ecotypes, and cultivars Sirosa, Sirolan, and Holdfast by hybridisation with ‘Australian’, followed by recurrent selection for various traits. Selection within the seed‐retaining Argentinian cultivar El Gaucho, gave ‘Seedmaster’, and a single mutant seed‐retaining plant within ‘Australian’ gave ‘Uneta’. Future cultivars are previewed and alternative selection methods, such as widespread testing of synthetics, are discussed.

Early productivity of binary mixtures and single grass species

An experiment was conducted on a fertile Walcanui silt loam in 1991/92 to examine the productivity of 4 perennial pasture grass species, Grasslands Roa tall fescue (Festuca arundinacea), Grasslands Marsden hybrid tyegrass (Lolium perenne x Lolium hybridum), Grasslands Maru phalaris (Phalaris aquatica), Grasslands Wana cocksfoot (Dactylis glomerata), and 2 binary mixtures, tall fescue plus cocksfoot and phalaris plus cocksfoot. Between July 1991 and September 1992 the highest production came from phalaris plus cocksfoot at 19.05 t DM/ha. Hybrid ryegrass, phalaris, tall fescue plus cocksfoot, cocksfoot, and tall fescue produced 17.44, 17.13, 16.96, 14.17, and 13.13t DM/ha respectively. The botanical composition of both mixtures averaged equal proportions of the sown species. The proportion of cocksfoot increased over the summer period then declined for the following autumn/winter period. The experiment shows that simple pasture grass mixtures may be highly productive. These findings support the increasing farmer practice of sowmg some pasture grasses in simple mixtures. Keywords: binary mixture, botanical composition, Dactylis glomerata, dry matter production, Festuca arundinuceu, Lolium perenne x Lolium hybridum, pasture mixtures, Phalaris aquatica, seasonal production

An evaluation of tall fescue, phalaris and cocksfoot in mixes as an alternative to single-species pastures

Seasonal and annual dry matter production of ryegrass was compared with drought- and grass grub-tolerant species Grasslands Roa tall fescue (Festuca arundinacea Schreb.), Grasslands Maru phalaris (Phalaris aquatica L.) and Grasslands Kara cocksfoot (Dactylis glomerata L.) as both single species and different combinations of mixes in two trials from 1982 to 1991. In trial 1, Nui ryegrass (damaged by Argentine stem weevil) produced significantly less than cocksfoot, phalaris and mixtures of the drought-tolerant grasses. Yatsyn-1 ryegrass in trial 2 was not subjected to stem weevil attack and the annual dry matter production was significantly higher than that of tall fescue and, although not significantly, higher than that of phalaris and cocksfoot. In both trials the highest producing mixture was the phalaris/ cocksfoot mix with the exception of the triple mix of phalaris/cocksfoot/tall fescue in trial 2. The phalaris/cocksfoot mix produced significantly more than phalaris as a single species and although not significant, 14% more than cocksfoot suggesting these species are complementary in a mix. The triple mix in trial 2 produced significantly more than all single species except ryegrass. Mixes of srgnificant. tall fescue/phalaris and tall fescue/cocksfoot had no advantage in DM production over single-species sowings of phalaris or cocksfoot, but improved yields over tall fescue. These results show possible complementary effects to sowing phalaris and cocksfoot. The addition of tall fescue to the mix had small and non-significant benefits. Keywords: Dactylis glomerata, Festuca arundinacea, Loliumperenne, Phalaris aquatica. grass grub, pasture mixes, pasture production, single species, summer dry spells

Factors affecting accumulation of summer grass for winter standing feed in the high country

A 0.5 ha 6-year trial compared 6 grass species x 4 N fertiliser rates x 2 times of closing for summersaved standing winter feed. The pre-winter yields averaged 3.4 t DM/ha from November, closing with a high browntoplsweet vernal component, as compared with 1.7 t DM/ha from December closings with a low browntop/sweet vernal component. Grasslands Kara cocksfoot was the highest yielding cultivar, followed by Grasslands Apanui cocksfoot, Grasslands Wana cocksfoot, Grasslands Roa tall fescue, Grasslands Nui perennial ryegrass and Grasslands Maru phalaris, with decreasing proportions of sown grass. Nitrogen fertiliser had a limited effect on prewinter yields but did have a carry-over effect into spring yields. Keywords: Dactylis glomerata, fertiliser, Festuca arundinacea, high country, Lolium perenne, nitrogen, Phalaris aquatica, winter feed

The persistence of five cultivars of phalaris after cutting during reproductive development in spring

Cultivars of phalaris (Phalaris aquatica L.) were cut at various stages of development between the vegetative state and anthesis, or fortnightly during spring, to determine the effects on subsequent regeneration and persistence. The treatments were applied for 2 years to plants growing on a 200 mm grid at two field sites in the A.C.T. Most of the effects were established in the first year, in which late spring and summer were dry and hot. At a site which was irrigated during the first spring, there was little effect of a single cut at each stage of development. However, autumn regeneration of plants cut again after 14 days or cut frequently was affected. At a less fertile site which was not irrigated, and where dormancy was interrupted during summer in the first year, reductions in autumn regeneration growth of greater than 50% were observed in plants cut once at the early stem elongation and early boot stages. Most plants observed to be dead in autumn at the second site had been cut at the early boot stage. When cut at earlier stages of development, most plants which subsequently died had been cut twice. Unlike a previous study under artificial conditions, differences in autumn regeneration between a reputedly persistent cultivar (cv. Australian) and newer cultivars were not large, probably due to only small differences in synchrony of reproductive stem development occurring under the competitive spring growth conditions of this study. However, higher rates of tillering and tiller survival by cv. Australian observed after cutting prior to stem elongation should reduce its susceptibility to damage during spring. Avoidance of repeated heavy grazing of phalaris during spring, or sudden heavy grazing of tall stands in the stem elongation phase, is recommended to enhance persistence should seasonal factors become unfavourable for tiller survival.

Persistence of dryland pasture species in mixed swards in Canterbury

Changes in dryland pasture composition were monitored over 5 years in pastures that were managed under a normal sheep farm management system. Grass grub population built up with time and appeared to be the main reason for plant loss and the resultant changes in pasture composition. Grass grub densities in ryegrass mixtures increased to a high level (220/m* ) by year three, with subsequent ioss of ryegrass plants. Grub densities increased more slowly in cocksfoot-, tall fescueand phalaris-based pastures, with no apparent loss of plants. Cocksfoot dominated pasture composition by year three, even when sown at only 25% of total seed mix. Phalaris did not increase its contribution and at no stage made a significant contribution to production when sown in mixtures with other grasses. As grass grub numbers declined there appeared to be some regeneration of the ryegrass component. The more persistent cocksfoot and tall fescue pastures increased their herbage yield advantage over ryegrass pastures with time. Autumn animal performance was directly related to the amount of green herbage on offer. Keywords: Costelytra zealandica, Dactylis glomerata,dryland pastures, Festuca arundinacea, Lolium perenne, Phalaris aquatica, pasture composition

Phosphorus efficiency in pasture species. VIII. Ontogeny, growth, P acquisition and P utilization of Italian ryegrass and phalaris under P deficient and P sufficient conditions

The P efficiency of Italian ryegrass (Lolium multiflorum Lamk. cv Grasslands Tama) and phalaris (Phalaris aquatica L. cv Sirosa) was compared on both a temporal and ontogenetic basis. As ontogeny and growth are interrelated, such a comparison allowed the growth and physiological responses to P level of the two species to be separated from responses due to the species being at different ontogenetic stages at the time of comparison. Plants were grown from seed through to anthesis under P deficient and P sufficient conditions in soil in a glasshouse. The ontogenies of Italian ryegrass and phalaris were similar, but the rate of development of Italian ryegrass was greater at both P rates. P deficiency resulted in arrested reproductive development in phalaris. At both P levels shoot, root and total biomass and net P uptake per plant by Italian ryegrass were greater than by phalaris when the two species were compared on a temporal basis, but when compared on an ontogenetic basis the two species were similar. There were some differences in the allocation of P between the acid-soluble P, lipid P, and residue P fractions, but biomass production was not determined by the efficiency of P utilization. The superior biomass production of Italian ryegrass on a temporal basis was due to its greater seed size and rate of ontogeny rather than differences in photosynthetic rate, unit leaf rate, leaf area ratio or shoot: root ratio. Similarly, the greater P uptake per plant of Italian ryegrass on a temporal basis was driven by its greater plant size and faster root extension rate rather than by P uptake per unit root length. The level of vesicular arbuscular mycorrhizal (VAM) infection in the roots of the two species was similar under P deficiency but greater in phalaris under P sufficient conditions. Overall, the different temporal responses to P of Italian ryegrass and phalaris were largely related to their different rates of ontogeny and the interrelationships between ontogeny and growth rate rather than to differences in their physiology in relation to P acquisition and utilization.

Seasonal development of roots under perennial and annual grass pastures

Studies in the field and in a rhizotron were conducted to examine the root growth of Phalaris aquatica L. (phalaris), Dactylis glomerata L. (cocksfoot) and Lolium rigidum Gaudin (annual ryegrass). Root and tiller development of the perennial grasses in autumn was also studied. In the field, annual ryegrass developed a more extensive surface rooting system than phalaris and cocksfoot by spring in a favourable season. Early root development of annual ryegrass was poor where the first rains of the season did not occur until winter. Growth rates of annual ryegrass roots at depth were similar to phalaris in mid spring in the rhizotron. Phalaris had a higher proportion of live roots than cocksfoot prior to the first autumn rain. Cocksfoot did not regenerate a substantial new root system until it developed secondary tillers, about a month after initial rains. Collectively, these studies indicated that the seasonal development and extent of the root systems of cocksfoot and phalaris were different.

Internal phosphorus requirements of six legumes and two grasses

Critical phosphorus (P) values, both total (P,) and inorganic Pi, for the diagnosis of P deficiency were derived for a number of pasture species that are increasingly used in Australia. Trifolium balansae and Medicago murex, with T. subterraneum for comparison, were grown for 2 seasons in field experiments to which 7 rates of phosphate fertiliser were applied. The legumes T. balansae, M. murex, M. polymorpha, Ornithopus compressus, and Lotus pedunculatus, and the grasses Phalaris aquatica and Danthonia richardsonii, were grown in sand culture in glasshouse experiments and provided with nutrient solutions containing 6 rates of P (0.05-1.6 mmol/L). Diagnostic indices were derived for blades of the youngest open leaves (YOL) or youngest expanded blades, and for whole shoots. Critical Pt concentration in the YOL of T. balansae did not decline until full flowering and was the most stable indicator. The range of critical concentrations was 0.45-0.50% for both diagnosis of deficiency and prediction of seasonal yield. A Pi concentration of 150 mg/kg was critical for T. balansae during vegetative growth only. Critical concentrations in M. murex declined from an early stage, but a Pt concentration in YOL of 0.40% was the most useful indicator for diagnosis until flowering. The critical values for T. subterraneum agreed well with previously published data. Critical P concentrations in O. compressus were similar at 2 sampling times. For the remaining species, critical concentrations declined with time and it was necessary to know plant age when interpreting them.

Effect of Cutting During Reproductive Development on the Regrowth and Regenerative Capacity of the Perennial Grass, Phalaris aquatica L., in a Controlled Environment

Two cultivars of phalaris (Phalaris aquatica L.), Australian and Sirolan, were cut at four stages of development in a controlled environment to study factors involved in the sensitivity of phalaris to grazing during spring. Effects on tillering, regrowth after cutting and regenerative capacity after an artificially imposed summer dormant period were observed. Compared with Australian, Sirolan cut after the commencement of stem elongation was characterized by a higher degree of decapitation due to more synchronous elevation of its apices, and displayed a more severe reduction in regrowth, size of tiller bases and dormant buds and levels of carbohydrate reserves in summer relative to plants cut before stem elongation. Suppressed bud activity in tillers of Sirolan decapitated at early stem elongation, and the potential for profuse tillering associated with low bud dormancy after cutting at the early boot stage, could reduce persistence under field conditions. Relative to plants cut before stem elongation, regeneration growth after 'summer' by plants cut during reproductive development was depressed more severely for Sirolan (56-70%; P ⩽ 0·05) than Australian (28%; n.s), a result more closely related to regenerating tiller size than number. Regeneration growth did not differ significantly with stage reproductive development at cutting in either cultivar. Regenerative capacity of phalaris cut during reproductive development can be considered to depend on an increasing contribution from buds on bases of tillers decapitated when cut and a contribution from buds on intact tiller bases which declines as the stage of cutting becomes later. The balance between these source will depend on the environment.

Oversowing of five grass species and white clover on a Taupo hill country pumice soil

Abstract Methods of establishing perennial ryegrass (Lolium perenne L.), prairie grass (Bromus willdenowii Kunth), phalaris (Phalaris aquatica L.), cocksfoot (Dactylis glomerata L.), tall fescue (Festuca arundinacea Schreb.), and white clover (Trifolium repens L.) by oversowing on a hill country pumice soil near Taupo were investigated in spring 1982 and 1983. Four pre-sowing sward treatments (paraquat herbicide application, hard grazing by sheep, treading by sheep, or treading by cattle) were applied in two experiments. Populations of seedlings, tillers, and plants, and herbage growth, were monitored for 2 years after each sowing. Degree of sward suppression resulting from sward treatments was the main factor influencing establishment success. Hard grazing resulted in minimal suppression of resident sward growth and hence poor establishment (2% of sown grass seed). Sheep treading yielded an average establishment rate of 4% of sown seed. Cattle treading removed most of the resident vegetation and resulted...

Identification of canary grass (Phalaris aquatica) pollen allergens by immunoblotting: IgE and IgG antibody-binding studies.

The pollen of canary grass, which was introduced as a pasture grass from Europe, is a major allergen in the external environment of southern Australia. Seventeen allergenic fractions of canary grass pollen, ranging in mol. mass from 14 to 100 kDa, have been identified by immunoblotting, using IgE antibodies from sera of 24/30 grass-pollen-allergic subjects. The highest frequency of IgE binding (77%) was to a major 34-kDa fraction (tentatively designated Pha a I). This protein has been partially purified and identified as a group I allergen by immunodepletion experiments, with partially purified Lol p I (from rye-grass pollen), atopic serum, and Lol p I-specific MAb. In addition, microsequencing of the N-terminus of Pha a I showed an amino acid sequence identical to Lol p I. In a separate study, IgE binding to Western blots of Pha a I, Lol p I, and Cyn d I was investigated in 24 sera and found to occur in 19/24, 18/24, and 9/24, respectively. IgE binding to all three major allergens, and to both Pha a I and Lol p I, occurred in 8/24 sera. Our findings suggest that while the N-terminal sequence of Pha a I is identical to Lol p I, there may be specific allergenic epitopes exclusive to this allergen that are important for allergenicity in southern Australia.

Introduction, production, and persistence of five grass species in dry hill country

The production and persistence of five oversown grass species and resident pasture, were measured between 1979 and 1987 at six New Zealand sites, under several fertiliser (phosphate and/ or nitrogen (N)) and summer grazing severity treatments. ‘Grasslands Nui’ ryegrass (Lolium perenne L.), ‘Grasslands Wana’ cocksfoot (Dactylis glomerata L.) (‘Grasslands Apanui’ at Tekapo), ‘Grasslands Maru’ phalaris (Phalaris aquatica L.), ‘Grasslands Matua’ prairie grass (Bromus willdenowii Kunth), and ‘Grasslands Roa’ tall fescue (Festuca arundinacea Schreb.), established successfully at most sites. Findlay-Wilkinson analysis of annual total herbage accumulation (THA) of four sites, found that Maru production was above average and resident production was below average. Variation in THA between sites and years was related to variation in annual rainfall (621–1484 mm/ year). Wana was the most persistent grass at all sites (60% of THA after 4–6 years), followed by Nui (51% of THA after 4–6 years). Maru was only pe...

Introduction, production, and persistence of five grass species in dry hill country

A trial was conducted on a seasonally dry slope near Taupo as part of a national series investigating the persistence and productivity in dry hill country of five grass species established from oversowing under contrasting nitrogen (N) and summer grazing regimes. The average annual total herbage accumulation (HA) (1983–87) was greatest from phalaris (Phalaris aquatica L. ‘Grasslands Maru’) swards (12100 kg DM/ha, 65% Maru); followed by a species mixture (11700 kg DM/ha); tall fescue (Festuca arundinacea Schreb. ‘Grasslands Roa’) (11700 kg DM/ha, 47% Roa); prairie grass (Bromus willdenowii Kunth ‘Grasslands Matua’) (11300 kg DM/ha, 25% Matua); cocksfoot (Dactylis glomerata L. ‘Grasslands Wana’) (11100 kg DM/ha, 56% cocksfoot); resident swards (10640 kg DM/ha); and was least from ryegrass (Lolium perenne L. ‘Grasslands Nui’) (10200 kg DM/ha, 73% ryegrass). The average response from a split application of 50 kg N/ha in each of autumn and spring, was a 14% increase in annual HA. Summer grazing treatm...

On-farm establishment of drought-tolerant pastures on the east coast of the North Island

Seedling and tiller core measurements on 60 paddocks sown in autumn 1991 on the East Coast of the North Island were made to monitor the success of new pastures based on drought-tolerant grasses. Pastures sown into cultivated seedbeds were generally more successful than direct-drilled pastures, having higher content of sown species and less competition from volunteer perennial grasses. In paddocks sown with mixtures of tall fescue and Grasslands Wana cocksfoot, cocksfoot was becoming the dominant,grass, except in areas of paddocks with poor drainage. Cocksfoot establishment in oversown pastures was good, but tall fescue in these paddocks declined to low levels 19 months after sowing. White clover was well established in all classes of pasture, despite relatively low initial seedling numbers in direct drilled and oversown paddocks. In contrast, red clover content declined, particularly in directdrilled and oversown paddocks. Keywords: Dactylis glomerata, direct drilling, Festuca arundinacea, pasture establishment, Phalaris aquatica, oversowing

Effects of depth and time of sowing on emergence of Danthonia richardsonii Cashmore and Danthonia linkii Kunth

Two experiments examined the effects of sowing time and depth (surface and 10, 25, 50 mm) on emergence of Danthonia richardsonii Cashmore and Danthonia linkii Kunth. Experiment 1 was conducted from January to December 1990 on a loam/sand mixture in boxes. Emergence was highest in both species for seeds sown onto the soil surface in summer and autumn (P < 0.05). Sowing at any depth at any time of the year, or surface sowing in winter and spring, markedly reduced emergence. Experiment 2 was conducted in the field at Tamworth, northern New South Wales from September 1991 to August 1992, on a red brown earth and a black earth. This study confirmed that emergence in both species was highest from surface sown seed. Field emergence was lowest in winter, but in contrast to experiment 1, it was higher in spring, particularly on the black earth. Seedling emergence appeared to be related to mean maximum temperature, decreasing in winter as it declined below 20�C, and increasing in spring when it was greater than 23�C. Differences in seed weight were reflected in emergence of D. richardsonii and D. linkii in experiment 1. Similar emergence was recorded for the loamlsand mixture and sand, indicating that there was little effect of texture. Phalaris aquatica L. cv. Sirosa surface sown in December had lower emergence ( P < 0.05) than both Danthonia spp., but emergence of this larger seeded cultivar was higher at depths of 10 and 25 mm. Laboratory studies to determine reasons for the low emergence of D. richardsonii and D. linkii from depth, indicated that neither had an obligate light requirement for germination. Depth, however, reduced germination (P < 0.05) compared with surface sowing of seed. Seedlings at depth also were observed to have slower rates of shoot and root elongation. In the field, the most successful establishments of D. richardsonii and D. linkii seedlings are likely to occur from surface sowings in April and May. Sowing in spring may also be possible if mean maximum soil temperatures exceed 23�C, and seedlings can establish before the onset of hot, dry conditions in summer.

Introduction, production, and persistence of five grass species in dry hill country

As part of a national evaluation series, five grass species were oversown with white clover (Trifolium repens L.) into glyphosate-treated plots on a summer-dry northern face of the Hokonui hills, Southland. Swards of these species were compared with the resident pasture, under an annual fertiliser input of 0 or 250 kg superphosphate (0-9-0-1 l)/ha per year and several 7- or 30-day grazing periods/ year. Nui ryegrass (Lolium perenne L.) had the highest annual and seasonal pasture yields, especially in spring when pasture yields were at least 18% better than any other grass species. Wana cocksfoot (Dactylis glomerata L.) persisted on all slopes and had similar pasture yields to Nui in summer in the first 3 years and in autumn in the final 3 years. Maru phalaris (Phalaris aquatica L.) established slowly but spread and persisted to equal the yield of Wana in Year 5 and Nui in Year 6. Although the yield of Matua prairie grass (Bromus willdenowii Kunth) was second only to Nui in the first 3 years, it d...