Persistence traits in perennial pasture grasses: the case of phalaris (Phalaris aquatica L.)

2014 ◽  
Vol 65 (11) ◽  
pp. 1165 ◽  
Author(s):  
R. A. Culvenor ◽  
R. J. Simpson

Persistence is consistently claimed by Australian farmers as a high priority for perennial grasses in long-term pastures. Phalaris (Phalaris aquatica L.) is a productive perennial grass with proven persistence in south-eastern Australia. Nevertheless, factors that determine the persistence of pasture species in southern Australia related to climate (drought), soil (acidity), grazing pressure, and, importantly, their interaction can reduce persistence of phalaris and other species in various situations. These factors and their interactions are discussed in this review, and strategies to improve persistence with emphasis on plant breeding approaches are considered, with the most durable outcomes achieved when breeding and management options are employed concurrently. Two examples of breeding to improve persistence traits in phalaris are described. A program to improve acid-soil tolerance resulted first in the release of cv. Landmaster, and recently Advanced AT, which is the most aluminium (Al)-tolerant cultivar of phalaris to date. It was bred by recurrent selection on acid soils in a population containing genes from a related, more Al-tolerant species, P. arundinacea. The higher Al tolerance of cv. Advanced AT is of most benefit in more assured establishment on acid soils under variable moisture conditions and confers improved flexibility of sowing date. Cultivar Holdfast GT was bred to address complaints of poor persistence under heavy grazing by cultivars of the highly productive, winter-active type, since high grazing tolerance is needed to achieve profitable returns from developed pastureland. Evidence of good persistence under grazing for cv. Holdfast GT and possible tradeoffs with productivity are discussed. Maintaining high productivity under a predicted higher incidence of drought stress (climate change) and increasing areas of acid soils presents ongoing challenges for persistence in pastures.

2006 ◽  
Vol 46 (4) ◽  
pp. 439 ◽  
Author(s):  
W. McG. King ◽  
P. M. Dowling ◽  
D. L. Michalk ◽  
D. R. Kemp ◽  
G. D. Millar ◽  
...  

Temperate perennial grass-based pastures dominate the high rainfall zone of south-eastern Australia and support a major livestock production industry. This area has experienced a recent change in overall pasture condition, however, typified by a reduction in the abundance of perennial grasses and an increasingly prominent winter-annual grass weed component. Improving the condition and productivity of these pastures can be achieved by improved management but this requires better knowledge of the interactions between management options and pasture species composition and of the interaction between pasture vegetation and the complex effects of a heterogeneous landscape. This paper reports the results of an intensive survey of a 60-ha paddock that was designed to identify the species present, determine their patterns of distribution and examine the relationships between pasture vegetation and the environment. The survey of species present in late summer was supplemented by the identification of seedlings that later emerged from extracted soil cores and by soil physical and chemical analyses. Data were analysed using ordination and interpreted with GIS software so that topographic features could be considered. The most frequently identified taxa were Hypochaeris radicata, Austrodanthonia spp. and Bothriochloa spp. (in late summer) and Vulpia spp., Bromus molliformis and Trifolium subterraneum (winter-annual species). Austrodanthonia spp. were commonly found on the drier ridges and more acid soils with lower phosphate levels. These were also the areas dominated in spring by Vulpia spp. and were generally lower in plant species richness overall. The most species-rich areas occurred downslope where soil fertility was higher and less moisture stress was presumably experienced. The measured environmental factors explained a substantial proportion of the variation in the vegetation dataset, which underlined the importance of considering landscape effects in the management of typical tablelands pastures.


2004 ◽  
Vol 55 (6) ◽  
pp. 681 ◽  
Author(s):  
R. A. Culvenor ◽  
J. T. Wood ◽  
A. L. Avery ◽  
W. Dempsey ◽  
S. E. McDonald ◽  
...  

Half-sib families in the AT98 Phalaris aquatica × P. arundinacea × P. aquatica backcross population bred for acid soil tolerance were compared for establishment, persistence, and yield with phalaris (P. aquatica L.) controls and cocksfoot (Dactylis glomerata L. cv. Porto) at 4 sites in south-eastern Australia with the aim of selecting the parents of a new cultivar. The sites had strongly acid soils but differed in parent material, pH profile, soil fertility, and suitability for phalaris. Establishment by AT98 was clearly superior to all phalaris controls and similar to cocksfoot in an acid soil high in Al to depth at Chiltern, north-eastern Victoria, after sowing in early spring 2000. It was considered likely that better establishment by AT98 was due to its higher Al tolerance. In contrast, little variation in establishment was observed at 3 other sites sown in late autumn 1999, possibly due to a longer period free of moisture stress compared with the later sown Chiltern site. Once established, the control cultivars of phalaris at the autumn-sown sites in general persisted and yielded similarly to the mean of the AT98 families. Significant family variation was observed and predicted heritability on a family mean basis was high for persistence measured as basal frequency and moderately high for yield in the third year. Family by site interaction was relatively low for both attributes. A cultivar based on the best families should give more reliable establishment on acid soils high in Al under conditions where rapid root growth to depth is needed for survival, and give more flexibility of sowing date on these soils. Its best performance relative to cv. Landmaster in terms of third-year yield was predicted to occur on granite-derived soils in north-eastern Victoria.


2000 ◽  
Vol 40 (2) ◽  
pp. 125 ◽  
Author(s):  
D. R. Kemp ◽  
P. M. Dowling

Naturalised pastures across the higher rainfall (>600 mm) perennial pasture zone of south-eastern Australia are less productive than they were, while sown pastures fail to maintain their initial levels of production. Several factors have contributed to this, including lack of knowledge of suitable grazing practices, weed invasion, increasing acid soils, rising water tables and poor management practices during droughts. A key issue in each case is the decline in perennial grass species which is both a cause and effect of the decline in productivity and sustainability of these ecosystems. This paper introduces a volume devoted to the largest collaborative study done to evaluate tactics for better grazing management and to improve the sustainability of perennial pasture ecosystems. Grazing practices to manage the composition of pastures have been largely neglected in pasture research, but are an important first step in improving pasture sustainability. This paper also outlines a new, open communal grazing experimental design which was developed and used across 24 sites on farms in New South Wales, Victoria, Tasmania and South Australia, to evaluate tactics for grazing management. The general aim across these experiments was to maintain (if adequate) or enhance (if degraded), the proportion of desirable perennial grasses in the sward to achieve more sustainable pastures. The results will provide the basis for building more sustainable grazing systems.


1990 ◽  
Vol 30 (4) ◽  
pp. 539 ◽  
Author(s):  
AM Ridley ◽  
WJ Slattery ◽  
KR Helyar ◽  
A Cowling

Soil samples to a depth of 60 cm were collected from adjacent, 39-year-old, phalaris-based and annual pasture fields on an acid soil at Rutherglen, north-eastern Victoria. The fields had similar histories of fertiliser application and stock enterprise. Minimum net acid addition rates were determined under both pasture types, and the soil under annual pasture showed greater acidification. Carbon cycle acid addition contributed 1.3 1 and 1.36 kmol H+/ha.year to net acid addition on annual and phalaris pastures, respectively. Because slow alkaline soil reactions in the field contribute to buffering capacity on an acid soil and lead to underestimation of net acid addition rate and nitrate leaching, estimates of such reactions were made for both pasture types. If correct assumptions were used nitrate leaching was substantial under both pasture types but was reduced by 1.01 kmol H+/ha.year under phalaris pasture. This suggests that perennial grass based pastures can be used to reduce acidification on pastoral soils. Alkali addition to counteract net acidification may be necessary on acid soils to maintain management options for growing aluminium-sensitive species.


2006 ◽  
Vol 12 ◽  
pp. 89-92
Author(s):  
Richard Culvenor ◽  
Suzanne Boschma ◽  
Kevin Reed

Phalaris (Phalaris aquatica L.) is a perennial grass of Mediterranean origin used widely by the sheep and cattle industries of south-eastern Australia. Winter-active cultivars released since the 1970's have the potential for higher herbage productivity than the earlier, semi-winter dormant cultivars but have been reported to be less persistent under sub-optimal grazing management and soil conditions. To improve genetic potential for persistence in winter-active phalaris, a program of recurrent selection was conducted by subjecting three populations of half-sib families to two cycles of selection for persistence under heavy, largely continuous grazing pressure. Cycle 2 progeny families and bulked seedlots of each generation were grown in separate grazed plot trials in Western Victoria and the Southern Tablelands and North-West Slopes of New South Wales from 1999-2003 to assess response to selection. Positive linear response to selection was observed in all populations at the Western Victorian and Southern Tablelands sites. Response to selection was absent and persistence was very low under higher temperature and drought stress on the North-West Slopes. This high level of genotype × environment interaction for persistence was also observed among final generation families. Families with better persistence than current winteractive cultivars at the two southern sites were identified in each population and a new cultivar is being formed from the parents.


2016 ◽  
Vol 1 (2) ◽  
pp. 73
Author(s):  
Arief Vivi Noviati ◽  
Sri Hutami ◽  
Ika Mariska ◽  
Endang Sjamsudin

<p class="p1">Aluminum toxicity is a major constraint to soybean production in acid soils. Since variabilities on Al tolerance in plants are very limited, mutation breeding, and <em>in vitro </em>selection were used to increase the variability. Three soyben genotypes were produced from cultivars Wilis and Sindoro that have been gamma irradiated and selected <em>in vitro </em>for their tolerance to Al on Al and low pH media. These genotypes and their original cultivars were then planted in a greenhouse in an acid soil on May 2001. The results showed that the plant performances were varied, some were shorter and more compact than the original. Based on the yield components, a number of plants from the genotypes showed higher than those of the control cultivars. These plants were considered more tolerant to Al than the original cultivars.</p>


2012 ◽  
Vol 13 (1) ◽  
pp. 82
Author(s):  
Dewi Indriyani Roslim ◽  
Miftahudin Miftahudin ◽  
Utut Suharsono ◽  
Hajrial Aswidinnoor ◽  
Alex Hartana

Aluminum (Al) is one of the major limited factors in crop production on acid soils. Aluminum tolerant plants can beselected from plant breeding program by one of the physiological parameters representing Al tolerance character,such as root re-growth capability during recovery from the Al-stress. In this study we determined the concentrationand time exposure of Al stress that was able to differentiate the response of three local upland rice varieties(Grogol, Hawarabunar and Krowal) and an Al-sensitive rice variety (IR64) to Al-stress, and evaluated the effectivenessof root re-growth (RRG) characters as an Al tolerance parameter in rice. The study consisted of three experiments,which were 1) nutrient culture experiment with different Al concentration treatments in growth chamber, 2) potexperiment in greenhouse using Jasinga yellow red podzolic acid soil containing 26,66 me/100 g Al and pH 4,6 asplanting media, and 3) phenotyping of F2 population using RRG character. The results showed that Al treatment at15 ppm for 72 h was able to distinctly differentiate between Al-tolerant (Grogol and Hawarabunar) and Al-sensitivevarieties (Krowal and IR64). Planting of the rice varieties on acid soils showed similar result as that of the nutrientculture. Phenotyping of F2 population using RRG character indicated the existence of RRG value variation. Thesevariations demonstrated that RRG character can be used as an Al tolerance parameter in rice and therefore can beeffectively applied to screen rice F2 population that segregate to Al tolerance character.


2014 ◽  
Vol 65 (8) ◽  
pp. 767 ◽  
Author(s):  
M. L. Mitchell ◽  
J. M. Virgona ◽  
J. L. Jacobs ◽  
D. R. Kemp

Microlaena (Microlaena stipoides var. stipoides (Labill.) R.Br.) is a C3 perennial grass that is native to areas of south-eastern Australia. In this region, perennial grasses are important for the grazing industries because of their extended growing season and persistence over several years. This series of experiments focused on the population biology of Microlaena by studying the phenology (when seed was set), seed rain (how much seed was produced and where it fell), seed germination, germinable seedbank, seed predation and seedling recruitment in a pasture. Experiments were conducted at Chiltern, in north-eastern Victoria, on an existing native grass pasture dominated by Microlaena. Seed yields were substantial (mean 800 seeds m–2), with seed rain occurring over December–May. Microlaena has two distinct periods of high seed rain, in early summer and in early autumn. Seed predation is high. Within a 24-h period during peak seed production, up to 30% of Microlaena seed was removed from a pasture, primarily by ants. Microlaena seedlings recruited throughout an open paddock; however, seedling density was low (5 seedlings m–2). Microlaena represented only low numbers in the seedbank (0.01–0.05% of total); hence, any seedlings of Microlaena that germinate from the seedbank would face immense competition from other species. Management strategies for Microlaena-dominant pastures need to focus on the maintenance of existing plants.


1996 ◽  
Vol 18 (1) ◽  
pp. 3 ◽  
Author(s):  
VJ Anderson ◽  
KC Hodgkinson ◽  
AC Grice

This study examined the effects of previous grazing pressure, position in the landscape and apparent seed trapping capability of soil surface micro-sites on recruitment of the perennial grass Monachather paradoxa (mulga oats) in a semi-arid woodland. Seedling emergence was counted on small plots which had been kept moist for one month. The plots were on bare ground, or at grass tussocks, or at log mounds, sited in the run-off, interception and run-on zones of paddocks that had been grazed for six years at 0.3 and 0.8 sheep equivalent/ha. Few naturally occurring perennial grass seedlings emerged on any of the sites. The level of previous grazing pressure influenced the recruitment of grasses from natural sources as well as from seed of M. paradoxa broadcast on the soil surface; significantly more grass seedlings recruited in paddocks stocked at 0.3 than at 0.8 sheep/ha. Emergence of the sown grass did not differ significantly between the three zones in the landscape, but trends in the data suggest the interception zone may have been the most favourable. Recruitment from in situ grass seed was highest in the mulga grove (run-on) zone. Most seedlings of the sown grass emerged around the bases of existing perennial grass tussocks, but recruitment of volunteer perennial and annual grasses was more evenly distributed between the mulga log-mounds and perennial grass tussocks. It is concluded that very low levels of readily germinable seed of perennial grasses remained in the soil at the end of the drought and that areas with a history of high grazing pressure have less probability of grass recruitment when suitable rain occurs.


1985 ◽  
Vol 25 (4) ◽  
pp. 840 ◽  
Author(s):  
BD Hill

Fifteen perennial grass cultivars were compared in cutting trials in the medium rainfall (about 700 mm/year) area of central New South Wales. The perennial grasses were shown to have different growth patterns. Siro 1146 phalaris (Phalaris aquatica x P. arundinacea), Brignoles cocksfoot (Dactylis glomerata) and Demeter fescue (Festuca arundinacea) had the highest dry matter yields in late spring and summer. The phalaris (Phalaris aquatica) cultivars Special Select, Sirosa, Sirocco and El Golea had the highest yields in autumn and winter, while Kangaroo Valley perennial ryegrass (Lolium perenne) and the cocksfoot cultivars, Berber, Brignoles and Currie, yielded well in spring. When the total yields of pastures containing perennial grasses and annual species were compared with the total yields of annual species alone, it was found that the perennials generally did not increase yields when present at relatively low plant densities (5-20 plants/m2) and growing with a vigorous annual species component. When present at higher plant densities (over 20 plants/ m2) perennial grasses only increased total yields in autumn and winter when soil moisture was low and annual species did not grow well. The probable effects on animal production of including perennial grasses in pasture mixes are discussed and it is concluded that the perennials are most likely to be beneficial in late spring and summer when annuals become less palatable and have lower digestibility.


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