Agronomic variation in Centrosema virginianum in relation to its use as a sub-tropical pasture plant

1977 ◽  
Vol 17 (86) ◽  
pp. 435 ◽  
Author(s):  
RJ Clements
Keyword(s):  
Growing Season ◽  
North Coast ◽  
Tropical Pasture ◽  
Flowering Pattern ◽  
Seedling Regeneration ◽  
South Eastern ◽  
Herbage Yield ◽  
Macroptilium Atropurpureum ◽  
Potential Improvement ◽  
Pasture Plant

Nineteen accessions of Centrosema virginianum were grown in replicated short rows at four sites in south-eastern Queensland and one site on the wet tropical north coast, and some of their agronomic characteristics were observed and compared with those of Macroptilium atropurpureum cv. Siratro. Three sites were abandoned when the accessions grew poorly or died during the winter, although Siratro survived and grew vigorously. At the remaining sub-tropical sites the accessions persisted under weed-free conditions where seedling regeneration more than compensated for plant losses during the winter. In the second season at these sites, rows were cut for herbage yield assessment either every six weeks during the growing season or once at the end of the season. Treatments were continued for a third season at one site. In most respects Siratro was superior to all C. virginianum accessions. The accessions differed considerably in herbage yield, winter survival, seed production, seedling regeneration and leafiness, and differed slightly in leaf and stem digestibility. Many accessions flowered for very long periods in south-eastern Queensland, in contrast to the markedly bimodal flowering pattern of Siratro, but peak flowering dates of the accessions in the autumn differed by up to three months. Both C. virginianum and Siratro showed a reduction in percentage pod set during the middle of the growing season. Variation between accessions is discussed in relation to potential improvement of C. virginianum by plant breeding.

Temporal patterning of blooming phenology in Pedicularis on Mount Rainier

1983 ◽  
Vol 61 (3) ◽  
pp. 786-791 ◽  
Author(s):  
Virginia Dale Adams
Keyword(s):  
Pollen Grains ◽  
Growing Season ◽  
Sympatric Species ◽  
Temporal Patterning ◽  
Flowering Pattern ◽  
Subalpine Meadow ◽  
Evolutionary Force ◽  
Mount Rainier ◽  
Pollinator Sharing ◽  
Blooming Phenology

The temporal patterning of flowering of five sympatric species of Pedicularis in a subalpine meadow is documented. Two species bloom early in the growing season, one is intermediate, and two flower toward the later part of the season. The differences between species are related to the range of blooming periods (in days), the number of inflorescences at maximum bloom, and the time of peak bloom. No significant variation in flowering pattern occurred during the years of observation (1977, 1978, and 1979). More than 93% of the time individual bumblebees continued to forage on the same Pedicularis species as was previously visited; yet when switches in the diet of the bees occurred, they were more likely to be to another species of Pedicularis. Although individuals of other genera were in bloom, the bees switched to the Pedicularis species most synchronous in time and space to the previously preferred Pedicularis species. Counts were made of the number of pollen grains per flower, the reward for foraging bees. The last species to flower had the greatest reward but also had the largest ratio of the number of pollen grains to the number of ovules as compared with the previously flowering Pedicularis species. These results suggest that pollinator sharing is an important evolutionary force but that the quantity of the pollen reward may be more related to the number of ovules.

The Effect Of Grazing Compared With Cutting, at Different Frequencies, On a Lucerne-Cocksfoot Ley

1977 ◽  
Vol 88 (2) ◽  
pp. 483-492 ◽  
Author(s):  
D. Wilman
Keyword(s):  
Adverse Effect ◽  
Growing Season ◽  
N Content ◽  
The Third ◽  
Herbage Yield ◽  
Adjacent Site ◽  
One Year ◽  
Experimental Treatments ◽  
Harvest Year ◽  
Extreme Treatment

SUMMARYGrazing with sheep was compared with cutting, in each case at three frequencies, four, five and six defoliations per year, on a lucerne—cocksfoot ley. The treatments were applied in one year and their effects measured during that year and at cuts in June and August of the following year. One experiment began in 1963 in the second harvest year of a ley and a second began in 1964, on an adjacent site, in the third harvest year of the ley. Cutting four times in the year allowed lucerne to persist satisfactorily in both experiments. In the 1964 experiment cutting five or six times and grazing rather than cutting had no apparent, serious, adverse effect on the lucerne compared with cutting four times. In the 1963 experiment, however, increasing the number of cuts and grazing rather than cutting had a large adverse effect on the lucerne, and in the most extreme treatment, grazing six times, the proportion of lucerne was reduced to 2 % of total herbage yield the following June compared with 66% on the four-cut treatment. The contrasting results in the two experiments seem associated with weather differences, 1964 being a much drier, more sunny growing season than 1963, and perhaps with the differences in age of sward, individual lucerne plants perhaps having bigger roots with more reserves in 1964 than in 1963. During the treatment year increasing frequency of defoliation tended to increase the N content of both species and grazing compared with cutting generally increased the N content of cocksfoot. During the year following the treatment year the N content of the two species was little affected by the experimental treatments. The implications for farm practice are considered.

scholarly journals Effects of grazing animals on the plant availability of sulphur fertilisers in grazed pastures

1990 ◽  
pp. 181-185
Author(s):  
K.M. Goh ◽  
M.L. Nguyen'J
Keyword(s):  
Growing Season ◽  
Field Trials ◽  
Elemental Sulphur ◽  
Silt Loam ◽  
Sheep Grazing ◽  
Field Plot ◽  
Plant Availability ◽  
Animal Excreta ◽  
Loam Soil ◽  
Pasture Plant

Most field trials conducted in New Zealand for assessing pasture plant sulphur (S) requirements use the mowing and clipping return technique without the inclusion of grazing animals. A rotational grazing experiment and a field plot trial were conducted on a Templeton silt loam soil (Udic Ustochrept) in Canterbury using radioactive S35-labelled fertilisers to examine the effects of grazed sheep on the plant availability and cycling of applied S fertilisers. An additional plot trial was conducted to determine leaching losses of S35-labelled urine applied to pastures. The results obtained showed that maximum 3sS concentration in pastures treated with elemental S occurred 3 months earlier in the grazed trials compared with that of ungrazed plots. This increased herbage S was also reflected in the wool 35S of ewes which grazed the pastures. In addition, the amount of residual elemental S remaining in the soil after 3 months of its application was significantly lower in grazed than in ungrazed pastures. These results suggest that grazing animals enhanced the plant availability of elemental S probably because of the effects of animal trampling and the return of animal faeces. It was also found that about 36-44% of the applied 35S fertilisers and up to 68% of the applied urinary s35 were not recovered in the soil within one growing season in the field. __ Thus grazing animals enhanced not only the availability of elemental S, but were also responsible for substantial losses of S from pastures through animal excreta. The present data suggest that field trial results obtained from mowing plot trials without the inclusion of grazing animals are unlikely to assess adequately the plant availability of elemental S. Keywords sulphur, nutrient cycling, urine, sulphur leaching, recovery, fertiliser, elemental sulphur, oxidation, sheep grazing, mowing, grazing

Effect of stocking rate and grazing frequency on a Siratro (Macroptilium atropurpureum)/Setaria anceps cv. Nandi pasture

1979 ◽  
Vol 19 (98) ◽  
pp. 318 ◽  
Author(s):  
RM Jones
Keyword(s):  
Total Yield ◽  
Rest Period ◽  
Residual Effect ◽  
Stocking Rate ◽  
Animal Performance ◽  
Good Recovery ◽  
Seedling Regeneration ◽  
Seed Reserves ◽  
Macroptilium Atropurpureum ◽  
Stocking Rates

Five stocking rates, ranging from 0.8 to 2.8 beasts ha-1, and three frequencies of grazing were imposed on a five-year-old Siratro (Macroptilium atropurpureum)/Setaria anceps cv. Nandi pasture at Samford, south-east Queensland. The three grazing frequencies involved grazing for four days every three, six or nine weeks. Plots were individually grazed from 1972 to 1976 and the residual effect of treatments was measured over a grazing-free period in 1977. Within the three week grazing frequency both Siratro yield and total yield declined markedly with increased stocking rate, with an increased invasion of prostrate species such as blue couch (Digitaria didactyla). The decline in Siratro yield at higher stocking rates was less marked in the nine week system where there was much less invasion of prostrate species. However, it is suggested that the value of rotational grazing with a long rest period as a means of maintaining Siratro productivity could be largely at stocking rates where the pasture is overgrazed in terms of animal performance. Siratro density and seedling regeneration were largely unaffected by treatment and there was a good recovery of Siratro in the heavily grazed treatments during the grazing-free period at the end of the experiment. However, Siratro soil seed reserves declined with increased stocking rate and there was a much greater decline in flowering and seeding. On this basis it is predicted that if grazing treatments had been continued the heavily grazed pastures would eventually have reached the stage where Siratro would not recover with spelling.

scholarly journals Suitability of new subterranean clovers in the Canterbury region

2000 ◽  
pp. 161-165 ◽  
Author(s):  
K. Widdup ◽  
C. Pennell
Keyword(s):  
New Zealand ◽  
Seed Set ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Late Winter ◽  
Summer Drought ◽  
Seedling Regeneration ◽  
Breeding Lines ◽  
Herbage Yield ◽  
Late Maturity

The annual legume, subterranean clover, is adapted to permanent pastures in the summer drought-prone areas of eastern New Zealand. Dry summers over the last decade in Canterbury have renewed the interest from farmers in the use of sub clover. As the previously used cultivars Mt Barker and Tallarook are no longer available, a trial was established at AgResearch Templeton to evaluate a new series of cultivars and breeding lines from Australia together with recent New Zealand selections. The lines were sown in rows in May 1993 and assessed for seed set, autumn seedling regeneration and spring growth under sheep grazing for 4 years. The new Australian cultivars had improved seed set and consistently better seedling regeneration and herbage yield compared with older cultivars. The late-flowering, small-leaved and densely branched types were best adapted to the Canterbury environment. The late-maturity cultivars Denmark and Leura, selected from Sardinian germplasm, re-established 50% more seedlings and produced 25% greater late winter/ spring growth than Mt Barker and Tallarook in the third year. The New Zealand selection Ak 948 had similar performance to Denmark and Leura but the remaining selections were mediocre by the fourth year. The Sardinian ecotype breeding material appeared well-adapted to Canterbury conditions and future cultivars based on this material may be most suitable. Further trials are required in harsher sites to confirm these cultivar recommendations. Keywords: Australian cultivars, dry regions, herbage yield, seedling regeneration, subterranean clover, Trifolium subterraneum

scholarly journals Prospects for improving perennial legume persistence in mixed grazed pastures of south-eastern Australia, with particular reference to white clover

2019 ◽  
Vol 70 (12) ◽  
pp. 1141 ◽  
Author(s):  
R. C. Hayes ◽  
I. Ara ◽  
W. B. Badgery ◽  
R. A. Culvenor ◽  
R. E. Haling ◽  
...  
Keyword(s):  
Soil Fertility ◽  
White Clover ◽  
Genetic Improvement ◽  
Moisture Stress ◽  
Nutrient Deficiencies ◽  
Seedling Regeneration ◽  
South Eastern ◽  
Eastern Australia ◽  
Perennial Legume ◽  
South Eastern Australia

This review examines the prospect of improving perennial legume adaptation to grazed mixed pasture swards across the higher-altitude regions of south-eastern Australia through improved management, particularly as it relates to soil fertility. The range of adapted perennial species available to farmers often remains limited to only one perennial forage legume species, white clover (Trifolium repens L.). Despite recent advances in cultivars for increased persistence in dryland environments, white clover remains sensitive to drought with its inherently shallow root system and limited capacity to restrict water loss from herbage. With few alternative species likely to become widely available in the foreseeable future, prospects for extending the boundaries of perennial legume adaptation likely rely on a dual approach of improving soil fertility and further genetic improvement in white clover. Improved soil fertility would focus on overcoming soil acidity and addressing nutrient deficiencies, particularly of phosphorus, potassium, boron and molybdenum, which tend to be more widespread in the target region. Addressing these soil constraints would alleviate periodic moisture stress by: (1) increased water availability through improved infiltration and soil hydraulic properties; (2) increased root growth to maximise exploration of the soil volume; and (3) better maintenance of plant cell structures to foster improved osmotic regulation. However, the extent to which white clover adaption may be extended remains an issue of further research. This review highlights an opportunity for further genetic improvement of white clover by focusing on improving the capacity to recover from periodic droughts through seedling regeneration. Further breeding efforts in white clover should examine the feasibility of selecting for hard seed characteristics more similar to the best-adapted subterranean clover (Trifolium subterraneum L.) cultivars across this region to promote ongoing seedling regeneration.

Pueraria montana var. lobata (kudzu).

2021 ◽  
Author(s):  
Nick Pasiecznik
Keyword(s):  
Seed Dispersal ◽  
East Asia ◽  
Vegetative Growth ◽  
Growing Season ◽  
Significant Problem ◽  
Control Seed ◽  
South Eastern ◽  
Eastern Usa ◽  
The Usa ◽  
Marginal Habitats

Abstract P. montana, formerly known as P. lobata, is widely known in the USA as 'kudzu' is native to East Asia. However, it does not appear to be a significant problem anywhere except in south-eastern USA where it was extensively planted in the 1930s and 1940s for erosion control. Seed dispersal appears to be minor but vegetative growth in subtropical areas can be substantial, up to 18 m per growing season. It is a climbing vine and kills vegetation by completely smothering it, and it will also entirely cover telegraph poles and buildings if left to itself. Once introduced it is difficult to control, especially in forest and marginal habitats. There are three varieties, although only var. lobata is so far known to be invasive, in the USA.

Prediction of response to sulfur by established Siratro/grass pastures in south-eastern Queensland

1983 ◽  
Vol 23 (122) ◽  
pp. 280 ◽  
Author(s):  
GE Rayment
Keyword(s):  
Field Experiments ◽  
Laboratory Data ◽  
Model Fitting ◽  
Prediction Of Response ◽  
South Eastern ◽  
Critical Range ◽  
Plant Chemical ◽  
Diagnostic Samples ◽  
Macroptilium Atropurpureum ◽  
Sulfur Yield

Dry matter responses by component species of 18 established, commercial Macroptilium atropurpureum cv. Siratrolgrass pastures to gypsum topdressing treatments (0 or 25 kg S/ha) were assessed from field experiments conducted over a four-year period in south-eastern Oueensland under rain-grown conditions. The objective was to establish diagnostic criteria for the assessment of sulfur status by relating pasture yields to agronomic attributes and soil and plant chemical tests. Beneficial responses to gypsum were small (maximum of 32% in Siratro) and restricted to fewer than 25% of sites, whereas at disadvantaged sites (28% of total), grass yields were more severely depressed than Siratro yields. It was not possible to predict these effects from past sulfur fertilizer history, Siratro percentage in the pasture, or pasture age. Significant correlations between Siratro relative yields (100 x yield without sulfur/yield with sulfur applied, attenuated at 100 for model fitting) and both soil sulfate and plant sulfur concentrations confirmed the predictive value of these laboratory data. For Siratro, best prediction of responsiveness was provided by sulfur concentrations in either whole tops (R2 = 0.65) or diagnostic samples (tips of runners back to the fifth to sixth fully expanded leaf; R2 = 0.65). Critical value for diagnostic samples was 0. 16% S while for whole tops of Siratro the value varied with mathematical model from 0.13 to 0. 15% S. Phosphate-extractable sulfate was the most effective soil test but irrespective of sampling depth, it accounted for less than 50% of the variation in Siratro relative yields. Whether sampled at 0- 10 cm or 0-90 cm, a critical range of 3-5 ppm phosphate-extractable sulfate was indicated for the Siratro component. Grass and total pasture relative yields were not correlated with the chemical tests employed.

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