Seedling emergence and survival of annual pasture legumes in northern New South Wales

1996 ◽  
Vol 47 (4) ◽  
pp. 559 ◽  
Author(s):  
GM Lodge
Keyword(s):  
New South ◽  
Seedling Emergence ◽  
New South Wales ◽  
Survival Rates ◽  
Trifolium Subterraneum ◽  
Survival Curves ◽  
Vicia Villosa ◽  
Pasture Legumes ◽  
South Wales ◽  
Seedling Emergence And Survival

Seedling emergence and survival of 15 annual pasture legumes was studied in the field at Tamworth, northern New South Wales. Emergence was measured in permanent quadrats (0.09 m2) in covered and uncovered areas approximately every 15 days from 30 November 1983 to 30 November 1984. Survival of seedlings was estimated from 15 December 1983 to 31 August 1984, before plants senesced. Emergence was generally highest in summer and autumn following seed set and lowest in winter and spring. Two legumes, Medicago scutellata cv. Sava and Trifolium subterraneum cv. Seaton Park, had high emergence in winter (mid July). Total seedling emergence was highest ( P < 0.05) in covered areas of cv. Seaton Park and uncovered areas of T. hirtum cv. Hykon. All T. subterraneum cultivars, M. minima, Astragalus hamosus cv. Ioman, Vicia villosa cv. Namoi, and M. truncatula cv. Paraggio had higher total emergence in covered compared with uncovered areas. In contrast, total emergence of M. aculeata, M. truncatula cv. Jemalong, Sava, and Hykon was lowest in covered areas. Cover had little effect on the total emergence of M. truncatula cv. Sephi and T. glomeratum. Of the 7700 individual seedlings marked from November 1983 to August 1984, a mean of only 31% (covered) and 41% (uncovered) survived until 31 August 1984. For each emergence time, highest ( P < 0.05) survival rate coincided with the highest (P < 0.05) number of emerged seedlings in 4 of the legumes in covered areas (cv. Namoi, 31 January; cv. Ioman, 31 March; cv. Hykon, 15 April; cv. Sava, 15 July; Table 4) and 9 in uncovered areas (cvv. Nungarin, Seaton Park, and Namoi, 31 January; M. aculeata and cv. Sephi, 28 February; cvv. Jemalong and Ioman, 31 March; T. glomeratum, 15 April; cv. Sava, 15 July). In all other legumes there was no optimum time for emergence, since the highest (P < 0.05) survival rates were associated with seedling survivals <50%. Generally, survival curves with a mortality constant rather than a mortality rate were a better fit ( P < 0.05) for most legumes and times. This implied that these survival curves were determined at the time of recruitment, and declined at a constant rate, despite below-average post-emergence rainfall in May-June. Low rates of survival at times of highest ( P < 0.05) emergence indicated that there may have been some density-dependent regulation in some of the legumes.

Evaluation of annual pasture legumes in northern New South Wales. 2. Trifolium and Medicago spp. and other legumes

2007 ◽  
Vol 47 (5) ◽  
pp. 563 ◽  
Author(s):  
G. M. Lodge ◽  
S. Harden
Keyword(s):  
New South ◽  
New South Wales ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Smoothing Splines ◽  
Limited Data ◽  
Pasture Legumes ◽  
South Wales ◽  
Annual Medicago

Two studies to evaluate annual pasture legumes were sown in replicated plots near Tamworth, New South Wales. In the first (experiment 1), 24 entries were sown in 1995 and in a second study (experiment 2) 33 entries were sown in 1996. Green herbage mass (kg DM/ha) was assessed in the year of sowing (spring) and thereafter four times per year until spring 2000. Limited data were also collected to estimate maturity grading, seed yield and seedling regeneration. For each experiment, green herbage mass data were examined using cubic smoothing splines and at the end of each study, green herbage mass values predicted from the model were used to assess the significance (P = 0.05) of differences between cultivars or lines. In spring 2000 (experiment 1), Trifolium subterraneum var. brachycalycinum cv. Clare had the highest rank of the cultivars and lines, and T. michelianum cv. Paradana the lowest (previously cultivated site). For the native pasture site, CPI 70056B subterranean clover had the highest rank and Ornithopus compressus cv. Paros the lowest. In experiment 2, Clare had the highest rank in spring 2000 and T. resupinatum cv. Bolta had the lowest ranking. Long-term green herbage mass appeared to be strongly influenced by maturity grading, but other factors may have affected the performance of annual Medicago spp., O. compressus, T. resupinatum, and T. michelianum. Results from the current study and previous reported research indicated that T. subterraneum var. subterraneum cvv. York (evaluated as CPI 89846B) and Junee and T. subterraneum var. brachycalycinum cv. Clare performed best in northern New South Wales.

Evaluation of pasture legumes sown into a prepared seedbed at Tamworth, New South Wales. 2. Seed production and seed reserves

1993 ◽  
Vol 33 (3) ◽  
pp. 299 ◽  
Author(s):  
GM Lodge
Keyword(s):  
Seed Production ◽  
New South ◽  
New South Wales ◽  
Pasture Legumes ◽  
South Wales ◽  
Medicago Scutellata ◽  
Seed Reserves ◽  
Annual Medics ◽  
Perennial Legumes ◽  
Seed Yields

Plots sown in 1983 were used to examine the seed production and reserves (residual hardseeds) of 15 annual legumes over 5 years at Tamworth in northern New South Wales. Seed production characteristics were measured in 1983 for these annuals, and for 6 perennial legumes. After the annuals had set seed in 1983, an area of the plots was sprayed to prevent flowering in subsequent years, and the rates of decline in seed reserves were compared with those from areas that seeded annually. Seed yields of the perennials were often significantly lower than those of the annuals except Trifolium glomeratum. Seed yields of T. subterraneum var. subterraneum cvv. Seaton Park and Woogenellup were significantly higher than those of cv. Nungarin and T. subterrarzeum var. brachycalycinum cv. Clare. Seed numbers were lowest for Medicago scutellata cv. Sava among the annual medics, and for Nungarin among subterranean clovers. There was little relationship between the mean number of seeds produced from 1983-86 and maturity grading, and between seed numbers and relative dry matter yield. Seed reserves decreased over 5 years by more than 90% in the sprayed treatments of all species. This decrease was not continuous, with the largest declines occurring from December 1983 to August 1984. In the sprayed treatments of Seaton Park, Woogenellup, and Clare, and in both treatments of Astragalus hamosus cv. Ioman, Vicia dasycarpa var. villosa cv. Namoi, and T. hirtum cv. Hykon, none of the original 1983 seed was recovered in 1987. For the annual medics and Nungarin, the number of residual hardseeds in the sprayed treatments in 1987 was about 3-5% of the seed produced in 1983. From 1983 to 1987, seed numbers in the unsprayed treatments declined by 7040% for the annual medics and by 85-95% for Seaton Park, Woogenellup, and Clare. Long-term persistence of annual medics and Nungarin depended on seed production in most years and the maintenance of a high number of residual hardseeds in the soil. In contrast, the mid- and late-maturing subterranean clovers Woogenellup and Clare had low seed reserves and were dependent on seed production in most years for their continued regeneration.

The influence of various factors on survival rate to weaning of Merino lambs. I. Sex, strain, location, and age of ewe for single-born lambs

1965 ◽  
Vol 16 (6) ◽  
pp. 981 ◽  
Author(s):  
J Lax ◽  
Turner H Newton
Keyword(s):  
Survival Rate ◽  
New South ◽  
Strong Association ◽  
New South Wales ◽  
Survival Rates ◽  
Age Groups ◽  
Strain Differences ◽  
Marked Rise ◽  
South Wales ◽  
Improved Pasture

The influence of sex, strain, location, and age of ewe on survival rate to weaning of single-born Merino lambs has been examined in two sets of data: the strain trial, involving five strains run without selection at each of three locations (Cunnamulla, Qld.; Armidale, on the northern tablelands of New South Wales; Deniliquin, in the Riverina area of New South Wales), with six age groups of ewes; and the same five strains later included in selection groups at Armidale with seven age groups of ewes. The strain trial at Armidale ran mainly on native, and the selection groups mainly on improved pastures. Female lambs had a higher survival rate than either castrated or entire males, the differences in lambs weaned per lamb born being 0.03 and 0.04 respectively. No strain differences could be regarded as statistically significant, and neither could the strain x location interaction in the strain trial. Mean survival rates for the strains ranged from 0.673 to 0.786 on the Armidale native and from 0.802 to 0.850 on the Armidale improved pasture, from 0.746 to 0.859 at Cunnamulla, and from 0.838 to 0.894 at Deniliquin. The strains did not rank consistently in the same order. Location had a marked effect on survival rate, the means being 0.744 for the native and 0.824 for the improved pasture at Armidale, 0.810 at Cunnamulla, and 0.868 at Deniliquin. Age of ewe had a marked influence in the poorest environment (Armidale native pasture), survival rate rising with age and later falling sharply. The effect was less marked in the intermediate environments (Armidale improved pasture and Cunnamulla) and negligible at Deniliquin. The patterns at Cunnamulla and Deniliquin are confirmed by data from other experiments on these stations. Survival rate is one component of number of lambs weaned. The other component, number of lambs born, has a higher mean value at Deniliquin than Cunnamulla, but shows a strong association with age of ewe in both environments. Number of lambs born responds rapidly to selection, but no information is yet available concerning the likely response in survival rate. If improvement in environment can raise the survival rate, particularly in the youngest and oldest ewes, then selection for number of lambs born, combined with improved environment, should lead to a marked rise in the number of lambs weaned.

Characterisation of naturalised strains of Trifolium subterraneum var. brachycalycinum cv. Clare in northern New South Wales

1994 ◽  
Vol 34 (1) ◽  
pp. 33 ◽  
Author(s):  
GM Lodge
Keyword(s):  
Seed Weight ◽  
New South ◽  
New South Wales ◽  
Trifolium Subterraneum ◽  
Summer Rainfall ◽  
Median Number ◽  
South Wales ◽  
The Mean ◽  
Floral Characters ◽  
Number Of Seeds

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.

Occurrence of Phytophthora clandestina in Trifolium subterraneum paddocks in Australia

2001 ◽  
Vol 41 (2) ◽  
pp. 187 ◽  
Author(s):  
R. Aldaoud ◽  
W. Guppy ◽  
L. Callinan ◽  
S. F. Flett ◽  
K. A. Wratten ◽  
...  
Keyword(s):  
Western Australia ◽  
Root Rot ◽  
New South ◽  
New South Wales ◽  
South Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Soil Samples ◽  
South Wales ◽  
Differential Cultivars

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.

Ecology of Nassella neesiana, Chilean needle grass, in pastures on the Northern Tablelands of New South Wales. II. Seedbank dynamics, seed germination, and seedling recruitment

2003 ◽  
Vol 54 (6) ◽  
pp. 621 ◽  
Author(s):  
M. R. Gardener ◽  
R. D. B. Whalley ◽  
B. M. Sindel
Keyword(s):  
Seed Production ◽  
Seedling Recruitment ◽  
Seedling Survival ◽  
New South ◽  
Seedling Emergence ◽  
New South Wales ◽  
Separate Experiment ◽  
Bare Ground ◽  
Total Percentage ◽  
South Wales

This is the second in a series of papers investigating the ecology of Nassella neesiana (Trin. & Rupr.) Barkworth (Chilean needle grass) in pastures on the Northern Tablelands of New South Wales. The reasons for its success as a pasture weed are discussed. Nassella neesiana has a large and persistent soil seedbank. After 3 years without seed input, the seedbank declined from 4676 to 1323 seeds/m2. When an exponential decay curve was fitted to the data it was predicted that the seedbank would reach 10 seeds/m2 after 12.4 years. When seed production was large in 1996, 41.6% of seeds produced were incorporated into the seedbank, whereas in 1995 and 1997 the smaller seed production was only sufficient to maintain seedbank numbers. Furthermore, it is likely that the seedbank numbers were underestimated because they did not include basal cleistogenes. In a separate experiment, basal cleistogenes were found to contribute a further 20% to the seedbank.A small proportion of the viable seeds in a natural seedbank emerged from bare ground over 2 years. Seedling survival was high, with 78% of those germinating from bare ground surviving for at least 20 months. Several experiments were designed to investigate the mechanisms of this germination and survival. It appears that the seeds of N. neesiana have an after-ripening requirement of between 3 months and 1 year for maximum germination. Lemma removal from seeds stored for 8 months increased germination from 49 to 82%. The rate of germination and the total percentage of seeds germinating also increased with time of burial in the ground. Of seeds that had been buried for 2 years, 90% germinated after laboratory incubation compared with 48% of seeds stored in the laboratory as controls. Depth of seed burial appears to affect seedling emergence and survival. A smaller number of seedlings emerged from 0–10 mm and they had lower survival than those from seed buried at 10–20 mm.

The plant nutrient status of granite soils from the Bendemeer area of New South Wales

1966 ◽  
Vol 6 (20) ◽  
pp. 17 ◽  
Author(s):  
F McMullen
Keyword(s):  
Dry Matter ◽  
New South ◽  
Soil Phosphorus ◽  
New South Wales ◽  
Trifolium Subterraneum ◽  
Nutrient Status ◽  
Calcium Sulphate ◽  
Plant Nutrient ◽  
First Order ◽  
South Wales

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.

Efficiency of aerial techniques for long term control of serrated tussock (Nasella trichotoma)

1974 ◽  
Vol 14 (68) ◽  
pp. 405 ◽  
Author(s):  
MH Campbell
Keyword(s):  
New South ◽  
New South Wales ◽  
Late Summer ◽  
Trifolium Subterraneum ◽  
Botanical Composition ◽  
Fertile Soil ◽  
South Wales

In three experiments near Rockley and Gunning, New South Wales, non-arable areas of serrated tussock (Nassella trichotoma) were aerially sprayed with 2,2-DPA in late summer and, in the following autumn, aerially fertilized and sown with pasture species. Measurements of tussock density and the botanical composition of the pastures were made for up to ten years after sowing. The experiments commenced in 1963, 1964 and 1966. About 90 per cent of the tussock plants were killed by applying the herbicide at 16.6 kg a.e. ha-l; higher rates effected little improvement. Aerially sown pastures further reduced tussock numbers and provided long term control. Best results were obtained on fertile soil and where tussock has not been retarded by burning. Of the pasture species sown Trifolium subterraneum and Phalaris tuberosa were the most effective for long term control.

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