The control of slender thistle, Carduus pycnocephalus L. and C. tenuiflorus Curt. (Compositae), in pasture by grazing management

1973 ◽  
Vol 24 (6) ◽  
pp. 831 ◽  
Author(s):  
GM Bendall

The effect of grazing management on slender thistle populations and botanical composition of improved pasture was studied in two field trials in southern Tasmania. Deferring grazing until winter or spring reduced slender thistle populations in both trials. The reasons underlying these observations are discussed. Spring grazing favourably altered pasture botanical composition by increasing the frequency of perennial ryegrass and subterranean clover and reducing the frequency of weed grasses. These changes arc discussed in relation to thistle control. It is suggested that deferred autumn grazing may be incorporated into the farm programme as an economical method for the control of slender thistle in pasture.

2001 ◽  
Vol 41 (8) ◽  
pp. 1109 ◽  
Author(s):  
R. A. Waller ◽  
P. W. G. Sale ◽  
G. R. Saul ◽  
G. A. Kearney

A 4-year field experiment was carried out in south-western Victoria to determine whether tactical stocking might improve perennial ryegrass (Lolium perenne L.) persistence and prime lamb production, compared with the more common practice of continuous stocking. Tactical stocking consisted of variable-length summer, autumn and winter rotations and continuous stocking in spring. The 2 grazing strategies were compared on 2 contrasting pastures: an upgraded pasture, sown with newer cultivars of perennial ryegrass and subterranean clover (Trifolium subterraneum L.) with 26 kg phosphorus/ha.year, and a more typical naturalised perennial ryegrass pasture receiving 6 kg phosphorus/ha.year. Paddocks were grazed by Border Leicester x Merino ewes, which were mated to a terminal sire to lamb in September. The effects of the grazing systems and pasture treatments on ryegrass persistence and pasture botanical composition are presented in this paper. The perennial ryegrass component of the sward decreased from an average mass of 1000 kg dry matter/ha on the upgraded pasture and 400 kg dry matter/ha on the typical pasture in spring 1996 to 100 kg dry matter/ha and <50 kg/ha for the 2 pasture types, respectively, in spring 1998. This occurred irrespective of the grazing system imposed. The decline of ryegrass was attributed to several factors including the very dry 3-year period, summer rainfall events that caused ryegrass buds to break dormancy then die when dry conditions resumed, the gravelly soil type where the experiment was located, and the high grazing pressure used. A number of species became more prevalent in the pastures as the ryegrass disappeared. Silver grass (Vulpia spp.) increased 4–5-fold on all treatments. By the fourth year, barley grass (Hordeum leporinum) and Bromus spp. had increased significantly with tactical stocking compared with continuous stocking. Capeweed (Arctotheca calendula L.) and Erodium spp. increased on both the continuously stocked and upgraded pastures. The subterranean clover component was maintained across all treatments over the 4 years, indicating that tactical stocking did not adversely affect clover persistence. Since ryegrass declined irrespective of treatment, the tactical stocking system used in this study cannot be recommended for improving ryegrass persistence.


1978 ◽  
Vol 29 (1) ◽  
pp. 19 ◽  
Author(s):  
SJ Cook ◽  
GJ Blair ◽  
A Lazenby

Fertilizer application and grazing management were shown to be important factors affecting trends in botanical composition in a 5-year-old perennial ryegrass–white clover pasture showing signs of pasture degeneration. In the absence of continuing superphosphate application, native and weed species invaded the pasture, irrespective of grazing management. However, where superphosphate was applied at 500 kg ha-1 year-1, the subsequent trends in botanical composition were dependent on the grazing strategy used. Pastures which were intensively grazed during the winter-spring period were invaded by red grass and other native grass species following a decline in the perennial ryegrass component, whatever the grazing management of other times of the year. In contrast, lax grazing, or pasture spelling, during this winter-spring period led to an increase in the basal area of ryegrass and checked the encroachment of unsown species. The role of superphosphate and grazing management in maintaining stable and productive pastures on the Northern Tablelands of New South Wales is discussed. Part I, Aust. J. Agric. Res., 29: 9 (1978).


Author(s):  
J.S. Bircham

The effects of summer spelling, frequency and severity of defoliation on improved pasture which had reverted to browntop dominance in spite of adequate topdressing were investigated on northwest and south-east aspects in North Wairarapa hill country pastures. Frequency and severity of defoliation affected both pasture production and botanical composition on the south-east aspect but had little significant effect on the north-west aspect. A pasture improvement programme based on the field trial results was devised and applied. The interim results of this programme are given.


2016 ◽  
Vol 5 (07) ◽  
pp. 4694 ◽  
Author(s):  
Viliana Vasileva ◽  
Anna Ilieva

In pot trial the biochemical composition and phosphorus use efficiency of birdsfoot trefoil, sainfoin and subterranean clover grown pure and in mixtures with perennial ryegrass in the next ratios were studied in the Institute of Forage Crops, Pleven, Bulgaria: birdsfoot trefoil + perennial ryegrass (50:50%); sainfoin + perennial ryegrass (50:50%); subterranean clover + perennial ryegrass (50:50%); birdsfoot trefoil + subterranean clover + perennial ryegrass (33:33:33%); sainfoin + subterranean clover + perennial ryegrass (33:33:33%). The highest crude protein content was found in the aboveground mass of birdsfoot trefoil (19.17%) and sainfoin (19.30%). The water soluble sugars contents in mixtures was found higher compared to the pure grown legumes. Birdsfoot trefoil showed the highest phosphorus use efficiency for plant biomass accumulation and nodules formation. In mixtures the phosphorus use efficiency was found be higher as compared to the same in pure grown legumes.


1971 ◽  
Vol 22 (1) ◽  
pp. 81 ◽  
Author(s):  
PG Ozanne ◽  
KMW Howes

The applied phosphorus requirement of a pasture sown to subterranean clover was measured with and without grazing. Under moderate grazing pressure, in the year of establishment, the pasture required about 50 % more phosphorus than when ungrazed. In the following season, at a higher stocking rate, the grazed areas needed twice as much phosphorus as the ungrazed to make 90% of their maximum growth. In both years this difference in requirement between stocked and unstocked treatments was present throughout the growing season. Increased phosphorus requirement under grazing is associated with the need for greater uptake of phosphorus under conditions where redistribution of absorbed phosphorus within the plant is prevented by defoliation. It does not appear to be due to effects of defoliation on root size. Nor does it depend on differential light interception or on changes in botanical composition.


Author(s):  
K.N. Tozer ◽  
G.B. Douglas ◽  
C.A. Cameron ◽  
T.J. Fraser ◽  
R.A. Moss ◽  
...  

To determine the best method of pasture establishment on non-cultivable hill country (>20o slope), four treatments were compared in one year on north and south aspects at four sites with contrasting climates and soil types. Sites were located in Waikato (1), Hawke's Bay (2) and Canterbury (1). The treatments included seed mix (grasses, legumes and herbs (GLH); legumes only (LEG)) and sowing time (spring; autumn). Six weeks after sowing, seedling establishment, as a percentage of viable seeds sown, was: i) greater on south than north aspects for perennial ryegrass (31% vs 18%) and birdsfoot trefoil (5% vs 4%); ii) greater for total sown species (14% vs 8%), subterranean clover (7% vs 4%) and red clover (25% vs 14%) in the GLH than LEG mix, but greater for white clover in the LEG than GLH mix (17% vs 8%); iii) greater in autumn than spring for perennial ryegrass (36% vs 13%) and total sown grasses (22% vs 9%) but greater in spring than autumn for lotus (6% vs 3%). Plantain established well in spring in summer-wet environments, while in summer-dry environments establishment was greater in autumn. Broadcasting seed on south aspects during autumn is likely to result in the highest establishment of sown grasses and legumes, but not necessarily of herbs. The trials were conducted in an unusually wet season. Repeating a subset of the treatments at these sites will provide a greater understanding of responses to climatic variation. Keywords: pasture renewal; pasture establishment; pasture mixtures; oversowing.


2000 ◽  
Vol 53 ◽  
pp. 436-440 ◽  
Author(s):  
N.W. Waipara ◽  
S.K. Hawkins

A preliminary survey of pastures sprayirrigated with dairyshed effluent revealed a significant increase in the population of plant pathogenic Pythium species isolated from both soil and roots In vitro pathogenicity tests showed the majority of these isolates to be pathogenic when inoculated onto the seedlings of white clover subterranean clover and perennial ryegrass although both clover species were more susceptible to Pythiuminduced disease than ryegrass


Author(s):  
H.S. Easton ◽  
B.M. Cooper ◽  
T.J. Frasers ◽  
K.H. Widdup

Crown rust infection of 11 perennial ryegrass cultivars vaned significantly and consistently over 6 sites. 'Grasslands Ariki,' the new cultivar 'Yatsyn' and Grasslands selections G26 and G33 were less infected than 'Grasslands Nui', 'Ellett' or 'Grasslands Ruanui'. 'Droughtmaster' and 'Marathon' proved more susceptible than most. Keywords: Crown rust, Puccinia coronata. perenmal ryegrass


1999 ◽  
Vol 7 ◽  
pp. 19-26
Author(s):  
R.H. Watson ◽  
R.G. Keogh ◽  
M.F. Mcdonald

Two groups (n=39) of Romney breeding ewes were maintained under the same grazing management on either endophyte-infected (E+) or endophytefree (E-) perennial ryegrass pasture for two years (1997-1998) following a one-year equilibration period. The ewes were naturally mated in March each year and ovulation rate at 1st mating was measured, and conception and the number of lambs born and weaned were recorded. All ewes were weighed monthly and lamb growth rates were determined between birth and weaning. Mean mating date was delayed by 1.8 days (P


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