Evaluation of five Mediterranean annual pasture species during early growth

1972 ◽  
Vol 23 (4) ◽  
pp. 703 ◽  
Author(s):  
RCG Smith ◽  
EF Biddiscombe ◽  
WR Stern
Keyword(s):  
Growth Form ◽  
Species Differences ◽  
Subterranean Clover ◽  
Early Growth ◽  
Annual Species ◽  
Critical Weight ◽  
Continuous Grazing ◽  
Wimmera Ryegrass ◽  
Grazed Swards ◽  
Better Than

Pasture factors causing differences in the liveweight gain of sheep stocked at 10 sheep ha-l on continuously grazed swards of five annual species were examined during autumn and early winter. Differences in liveweight gain were due to the availability of the pasture species for prehension by grazing sheep, and depended on the weight of pasture offered and also on the growth form of the grazed plants. Subterranean clover and the volunteer species, silver grass and erodium, rapidly assumed a prostrate form under continuous grazing, thereby restricting apparent intake. Wimmera ryegrass changed less in growth form in response to grazing and for this reason liveweight gain on ryegrass in autumn was better than on clover, silver grass, and erodium. These species differences were reflected in the "critical" weight of herbage required for sheep to maintain their liveweight. Critical weight was lowest in the erect-growing Wimmera ryegrass (c. 130 kg ha-l) and highest (635 kg ha-l) in the prostrate erodium.

Effect of spelling newly sown pastures

1973 ◽  
Vol 13 (64) ◽  
pp. 549 ◽  
Author(s):  
RCG Smith ◽  
EF Biddiscombe ◽  
WR Stern
Keyword(s):  
Growth Form ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Growing Season ◽  
Lolium Rigidum ◽  
Beneficial Effects ◽  
Continuous Grazing ◽  
Seed Reserves ◽  
Wimmera Ryegrass

Newly sown pure swards of Wimmera ryegrass (Lolium rigidum) and subterranean clover (Trifolium subterraneum) were either grazed or spelled (deferred) for five weeks after emergence in autumn and then evaluated with young Merino wethers stocked at 10 sheep ha-1. Sheep on deferred pastures had higher intakes and liveweight than on plots continuously grazed. Spelling increased the availability of pasture for prehension due to a greater weight of herbage being offered and the more erect growth form. Under continuous grazing the animal productivity on clover was much lower than on ryegrass but following deferment, both species had similar productivity. The beneficial effects of spelling after emergence were manifest over the ensuing ten months by liveweight, fleeceweight and number of days of grazing. Spelling also increased seed reserves at the end of summer and the number of plants re-establishing at the beginning of the next growing season.

Selection by grazing sheep of pasture plants at low herbage availability and responses of the plants to grazing

1986 ◽  
Vol 37 (5) ◽  
pp. 527 ◽  
Author(s):  
DM Broom ◽  
GW Arnold
Keyword(s):  
Dry Matter ◽  
Growth Form ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Growing Season ◽  
Abundant Species ◽  
Ecological Implications ◽  
Wimmera Ryegrass ◽  
Erodium Botrys ◽  
Pasture Plants

Merino sheep grazing annual pasture at the beginning of the growing season when the amount of herbage on offer was small, preferred to graze Wimmera ryegrass Lolium rigidum or subterranean clover Trifolium subterraneum rather than capeweed Arctotheca calendula, and Erodium botrys was avoided completely. Behaviour observations showed that capeweed plants were usually avoided. When the plants were grasped they were sometimes pulled up by the roots and then dropped so that the number of capeweed plants in the pasture declined. Supplementation with oats reduced grass intake. Harvesting behaviour changed with pasture conditions: as grass height declined in the pasture, the rates of biting, stepping and head swinging increased. Pasture measurements showed that, whilst capeweed plants continued to increase in height during grazing, as did ungrazed controls, ryegrass and clover plants decreased or remained short. Herbage dry matter increased in all species, owing especially to basal growth. The proportion of shoots and petioles which were erect increased in ungrazed plants, but the proportion which were prostrate was much greater in grazed plants. Individual plants adapted their growth form in a way which counteracted the depredations of grazers. The ecological implications of these findings are important. Firstly, the sheep were not foraging optimally in terms of maximising rate of intake, since two abundant species were largely ignored even though food availability was low. Secondly, because of their selectivity the sheep were giving the capeweed and Erodium a competitive advantage which, in these pastures, will persist through the growing season.

Species differences in early growth and rust incidence of loblolly and slash pine

2000 ◽  
Vol 132 (2-3) ◽  
pp. 211-222 ◽  
Author(s):  
J López-Upton ◽  
T.L White ◽  
D.A Huber
Keyword(s):  
Species Differences ◽  
Early Growth ◽  
Slash Pine

The effect of leaf removal on flowering time in subterranean clover

1970 ◽  
Vol 21 (6) ◽  
pp. 893 ◽  
Author(s):  
WJ Collins ◽  
Y Aitken
Keyword(s):  
Flowering Time ◽  
Subterranean Clover ◽  
Early Growth ◽  
Grazing Management ◽  
Flower Initiation ◽  
Leaf Removal ◽  
Main Shoot ◽  
Delayed Flowering ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

The removal of fully expanded leaves delayed flowering by up to 30 days in subterranean clover cv. Mt. Barker sown in winter at Melbourne (38�S.). This effect on flowering was attributable partly to a delay in flower initiation and partly to a slower rate of leaf appearance after flower initiation. Thus leaf removal may be added to the factors already known to influence flower initiation in subterranean clover. When plants were grown under a 24 hr photoperiod. leaf removal had no effect on flower initiation; the slight delay that leaf removal caused in flowering was therefore due entirely to its effect in reducing the rate of leaf appearance. In other experiments leaf removal delayed the time of flower initiation but had no effect on the rate of leaf appearance. The effect of leaf removal on the time of flowering on the main shoot in lateral-dominant plants (as occur in the field) was qualitatively the same as in plants from which the laterals had been removed. Grazing management of subterranean clover which results in severe defoliation during early growth may delay flowering to such an extent that seed production is reduced substantially, and persistence thereby prejudiced.

The effect of rate of stocking with sheep on the botanical composition of an annual pasture in southern Victoria

1964 ◽  
Vol 4 (12) ◽  
pp. 34 ◽  
Author(s):  
MJ Sharkey ◽  
IF Davis ◽  
PA Kenney
Keyword(s):  
Subterranean Clover ◽  
Botanical Composition ◽  
Present Level ◽  
Wimmera Ryegrass ◽  
Clover Seed

The botanical composition of an annual unirrigated pasture at Werribee, twenty miles west of Melbourne, Victoria, grazed at one, three, and six sheep to an acre was greatly influenced by level of stocking. The areas grazed at one sheep to an acre became dominated by Wimmera ryegrass and had large reserves of grass and subterranean clover seeds in the soil. In those grazed at six sheep to an acre the original Wimmera ryegrass and subterranean clover had virtually disappeared at the end of three years, and there were few grass and clover seeds in the soil. Some change in botanical composition occurred from year to year in the areas grazed at three sheep to an acre but it was not progressive and the pasture at the end of the observations was similar to that at the beginning. The reserves of grass and clover seed, although lower in these plots than in those grazed at one sheep to an acre, were considerably above the level of those grazed at six sheep to an acre. It is concluded that at their present level of productivity these pastures will not carry six sheep to the acre continuously, but they may carry more than three sheep to the acre.

Levels of total nitrogen and total volatile fatty acids in the rumen fluid of sheep under different grazing management systems

1967 ◽  
Vol 7 (28) ◽  
pp. 434
Author(s):  
WR McManus
Keyword(s):  
Fatty Acids ◽  
Total Nitrogen ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Subterranean Clover ◽  
Grazing Management ◽  
Stocking Rate ◽  
Continuous Grazing ◽  
Grazing System ◽  
Stocking Rates

Concentrations of total nitrogen and total volatile fatty acids in the rumen fluid of sheep grazing improved pastures were measured for ten months in a dry year on the southern tablelands of New South Wales, and the concentrations of nitrogen and volatile fatty acids (V.F.A.) were related to season, wool production, and grazing management. The observations were made during two long-term grazing management experiments. In the first experiment four groups of breeding Merino ewes grazed a Wimmera ryegrass-subterranean clover (Lolium rigidum Gaud.-Trifolium subterraneum L.) pasture. A deferred grazing system (autumn saving) of pasture management was compared with continuous grazing at stocking rate treatments equivalent to 7.0 and 3.5 ewes to the acre. In the second experiment two groups of Merino weaners grazed a Phalaris tuberosa-subterranean clover pasture at a stocking rate equivalent to 8.6 sheep to the acre. One group received a hay supplement, the other did not. In both experiments nitrogen values were low between late autumn and mid-winter and again between late spring and summer, and high in early autumn and again in spring (P<0.05). The low levels were about 55 per cent of peak autumn and spring levels in (experiment 1) and 60 per cent of peak autumn and spring levels in (experiment 2). Total V.F.A. did not vary significantly between seasons in either experiment. At the higher stocking rate the ewes had lower levels of rumen total nitrogen than at the lower stocking rate. V.F.A. did not vary consistently between stocking rates. At both stocking rates ewes on the autumn saving system of grazing management had more nitrogen in the rumen fluid during late pregnancy and early lactation than did those on the continuous grazing system (P<0.001). After the ewes had access to the saved pasture, autumn saving resulted in a higher concentration of volatile fatty acids than continuous grazing (P< 0.05). Although feeding a hay supplement benefited the weaners the concentrations of total nitrogen in the rumen fluid of the two groups of sheep were similar. There was a fairly consistent tendency for the group receiving hay to have lower concentrations of volatile fatty acids in their rumen fluid. Possible reasons for these effects are discussed.

A new hybrid between blue spruce and white spruce

1969 ◽  
Vol 47 (11) ◽  
pp. 1693-1700 ◽  
Author(s):  
James W. Hanover ◽  
Ronald C. Wilkinson
Keyword(s):  
Picea Glauca ◽  
Interspecific Hybrids ◽  
Growth Form ◽  
Female Parent ◽  
White Spruce ◽  
Early Growth ◽  
Hybrid Seed ◽  
Blue Spruce ◽  
Picea Pungens ◽  
Biochemical Analyses

Controlled pollinations were made within and between blue spruce (Picea pungens Engelm.) and white spruce (Picea glauca (Moench) Voss) in 1967 and 1968. Interspecific hybrids were obtained and verified by comparative measurements of several traits. The cross was successful when either species was used as the female parent. Hybrid seed germinated more rapidly than that of either species and hybrid seedlings showed some heterosis for early growth. Also, hybrid seedlings had needles intermediate between, and significantly different from, the parental seedlings. Growth form of the hybrid was quite variable compared with that of either species. Further evidence for the successful crossing of blue spruce and white spruce was provided by biochemical analyses of monoterpene compounds in the parents and progeny.

Irrigated pasture productivity and its variability in the Shepparton region of northern Victoria

1983 ◽  
Vol 23 (121) ◽  
pp. 131 ◽  
Author(s):  
CR Stockdale
Keyword(s):  
Environmental Factors ◽  
Growth Curves ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Maximum Temperature ◽  
Lolium Rigidum ◽  
Growing Period ◽  
Wimmera Ryegrass ◽  
Maximum Temperatures ◽  
Pasture Productivity

The seasonal distribution and variability of growth of three types of irrigated pastures were measured at Kyabram over a period of up to seven years. The pasture types studied were (1) paspalum (Paspalum dilatatum)-dominant perennial pasture, (2) ryegrass (Lolium perenne)/clover (Trifolium repens) perennial pasture, and (3) annual pasture based on subterranean clover (Trifolium subterraneum) and Wimmera ryegrass (Lolium rigidum). The influence of environmental factors on the year-to-year variability in monthly growth rates was also examined. Annual growth curves were constructed for each pasture type, and examination of the variability about each monthly mean indicated that the spring months, and October in particular, were the most variable months for pasture growth. Environmental factors were found to account for part of the year-to-year variation in pasture growth of paspalum pastures in August, September, October, November and April. Higher mean maximum temperatures significantly increased growth in September, October and April, with the greatest response occurring in October; hours of sunshine was the significant factor influencing growth in August and November. Annual pasture growth also responded to changes in mean maximum temperature or hours of sunshine in September and October. The comparative mean annual production of paspalum pasture, ryegrass/clover pasture and annual pasture was 18.3, 18.3 and 11.0 t DM/ha, respectively. These levels of production represented 1.1, 1.2 and 1.6% conversion of photosynthetically active radiation during the growing period of the three pasture types, respectively. These levels of productivity and the animal production that should result, suggest that the pasture productivity on many irrigated dairy farms is either very low or the pasture that is grown is inefficiently utilized. Because animal productivity depends on pasture productivity more than any other single factor, farmers should make improvement of pasture growth their major aim while having regard for the variability in growth that can result from variations in environmental factors.

Evaluation of some annual Trifolium spp. under irrigation

1986 ◽  
Vol 26 (1) ◽  
pp. 79 ◽  
Author(s):  
KB Kelly ◽  
WK Mason
Keyword(s):  
Dry Matter ◽  
Subterranean Clover ◽  
Early Summer ◽  
Annual Species ◽  
Dry Matter Digestibility ◽  
Wide Range ◽  
Plant Habit ◽  
Germinable Seed ◽  
Early Establishment

Eighteen annual species (38 lines) of the genus Trifolium were sown in 1982 as nursery plots to evaluate their potential under irrigation at Kyabram in northern Victoria. A wide range in plant habit, plant growth and flowering time was observed both within and between species. This experiment was used to select species for further agronomic evaluation; those selected were T. balansae CPI45856, T. purpureum cv. Paratta, T. resupinatum cv. Maral and the subterranean clover species T. brachycalycinum cv. Clare, T. subterraneum cv. Woogenellup and T. yanninicum cv. Trikkala. Pure swards of T. balansae, T. resupinatum and a mixture of subterranean clover cultivars were sown on five occasions in 1983. The first four sowings were established by irrigation on 7 February, 28 February, 21 March and 11 April; the fifth was sown on 20 June. T. purpureum was included only on 28 February and 20 June. Establishment was low (35% of germinable seed sown) at the first two times of establishment, when temperatures and evaporation rates were high. Early establishment increased the productivity of all species, by increasing autumn-winter production with only slight indications of a decline in spring growth. Spring productivity of T. resupinatum was superior to all other species. Irrigation into early summer maintained the growth of T. resupinatum but not of the other species. Data on growth rates, in vitro dry matter digestibility and nitrogen content are also presented.

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