Fire and survival of Stylosanthes spp. in the dry savanna woodlands of the Northern Territory

1982 ◽  
Vol 33 (2) ◽  
pp. 203 ◽  
Author(s):  
JJ Mott
Keyword(s):  
Dry Matter ◽  
Northern Territory ◽  
The Other ◽  
Dry Matter Yield ◽  
Stocking Rate ◽  
Wet Season ◽  
Native Grass ◽  
Hard Seed ◽  
Stylosanthes Humilis ◽  
Good Germination

A series of burns was carried out during the early and late, dry season and early wet season, in mixed native grass-legume plots containing Stylosanthes humilis, S. hamata, S, scabra and S. viscosa as the legume component. The least mortality was shown by S. scabra, but its survival was poor in any sward more than 3 years old. After burning the other species relied solely on seedling regeneration for subsequent season's growth. Fire killed a considerable quantity of seed, but its heat softened hard seed in the soil and good germination occurred with summer rains. However, the presence of a large proportion of soft seed through the winter months could lead to out-of-season germination and subsequent death of seedlings after unseasonal winter rains. Although the total dry matter yield of swards was reduced by all fires, burning could play an important part in increasing yields of S. hamata in swards overgrown by dense native grass, since it increases the amount of soft seed in the soil. If burning causes a high mortality of mature plants of the perennials S. scabra and S. viscosa, a reduction in stocking rate may be needed to ensure regeneration of a productive sward, as these species have slow seedling growth rates.

Wet season grazing of Townsville stylo pasture at Katherine, N.T

1970 ◽  
Vol 10 (47) ◽  
pp. 710 ◽  
Author(s):  
MJT Norman ◽  
LJ Phillips
Keyword(s):  
Dry Matter ◽  
Correlation Coefficients ◽  
Dry Matter Yield ◽  
Stocking Rate ◽  
Wet Season ◽  
Nitrogen Yield ◽  
Stylosanthes Humilis ◽  
Townsville Stylo ◽  
Using Data ◽  
Stocking Rates

At Katherine, N.T., stocking rates of 1.33, 1.00, and 0.67 Shorthorn steers an acre for a period of 18 weeks in the wet season beginning January were imposed on established pastures sown to Townsville sty10 (Stylosanthes humilis) alone but subsequently invaded to varying degrees by annual grasses. The experiment was repeated over three years. There were no significant differences in mean liveweight gain per head over three years ; hence liveweight gain per acre at the heaviest stocking rate was approximately twice that at the lightest rate. The mean dry matter yield of grass increased significantly with decreasing stocking rate, but there were no significant differences between stocking rates in Townsville stylo dry matter yield, nitrogen yield, or phosphorus yield. Correlation coefficients were calculated using data from individual paddocks and years. There was a highly significant positive correlation between liveweight gain per head and pasture nitrogen yield, and between liveweight gain per head and pasture phosphorus yield.

Effect of time of cessation of wet season grazing on Townsville stylo-annual grass pasture at Katherine, N.T

1973 ◽  
Vol 13 (64) ◽  
pp. 544 ◽  
Author(s):  
MJT Norman ◽  
LJ Phillips
Keyword(s):  
Dry Matter ◽  
Recovery Period ◽  
Dry Matter Yield ◽  
Annual Grass ◽  
Wet Season ◽  
Active Growth ◽  
Heavy Grazing ◽  
Stylosanthes Humilis ◽  
Dry Conditions ◽  
Townsville Stylo

A Townsville stylo (Stylosanthes humilis)-annual grass pasture at Katherine, N.T., was subjected to a series of treatments in 1969-70 and 1970-71 under which plots were grazed heavily from the beginning of the wet season for a period and then allowed to recover undefoliated for the remainder of the season. The dates at which heavy grazing ceased were spaced at 2-week intervals from November 24 to March 16. At the end of the wet season, total dry matter yield was linearly related to length of recovery period. Townsville stylo yield declined as recovery period was reduced from 18 to 8 weeks, but showed little response to a further reduction to 4 weeks. In contrast, annual grass yield showed little change as recovery period was reduced from 18 to 8 weeks, but fell with a further reduction to 4 weeks. As a result, the proportion of Townsville stylo in the pasture at the end of the season was high with long and short recovery periods but reached a minimum with an 8 - 10 week recovery period. Dry conditions prevailed in the first half of both seasons. The evidence suggests that young Townsville stylo is sensitive to heavy grazing when under water stress, and that early grazing for grass control should be imposed only during periods of active growth.

Effect of weeds and nitrogen fertiliser on yield and grain protein concentration of wheat

1996 ◽  
Vol 36 (4) ◽  
pp. 443 ◽  
Author(s):  
MG Mason ◽  
RW Madin
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Dry Matter ◽  
Protein Concentration ◽  
The Other ◽  
Grain Protein ◽  
Dry Matter Yield ◽  
Wheat Grain ◽  
Grain Protein Concentration ◽  
Nitrogen Fertiliser

Field trials at Beverley (19911, Salmon Gums (1991; 2 sites) and Merredin (1992; 2 sites), each with 5 rates of nitrogen (N) and 3 levels of weed control, were used to investigate the effect of weeds and N on wheat grain yield and protein concentration during 1991 and 1992. Weeds in the study were grasses (G) and broadleaf (BL). Weeds reduced both vegetative dry matter yield and grain yield of wheat at all sites except for dry matter at Merredin (BL). Nitrogen fertiliser increased wheat dry matter yield at all sites. Nitrogen increased wheat grain yield at Beverley and Merredin (BL), but decreased yield at both Salmon Gums sites in 1991. Nitrogen fertiliser increased grain protein concentration at all 5 sites-at all rates for 3 sites [Salmon Gums (G) and (BL) and Merredin (G)] and at rates of 69 kg N/ha or more at the other 2 sites [Beverley and Merredin (BL)]. However, the effect of weeds on grain protein varied across sites. At Merredin (G) protein concentration was higher where there was no weed control, possibly due to competition for soil moisture by the greater weed burden. At Salmon Gums (G), grain protein concentration was greater when weeds were controlled than in the presence of weeds, probably due to competition for N between crop and weeds. In the other 3 trials, there was no effect of weeds on grain protein. The effect of weeds on grain protein appears complex and depends on competition between crop and weeds for N and for water at the end of the season, and the interaction between the two.

RESPONSE OF SIX-YEAR-OLD GRASS–ALFALFA PASTURES TO NITROGEN FERTILIZER IN NORTHEASTERN SASKATCHEWAN

1968 ◽  
Vol 48 (2) ◽  
pp. 167-173 ◽  
Author(s):  
D. A. Cooke ◽  
S. E. Beacom ◽  
W. K. Dawley
Keyword(s):  
Nitrogen Fertilizer ◽  
Dry Matter ◽  
Linear Increase ◽  
Bromus Inermis ◽  
Dry Matter Yield ◽  
Stocking Rate ◽  
Intermediate Wheatgrass ◽  
Nitrogen Requirement ◽  
Medicago Sativa L ◽  
N Treatment

Two 6-year-old grass–alfalfa mixtures were compared when fertilized with 0, 84 and 168 kg nitrogen per hectare and grazed by yearling Hereford steers. The effect of stocking rate, fertilization, forage mixture and year on the cumulative liveweight gain per hectare was also determined. The bromegrass (Bromus inermis L.) and alfalfa (Medicago sativa L.) mixture showed a linear increase in dry matter yield, but the nitrogen requirement of the intermediate wheatgrass (Agropyron intermedium L.) and alfalfa mixture was fully met by the 84-kg/ha N treatment. In 1960, the addition of 84 and 168 kg/ha N to the bromegrass–alfalfa increased animal production by 61 and 98% respectively. Corresponding increases of 53 and 56% were obtained from the fertilized intermediate wheatgrass–alfalfa mixture. Similar percentage increases were obtained in 1961. The 84-kg/ha N treatment reduced the alfalfa content of both mixtures by more than 40%. The 168-kg/ha N treatment practically eliminated the alfalfa from the stands. Nitrogen recovery by the bromegrass–alfalfa was similar at both fertility levels and amounted to 62% in 1960, and 24% in 1961. Recovery of nitrogen by intermediate wheatgrass–alfalfa was 62 and 36% from the 84- and 168-kg/ha N treatments in 1960, and 23 and 12% respectively in 1961.

Herbicides for weed control in grain sorghum crops in the Northern Territory

1970 ◽  
Vol 10 (46) ◽  
pp. 588
Author(s):  
IMW Wood
Keyword(s):  
Good Control ◽  
Dry Weight ◽  
Grain Sorghum ◽  
Northern Territory ◽  
Research Station ◽  
Wet Season ◽  
Grain Yields ◽  
Stylosanthes Humilis ◽  
Townsville Stylo ◽  
Grass Weed

In experiments conducted in the 1968-69 wet season at the Katherine Research Station, Northern Territory, a number of herbicides gave good control of the grass weed Pennisetum polystachyon in grain sorghum crops. Linuron at 3 lb a.i. an acre and PCP at 20 lb a.i. an acre as pre-emergence applications effectively controlled grasses with no apparent adverse affects on the crop. With both there were significantly higher grain yields than on unweeded control plots containing an average of 1378 lb dry weight of P. polystachyon an acre. Fluometuron at 3 lb a.i. an acre late pre-emergence and early post-emergence and chlorthal at 7 lb a.i. an acre pre-emergence controlled grasses but did not increase grain yields. Further investigations are warranted with these herbicides, as banded applications to the interrow may overcome the apparent problem of crop phytotoxicity. Chlorthal at rates that gave good grass control had no adverse effect on Townsville stylo (Stylosanthes humilis). This could be an important advantage when sorghum is sown in rotation with Townsville stylo pasture or where the crop is undersown with Townsville stylo.

The effect of chisel ploughing and inter-row cultivation on soil water content and yield of bulrush millet (Pennisetum typhoides) at Katherine, N.T

1966 ◽  
Vol 6 (20) ◽  
pp. 48
Author(s):  
LJ Phillips ◽  
MJT Norman
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Dry Matter ◽  
Dry Matter Yield ◽  
Wet Season ◽  
Pennisetum Typhoides ◽  
Nitrogen Yield ◽  
Multifactorial Experiment

A multifactorial experiment comprising combinations of three pre-wet-season chisel ploughing treatments, three wet-season chisel ploughing treatments, and three inter-row cultivation treatments was carried out on bulrush millet (Pennisetum typhoides S. & H.) at Katherine, N.T., in 1963-64, and was repeated in 1964-65. Pre-wet-season ploughing throughout the growth of the nitrogen yield of millet when treatments had very little effect on the dry matter or nitrogen yield of millet crop. Increasing the depth of wet-season ploughing increased the dry matter and sampled at 7 and 12 weeks after sowing, but at the final sampling, 18 weeks after sowing, only the differences in dry matter yield were maintained. Responses in dry matter and nitrogen yield were obtained to one inter-row cultivation, but not to a second. Differences in dry matter yield due to wetseason ploughing and inter-row cultivation were associated with differences in soil water content measured in the 1-4 feet profile in 1964-65.

Herbicides for the control of grass weeds in pastures of Townsville stylo (Stylosanthes humilis)

1970 ◽  
Vol 10 (47) ◽  
pp. 790
Author(s):  
IMW Wood
Keyword(s):  
Dry Matter ◽  
Plant Population ◽  
Dry Matter Yield ◽  
Growing Period ◽  
Stylosanthes Humilis ◽  
Annual Grasses ◽  
Total Plant ◽  
Townsville Stylo

The use of herbicides to control annual grasses in pastures of Townsville stylo (Stylosanthes humilis) was studied at Katherine, N.T. The herbicides chlorthal, trifluralin, benefin, sindone B, and siduron all controlled the annual grasses Digitaria adscendens and Brachiaria ramosa. The outstanding herbicide was chlorthal, which at 6 lb a.i. an acre pre-emergence gave a Townsville stylo dry matter yield of 3250 lb an acre compared with 1130 lb an acre for the unweeded control and 2440 lb an acre for the handweeded control. At maturity there was no grass in the chlorthal plots and 1940 lb an acre in the unweeded control plots. The data suggest that, without defoliation during the growing period, total suppression of Townsville stylo can be expected when the grass population at establishment exceeds 37 per cent of the total plant population.

The use of fire to establish Townsville lucerne in the Northern Territory

1966 ◽  
Vol 6 (22) ◽  
pp. 277 ◽  
Author(s):  
GC Stocker ◽  
JD Sturtz
Keyword(s):  
Northern Territory ◽  
Wet Season ◽  
Seeding Rate ◽  
Stylosanthes Humilis ◽  
Grass Growth ◽  
Rainfall Region

During the wet season of 1964-65 two trials were established near Darwin to determine if Townsville lucerne (Stylosanthes humilis H.B.K.) could be established in undisturbed annual sorghum (Sorghum intrans F. Muell. ex Benth.) pastures after wet season burning had controlled grass growth. In the first trial, plots were burnt at intervals throughout the wet season. Townsville lucerne pods were broadcast immediately after burning. Grass control and Townsville lucerne establishment were satisfactory in plots burnt after December 6. The second trial examined the effect on Townsville lucerne establishment and S. intrans control of burning, seeding rate, superphosphate, and weedicide treatments. Burning had the most important effect ; seeding rate had little significant effect and superphosphate none. The weedicide treatment was ineffective. The trials indicate that provided wet season burning is used to control S. intrans, Townsville lucerne can be established cheaply over wide areas of the higher rainfall region of the Northern Territory.

scholarly journals Effects of a New Herbicide (Aminocyclopyrachlor) on Buffalograss and Forbs in Shortgrass Prairie

2012 ◽  
Vol 26 (3) ◽  
pp. 455-459 ◽  
Author(s):  
Keith R. Harmoney ◽  
Phillip W. Stahlman ◽  
Patrick W. Geier ◽  
Robert Rupp
Keyword(s):  
Growth Regulator ◽  
Dry Matter ◽  
Leaf Growth ◽  
Growing Season ◽  
Grass Species ◽  
Dry Matter Yield ◽  
Native Grass ◽  
Synthetic Auxin ◽  
Shortgrass Prairie ◽  
And Control

Herbicides used to control many forb species in pastures may injure desirable native grass species. Buffalograss, a major component of shortgrass rangeland, often is injured by some growth regulator herbicides, such as 2,4-D and dicamba. Aminocyclopyrachlor (formerly known as DPX-MAT28 and herein termed ACPCR), a new synthetic auxin herbicide chemistry for control of broadleaf weeds, was investigated for injury to buffalograss and control of forbs in shortgrass prairie at varying rates of application. In the season of application, ACPCR at rates of 140 g ai ha−1or less caused buffalograss injury that was either negligible or short-lived, and visual estimates of grass injury were 8% or less at the end of the growing season. At ACPCR rates of 280 g ha−1, more injury was evident at 3 wk after treatment (WAT) than at the end of the season if adequate precipitation was available for new leaf growth. When precipitation was lacking, evidence of injury persisted through to the end of the season when treated at the greatest rate of ACPCR. Buffalograss injury was mainly in the form of browned leaf tips, but total buffalograss dry matter yield was not different between any treatments in either year. The year after treatment, no buffalograss injury was evident from any of the herbicide rates. Final forb control was 97% or greater each year for ACPCR at the 140 and 280 g ha−1rates. In this experiment, rates as low as ACPCR at 140 g ha−1provided excellent forb control and maintained buffalograss productivity.

EFFECT OF DATES OF CUTTING ON DRY MATTER PRODUCTION AND CHEMICAL CONTENT OF ALFALFA AND BIRDSFOOT TREFOIL

1969 ◽  
Vol 49 (3) ◽  
pp. 339-349 ◽  
Author(s):  
H. Gasser ◽  
L. Lachance ◽  
P. Gervais
Keyword(s):  
Nitrogen Content ◽  
Protein Content ◽  
Dry Matter ◽  
The Other ◽  
Dry Matter Production ◽  
Birdsfoot Trefoil ◽  
Dry Matter Yield ◽  
Matter Production ◽  
Chemical Content

In two experiments, one with alfalfa and the other with birdsfoot trefoil, we have been able to show that a late cut in October does not adversely affect dry matter yield (DAI) of the legumes. Three cuts during a harvesting season ending on September 5 were detrimental to alfalfa, since lower yields were obtained the following year of harvest. Birdsfoot trefoil varieties were affected differentially. Three cuts did not affect the yield of Viking the following year, but did so of Empire. Significant differences in dry matter yields were obtained between DuPuits and Vernal and between Viking and Empire. Protein in the forage followed inversely the same pattern as that of DM yields, that is, where the intervals were shortest, the protein content was highest, and conversely. The total available carbohydrate and the nitrogen content of the roots were lowest following the treatments which had the shortest intervals between them.

Sign in / Sign up

Export Citation Format

Share Document