Stability of the Townsville stylo-annual grass pasture ecosystem on cleared Tippera clay loam

1975 ◽  
Vol 15 (76) ◽  
pp. 671 ◽  
Author(s):  
BWR Torssell
Keyword(s):  
Land Development ◽  
Vegetation Pattern ◽  
Clay Loam ◽  
Annual Grass ◽  
Bare Ground ◽  
Stylosanthes Hamata ◽  
Stylosanthes Humilis ◽  
Main Period ◽  
Townsville Stylo ◽  
Pasture Area

Competition was measured between the annual self-seeding legume Townsville stylo (Stylosanthes humilis) and each of the annual grass weeds Digitaria ciliaris, Brachiaria pubrigera, Echinochloa crus-galli and Brachyachne convergens. Digitaria was the most competitive of the grasses, all of which were stronger competitors than the legume in the main period of growth. The results of the competition experiments assisted in interpretation of nine years' observations of vegetation pattern in a Stylosanthes pasture sown in a cleared woodland on Tippera clay loam at Katherine, N.T. An apparently stable situation was reached in the eighth year, when the legume occupied 14 per cent, palatable grasses (primarily annuals) 3 per cent and unpalatable grasses (Brachyachne, Aristida) and bare ground 83 per cent of the pasture area, the corresponding dry matter yields being 12, 35 and 53 per cent respectively of the total pasture yield. The Townsville stylo-annual grass pasture ecosystem is basically unstable in cleared and ploughed woodland where it will persist only under careful grazing management. It is suggested that, for the situation studied, Stylosanthes humilis should be replaced by Stylosanthes hamata, since in other experiments it has proved more competitive than Stylosanthes humilis. The implication of the results for further land development and experimentation in the Katherine area is briefly discussed.

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.

Nitrogen accretion and other soil changes in Tindall clay loam under Townsville stylo/grass pastures

1976 ◽  
Vol 16 (78) ◽  
pp. 94 ◽  
Author(s):  
RJK Myers
Keyword(s):  
Organic Carbon ◽  
Available Phosphorus ◽  
Clay Loam ◽  
Clay Loam Soil ◽  
Available Nitrogen ◽  
Absolute Value ◽  
Stylosanthes Humilis ◽  
Loam Soil ◽  
Townsville Stylo ◽  
Soil Changes

Soil changes after 3-15 years of fertilized leguminous pastures on Tindall clay loam soil at Katherine, N.T. were studied by comparison of leguminous pasture soils with their native counterparts. Soil organic carbon, total nitrogen, C/N ratio and pH were unchanged by the presence of Townsville stylo (Stylosanthes humilis). Available phosphorus (bicarbonate extraction) was significantly higher under legume pasture, reflecting its fertilizer history, but there was no pattern of increase with time, nor with quantity of fertilizer. Available nitrogen (boiling water extraction) was higher under legume pasture, and both the absolute value under legume pasture and the change in amount were correlated significantly with the age of the pasture. Available nitrogen after three years of legume pasture was equal to that under unimproved pasture, suggesting that gains in this period merely balanced losses during clearing and establishment.

The control of grass weeds in Townsville stylo (Stylosanthes humilis) experiments

1970 ◽  
Vol 10 (47) ◽  
pp. 795
Author(s):  
MJ Fisher ◽  
JR Ive
Keyword(s):  
Annual Grass ◽  
Stylosanthes Humilis ◽  
Weed Seeds ◽  
Heavy Burden ◽  
Excellent Control ◽  
Townsville Stylo ◽  
Grass Weed

Chlorthal applied at 4 lb a.i. an acre before simulated germinating rain gave excellent control of annual grass weeds in an old Townsville stylo (Stylosanthes humilis) sward carrying a heavy burden of grass weed seeds at Katherine, N.T. The technique was used successfully to control annual grass weeds in a long-term residual phosphate experiment. Trifluralin and dalapon were not effective.

Performance of Townsville stylo (Stylosanthes humilis) lines in pure swards and with the annual grass (Digitaria ciliaris) under various defoliation treatments at Katherine, N.T

1974 ◽  
Vol 14 (69) ◽  
pp. 495 ◽  
Author(s):  
JR Ive ◽  
MJ Fisher
Keyword(s):  
Dry Matter ◽  
Certified Seed ◽  
Phosphorus Concentration ◽  
Annual Grass ◽  
Nitrogen And Phosphorus ◽  
Matter Production ◽  
Stylosanthes Humilis ◽  
Townsville Stylo ◽  
Better Than ◽  
Late Sowing

Townsville stylo (Stylosanthes humilis) selections collected from twelve naturalized populations, in Queensland and the Northern Territory, and certified seed of the Katherine ecotype ('lines'), were grown for three years in a field experiment at Katherine, N.T. (latitude 14.3�S). In the third year, the experiment was oversown with Digitaria ciliaris. Flowering of all lines was delayed by late sowing, but was hastened by drought. However, the order in which the lines flowered was basically the same for all three years, and similar to that at Lansdown, Queensland (latitude 19.7�S). Although seasonally dependent, highest dry matter production was associated with erect mid- or late mid-season maturity lines which were often lowest in nitrogen and phosphorus concentration. There were no differences between lines in their ability to compete with Digitaria. Grazing reduced the proportion of grass in the swards compared with the forage harvested and non-defoliated treatments largely because Townsville stylo appeared to withstand grazing and trampling better than Digitaria.

Comparison of Stylosanthes humilis with S. hamata and S. subsericea in the Queensland dry tropics: effects on pasture composition and cattle liveweight gain

1980 ◽  
Vol 31 (1) ◽  
pp. 205 ◽  
Author(s):  
P Gillard ◽  
LA Edye ◽  
RL Hall
Keyword(s):  
Soil Fertility ◽  
Annual Rainfall ◽  
Stylosanthes Hamata ◽  
Dry Tropics ◽  
Stylosanthes Humilis ◽  
Townsville Stylo ◽  
Perennial Legume ◽  
One Year ◽  
High Yields ◽  
Perennial Legumes

Two new accessions of perennial legumes, Stylosanthes hamata cv. Verano and S. subsericea, were compared under grazing with the annual S. humilis (Townsville stylo) at four sites in the dry tropics. One of the new accessions, S. subsericea, was largely eliminated from the comparison because of its susceptibility to anthracnose. Although Townsville stylo was well adapted at two of the sites where average rainfall exceeded 850 mm annually (Lansdown and Wrotham Park), the yield of Verano was significantly more after the establishment year. At these sites the original grasses were replaced by the annuals Diqitaria ciliaris and Brachiaria miliiformis. Where soil fertility was high (Lansdown), these grasses competed vigorously with the legumes; where soil fertility was low (Wrotham Park), the sward remained legume-dominant. The yield of Townsville stylo was low at the two sites where annual rainfall was less than 750 mm annually (Kangaroo Hills and Westwood). Verano produced very high yields at the warmer site (Kangaroo Hills) and became dominant in the third year; in subsequent years there was an increase in the improved grass Urochloa mosambicensis, which responded to the increase in soil fertility. At the cooler site (Westwood) the yield of Verano was poor. Cattle liveweight gains were similar on both the Townsville stylo and Verano pastures at Lansdown, and better on the Verano pasture only in one year at Wrotham Park. At Kangaroo Hills and Westwood, liveweight gains were significantly greater on the Verano pastures. The data suggested that differences in liveweight gain did not occur when the legume yield on both pastures exceeded 600 kg ha-1. This threshold was usually achieved at Lansdown and Wrotham Park, but rarely with Townsville stylo at Kangaroo Hills. Townsville stylo has until recently been the only legume suited to pasture improvement in the dry tropics. The results from this experiment show that the perennial legume Verano can now extend the range of legume-based pasture improvement in the dry tropics of northern Australia.

The inheritance of flowering time in Townsville stylo (Stylosanthes humilis)

1976 ◽  
Vol 27 (6) ◽  
pp. 825 ◽  
Author(s):  
DF Cameron
Keyword(s):  
Flowering Time ◽  
Dominant Gene ◽  
Diallel Cross ◽  
Early Flowering ◽  
Multiple Alleles ◽  
Locus Model ◽  
Stylosanthes Humilis ◽  
Townsville Stylo ◽  
Maturity Groups ◽  
Early Flowering Phenotype

The inheritance of flowering time was studied in F1, F2 and F3 populations derived from a diallel cross among nine naturalized Australian lines of Townsville stylo (Stylosnnthes humilis) and in F1 and F2 populations from a small number of crosses between naturalized Australian lines and introductions from Mexico and Brazil. Strong dominance for lateness of flowering was observed in both the (Australian x Australian) and the (Australian x Mexican/Brazilian introductions) crosses, and some F2 and F3 progenies included small numbers of extremely early plants, flowering up to 55 days earlier than the earliest parent. The flowering time distributions of the (Australian x Australian) crosses could be explained by a three-locus model with multiple alleles at two loci. Proposed genotypes for the four maturity groups are as follows: late, LLM2M2EE; late-midseason, LLmmEE; mid-season, l2l2M2M2EE; early, l1l1M1M1EE; very early, LLM2M2ee. Only one major dominant gene for lateness of flowering could be detected from the distribution of the two (Australian x introduced line) F2 populations, but the segregation of extremely early types and the low recovery of the early-flowering phenotype suggested that other gene loci were segregating.

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 initial and residual responses to phosphorus fertilizers of Townsville stylo in pure ungrazed swards at Katherine, N.T

1972 ◽  
Vol 12 (58) ◽  
pp. 488 ◽  
Author(s):  
MJ Fisher ◽  
NA Campbell
Keyword(s):  
Field Experiment ◽  
Residual Effects ◽  
Yield Data ◽  
Christmas Island ◽  
Stylosanthes Humilis ◽  
Phosphorus Fertilizers ◽  
Nitrogen Concentrations ◽  
Townsville Stylo ◽  
Residual Values ◽  
Second Year

The response of a pure sward of Townsville stylo (Stylosanthes humilis) to various initial and annual dressings of both superphosphate and calcined Christmas Island C-grade phosphate (CCICP) was determined in a field experiment at Katherine, N.T. Townsville stylo responded to superphosphate up to at least 750 kg ha-1. Initial responses and residual effects in the second year and three-year totals were much greater with superphosphate than with CCICP. CCICP gave very variable yields in the second and third years. Nitrogen concentrations were not affected by applied phosphorus but phosphorus concentrations were increased, more by superphosphate than by CCICP. Residual values of superphosphate were derived from Mitscherlich curves fitted to phosphorus yield data, and from these it was determined that 250 kg ha-1 initial and 100 kg ha-1 annual dressing of superphosphate would give stable uptake of phosphorus at the same level as 250 kg ha-1 in the initial year.

Effect of time of sowing on flowering and growth of Townsville stylo (Stylosanthes humilis)

1974 ◽  
Vol 14 (67) ◽  
pp. 182 ◽  
Author(s):  
Mannetje L t ◽  
KHLvan Bennekom
Keyword(s):  
Low Temperatures ◽  
Dry Matter ◽  
Late Summer ◽  
Growing Season ◽  
Sowing Date ◽  
Stylosanthes Humilis ◽  
Maturity Type ◽  
Townsville Stylo ◽  
Late Start ◽  
Spring Sowing

A midseason maturity type of Townsville stylo sown at monthly intervals throughout a year in a glasshouse in Brisbane (27�30' south) started flowering from 42 to 76 days after sowing between February and September, with dry matter yields at flowering ranging from 0.05 to 5.82 g/per plant. Sowings between October and January resulted in flowering after 98 to 157 days, with yields ranging from 26.41 to 54.75 g/per plant. Flowering was mainly determined by daylength, although low temperatures during winter delayed inflorescence elongation. Growth after onset of flowering was measured in plants sown in winter, spring and late summer. Plant weights increased after flowering in all sowings. In the spring sowing this consisted entirely of stem and inflorescence, but in the other sowings leaf was formed after onset of flowering as well. Winter and spring sowings gave the highest, late summer sowing the lowest final yields. The main agronomic implication is that sowing early in the growing season is necessary for obtaining a good first year's yield, but that seed production is little affected by sowing date, ensuring good regeneration even in years with a late start of the growing season.

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.

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