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.

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.

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 influence of water stress on the growth and development of Townsville stylo (Stylosanthes humilis) in pure ungrazed swards at Katherine, Northern Territory

1977 ◽  
Vol 17 (87) ◽  
pp. 598 ◽  
Author(s):  
MJ Fisher ◽  
NA Campbell
Keyword(s):  
Water Stress ◽  
The Other ◽  
Stylosanthes Humilis ◽  
Relative Water ◽  
Influence Of Water ◽  
Leaf Relative Water Content ◽  
Final Yield ◽  
Townsville Stylo ◽  
Effect On Yield

In order to understand more fully the effect of water stress on the growth of Townsville stylo (Stylosanthes humilis) (TS), five drought treatments, imposed by the use of rain shelters, were compared with an unstressed control in a field experiment. Droughts were imposed during the early vegetative (EV) and late vegetative (LV) stages, and during flowering (F) until leaf relative water content at 2.30 p.m fell to 60 per cent. Further unrelieved drought was re-applied to these three treatments when seeding was well advanced. The other two treatments were subjected to unrelieved drought, one starting at late flowering (LF) and the other seeding (S). The drought treatments had no effect on the final yield of dry matter compared with the control. Stress during the vegetative stage reduced growth, but the relief of stress was followed by a period of rapid growth which largely compensated for the loss. However, because the EV stress killed 40 per cent of the sward (the plants were unable to use water from depths below 75-1 00 cm), the compensatory phase in this treatment was less marked, but more sustained. Because of the decline in growth rate with approaching maturity, stresses during and after flowering had little effect on yield. Stress during vegetative growth hastened flowering by two weeks; however, pod yields were only reduced in the LF treatment. In general these observations demonstrate important aspects of the plants' good adaptation to the dry monsoonal tropics, and explain its stable long-term yields when maintained in near-pure swards.

Predation of annual grass weed seeds in arable field margins

1993 ◽  
Vol 122 (2) ◽  
pp. 323-328 ◽  
Author(s):  
F. D. POVEY ◽  
H. SMITH ◽  
T. A. WATT
Keyword(s):  
Field Margins ◽  
Annual Grass ◽  
Arable Field ◽  
Weed Seeds ◽  
Grass Weed

Management options for increasing the productivity of tropical savanna pastures. IV. Population biology of introduced Stylosanthes spp

1989 ◽  
Vol 40 (6) ◽  
pp. 1227 ◽  
Author(s):  
JJ Mott ◽  
WH Winter ◽  
RW McLean
Keyword(s):  
Population Biology ◽  
Large Scale ◽  
Rapid Decline ◽  
Management Options ◽  
Hard Seed ◽  
Long Term Stability ◽  
Stylosanthes Humilis ◽  
Townsville Stylo ◽  
Fertilizer Rates

In a large-scale grazing experiment in the Monsoon Tallgrass savannas of the Northern Territory, Townsville stylo (Stylosanthes humilis), Caribbean stylo (S. hamata) and perennial stylo (S. scabra + S. viscosa) were sown into native pasture and grazed at three stocking rates, under two fertilizer rates and with trees killed and unkilled. These treatments, together with the occurrence of anthracnose, led to the rapid decline in both yield and numbers of plants in those pastures sown to Townsville stylo. In contrast, yields of Caribbean stylo and Perennial stylo stabilized after three years in both fertilized and unfertilized swards. While total legume yield of these latter two treatments was similar, the dominant contribution in Caribbean stylo was made by annual plants, while in Perennial stylo swards individuals more than 18 months old contributed 80% of the yield.There were marked differences between all species in their population biology. Townsville stylo declined in numbers with death of individuals prior to seed set and the rapid depletion of the soil seed pool which had little long-lived seed. In contrast, in swards of Caribbean stylo a large amount of hard seed rapidly built up in the soil seed pool and ensured continuity of productivity even if seed was not set in some years. In the perennial stylos, seed softened quickly, and the soil seed pool remained small and short-lived. In these latter Stylosanthes spp., long-term stability depended on the survival of perennating plants rather than seed.Pasture management must take into account these different patterns of population dynamics. In particular, while fire is a potentially useful tool in renovating Caribbean stylo swards with their large soil seed pool, it can be extremely detrimental to perennial stylo swards where individuals are susceptible to burning and there is little soil seed available to re-establish the sward.

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.

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.

scholarly journals Outcomes of excessive alcohol drinkers without baseline evidence of chronic liver disease after 15 years follow-up: Heavy burden of cancer and liver disease mortality

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0252218
Author(s):  
Sónia Bernardo ◽  
Ricardo Crespo ◽  
Sofia Saraiva ◽  
Rui Barata ◽  
Sara Gonçalves ◽  
...  
Keyword(s):  
Liver Disease ◽  
Alcohol Consumption ◽  
Chronic Liver Disease ◽  
Alcohol Intake ◽  
Chronic Liver ◽  
Portuguese Population ◽  
Heavy Drinkers ◽  
Heavy Burden

Background Most long-term heavy drinkers do not have clinically evident chronic liver disease (CLD). However, at any time-point, their risk of developing CLD remains unknown. We aimed to evaluate the long-term outcomes of a group of heavy drinkers, without evidence of CLD at baseline. Methods A cohort of 123 long-term heavy drinkers without CLD were prospectively recruited in 2002 and retrospectively followed until 2018. Results At baseline (2002), median alcohol consumption was 271±203g/day during 21.5±20 years, 65% being abstinent during the previous 1.75±5 months. Patients were followed for 14±3 years. During follow-up, 53% reported any alcohol intake. Alcohol consumption during follow-up associated weakly with either 1- or 6-months previous abstinence at baseline. Until 2018, progression to CLD occurred in 6%, associating with years of alcohol intake during follow-up (OR 1.15 [1.01–1.31]) and baseline alkaline-phosphatase (OR 1.05 [1.01–1.10]). During follow-up, being abstinent for at least 1 year positively associated with CLD-free survival. 27% died (55% of cancer–mostly oropharyngeal cancer, 27% of cardiovascular disease, and 9% of liver disease), with a mean age of 71 years [69–74] (10 years less than the expected in the Portuguese population). Achieving abstinence for at least 1 year positively associated with overall survival, while smoking, and hepatic steatosis at baseline associated negatively. Conclusion Long-term heavy drinkers seemed to have a decreased life expectancy compared with the overall Portuguese population. Cancer was the main cause of death. Our results suggest that progression to CLD depends mostly on continued alcohol intake. Alcohol abstinence, even if temporary, seems to decrease the risks of CLD and mortality.

scholarly journals Molecular Basis for Resistance to Fluazifop-P-Butyl in Itchgrass (Rottboellia cochinchinensis) from Costa Rica

2016 ◽  
Vol 34 (1) ◽  
pp. 143-150 ◽  
Author(s):  
R. CASTILLO-MATAMOROS ◽  
A. BRENES-ANGULO ◽  
F. HERRERA-MURILLO ◽  
L. GÓMEZ ALPÍZAR.
Keyword(s):  
Costa Rica ◽  
Molecular Basis ◽  
Pcr Amplification ◽  
Costa Rican ◽  
Acetyl Coa Carboxylase ◽  
Annual Grass ◽  
San Jose ◽  
Weed Species ◽  
Rottboellia Cochinchinensis ◽  
Grass Weed

Rottboellia cochinchinensis is an annual grass weed species known as itchgrass, or "caminadora" in America´s Spanish speaking countries, and has become a major and troublesome weed in several crops. The application of fluazifop-P-butyl at recommended rates (125 g a.i. ha-1) was observed to be failing to control itchgrass in a field in San José, Upala county, Alajuela province, Costa Rica. Plants from the putative resistant R. cochinchinensis population survived fluazifop-P-butyl when treated with 250 g a.i. ha-1 (2X label rate) at the three- to four-leaf stage under greenhouse conditions. PCR amplification and sequencing of partial carboxyl transferase domain (CT) of the acetyl-CoA carboxylase (ACCase) gene were used to determine the molecular mechanism of resistance. A single non-synonymous point mutation from TGG (susceptible plants) to TGC (putative resistant plants) that leads to a Trp-2027-Cys substitution was found. This Trp-2027-Cys mutation is known to confer resistance to all aryloxyphenoxyproprionate (APP) herbicides to which fluazifop-P-butyl belongs. To the best of our knowledge, this is the first report of fluazifop-P-butyl resistance and a mutation at position 2027 for a Costa Rican R. cochinchinensis population.

scholarly journals Seed shattering phenology at soybean harvest of economically important weeds in multiple regions of the United States. Part 2: grass species

Weed Science ◽  
2020 ◽  
pp. 1-19
Author(s):  
Lauren M. Schwartz-Lazaro ◽  
Lovreet S. Shergill ◽  
Jeffery A. Evans ◽  
Muthukumar V. Bagavathiannan ◽  
Shawn C. Beam ◽  
...  
Keyword(s):  
The United States ◽  
Grass Species ◽  
Annual Grass ◽  
Weed Seed ◽  
Weed Species ◽  
Seed Shattering ◽  
Physiological Maturity ◽  
Rate Of Progression ◽  
Multiple Regions ◽  
Grass Weed

Abstract Seed shatter is an important weediness trait on which the efficacy of harvest weed seed control (HWSC) depends. The level of seed shatter in a species is likely influenced by agroecological and environmental factors. In 2016 and 2017, we assessed seed shatter of eight economically important grass weed species in soybean [Glycine max (L.) Merr.] from crop physiological maturity to four weeks after maturity at multiple sites spread across eleven states in the southern, northern, and mid-Atlantic U.S. From soybean maturity to four weeks after maturity, cumulative percent seed shatter was lowest in the southern U.S. regions and increased as the states moved further north. At soybean maturity, the percent of seed shatter ranged from 1 to 70%. That range had shifted to 5 to 100% (mean: 42%) by 25 days after soybean maturity. There were considerable differences in seed shatter onset and rate of progression between sites and years in some species that could impact their susceptibility to HWSC. Our results suggest that many summer annual grass species are likely not ideal candidates for HWSC, although HWSC could substantially reduce their seed output at during certain years.

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