Influence of environmental factors on the germination of barley grass (Hordeum glaucum) and annual ryegrass (Lolium rigidum)

1987 ◽  
Vol 27 (4) ◽  
pp. 525 ◽  
Author(s):  
PM Kloot
Keyword(s):  
Physical State ◽  
Soil Surface ◽  
Soil Disturbance ◽  
Chemical Characteristics ◽  
Field Observations ◽  
Soil Cores ◽  
Annual Ryegrass ◽  
Alkaline Soils ◽  
Lolium Rigidum ◽  
Undisturbed Soil

The ability of Hordeum glaucum to germinate and initially grow faster than Lolium rigidum was found to be influenced by the soil's physical state and its chemical characteristics. Glasshouse studies showed that the replacement of Lolium by Hordeum in undisturbed situations was due to the advantage of the latter having awned florets which anchor and lever the seed on smooth, compacted surfaces. Soil disturbance produces a broken surface upon which Hordeum has no advantage over Lolium. Hordeum is also able to germinate under higher osmotic pressures than is Lolium. Higher osmotic pressures will arise on stock camps and on alkaline soils where the salts are of biological and pedological origin respectively. Glasshouse and field observations showed that the top 3 mm of the soil surface are drier and more saline than the soil profile generally as indicated from measurements on soil cores. In undisturbed soil this surface layer will favour the dominance of Hordeum over Lolium. In cultivated soil the layer will be diluted throughout the depth of cultivation.

Germination of annual ryegrass seeds (Lolium rigidum Gaud.) as influenced by temperature, light, storage environment, and age

1972 ◽  
Vol 23 (5) ◽  
pp. 779 ◽  
Author(s):  
D Gramshaw
Keyword(s):  
Germination Rate ◽  
Soil Surface ◽  
Day Length ◽  
Annual Ryegrass ◽  
Lolium Rigidum ◽  
Light Storage ◽  
Seed Age ◽  
Germination Behaviour ◽  
Alternating Temperature ◽  
The Relationship

Germination of Lolium rigidum seeds, in the light (12 hr day length) and in the dark, at constant temperatures of 12, 18, and 24°C and an alternating temperature of 24/12° (12 / 12 hr), was studied in freshly harvested seeds and in seeds stored for 18 weeks. In freshly harvested seeds the highest germinability (80%) was recorded at 12° in either light or dark and at 24/12° in the light. After 18 weeks' storage, a germinability of between 95 and 100% was observed at 12° and 24/12° in the dark and at 24° and 24/12° in the light. In another experiment in which seeds from a different source were used, seeds kept in six different environments and recovered at 3-weekly intervals during a 21 week post-harvest period were examined for germinability and germination rate. The six environments were: storage in a room, storage in a 60/15°C temperature cabinet, and four field treatments in which seeds were buried 0.2 and 1.0 cm under both a bare and a mulched soil surface. Germination was tested in the light and in the dark at an alternating temperature of 24/12°. Major increases in seed germinability with age occurred during the first 9 weeks after harvest. The different environments influenced the relationship between seed age and germinability only during the first 9 weeks. Seeds located 0.2 cm beneath either a bare or a mulched soil surface during summer germinated at a faster rate than seeds kept in the other environments. These findings are discussed in relation to the germination behaviour of seeds in the field.

Residual effects of a slant-legged subsoiler on some soil physical conditions and the root growth of spring barley

1988 ◽  
Vol 110 (3) ◽  
pp. 481-489 ◽  
Author(s):  
N. A. Hipps ◽  
D. R. Hodgson
Keyword(s):  
Root Growth ◽  
Bulk Density ◽  
Spring Barley ◽  
Soil Strength ◽  
Soil Disturbance ◽  
Residual Effects ◽  
Soil Cores ◽  
Undisturbed Soil ◽  
Cone Resistance ◽  
Trade Name

SummarySoil disturbance caused by a slant-legged subsoiler (Trade name, ‘Paraplow’) and the duration of its effect was investigated in an experiment comparing long-term direct drilling with shallow tine cultivation and mouldboard ploughing. The ‘Paraplow’ significantly reduced soil strength, measured by cone resistance, to the depth of cultivation (33–35 cm) for up to 20 months, after which soil recompacted. The ‘Paraplow’ increased the volume of soil with cone resistance < 1·5 MPa by 52% within its working depth, compared with an equivalent depth of undisturbed soil. Contour diagrams of cone resistances clearly illustrate the patterns of soil loosening caused by the ‘Paraplow’.Measurements on soil cores (73 mm diameter × 50 mm) show that the ‘Paraplow’ did not appear to increase significantly the volume of macropores (> 60 μm) in direct-drilled soil, nor did it reduce the bulk density in the top 5 cm as effectively as the mouldboard plough.The root density of spring barley, measured at the beginning and end of tillering, was significantly increased within the horizon disturbed by the ‘Paraplow’ but below the depth of loosening there were no differences. This improvement of root growth probably resulted from an increase in the number of large pores (which could not be measured adequately in the soil cores), as well as the reduced soil strength. Better drainage of the soil loosened with the ‘Paraplow’ suggested that macroporosity was improved. The need to sample large volumes of soil to detect changes in bulk density and macroporosity is stressed.

Survival of annual ryegrass (Lolium rigidum Gaud.) seed in a Mediterranean type environment. II.* Effects of short-term burial on persistence of viable seed

1977 ◽  
Vol 28 (1) ◽  
pp. 93 ◽  
Author(s):  
D Gramshaw ◽  
WR Stern
Keyword(s):  
Soil Disturbance ◽  
Burial Depth ◽  
Annual Ryegrass ◽  
Dormant Seed ◽  
Lolium Rigidum ◽  
Short Term ◽  
Gaseous Environment ◽  
Seed Population ◽  
Total Seed ◽  
Soil Temperature And Moisture

Two seed components, dark dormant and non-dark dormant, were identified in experiments in which germination and survival of seeds buried in soil were examined. These comprised c. 10–20% and 80–90% of the seed population respectively. About 12% of the dark dormant seeds (1–2% of total seed population) germinated when first buried between 0 and 2 cm depth, and subsequent disturbance of the soil on two occasions caused further germinations. In contrast, all non-dark dormant seed rapidly germinated when buried at 2 cm; however, germination of non-dark dormant seeds decreased progressively as burial depth increased, until at 11 and 14 cm no seed germinated. In one experiment, seed that failed to germinate when buried at 14 cm was found to germinate readily if transferred to a depth of 2 cm without soil disturbance. This indicated that dormancy was enforced, rather than induced, in seeds buried relatively deeply for short periods. In these experiments soil temperature and moisture were favourable for germination, and it is suggested that an unfavourable gaseous environment around deeply buried seeds is the factor enforcing dormancy. The implication of these findings for the persistence of annual ryegrass in the pasture-crop rotation is discussed. _____________________ *Part I, Aust. J. Agric. Res., 28: 81 (1977).

Stimulating dormancy release and emergence of annual ryegrass (Lolium rigidum) seeds using short-term hydrated storage in darkness

2004 ◽  
Vol 55 (7) ◽  
pp. 787 ◽  
Author(s):  
Kathryn J. Steadman ◽  
Gavin P. Bignell ◽  
Pippa J. Michael
Keyword(s):  
Effective Means ◽  
Soil Surface ◽  
Dormancy Release ◽  
Annual Ryegrass ◽  
Moist Soil ◽  
Lolium Rigidum ◽  
Short Term ◽  
Water Conditions ◽  
Buried Seeds ◽  
Diurnal Temperatures

Experiments were performed to determine whether the dormancy release effect of hydrated storage in darkness (dark-stratification) is common amongst annual ryegrass populations and has the potential to occur under field conditions. Dormant seeds from all populations tested (22) became sensitive to light during dark-stratification, enabling them to germinate when subsequently exposed to light. Under controlled temperature (25/15°C), light (12-h photoperiod), and hydration (solidified agar-water) conditions, more seeds germinated by 28 days if the first 14 days were in darkness followed by exposure to light for 12 h per day than if they were exposed to light throughout or darkness throughout. Constraint over the conditions imposed during dark-stratification and germination was gradually reduced to investigate whether the dormancy release effect was diminished. Dark-stratification was effective in promoting germination when performed under natural diurnal temperatures, and burial in moist soil provided suitable conditions for dark-stratification to occur. The surface of moist soil, with natural diurnal temperatures and sunlight, was suitable for germination of dark-stratified seeds. Dark-stratification is a quick and effective means to enhance the sensitivity of dormant annual ryegrass seeds to light, enabling the majority of the population to germinate. However, large quantities of light are required to promote germination of dark-stratified seeds, so buried seeds must be moved to the soil surface to allow exposure to adequate light for germination.

Isoproturon movement and dissipation in undisturbed soil cores from a grassed buffer strip

Agronomie ◽  
2000 ◽  
Vol 20 (3) ◽  
pp. 297-307 ◽  
Author(s):  
Pierre Benoit ◽  
Enrique Barriuso ◽  
Philippe Vidon ◽  
Benoit Réal
Keyword(s):  
Soil Cores ◽  
Undisturbed Soil ◽  
Buffer Strip ◽  
Undisturbed Soil Cores

scholarly journals Impact of Weed Control by Hand Tools on Soil Erosion under a No-Tillage System Cultivation

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 974
Author(s):  
Rafael Blanco-Sepúlveda ◽  
Amilcar Aguilar-Carrillo ◽  
Francisco Lima
Keyword(s):  
Soil Erosion ◽  
Weed Control ◽  
Soil Cover ◽  
Soil Surface ◽  
Conservation Agriculture ◽  
Soil Disturbance ◽  
No Tillage ◽  
Tropical Mountains ◽  
Litter Cover ◽  
Vegetal Cover

In conservation agriculture, the no-tillage cultivation system and the retention of permanent vegetal cover are crucial to the control of soil erosion by water. This paper analyses the cultivation of maize under no-tillage, with particular reference to the effect produced on soil erosion when weed control is performed by a hand tool (machete), which disturbs the surface of the soil, and to the behavior of the soil cover in these circumstances. The study area is located in the humid tropical mountains of northern Nicaragua (Peñas Blancas Massif Nature Reserve). The results obtained show that 59.2% of the soil surface was affected by appreciable levels of sheet and splash erosion, although the vegetal cover of the soil was relatively high (with average weed and litter cover of 33.9% and 33.8%, respectively). The use of machetes for weed control provoked considerable soil disturbance, which explained the high rates of erosion observed. Moreover, this form of soil management disturbs the litter layer, making it less effective in preventing erosion. The litter remains loose on the soil surface, and so an increase in soil cover does not achieve a proportionate reduction in the area affected by erosion; thus, even with 80–100% weed and litter cover, 42% of the cultivated area continued to present soil erosion.

Alleviation of dormancy in annual ryegrass (Lolium rigidum) seeds by hydration and after-ripening

Weed Science ◽  
2004 ◽  
Vol 52 (6) ◽  
pp. 968-975 ◽  
Author(s):  
Robert S. Gallagher ◽  
Kathryn J. Steadman ◽  
Andrew D. Crawford
Keyword(s):  
Seed Germination ◽  
Relative Humidity ◽  
Germination Rate ◽  
Dormancy Release ◽  
Annual Ryegrass ◽  
Dormant Seed ◽  
Lolium Rigidum ◽  
Time Model ◽  
Treatment Regimens ◽  
Two Populations

The effect of hydration (priming) treatment on dormancy release in annual ryegrass seeds from two populations was investigated. Hydration duration, number, and timing with respect to after-ripening were compared in an experiment involving 15 treatment regimens for 12 wk. Seeds were hydrated at 100% relative humidity for 0, 2, or 10 d at Weeks 1, 6, or 12 of after-ripening. Dormancy status was assessed after each hydration treatment by measuring seed germination at 12-hourly alternating 25/15 C (light/dark) periods using seeds directly from the hydration treatment and seeds subjected to 4 d postpriming desiccation. Seeds exposed to one or more hydration events during the 12 wk were less dormant than seeds that remained dry throughout after-ripening. The longer hydration of 10 d promoted greater dormancy loss than either a 2-d hydration or no hydration. For the seed lot that was most dormant at the start of the experiment, two or three rather than one hydration event or a hydration event earlier rather than later during after-ripening promoted greater dormancy release. These effects were not significant for the less-dormant seed lot. For both seed lots, the effect of a single hydration for 2 d at Week 1 or 6 of after-ripening was not manifested until the test at Week 12 of the experiment, suggesting that the hydration events alter the rate of dormancy release during subsequent after-ripening. A hydrothermal priming time model, usually used for modeling the effect of priming on germination rate of nondormant seeds, was successfully applied to dormancy release resulting from the hydration treatments.

Annual ryegrass (Lolium rigidum) seed survival and digestibility in cattle and sheep

2002 ◽  
Vol 42 (2) ◽  
pp. 111 ◽  
Author(s):  
R. Stanton ◽  
J. Piltz ◽  
J. Pratley ◽  
A. Kaiser ◽  
D. Hudson ◽  
...  
Keyword(s):  
Dry Matter ◽  
Control Diet ◽  
Basal Diet ◽  
Annual Ryegrass ◽  
Lolium Rigidum ◽  
Seed Survival ◽  
Dry Matter Digestibility ◽  
Cattle And Sheep

A trial was conducted to investigate the survival and digestibility of annual ryegrass (ARG) seed (Lolium rigidum L.) eaten by sheep and cattle. Sheep (n= 8) and cattle (n = 8) were fed a basal diet containing 1:1 lucerne chaff:oaten chaff with (ARG) or without (control) the inclusion of 20% total dry matter of annual ryegrass seed in a changeover design. Intake was restricted to 17 g/kg liveweight. Digestibility of the control diet was lower (P<0.01) for sheep than cattle. Annual ryegrass seed was present (P<0.01) in the faeces of both sheep and cattle within 24 h of first ingestion. Some 10.8 and 32.8% of seed ingested was excreted by sheep and cattle respectively, with 3.9% (sheep) and 11.9% (cattle) remaining germinable. Annual ryegrass seed continued to be excreted by both sheep and cattle up to 5 days after removal from the diet. Dry matter digestibility of the annual ryegrass diet was 53% in cattle.

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