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.

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.

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.

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).

Seed Longevity of Six Native Forbs in a Closed Themeda triandra Grassland

1995 ◽  
Vol 43 (5) ◽  
pp. 439 ◽  
Author(s):  
ID Lunt
Keyword(s):  
Soil Seed Bank ◽  
Seed Mass ◽  
Soil Surface ◽  
Seed Longevity ◽  
Short Term ◽  
Themeda Triandra ◽  
Native Grassland ◽  
Buried Seeds ◽  
Small Seed ◽  
Closed Canopy

Seeds of six native forbs̵2Arthropodium strictum R.Br., Burchardia umbellata R.Br., Bulbine bulbosa (R.Br.) Haw., Chrysocephalum apiculatum (Labill.) Steetz, Craspedia variabilis Everett & Doust and Leptorhynchos squamatus (Labill.) Less.-were sown on and below the soil surface in a closed, native grassland dominated by Themeda triandra Forsskal. Replicate seed lots were recovered after 2, 4, 6, 9 and 12 months, and viability was assessed. Less than 7% of sown surface seeds of B. bulbosa, B. umbellata, C. variabilis and L. squamatus, and less than 10% of buried seeds of A. strictum, B. umbellata and C. variabilis remained viable after 12 months. Virtually all losses of Liliaceae seeds were due to germination. Fates of Asteraceae seeds were difficult to assess accurately after 6 months, but germination accounted for most seed losses. Burial significantly promoted longevity of B. bulbosa, C. variabilis and L. squamatus seeds. No obvious relationship existed between seed longevity and taxonomic group (Liliaceae versus Asteraceae) or seed mass, for surface or buried seeds; the response of the large-seeded lily, B. bulbosa, was most similar to that of the small-seeded daisy, L. squamatus. Of the six species, C. apiculatum appears to have the greatest potential to accumulate a soil seed bank beneath a closed grass canopy, owing to its small seed size, inhibition of germination beneath a closed canopy, both on and below the soil surface, and sustained viability of buried seeds. Naturally dispersed seeds of the other five species are likely to form smaller, transient or short-term seed banks.

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.

scholarly journals Cross-Resistance to Herbicides in Annual Ryegrass (Lolium rigidum)

1990 ◽  
Vol 94 (3) ◽  
pp. 1180-1186 ◽  
Author(s):  
John M. Matthews ◽  
Joseph A. M. Holtum ◽  
David R. Liljegren ◽  
Barbara Furness ◽  
Stephen B. Powles
Keyword(s):  
Cross Resistance ◽  
Annual Ryegrass ◽  
Lolium Rigidum ◽  
Resistance To Herbicides

Temperature/light interactions and the effect of seed source on germination of annual ryegrass (Lolium rigidum Gaud.) seeds

1976 ◽  
Vol 27 (6) ◽  
pp. 779 ◽  
Author(s):  
D Gramshaw
Keyword(s):  
Constant Temperature ◽  
Day Length ◽  
Maximum Temperature ◽  
Annual Ryegrass ◽  
Lolium Rigidum ◽  
Average Temperature ◽  
Seed Sources ◽  
Alternating Temperature ◽  
Germinating Seeds ◽  
Temperature Optima

Germination of Lolium rigidum seeds, in the light (12 hr day length) and in the dark, was studied at constant and alternating (12/12 hr) temperatures in the range 8–35°C. Seeds had after-ripened for 22 weeks. Different constant temperature optima for germinability were found: 27° in light and 11° in dark. Germinability at alternating temperatures in darkness was determined solely by the minimum temperature of the alternation, and there was no response to thermoperiodicity per se. In contrast, light and alternating temperature appeared to interact to increase germinability, although the highest germinability occurred only when the maximum temperature was close to the optimum constant temperature, i.e. about 27°. Germination in both light and dark was most rapid where either the constant or the average temperature of an alternating regime was between 18 and 29°. Below 18° germination rates decreased markedly, and at 8°, rates were one-third of those at 18°. Seeds germinated more slowly in light than in darkness at all temperatures, but the differences were small relative to the effects of low temperatures.In another study, seeds collected from plants naturalized in eight different localities in the cereal belt of Western Australia and subsequently planted together in two contrasting environments were examined for germinability at 24/12°C in light and dark 18 weeks after harvest. Dark germinability differed between seed sources but not between planting sites, and ranged between 78 and 93%. Exposure of germinating seeds to light substantially alleviated dormancy in seeds from all sources.

scholarly journals Crop residues on short-term CO2 emissions in sugarcane production areas

2013 ◽  
Vol 33 (4) ◽  
pp. 699-708 ◽  
Author(s):  
Mariana M. Corradi ◽  
Alan R. Panosso ◽  
Marcílio V. Martins Filho ◽  
Newton La Scala Junior
Keyword(s):  
Co2 Emissions ◽  
Field Experiments ◽  
Crop Residues ◽  
Soil Surface ◽  
Dry Mass ◽  
Agricultural Crop ◽  
Short Term ◽  
Sugarcane Production ◽  
Soil Temperatures ◽  
Production Areas

The proper management of agricultural crop residues could produce benefits in a warmer, more drought-prone world. Field experiments were conducted in sugarcane production areas in the Southern Brazil to assess the influence of crop residues on the soil surface in short-term CO2 emissions. The study was carried out over a period of 50 days after establishing 6 plots with and without crop residues applied to the soil surface. The effects of sugarcane residues on CO2 emissions were immediate; the emissions from residue-covered plots with equivalent densities of 3 (D50) and 6 (D100) t ha-1 (dry mass) were less than those from non-covered plots (D0). Additionally, the covered fields had lower soil temperatures and higher soil moisture for most of the studied days, especially during the periods of drought. Total emissions were as high as 553.62 ± 47.20 g CO2 m-2, and as low as 384.69 ± 31.69 g CO2 m-2 in non-covered (D0) and covered plot with an equivalent density of 3 t ha-1 (D50), respectively. Our results indicate a significant reduction in CO2 emissions, indicating conservation of soil carbon over the short-term period following the application of sugarcane residues to the soil surface.

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