Effect of pasture renovation on the size and composition of the germinable fraction of the seed pool beneath bent grass (Agrostis castellana) pastures in southern Victoria

1999 ◽  
Vol 50 (1) ◽  
pp. 87 ◽  
Author(s):  
M-G. Batson
Keyword(s):  
Depth Distribution ◽  
Seedling Emergence ◽  
Positive Change ◽  
Soil Samples ◽  
Percentage Change ◽  
Weed Seeds ◽  
Agrostis Castellana ◽  
Total Seed ◽  
Germinable Seed ◽  
Germinated Seeds

This paper investigated the potential for propagation of grass weeds from seed by measuring changes in the size and composition of the germinable fraction of the seed pool beneath 4 bent grass (Agrostis castellana) pastures in southern Victoria during renovation. Soil samples, for the estimation of the seed pool by seedling emergence in the glasshouse, were taken from a control and a renovated pasture on 3 occasions during renovation at each of the 4 sites. The depth distribution of seeds in the top 0–100 mm was assessed by dividing collected soil samples into depths of 0–30 mm and 30–100 mm. The total germinable seed pool (0–30 mm) ranged from 17 620 to 83 540 seedlings/m2, as affected by the time of sampling. There were seedlings from 14 grass genera (12% contribution to the total seed pool), Juncus (60%), 4 leguminous genera (17%), and 22 other dicotyledonous genera (12%). The percentage change in the number of germinated seeds of grasses and dicotyledons between the first and second sampling was negative ( –7·3% to –31·4%) beneath renovated pasture, as opposed to a positive change (29·0–174·4%) beneath undisturbed pasture; this was attributed to the prevention of seeding due to the cultivation of the pasture associated with renovation. The percentage change in the number of germinated seeds of grasses and dicotyledons did not differ significantly between renovated and undisturbed pasture between the second and third sampling, which suggested that no more seed germinated in response to renovation. Re-distribution of germinable seed to lower depths (30–100 mm) with renovation was apparent for grasses and other dicotyledons, and would depress successful emergence of these seedlings. Renovation prevented re-seeding of weeds and buried surface seed, but did not significantly stimulate additional seed to germinate the following autumn after renovation. Weed seeds were still present in the soil seed pool after renovation, which indicated that these species could potentially germinate and establish in new pastures.

scholarly journals Predicting broadleaf weed populations in maize from the soil seedbank

2004 ◽  
Vol 57 ◽  
pp. 281-285 ◽  
Author(s):  
A. Rahman ◽  
T.K. James ◽  
J.M. Mellsop ◽  
N. Grbavac
Keyword(s):  
White Clover ◽  
Chenopodium Album ◽  
Seedling Emergence ◽  
Soil Samples ◽  
Weed Species ◽  
Linear Relationships ◽  
Weed Seeds ◽  
Soil Seedbank ◽  
The Relationship ◽  
Field Plots

Investigations over three years studied the relationship between weed seeds in the soil seedbank and the resultant populations of broadleaf weeds in maize fields Plots were protected from preemergence herbicide after which soil samples (100 mm) were collected and weed seeds therein enumerated Emerged weed seedlings in field plots were counted over the following 8 weeks Up to 67 broadleaf weed species were identified although not all were found at every site and some were specific to a region or soil type On average 2182 of the seed in the soil seedbank emerged For most weeds strong linear relationships were noted between seedling numbers and the seed numbers in the soil although for some like white clover (Trifolium repens) only a weak relationship was observed In the case of fathen (Chenopodium album) which had the largest seedbank there was evidence of asymptotic behaviour with seedling emergence levelling off at high seed numbers

scholarly journals Effect of period of sugarcane cultivation on the abundance and distribution of weed seeds in the soil profile

2014 ◽  
Vol 32 (3) ◽  
pp. 507-513
Author(s):  
R.O. Adereti ◽  
F.O Takim ◽  
Y.A. Abayomi
Keyword(s):  
Land Use ◽  
Soil Depth ◽  
Seed Banks ◽  
Soil Samples ◽  
Soil Tillage ◽  
Fallow Period ◽  
Tillage Practices ◽  
Weed Seeds ◽  
Seed Distribution ◽  
Screen House

An experiment was laid down in a screen house to determine the distribution of weed seeds at different soil depths and periods of cultivation of sugarcane in Ilorin, Nigeria. Soil samples from different depth levels (0-10 cm, 11-20 cm and 21-30 cm) were collected after harvesting of canes from three different land use fields (continuous sugarcane cultivation for > 20 years, continuous sugarcane cultivation for < 10 years after long fallow period and continuous sugarcane cultivation for < 5 years after long fallow period) in November, 2012. One kilogram of the sieved composite soil samples was arranged in the screen house and watered at alternate days. Germinating weed seedlings were identified, counted and then pulled out for the period of 8 months. Land use and soil depth had a highly significant (p £ 0.05) effect on the total number of weeds that emerged from the soil samples. The 010 cm of the soil depth had the highest weed seedlings that emerged. There was an equal weed seed distribution at the 11-20 cm and 21-30 cm depths of the soil. Sugarcane fields which have been continuously cultivated for a long period of time with highly disturbing soil tillage practices tend to have larger seed banks in deeper soil layers (11-20 cm and 21-30 cm) while recently opened fields had significantly larger seed banks at the 0-10 cm soil sampling depth.

A New Soil Sampler and Elutriator for Collecting and Extracting Weed Seeds from Soil

1996 ◽  
Vol 10 (1) ◽  
pp. 35-41 ◽  
Author(s):  
Lori J. Wiles ◽  
Douglass H. Barlin ◽  
Edward E. Schweizer ◽  
Harold R. Duke ◽  
Douglas E. Whitt
Keyword(s):  
Soil Texture ◽  
Soil Samples ◽  
Core Size ◽  
Intensive Study ◽  
Redroot Pigweed ◽  
Weed Seeds ◽  
Improved Technology

A soil sampler, elutriator, and associated sample flushing device were designed and constructed for an intensive study of weed seedbanks. This equipment was used in 1993 to collect and process 4980 soil samples. The sampler was durable, core size was consistent, and sampling was efficient. Cores were approximately 200 cm3and two people could take 120 cores/h. The elutriator separated weed seeds from 36 of these cores at a time. Washing required 60 to 75 min depending on soil texture. Seeds as small as 0.3 mm in diam were recovered and almost 100% of the seeds were recovered from samples spiked with barnyardgrass, redroot pigweed, velvetleaf, and witchgrass. The flushing device was used to transfer sample contents from strainers of the elutriator to propyltex bags for drying and storing. Equipment like this, plus improved technology for identifying and counting seeds, is needed to make weed seedbank studies more feasible.

Distribution of Weed Seed Among Soil Structural Units

Weed Science ◽  
1985 ◽  
Vol 33 (2) ◽  
pp. 182-189 ◽  
Author(s):  
Mario R. Pareja ◽  
David W. Staniforth ◽  
Gilda P. Pareja
Keyword(s):  
Depth Distribution ◽  
Soil Depth ◽  
Soil Aggregates ◽  
Conventional Tillage ◽  
Soil Aggregate ◽  
Soil Samples ◽  
Reduced Tillage ◽  
Weed Seed ◽  
Structural Units ◽  
Seed Distribution

The depth distribution of weed seed, their location in relation to soil aggregates, and the size distribution of soil aggregates were determined in fields that had been under continual conventional or reduced tillage for more than 12 years. Soil samples were taken at three depths in the spring and fall of 1982, and soil aggregates were classified into seven size classes by dry, rotary sieving. Subsamples were deflocculated and washed through sieves to recover weed seed. In the spring, 85% of all seed in the reduced-tillage and 28% of those in the conventional-tillage soil were in the 0- to 5-cm-depth layer. Conventional tillage incorporated weed seed uniformly into various soil aggregate classes, whereas with reduced tillage more seed accumulated in the unaggregated fraction of the soil. In the fall, weed seed distribution in relation to soil depth and among soil aggregate classes was similar for both tillage regimes.

Seed and seedling studies of three Trifolium subterraneum var. brachycalycinum lines, in a predominantly summer rainfall environment

1995 ◽  
Vol 35 (8) ◽  
pp. 1101
Author(s):  
GM Lodge
Keyword(s):  
Seed Production ◽  
Field Experiments ◽  
Seedling Survival ◽  
Seedling Emergence ◽  
Trifolium Subterraneum ◽  
Summer Rainfall ◽  
Sowing Time ◽  
Buried Seeds ◽  
Initial Seed ◽  
Total Seed

Field experiments were conducted in a predominantly summer rainfall environment to investigate burr burial, seed production, seed characteristics, seedling emergence and survival, and the effects of time of sowing on 3 Trifolium subterraneum var. brachycalycinum lines (cv. Clare and 2 local lines). Each line produced more surface than buried burrs; surface burrs were 59% (range 56-62%) of the total number of burrs recovered and produced 59% of the total seed number. Numbers of seeds per burr were similar for surface and buried burrs, however, buried seeds were 0.97 mg heavier (P<0.05) than surface seeds. Storage for 5 months at 25/60�C decreased hardseed content of surface seed by 50% and buried seed by 70%. Surface and buried seeds stored at 25/25�C for 3 months prior to sowing in trays had a total emergence of <10%, compared with 70% emergence for seeds stored at 25/60�C before sowing. These emergence differences reflected their levels of hardseededness. Numbers of seeds recovered from the soil were not significantly different among lines, declining from about 4200 seeds/m2 after initial seed set to 150 seeds/m2 by the following winter, a 97% decrease. Seed production in the second year increased seed reserves to about 8730 seeds/m2. With no further seed production, levels had declined by 93% in June 1990 and by 99% in May 1991. These data confirm the importance of annual seed production for persistence. Total seedling emergence in summer-autumn accounted for only 10% of the estimated seed production in each year. Seedling survival in summer-autumn 1988-89 was 92.7%, more than double the survival in 1989-90. The effect of sowing time on flowering was always significant, with time to first flower being highest (196 days) for the earliest sowing in March (P<0.05), progressively decreasing (P<0.05) to 108 days for the latest sowing in July. In March, April and May sowings, inflorescence numbers on the first day of flowering were similar at about 120/m2, but increased markedly (P<0.05) for sowing in June or July. However, for the March and July sowings, number of inflorescences at the 9 November 1990 count, were lowest (P<0.05). May or June sowings had the highest number of burrs and seeds (P<0.05), indicating that these may be the best sowing times for maximum seed production in these Trifolium subterraneum var. brachycalycinum lines.

Effects of soil moisture and temperature on seedling emergence from natural and pre-germinated onion seeds

1986 ◽  
Vol 107 (2) ◽  
pp. 249-256 ◽  
Author(s):  
W. E. Finch-Savage
Keyword(s):  
Soil Moisture ◽  
Water Availability ◽  
Seedling Emergence ◽  
Moisture Stress ◽  
Start Time ◽  
Mean Temperature ◽  
Changing Patterns ◽  
Moisture Conditions ◽  
Germinating Seeds ◽  
Germinated Seeds

SummaryThe emergence of seedlings from natural, germinating and selected uniformlygerminated onion seeds was compared in a range of changing patterns of soil moisture. The timing, spread and amount of seedling emergence from seeds in all three treatments were affected by the timing of water availability in the seed bed and these effects differed between treatments.The rate of seedling emergence in all three treatments under non-limiting soil moisture conditions was correlated with mean temperature, but this relationship was obscured in irrigation treatments where water stress occurred. However, if the seed bed was moist at sowing irrespective of subsequent moisture stress the reciprocals of the time to the start, time to 50% and time to the end of seedling emergence from uniformly germinated seeds were correlated with mean temperature (r > 0·87, D.F. 27).The results show that if the seed bed is irrigated prior to sowing and soil moisture is maintained during the first 3 days following sowing high levels of seedling emergence with both predictable timing and uniformity can be achieved by sowing uniformlygerminated seeds. Seedling emergence from natural and germinating seeds was much less predictable.

Seed and Germination Biology ofDittrichia graveolens(Stinkwort)

2013 ◽  
Vol 6 (3) ◽  
pp. 371-380 ◽  
Author(s):  
Rachel N. Brownsey ◽  
Guy B. Kyser ◽  
Joseph M. DiTomaso
Keyword(s):  
Seed Germination ◽  
Seedling Emergence ◽  
Management Strategies ◽  
Seed Viability ◽  
Base Temperature ◽  
Time Model ◽  
Wide Range ◽  
Total Seed ◽  
Thermal Time Model ◽  
Seed Characteristics

AbstractUnderstanding seed characteristics and seedling establishment patterns is essential for the development of effective management strategies for invasive annual species.Dittrichia graveolens(stinkwort) has increased its range rapidly within California since 1995, yet its biology is not well understood, which has led to poorly timed management. In this study, seed viability, germination, longevity, and dormancy, as well as seedling emergence characteristics ofD. graveolenswere evaluated in field, greenhouse, and laboratory experiments in Davis, CA, over a 2-yr period (fall 2010 to summer 2012). In the laboratory, seed germination ofD. graveolensoccurred at a wide range of constant temperatures (12 to 34 C). Cumulative germination was comparable to total seed viability (80 to 95%) at optimal germination temperatures, indicating that primary (innate) dormancy is likely absent. The base temperature for germination was identified using a thermal time model: 6.5 C and 4 C for 2010 and 2011 seed populations, respectively. In the field, seedlings emerged from fall through spring following precipitation events. A very low percentage of seedlings (2.5%) emerged in the second year after planting. Equivalent seedling emergence was observed over a wide range of light conditions (100, 50, 27, and 9% of available sunlight) in a greenhouse experiment, indicating that seed germination is not limited by high or low light. Results from these seed experiments improve our understanding of the reproductive biology of this rapidly expanding exotic annual and provide valuable information for developing effective timing and longevity of management programs.

Seed rain and seed bank along an alpine altitudinal gradient in Swedish Lapland

2000 ◽  
Vol 78 (6) ◽  
pp. 728-747 ◽  
Author(s):  
Ulf Molau ◽  
Eva-Lena Larsson
Keyword(s):  
Seed Bank ◽  
Altitudinal Gradient ◽  
Vascular Plant ◽  
Seed Rain ◽  
Forest Site ◽  
Long Distance ◽  
Empetrum Hermaphroditum ◽  
Study Sites ◽  
Total Seed ◽  
Germinable Seed

We studied the seed flux, including seed rain and seed bank (germinable and total), at twelve sites along an altitudinal gradient in the Abisko area in northernmost Swedish Lapland during a period of 3 years with contrasting summer climates. The study sites were evenly spaced in altitude from the timberline at 700 m above sea level to the highest peaks in the area (1560 m). A subalpine birch forest site was included for comparison. Each site was equipped with seed traps, replaced and emptied directly upon snow-melt each summer. Soil samples for seed bank assessment were taken at all sites, and inventories of the vascular plant flora were carried out in the 10 m radius neighborhood of the traps. The results revealed high variation among years with regard to seed rain and its partitioning over various functional types of plants. Even though most of the seed rain could be attributed to species present in the plant community of the trap sites themselves, some more long-distance dispersal takes place every year. A number of extrazonal recoveries are reported, often several hundred m above the distributional limit of the species. Even though seed number and species diversity declined rapidly from seed rain over total seed bank to germinable seed bank, the correlation among all three aspects of the seed pool was high. The dominant species in the seed flux at moderate altitudes, Empetrum hermaphroditum Hagerup, has a persistent seed bank with an average turnover of more than 200 years.Key words: seed rain, seed bank, total seed bank, germinable seed bank, alpine, dispersal.

scholarly journals Soil Seedbank of Parthenium Weed (Parthenium hysterophorus L.)

2018 ◽  
Author(s):  
S M R Karim ◽  
Maszura Che Mat ◽  
Nor Hafizah Md Zain
Keyword(s):  
Sustainable Management ◽  
Invasive Alien Species ◽  
Soil Depth ◽  
Soil Samples ◽  
Parthenium Hysterophorus ◽  
Soil Core ◽  
Weed Seeds ◽  
Soil Seedbank ◽  
Weed Infestation ◽  
Parthenium Weed

Weed seedbank is an indication of future weed infestation potential of the species and is essential for making strategic planning for its sustainable management. Parthenium weed (Parthenium hysterophorus L.) is an invasive alien species threatening the biodiversity and the environment in Malaysia. A study was, therefore, conducted to estimate the soil seedbank of the weed at four soil depths of four villages of Kuala Muda, Kedah. The aim was to indicate the critical s of parthenium weed seedbank in Malaysia. Soil samples were collected from the sites using a soil core. The seeds were extracted from the soil samples with sieve shaker at the Universiti Malaysia Kelantan laboratory, Jeli Campus. The study indicates that the weed seedbank is in critical level at the area. The highest number of weed seeds (6915/m2) was found in Kg. Kongsi 6, followed by Kg. Sungai Tok Rawang (4481 seeds/m2). The top layer of soil, 0-5 cm, contained the maximum number of weed seeds (4878 seeds/m2) and a significant number of seeds (316 seeds/m2) were noticed at 10-15 cm soil depth. The study suggests the Malaysian government to take immediate action to control parthenium weed seedbank of the sites.

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