Reproductive ecology of invasive Ochna serrulata (Ochnaceae) in south-eastern Queensland

2006 ◽  
Vol 54 (1) ◽  
pp. 43 ◽  
Author(s):  
Carl R. Gosper ◽  
Gabrielle Vivian-Smith ◽  
Kate Hoad
Keyword(s):  
Field Experiments ◽  
Invasive Plant ◽  
Reproductive Ecology ◽  
Seed Viability ◽  
Dry Weight ◽  
South Eastern ◽  
Seed Sources ◽  
Seed Processing ◽  
Eastern Australia ◽  
Viable Seeds

We investigated aspects of the reproductive ecology of Ochna serrulata (Hochst.) Walp., an invasive plant in eastern Australia. O. serrulata drupes were similar in size to fleshy fruits of other local invasive plants, but showed some distinct differences in quality, with a very high pulp lipid content (32.8% of dry weight), and little sugar and water. Seeds were dispersed by figbirds, Sphecotheres viridis Vieillot, a locally abundant frugivore, and comprised between 10 and 50% of all non-Ficus spp. fruit consumed during October and November. The rate of removal of O. serrulata drupes was greater in bushland than suburban habitats, indicating that control in bushland habitats should be a priority, but also that suburban habitats are likely to act as significant seed sources for reinvasion of bushland. Germination occurred under all seed-processing treatments (with and without pulp, and figbird gut passage), suggesting that although frugivores are important for dispersal, they are not essential for germination. Recruitment of buried and surface-sown seed differed between greenhouse and field experiments, with minimal recruitment of surface-sown seed in the field. Seed persistence was low, particularly under field conditions, with 0.75% seed viability after 6 months and 0% at 12 months. This provides an opportunity to target control efforts in south-eastern Queensland in spring before fruit set, when there is predicted to be few viable seeds in the soil.

Dung burial by native and introduced dung beetles (Scarabaeidae)

1994 ◽  
Vol 45 (8) ◽  
pp. 1799 ◽  
Author(s):  
M Tyndale-Biscoe
Keyword(s):  
Introduced Species ◽  
Native Species ◽  
Dry Weight ◽  
Dung Beetle ◽  
Dung Beetles ◽  
South Eastern ◽  
Eastern Australia ◽  
South Eastern Australia

The quantity of dung buried and shredded by dung beetles at four sites in south-eastern Australia was found to be positively correlated with the dry weight (biomass) of beetles in the pads. Each of the four sites has two abundant native species of dung beetles, and one to five well-established introduced species present. At Uriarra, where only one introduced species is common, a mean of 7 . 2 l � 1.94% (1990-91) and 6.01�1.31% (1991-92) of the dung was buried per week. At Fyshwick, with two common introduced species of dung beetles, 22.27� 4.03% (1990-91) and 12 04�2 72% (1991-92) of the dung was buried per week. Braidwood, with four introduced species, had a mean of 15.81� 2.82% (1991-92) weekly dung buried, and Araluen, with five introduced species, had 30.18�8- 73% (1992-93) dung buried per week. Dung beetle numbers were low at all sites during the first half of 1991-92 season due to a drought throughout the region. Dung shredding averaged less than 12% over the seasons at all sites, but fluctuated from 0 to 70%, depending mainly on beetle numbers in the dung pads on individual occasions. Increasing numbers of exotic dung beetles throughout the pastoral areas of Australia should result in increased amounts of dung buried and shredded, with correspondingly increased benefits to Australian agriculture.

scholarly journals Enhancing the Viability of Rosella Seeds (Hibiscus sabdariffa L.) through Tetrazolium and Paper Media Test

2019 ◽  
Vol 4 (1) ◽  
pp. 23-30
Author(s):  
Taufiq Hidayat RS ◽  
Mayasari Yamin
Keyword(s):  
Seed Viability ◽  
Dry Weight ◽  
Tetrazolium Salt ◽  
Hibiscus Sabdariffa ◽  
Germination Capacity ◽  
Randomized Design ◽  
Vigor Index ◽  
Normal Seedling ◽  
Best Parameter ◽  
Viable Seeds

This study was aimed to determine the viability rate of rosella seed, to obtain the best result of seed testing for enhancing rosella seed viability, to find the best seed invigoration method for enhancing rosella seed viability, to obtain staining pattern through tetrazolium test of rosella seed, and to determine viability and vigor of rosella seed to be further used as estimation indicator for rosella plant growth in the field. The study was conducted in the Seed Laboratory, Indonesian Sweetener and Fiber Crops Research Institute (ISFCRI), Malang, East Java during July - August 2018. The material used included accessions of rosella seed (Hibiscus sabdariffa L.) ACC. 1148 from the year 2015 and collection of ISFCRI, 100 ml of Tetrazolium solution (40 ml KH2PO4, 60 ml Na2HPO4 and 1 gr of Tetrazolium powder). This research applied Completely Randomized Design (CRD) consisted of seed treatments of control (no immersion/0 hour), immersion for 5 hours, immersion for 10 hours, and scarification, each with 4 replications. Result of this study showed that the use of tetrazolium salt was found to be better in enhancing the viability of rosella seeds. Viable seeds was found to have bright red embryonic axis and bright red cotyledon. Testing using paper media on several seed invigoration treatments resulted in significantly different effect on parameters of vigor index, germination capacity, and dry weight of normal seedling. The best parameter of germination capacity and dry weight of normal seedling was obtained by treatment immersed in water at temperature of 27°C for 10 hours

Mecury Concentrations in Ten Species of Australian Waterfowl (Family Anatidae)

1984 ◽  
Vol 11 (2) ◽  
pp. 387 ◽  
Author(s):  
GJ Bacher ◽  
FI Norman
Keyword(s):  
Significant Positive Correlation ◽  
Total Mercury ◽  
Dry Weight ◽  
Positive Correlation ◽  
South Eastern ◽  
Black Duck ◽  
Eastern Australia ◽  
Wet Weight ◽  
South Eastern Australia

Total mercury concentrations in wing muscle of 10 species of waterfowl (Anatidae) collected during 1977 and 1978 in south-eastern Australia ranged from 0.08 � 0.04 (mean � SD) g g-1 wet weight in Australian shelduck Tadorna tadornoides and Pacific black duck Anas superciliosa, to 0.17 � 0.08 g g-1 in freckled duck Stictonetta naevosa. No significant differences in concentrations of mercury in muscle were found between sexes or between juvenile and adult birds. Total mercury concentrations in feathers were 3.01 � 0.09 g g-1 dry weight in Pacific black duck and 3.27 � 1.11 g g-1 in grey teal Anas gibberifrons. A significant positive correlation (r= 0.7783; P<0.01) was found between mercury concentrations in wing muscles and feathers of Pacific black duck.

scholarly journals Field priming with cytokinins enhances seed viability of wheat after low temperature storage

2021 ◽  
Vol 67 (No. 2) ◽  
pp. 77-84
Author(s):  
Radoslav Chipilski ◽  
Irina Moskova ◽  
Albena Pencheva ◽  
Konstantina Kocheva
Keyword(s):  
Low Temperature ◽  
Field Experiments ◽  
Growth Parameters ◽  
Seed Viability ◽  
Dry Weight ◽  
Grain Filling ◽  
Seedling Vigour ◽  
Cell Membrane Stability ◽  
Low Temperature Storage ◽  
Temperature Storage

Field experiments were conducted with two winter wheat cultivars that were primed with 6-benzylaminopurine (6-BA) or kinetin at the concentration 10 mg/L twice during the grain filling stage. After priming, wheat physiological parameters were measured in the field, and the analysis of yield was performed after harvest. Harvested seeds were subjected to low temperature storage for 12 months at –18 °С simulating conservation conditions in genebanks. In field experiments, treated plants exhibited up to 14% higher productivity, higher fresh and dry weight, and chlorophyll content index of flag leaves. Priming significantly improved germination, seedling vigour and growth parameters. In 5-days-old seedlings developed from low temperature stored seeds of field primed plants, the average accumulation of malondialdehyde and H<sub>2</sub>O<sub>2</sub> was estimated 25% lower, which contributed to higher cell membrane stability. These results correlated positively with growth characteristics of 15-days-old seedlings. The stimulating action of cytokinin priming was more pronounced in the modern cv. Geya-1 compared to the older cv. Sadovo 772 and could be attributed to improved anti-aging mechanism connected with better protection against oxidative damage.  

scholarly journals Studies in the epidemiology of infectious myxomatosis of rabbits: II. Field experiments, August–November 1950, and the first epizootic of myxomatosis in the riverine plain of south-eastern Australia

1954 ◽  
Vol 52 (1) ◽  
pp. 47-59 ◽  
Author(s):  
K. Myers
Keyword(s):  
Field Experiments ◽  
Sudden Change ◽  
Close Correlation ◽  
Test Site ◽  
Disease Spread ◽  
South Eastern ◽  
Murray River ◽  
Eastern Australia ◽  
Large Populations ◽  
South Eastern Australia

An account is given of experiments designed to study the spread of myxomatosis in populations of rabbits living under natural conditions on a number of sites in the Eastern Riverine Plain of south-eastern Australia. In five different trials the disease spread from inoculated rabbits, but failed to gain momentum and died down within a few weeks of its introduction.In December 1950, when the disease was persisting at low incidence on one test site and seemed to have died out in the others, an epizootic broke out in the neighbourhood which spread, in a few months, over the greater part of south-eastern Australia. The only factor, apart from climatic ones, which could account for this sudden change in the activity of the disease was the development of large populations of two rabbit-feeding mosquitoes, Anopheles annulipes and Culex annulirostris. A close correlation was demonstrated, on the flats bordering the Murray River, between the distribution of these insects and myxomatosis activity.The author is indebted to Mr F. N. Ratcliffe, officer-in-charge, Mr J. le G. Brereton, Mr J. Calaby, and Dr R. Mykytowycz, all of the Wildlife Survey Section, Commonwealth Scientific and Industrial Research Organization, for assistance given during the course of the work and to Mr Ratcliffe, and Prof. F. Fenner of the Australian National University, for guidance in the presentation of the results.

Timing and Measurement of Weed Seed Shed in Corn (Zea mays)

1996 ◽  
Vol 10 (3) ◽  
pp. 535-543 ◽  
Author(s):  
Frank Forcella ◽  
Dean H. Peterson ◽  
James C. Barbour
Keyword(s):  
Seed Production ◽  
Dry Weight ◽  
Weed Seed ◽  
Common Lambsquarters ◽  
Redroot Pigweed ◽  
Seed Processing ◽  
Wild Mustard ◽  
Green Foxtail ◽  
Viable Seeds ◽  
Total Seed

In west central Minnesota the extent and duration of weed seed shed was measured for two years in corn that received cultivation but no herbicides. Percentage of seed production represented by viable (filled) seeds was about 79% for green foxtail, 68% for wild mustard, 49% for Pennsylvania smartweed, 48% for common lambsquarters, and 35% for redroot pigweed. Percentage viable seeds varied from 11% in 1993 to 59% in 1994 for redroot pigweed, but was more stable for other species. Seed shed commenced in late August in a cool year (1993) and early August in a warm year (1994). Average growing degree days (base 10 C) from corn planting until 25% seed shed was 983 for common lambsquarters, 984 for wild mustard, 1004 for Pennsylvania smartweed, and 1034 for both green foxtail and redroot pigweed. Brief weather events, such as wind storms, dispersed large percentages of total seed production within a single day. More than one-fifth of all viable seeds of green foxtail, redroot pigweed, and common lambsquarters were retained by the seedheads and dispersed by combines at harvest. In contrast, seeds of early-maturing species, such as wild mustard, were completely dispersed before corn harvest in the warmer year, but one-third of seeds were retained by seedheads at harvest in the cooler year. Measurement of seed shed was compared using five seed trap designs. The preferred design consisted of a 10-cm-diam plastic cup, whose bottom was replaced by a brass screen, and the entire unit attached to a small wooden stake for support. This design provided, on average, the highest estimates of seed production, least among-replication variability, highest correlation with weed population density and aboveground dry-weight, lowest assembly cost, and greatest ease for sample access and seed processing.

scholarly journals Seed Viability of Heracleum mantegazzianum (Apiaceae) Is Quickly Reduced at Temperatures Prevailing in Biogas Plants

Agronomy ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 332
Author(s):  
Tanke ◽  
Müller ◽  
de Mol
Keyword(s):  
Weed Management ◽  
Invasive Plant ◽  
Operating Temperature ◽  
Seed Viability ◽  
Seed Survival ◽  
Ripening Stages ◽  
Heracleum Mantegazzianum ◽  
Biogas Plants ◽  
65 H ◽  
Viable Seeds

Heracleum mantegazzianum is an invasive plant species with enormous effect on ecosystems and human health. Mechanical weed management often results in large amounts of biomass. Fermentation in biogas plants can be used for disposal of this biomass contaminated with seeds and for energetic utilization, if spreading of viable seeds with fermentation residues is prevented. Our aim is to quantify the risk of seed survival in mesophilic biogas plants. Seeds were harvested at three ripening stages in central Germany. They were incubated for 0, 0.5, 1, 2, 4, and 8 days at 35 and 42 °C in water baths. Thereafter, seed viability was assessed by a tetrazolium test. Furthermore, germinative capacity of seeds which had passed an incubation of 48 h at 35 °C were tested. After eight days in water bath none of the 1199 tested seeds were viable anymore. The time until half of the seeds died (ED50) ranged from 9 to 65 h, whereby high temperature accelerated the mortality. Germinative capacity was similar to the seed survival rate. The results suggest that fermentation of H. mantegazzianum biomass poses only a low risk of viable seed spread, if the operating temperature of the biogas plant achieves 42 °C and a high retention time is ensured.

The effect of dwarfing genes in spring wheat in dry environments. I. Agronomic characteristics

1992 ◽  
Vol 43 (3) ◽  
pp. 517 ◽  
Author(s):  
RA Richards
Keyword(s):  
Harvest Index ◽  
Field Experiments ◽  
Dry Weight ◽  
Mean Value ◽  
Kernel Weight ◽  
Dwarfing Genes ◽  
Kernel Number ◽  
Agronomic Characteristics ◽  
Eastern Australia ◽  
The Mean

Near-isogenic lines of wheat were used to investigate the possible yield penalty of dwarfing genes in rainfed environments. Field experiments were conducted over seven years in south-eastern Australia which were characterized by drought becoming progressively more intense as crop maturity approached. Isogenic sets for the Rht1 and Rht2 genes were chosen to cover a range of heights for the tall (rhtrht) lines, from 100 to 130 cm when grown in the absence of drought before anthesis. Rht1 or Rht2 reduced this height by about 23% whereas Rht1 and Rht2 together or Rht3 alone reduced this ceiling height by about 47%. Highest grain yields were achieved by lines with a height between 70 and 100 cm. Although major were usually required to achieve this optimum height, no specific advantage of the major dwarfing genes was found. Likewise, in tall and short isogenic populations, the short populations yielded more than the tall populations even though they all contained Rht1. The expression of the major dwarfing genes and their effect on agronomic characteristics varied depending on the genetic background but general trends were evident. Above-ground dry weight was reduced by 4.4% of the mean weight for each 10 cm reduction in height below 100 cm. Above 100 cm there was little change in above-ground dry weight. Harvest index decreased by 3.7% of the mean value for each 10 cm increase in height above 65 cm. When height was less than 65 cm, harvest index remained constant. Kernel number was more sensitive to variation in height than was kernel weight. In only one of the isogenic sets was there evidence for compensation between kernel number and kernel weight; in four sets, both kernel number and kernel weight matched variation in yield in a positive way.

Effectiveness of liming to minimise uptake of cadmium by wheat and barley grain grown in the field

1996 ◽  
Vol 47 (7) ◽  
pp. 1181 ◽  
Author(s):  
DP Oliver ◽  
KG Tiller ◽  
MK Conyers ◽  
WJ Slattery ◽  
AM Alston ◽  
...  
Keyword(s):  
Soil Ph ◽  
Maximum Permissible Concentration ◽  
Field Experiments ◽  
New South ◽  
New South Wales ◽  
Barley Grain ◽  
Wagga Wagga ◽  
South Eastern ◽  
South Wales ◽  
Eastern Australia

The effects of soil pH on cadmium (Cd) concentration in wheat and barley grain were determined from 8 field experiments in the Rutherglen (Victoria) and Wagga Wagga (New South Wales) regions of south-eastern Australia. Generally, raising soil pHc, from 4.0 to 5.0 using lime decreased Cd concentration in the grain. However, the response was variable between sites and years, with the greatest variation occurring between years. At those sites where there were statistically significant decreases in Cd concentration with increasing pH, the rate of decrease was small. The Cd concentration exceeded the maximum permissible concentration (MPC) of 0.05 mg/kg in barley grain at 3 sites and in wheat at 1 site. In some cases, raising soil pHCa, to 6.0 was not sufficient to decrease Cd concentration in grain below the MPC and raising soil pH above this value would not be considered economically viable in many areas.

MODELING AND EXPERIMENTAL VERIFICATION OF AIR-THERMAL AND MICROWAVE-CONVECTIVE PRESOWING SEED TREATMENT

2020 ◽  
Vol 4 (41) ◽  
pp. 35-43
Author(s):  
ALEKSEY A. VASIL’EV ◽  
◽  
ALEKSEY N. VASIL’EV ◽  
DMITRIY BUDNIKOV ◽  
ANTON SHARKO
Keyword(s):  
High Frequency ◽  
Seed Treatment ◽  
Field Experiments ◽  
Research Purpose ◽  
Dense Layer ◽  
Technological Equipment ◽  
External Influence ◽  
Ultra High Frequency ◽  
Grain Processing ◽  
Seed Processing

The use of electrophysical influences for pre-sowing treatment of seeds is an effective way to increase their sowing quality. The use of these methods is limited by the fact that their implementation requires new technological equipment in grain processing lines. This problem is solved more easily when pre-sowing processing is performed using installations for active ventilation and grain drying. (Research purpose) The research purpose is in determining the possibility of using active ventilation units and ultra-high-frequency convective grain dryers for pre-sowing grain processing and to evaluating the effectiveness of such processing using computer modeling. (Materials and methods) It is necessary to ensure the uniformity of processing with external influence the seeds placed in a dense layer. Authors carried out pre-sowing treatment of seeds on real installations. Treated seeds were sown in experimental plots and the results of treatment were evaluated. (Results and discussion) The article presents graphs of changes in grain temperature and humidity during processing. To check the feasibility of pre-sowing treatment, authors performed modeling of air-heat and ultra-high-frequency convective seed treatment processes. Based on the results of field experiments, air-heat treatment stimulates the development of secondary plant roots, contributes to an intensive increase in the green mass of plants; ultra-high-frequency convective seed treatment allows increasing the number of productive stems in plants, the number of ears in one plant. (Conclusions) Technological equipment designed for drying and active ventilation of grain can be effectively used for pre-sowing seed processing. In the course of field experiments, it was revealed the possibility of controlling the structure of the crop using different types of external influence on seeds during their pre-sowing processing.

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