Effects of depth and time of sowing on emergence of Danthonia richardsonii Cashmore and Danthonia linkii Kunth

1993 ◽  
Vol 44 (6) ◽  
pp. 1311 ◽  
Author(s):  
GM Lodge ◽  
AJ Schipp
Keyword(s):  
New South ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Maximum Temperature ◽  
Sowing Time ◽  
Sand Mixture ◽  
South Wales ◽  
Seed Field ◽  
Dry Conditions ◽  
Soil Temperatures

Two experiments examined the effects of sowing time and depth (surface and 10, 25, 50 mm) on emergence of Danthonia richardsonii Cashmore and Danthonia linkii Kunth. Experiment 1 was conducted from January to December 1990 on a loam/sand mixture in boxes. Emergence was highest in both species for seeds sown onto the soil surface in summer and autumn (P < 0.05). Sowing at any depth at any time of the year, or surface sowing in winter and spring, markedly reduced emergence. Experiment 2 was conducted in the field at Tamworth, northern New South Wales from September 1991 to August 1992, on a red brown earth and a black earth. This study confirmed that emergence in both species was highest from surface sown seed. Field emergence was lowest in winter, but in contrast to experiment 1, it was higher in spring, particularly on the black earth. Seedling emergence appeared to be related to mean maximum temperature, decreasing in winter as it declined below 20�C, and increasing in spring when it was greater than 23�C. Differences in seed weight were reflected in emergence of D. richardsonii and D. linkii in experiment 1. Similar emergence was recorded for the loamlsand mixture and sand, indicating that there was little effect of texture. Phalaris aquatica L. cv. Sirosa surface sown in December had lower emergence ( P < 0.05) than both Danthonia spp., but emergence of this larger seeded cultivar was higher at depths of 10 and 25 mm. Laboratory studies to determine reasons for the low emergence of D. richardsonii and D. linkii from depth, indicated that neither had an obligate light requirement for germination. Depth, however, reduced germination (P < 0.05) compared with surface sowing of seed. Seedlings at depth also were observed to have slower rates of shoot and root elongation. In the field, the most successful establishments of D. richardsonii and D. linkii seedlings are likely to occur from surface sowings in April and May. Sowing in spring may also be possible if mean maximum soil temperatures exceed 23�C, and seedlings can establish before the onset of hot, dry conditions in summer.

Effects of depth and time of sowing and over-wintering on tropical perennial grass seedling emergence in northern New South Wales

2009 ◽  
Vol 60 (10) ◽  
pp. 954 ◽  
Author(s):  
G. M. Lodge ◽  
S. Harden
Keyword(s):  
Seedling Emergence ◽  
Perennial Grass ◽  
Soil Surface ◽  
Perennial Grasses ◽  
Sowing Time ◽  
Rhodes Grass ◽  
Factors Affecting ◽  
Nylon Mesh ◽  
South Wales ◽  
Digitaria Eriantha

Two studies were conducted in northern NSW to examine some of the factors affecting the successful emergence of seedlings of five species of tropical perennial grasses [Panicum coloratum var. makarikariense cv. Bambatsi (panic), Digitaria eriantha ssp. eriantha cv. Premier (digit), Chloris gayana cv. Katambora (Rhodes grass), Dichanthium aristatum cv. Floren (bluegrass), and Bothriochloa bladhii ssp. glabra cv. Swann (forest bluegrass)]. The first experiment investigated the effects of depth and time (month) of sowing on tropical perennial grass seedling emergence, while a second series of studies examined the effects of contact of dispersal/sowing units with the soil, particularly over winter, on subsequent seed germination and seedling emergence. No seedling emergence of any species occurred in September 2006 and June–August 2007. From October 2006 to May 2007 there were significant effects (P < 0.001) of species, sowing time, depth, and their interaction on predicted emergence. From December to March, predicted emergence was always lower for surface-sown caryopses compared with those sown at 10 and 25 mm depth, and Bambatsi was the only species that had >50% emergence from a depth of 50 mm. Recovery of intact caryopses from 300 μm nylon mesh bags stored in the soil for 6 and 12 months was low for all species. Similarly, predicted germination of caryopses from field soil surface and buried locations (2007 and 2008) and those from florets and coated seeds (2008) was low, indicating that these species had a poor ability to over-winter in moist soil.

Relationship between climate and relative performance of cotton in New South Wales

1986 ◽  
Vol 37 (1) ◽  
pp. 23 ◽  
Author(s):  
NJ Thomson
Keyword(s):  
New South ◽  
New South Wales ◽  
Field Trials ◽  
Maximum Temperature ◽  
Total Rainfall ◽  
Growing Seasons ◽  
South Wales ◽  
Rate Maximum ◽  
Dry Conditions ◽  
The Mean

Cumulative day-degrees, total rainfall and the mean daily values for evaporation rate, maximum temperature, minimum temperature and radiation for a period of 200 days from 1 October to 18 April were used to characterize the climates of cotton-growing seasons at Narrabri (30�S.), N.S.W. Yields (expressed as percentages of standards) of some cultivars included in field trials in cotton-growing districts of New South Wales, were then regressed on these climatic indices. In a number of cases strong, significant linear associations of performance with one or more of the indices were found. Such cultivars were either more or less advantaged by warm, dry conditions than the standards, and vice versa for cool, wet conditions. The implications of these results in studies of genotype x environmental interaction are discussed.

Distribution of the Soil Seedbank and Influence of Fire on Seedling Emergence in Acacia saligna Growing on the Central Coast of New South Wales

1998 ◽  
Vol 46 (6) ◽  
pp. 743 ◽  
Author(s):  
M. G. Tozer
Keyword(s):  
New South ◽  
Seedling Emergence ◽  
New South Wales ◽  
Soil Surface ◽  
Seed Density ◽  
Acacia Saligna ◽  
Seedling Mortality ◽  
Central Coast ◽  
Seed Mortality ◽  
South Wales

The distribution of seed in the soil and its response to simulated fires were examined in a population of Acacia saligna (Labill.) H.L.Wendl. on the central coast of New South Wales (NSW). Soil seed density was measured by excavating and sieving soil samples, and was estimated to be 1389 ± 297 seeds m–2 and 3600 ± 279 seeds m–2 at two sites within the population. Seed density declined with depth, with 80% of the seedbank located in the upper 6 cm of soil. The passage of fire was simulated by heating the soil surface with a propane burner over an area of 0.25 m2 for durations of 2 or 4 min. A large percentage (88–94%) of the seedbank remained dormant following heating. Temperatures measured in the soil during heating showed that the 4-min treatment approximated the level of soil heating expected during a fire in which all fine ground fuel was consumed; therefore, the seedbank of A. saligna is unlikely to be significantly depleted following a single fire. A frequency distribution of the depths from which seedlings emerged was constructed using measurements of the distance between the soil surface and the hypocotyl–radical junction. A zone of lower than expected seedling emergence occurred from 0–2 cm, but the depth of this zone was not consistent with seed mortality due to excessive heating. Reduced emergence from 0–2 cm may be the result of seedling mortality due to temperature or water stress, which may be influenced by changes in the soil structure or chemistry caused by heating.

The effects of sowing time, sowing technique and grazing on tall fescue (Festuca arundinacea Schreb.) establishment

1992 ◽  
Vol 32 (5) ◽  
pp. 627 ◽  
Author(s):  
GW Charles ◽  
GJ Blair ◽  
AC Andrews
Keyword(s):  
Tall Fescue ◽  
Festuca Arundinacea ◽  
New South ◽  
Sowing Time ◽  
South Wales ◽  
Heavy Grazing ◽  
Direct Drilling ◽  
Aerial Seeding ◽  
Spring Sowing ◽  
Autumn Sowing

The effects of sowing time (autumn and spring) and technique (conventional cultivation, inverted T direct drill, triple disc direct drill and aerial seeding), on the establishment of tall fescue into a weed infested pasture on the Northern Tablelands of New South Wales were examined. A pre-sowing herbicide treatment was included in the 2 direct drilling treatments, and heavy pre-sowing grazing was used in the autumn sowing. The design used 38 plots of 0.12 ha, analysed as 2 separate, complete block experiments, with some common treatments. Tall fescue establishment, 120 days after the autumn sowing, averaged 48 seedlingslm2 on the inverted T treatment (16% establishment). Establishment was improved by 63%, to 78 seedlings/m2, with herbicide and 46%, to 70 seedlings/m2, by heavy grazing. These effects were additive, giving 105 seedlings/m2 for the combined treatments. Only 52 seedlings/m2 established on the triple disc treatment with heavy grazing and herbicide, while establishment on the cultivated seedbed was not different from the inverted T (93 seedlings/m2). There was no establishment after the aerial seeding at either sowing. Fescue establishment showed the same trends in the spring sowing, with 140 seedlings/m2 on the inverted T treatment with pre-sowing herbicide, which was higher than the establishment of 107 seedlings/m2 on the cultivated seedbed. The fescue yield, 18 months after the autumn sowing, was highest in the autumn sown, inverted T treatment with pre-sowing herbicide and heavy grazing (123 kg/ha). In the spring sowing, fescue was recorded only on the cultivated treatment (84 kg/ha) and on the inverted T treatment with pre-sowing herbicide (39 kg/ha). These results show that tall fescue can be re-established into weed dominated pastures on the Northern Tablelands with direct drilling, in either autumn or spring, and that heavy, pre-sowing grazing and herbicide increase fescue establishment.

What lies beneath? The pattern and abundance of the subterranean tuber bank of the invasive liana cat's claw creeper, Macfadyena unguis-cati (Bignoniaceae).

2009 ◽  
Vol 57 (2) ◽  
pp. 132 ◽  
Author(s):  
Olusegun O. Osunkoya ◽  
Karina Pyle ◽  
Tanya Scharaschkin ◽  
Kunjithapatham Dhileepan
Keyword(s):  
New South ◽  
Soil Surface ◽  
Stem Density ◽  
Riparian Areas ◽  
South Wales ◽  
Large Trees ◽  
Tuber Traits ◽  
Standing Vegetation ◽  
Multiple Stems ◽  
Environmental Weed

Cat’s claw creeper, Macfadyena unguis-cati (L.) Gentry (Bignoniaceae) is a major environmental weed of riparian areas, rainforest communities and remnant natural vegetation in coastal Queensland and New South Wales, Australia. In densely infested areas, it smothers standing vegetation, including large trees, and causes canopy collapse. Quantitative data on the ecology of this invasive vine are generally lacking. The present study examines the underground tuber traits of M. unguis-cati and explores their links with aboveground parameters at five infested sites spanning both riparian and inland vegetation. Tubers were abundant in terms of density (~1000 per m2), although small in size and low in level of interconnectivity. M. unguis-cati also exhibits multiple stems per plant. Of all traits screened, the link between stand (stem density) and tuber density was the most significant and yielded a promising bivariate relationship for the purposes of estimation, prediction and management of what lies beneath the soil surface of a given M. unguis-cati infestation site. The study also suggests that new recruitment is primarily from seeds, not from vegetative propagation as previously thought. The results highlight the need for future biological-control efforts to focus on introducing specialist seed- and pod-feeding insects to reduce seed-output.

The effect of soil temperature on nodulation of cowpeas (Vigna sinensis)

1967 ◽  
Vol 7 (27) ◽  
pp. 372 ◽  
Author(s):  
H Philpotts
Keyword(s):  
Soil Temperature ◽  
New South ◽  
New South Wales ◽  
Vigna Sinensis ◽  
Sowing Depth ◽  
Chernozemic Soil ◽  
Straw Mulch ◽  
Pot Experiments ◽  
South Wales ◽  
Soil Temperatures

In two pot experiments at Narrabri, New South Wales, Poona cowpeas (Vigna sinensis) were sown in a black chernozemic soil at 1, 2, and 4 inches, and at 1 1/2 and 4 inches with and without a straw mulch, to give a range of soil temperatures at the depth of sowing. It was found that the higher the soil temperature at sowing depth the lower was the percentage of plants with nodules and the number of nodules per plant.

Wheat for fodder and grain on the Northern Tablelands of New South Wales

1995 ◽  
Vol 35 (1) ◽  
pp. 93 ◽  
Author(s):  
RD FitzGerald ◽  
ML Curll ◽  
EW Heap
Keyword(s):  
Grain Yield ◽  
New South ◽  
New South Wales ◽  
Annual Rainfall ◽  
Sowing Time ◽  
Wheat Varieties ◽  
Dual Purpose ◽  
Grain Yields ◽  
High Rainfall ◽  
South Wales

Thirty varieties of wheat originating from Australia, UK, USA, Ukraine, and France were evaluated over 3 years as dual-purpose wheats for the high rainfall environment of the Northern Tablelands of New South Wales (mean annual rainfall 851 mm). Mean grain yields (1.9-4.3 t/ha) compared favourably with record yields in the traditional Australian wheatbelt, but were much poorer than average yields of 6.5 t/ha reported for UK crops. A 6-week delay in sowing time halved grain yield in 1983; cutting in spring reduced yield by 40% in 1986. Grazing during winter did not significantly reduce yields. Results indicate that the development of wheat varieties adapted to the higher rainfall tablelands and suited to Australian marketing requirements might help to provide a useful alternative enterprise for tableland livestock producers.

Recruitment of Curly Mitchell Grass (Astrebla Lappacea) in North-Western New South Wales.

1996 ◽  
Vol 18 (1) ◽  
pp. 179 ◽  
Author(s):  
MH Campbell ◽  
AM Bowman ◽  
WD Bellotti ◽  
DJ Munich ◽  
HI Nicol
Keyword(s):  
Seed Bank ◽  
Seedling Recruitment ◽  
New South ◽  
Rainfall Events ◽  
South Wales ◽  
Grazing System ◽  
Dry Conditions ◽  
Annual Weeds ◽  
North Western ◽  
Germinable Seed

The recruitment of Astrebla lappacea was studied from 1986 to 1995 in a pasture in north-western NSW where the density of plants had declined from 1 to 3 plants/m2 in 1970 to 0.023 plants/m2 in 1986. Three treatments were imposed: ungrazed-sprayed-slashed, where annual weeds were treated with herbicides and slashing to reduce competition during recruitment; ungrazed-only; and grazed-only. The seed bank of A. lappacea was measured on four occasions and densities of A. lappacea plants determined after major rainfall events mainly in summer and autumn. On the ungrazed treatments the seed bank of A. lappacea increased from 0 in 1988 to 908, 898 and 286 germinable seed/m2 in, respectively, 1992, 1993 and 1995. Flowering and seedling recruitment occurred each year from 1988 to 1995 but seedlings only survived to become mature plants from the 1988 and 1992 recruitments. The major reason for the death of seedlings was dry conditions in the latter half of the year (1 10 to 135 mm of raid6 months). Frosts and competition from Brassicaceae weeds (mainly Raphistrum rugosum) in winter and spring also contributed to death of seedlings. Recruitment of seedlings and their survival to mature plants was higher on the ungrazed-sprayed-slashed treatment than on the other treatments. Recruitment and survival on the ungrazed-only treatment occurred because Brassicaceae weeds did not establish when recruiting rains fell in summer. Plant densit increased from 0.023 plants/m2 in 1986 to, respectively, 0.86, 0.64 Y and 0.004 mature plantdm and 7.88, 6.37, 0.10 seedlings/m2 on the ungrazed-sprayed-slashed, ungrazed-only and grazed-only treatments in 1995. On the grazed-only treatment the methods used to detect seeds revealed none in the soil during the experiment. However, some seeds were present because there was a low level of recruitment none of which survived to mature plants. The number of mature plants declined from 0.023 to 0.004/m2 indicating that under the present grazing system the complete elimination of A. lappacea from pastures in north-western NSW is possible if some form of managed recruitment is not devised.

Some investigations into soil and vegetation relationships associated with alkaline-saline soil surfaces in the Walcha area, Northern Tablelands, New South Wales

1995 ◽  
Vol 46 (1) ◽  
pp. 209 ◽  
Author(s):  
KH Kreeb ◽  
RDB Whalley ◽  
JL Charley
Keyword(s):  
Cynodon Dactylon ◽  
New South ◽  
New South Wales ◽  
Soil Surface ◽  
Tree Planting ◽  
Soil Parameters ◽  
Alkali Cations ◽  
Grazing Land ◽  
South Wales ◽  
Wide Range

The characteristics of the soil, vegetation and groundwater at a dryland salinity site on Miramoona, a property near Walcha on the Northern Tablelands of New South Wales, were investigated. Soil parameters measured at 23 points along a 200 m transect were highly correlated with the pattern of vegetation. Of overriding significance was soil pH, which varied from a high of over 10 on bare areas delineated by Critesion marinum and Cynodon dactylon to a low of less than 5 on grazing land supporting the growth of a wide range of pasture species. The bare areas were characterized by alkalinity. While they were sodic at all depths measured, they were only marginally saline and then only at the soil surface. The chemical composition of the groundwater collected from three piezometer tubes varied quite markedly over the site. It is hypothesized that the presence of alkaline bare areas on the Northern Tablelands is not a new problem, but rather the natural result of alternating wet and dry periods which have induced accumulation of carbonates and bicarbonates of the alkali cations, notably sodium. Drainage of the original perched swamps by the early landholders, tree clearing and the grazing of domestic livestock would have accelerated the process since European settlement. However, tree planting would appear unlikely to have any impact on the reclamation process in the short term. A more viable option would be the recreation of the original swamps in suitable situations, although this solution would create problems for grazing management.

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