Emergence, survival and seed production of Enteropogon ramosus in a pasture - wheat rotation or continuous pasture rotation in the wheatbelt of Western Australia

2010 ◽  
Vol 61 (8) ◽  
pp. 601 ◽  
Author(s):  
C. P. D. Borger ◽  
G. P. Riethmuller ◽  
A. Hashem
Keyword(s):  
Seed Production ◽  
Crop Rotation ◽  
Western Australia ◽  
Plant Density ◽  
Cropping System ◽  
Soil Disturbance ◽  
Grass Species ◽  
Competitive Effect ◽  
Minimum Tillage ◽  
C4 Grass

Enteropogon ramosus is a native, perennial, C4 grass species found within the wheatbelt of Western Australia. Emergence, survival, seed production and seed dormancy of E. ramosus was investigated in a continuous pasture rotation, a pasture–minimum tillage wheat rotation, and a pasture–minimum tillage wheat rotation where a cultivation event at the beginning of the pasture year was used to kill all E. ramosus plants. The results indicated that E. ramosus could germinate throughout the year, although plant density (ranging annually from 0 to 17 plants m−2) was lowest in conditions of low rainfall (summer–autumn drought). Seed production (estimated from seed head production, r = 91.7, P < 0.001) ranged from 0 to 2274 m–2 and was greatest in spring, in the continuous pasture rotation. Seed germinability reached 80–89%, following an initial 3 months of dormancy directly after seed production. Cultivation at the beginning of the pasture-crop rotation killed all plants, reduced emergence and prevented seed production for the 2-year period of the experiment. Soil disturbance from minimum tillage crop sowing reduced but did not eliminate E. ramosus plants. As a result, E. ramosus grew throughout the year in the minimum tillage cropping system. Further research is required to determine the competitive effect of E. ramosus on crop growth.

Emergence, survival, biomass production, and seed production of Chloris truncata (windmill grass) in the Western Australian wheatbelt

2011 ◽  
Vol 62 (8) ◽  
pp. 678 ◽  
Author(s):  
C. P. D. Borger ◽  
G. P. Riethmuller ◽  
A. Hashem
Keyword(s):  
Seed Production ◽  
Biomass Production ◽  
Plant Density ◽  
Cropping Systems ◽  
Cropping System ◽  
Early Summer ◽  
Grass Species ◽  
Seed Germinability ◽  
Plant Emergence ◽  
Western Australian

Chloris truncata is a C4 grass species, native to Australia. Within the wheatbelt of Western Australia (WA), it is a weed of grain cropping systems and a beneficial forage species within pasture systems. Plant emergence, density, survival, biomass production, seed production, and seed germinability were investigated, in pasture or cropping systems, at two trial sites (in Merredin, WA) over two years (from 2007 to 2009). Chloris truncata predominantly emerged and set seed during spring and early summer. This species is usually referred to as a short-lived perennial, and could survive for >14 months, but predominantly grew as a spring/summer annual in the WA wheatbelt. Maximum plant density, biomass, and seed production were, respectively, 4.2–28.2 plants/m2, 8.3–146.1 g dry biomass/m2, and 3325–61 383 seeds/m2, depending on location. Cohorts emerging in spring produced more seeds than those that emerged during other seasons. Average seed germinability reached a maximum of 62%, following an initial 3–4-month period of dormancy. There are few herbicides to control plants growing within the winter/spring annual grain crops, and so further research into increased crop competitive ability is required to reduce growth of spring cohorts and potentially reduce seed set. However, the biomass produced by C. truncata (range 0–1460 kg/ha) can be used as forage in a pasture system, or over the summer/autumn feed gap in a cropping system.

Incidence of root and hypocotyl diseases in lupin crops in Western Australia between 1986 and 2005

2010 ◽  
Vol 61 (3) ◽  
pp. 241 ◽  
Author(s):  
G. J. Thomas ◽  
W. J. MacLeod ◽  
M. W. Sweetingham
Keyword(s):  
Crop Rotation ◽  
Western Australia ◽  
Root Rot ◽  
Plant Density ◽  
Management Systems ◽  
Sowing Depth ◽  
Root Rots ◽  
The Past ◽  
Predominant Pathogen ◽  
Growing Region

Three separate surveys were carried out in commercial lupin crops in the major lupin growing region of Western Australia in 1986, 1990, and 2004–05. In total, 333 sites were sampled and plants assessed for the incidence and cause of root and hypocotyl rots. Measurements were made of plant density and sowing depth at all sites. In all surveys, root rot was more common than hypocotyl rot. Root rot occurred in more than 95% of sites in each survey; however, a greater proportion of sites had high levels of root rot in early surveys. The incidence of root rot within sites decreased from an average of 34.9% in 1986 to 10.2% in 2004–05. Hypocotyl rot incidence varied among surveys, incidence of infected paddocks, and within-paddock incidence was greatest in the 1990 survey. Hypocotyl rot incidence was lowest in the 2004–05 survey. Rhizoctonia solani and Pleiochaeta setosa were commonly isolated from root lesions and R. solani was the predominant pathogen isolated from hypocotyl lesions. Analysis of the R. solani isolates by pectic zymogram showed that the ZG3 strain was most regularly isolated from roots and hypocotyls. This series of surveys indicates that the incidence of root rots in commercial lupin paddocks in Western Australia has decreased dramatically over the past 20 years; however, root rot still occurs in most paddocks regardless of soil type, location, crop rotation, and management systems.

Effect of nitrogen fertilizer rate, herbicide rate, and soil disturbance at seeding on the productivity of a wheat-pea rotation

2007 ◽  
Vol 87 (2) ◽  
pp. 241-253 ◽  
Author(s):  
R. M. Mohr ◽  
D. A. Derksen ◽  
C. A. Grant ◽  
D. L. McLaren ◽  
M. A. Monreal ◽  
...  
Keyword(s):  
Nitrogen Fertilizer ◽  
Plant Density ◽  
Cropping System ◽  
Triticum Aestivum L ◽  
Soil Disturbance ◽  
Fertilizer Rate ◽  
N Losses ◽  
High Soil ◽  
N Removal ◽  
Nitrogen Fertilizer Rate

Rotational productivity is a function of the rotational crops and their interactions, as well as the management employed. Understanding the functioning of the overall production system, as well as its component parts, may contribute to improved management. Effects of nitrogen fertilizer rate (25, 50, 75, 100 kg N ha-1 as urea) and herbicide rate (66 or 100% of recommended) applied to wheat, and of the level of soil disturbance at seeding, on the productivity and N status of a 2-yr rotation of spring wheat (Triticum aestivum L.) and field pea (Pisum sativum L.) were assessed over two rotation cycles at two locations in southwestern Manitoba. Management factors typically acted independently to influence the cropping system. In both wheat and pea, high soil disturbance at seeding reduced or tended to reduce plant density in most site-years, resulting in reduced yields in about half of site-years. In 2 site-years where weed pressure was high, wheat yields for high disturbance treatments were less than 60% of low disturbance seeding, demonstrating the importance of adequate plant stands under sub-optimal growing conditions. The herbicide rate applied to wheat had few significant effects on wheat and pea. In most site-years, N fertilization had limited or negative effects on wheat yields due partly to relatively high soil NO3-N levels. Soil NO3-N levels declined over the years of the study, suggesting that N contributions from peas did not exceed crop N removal and/or N losses from the wheat-pea rotation. The N rate applied to wheat typically did not affect pea yields. Key words: Wheat, pea, rotation, herbicide, nitrogen, soil disturbance

Seed production from three annual species of Trifolium on sandy soils in the wheat belt of Western Australia

1969 ◽  
Vol 9 (36) ◽  
pp. 92 ◽  
Author(s):  
GB Taylor ◽  
RC Rossiter
Keyword(s):  
Soil Moisture ◽  
Seed Production ◽  
Western Australia ◽  
Plant Density ◽  
Subterranean Clover ◽  
Soil Conditions ◽  
Seeding Rate ◽  
Relative Water ◽  
Plant Densities ◽  
Seed Yields

Seed production and persistence of subterranean, cupped, and rose clovers were examined over a period of three years in undefoliated swards, at several plant densities, in the wheat belt of Western Australia. Subterranean clover, although earlier flowering, was outyielded by the other two species in the two driest years. No major differences were found between species in relative water content of leaves during periods of soil moisture deficit. Moreover, species differences in soil moisture exploitation were small. A high proportion of inflorescences failed to set seed in subterranean clover. This reproductive defect, which is associated with restricted inflorescence burial due to dry soil conditions, was thought to be the main reason for the poorer seed yield in this species. Despite low seed yields in the establishment year, plant density after the first year did not seriously limit seed yields, even at the lowest seeding rate, in any of the three species.

scholarly journals A Comprehensive Study of Orchid Seed Production Relative to Pollination Traits, Plant Density and Climate in an Urban Reserve in Western Australia

Diversity ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 123 ◽  
Author(s):  
Mark C. Brundrett
Keyword(s):  
Seed Production ◽  
Western Australia ◽  
Fruit Set ◽  
Plant Density ◽  
Resource Competition ◽  
Higher Plant ◽  
Trade Offs ◽  
Terrestrial Orchids ◽  
Plant Densities ◽  
Disturbance Tolerance

The pollination of 20 common terrestrial orchids was studied in a 60-ha urban banksia and eucalypt dominated woodland in Western Australia. Five years of data (24,000 flowers, 6800 plants) measured fruit set relative to floral areas, capsule volumes, climate, phenology, pollination mechanisms, disturbance tolerance and demography. Pollination varied from 0–95% of flowers, floral displays from 90–3300 mm2 and capsules from 15–1300 mm3 per spike. Pollination traits strongly influenced outcomes, with self-pollination highest (59—95%), followed by sexually deceptive autumn or winter-flowering (18–39%), visual deception (0–48%) and sexually deceptive spring-flowering (13–16%). Pollination was limited by drought in autumn or spring and cool winter temperatures. Some orchids were resilient to drought and one formed seed after the leaves withered. Plant density had the greatest impact on fruit set for orchids forming large groups, especially for sexually deceptive pollination. Consequently, small group average (SGA) pollination was up to 4× greater than overall averages and peak seed production occurred in the best locations for genetic exchange and dispersal. SGA rates and seedpod volumes were strongly linked to clonality, but not to demographic trends. Resource competition limited flowering at higher plant densities and competition within spikes resulted in smaller, later-forming seedpods. Pollination data from co-occurring common orchids identified five evolutionary trade-offs linked to pollination, provided baseline data for rare species and revealed impacts of changing climate.

APPLICATION OF THE INTENSIVE CROP GROWING TECHNOLOGIES IN CROP ROTATION IS THE STABILITY CONDITION OF THE HUMUS CONTENT OF SOIL

1970 ◽  
pp. 52-56
Author(s):  
V. А. Shchedrin
Keyword(s):  
Soil Fertility ◽  
Crop Rotation ◽  
Humus Content ◽  
Arable Land ◽  
Weighted Average ◽  
Cropping System ◽  
Investment Project ◽  
Crop Rotations ◽  
High Productivity ◽  
Labile Phosphorus

In OOO “Dubovitskoe” which was organized in 2006 as investment project of the AO “Shchelkovo Agrokhim” for 2010 – 2012 three advanced crop rotations have been developed. Before their introduction the grain crops fraction in the cropping system was 62%, then it fell to 49%. At the same time the portion of raw crops increased from 15 to 20%, legumes from 6 to 8%, others (buckwheat, grain maize, etc.) - up to 23%. As of 2017, the crops of leguminous crops have increased noteworthily. There are two predominant soil types here heavy clay loam podzolized chernozem (6615 ha) and grey forest soil (856 ha). Weighted average indicators (as of 2017): humus content in the soils of arable land is 5, 34%; acidity pH is 4.92; labile phosphorus - 111.8 mg / kg soil; exchange potassium - 144 mg / kg soil. The coefficient of the soil fertility in the enterprise (weighted average) is 0.66. This means that maintaining and increasing the soil fertility for arable land of the enterprise is critical task. As a result of the research, it has been established that the technologies introduced in the crop vegetation management (CVS) in the crop rotation conditions ensure high productivity of cultivated crops and stability of humus content in soils as an energy basis and a guarantor of increasing fertility. The indicators of the labile phosphorus Р205 and exchange potassium К20 in the soils depending on the crop rotation vary from a certain decrease to expressed steady growth. Therefore it is necessary to specify seeding rates based on actual data. Sustainable soil acidification in the crop rotations under crop cultivation in OOO “Dubovitskoe” it is the result of the acid feterlizers high rates application, during studying period did not carried out required agromelioration with calcium contenting elements.

Tillage intensity and crop rotation affect weed community dynamics in a winter wheat cropping system

2001 ◽  
Vol 81 (4) ◽  
pp. 805-813 ◽  
Author(s):  
R. E. Blackshaw ◽  
F. J. Larney ◽  
C. W. Lindwall ◽  
P. R. Watson ◽  
D. A. Derksen
Keyword(s):  
Winter Wheat ◽  
Crop Rotation ◽  
Community Dynamics ◽  
Cropping System ◽  
Conventional Tillage ◽  
Amaranthus Retroflexus ◽  
Zero Tillage ◽  
Downy Brome ◽  
Canada Thistle ◽  
Long Term Study

Development of improved weed manage ment systems requires more knowledge on how various weed species respond to changing agronomic practices. A long-term study was conducted to determine weed population responses to various tillage intensities and crop rotations in a winter wheat (Triticum aestivum L.) dominated cropping system. Weed density and species composition differed with tillage, rotation, year, and date of sampling within years. Weed community dynamics were most affected by year-to-year differences in environmental conditions, followed by crop rotation, and then tillage intensity. Russian thistle (Salsola iberica Sennen & Pau) and kochia [Kochia scoparia (L.) Schrad.] densities increased in years of low rainfall and above average temperatures. Winter annual weeds such as downy brome (Bromus tectorum L.) and flixweed [Descurainia sophia (L.) Webb ex Prantl], as well as the perennial weed dandelion (Taraxacum officinale Weber in Wiggers), increased in years where higher than average rainfall was received in fall or early spring. Continuous winter wheat facilitated a dense downy brome infestation to develop over time. Trifluralin is not efficacious on stinkweed (Thlaspi arvense L.) or Canada thistle [Cirsium arvense (L.) Scop.] and its use in canola resulted in an increase in these species in a winter wheat-canola rotation. Total weed densities were often greater in zero tillage than in either minimum or conventional tillage. Russian thistle, downy brome, kochia, and redroot pigweed (Amaranthus retroflexus L.) were associated with zero tillage while wild buckwheat (Polygonum convolvulus L.), lamb’s-quarters (Chenopodium album L.), flixweed, and wild mustard (Sinapis arvensis L.) were associated with conventional tillage. Perennials such as dandelion and perennial sowthistle (Sonchus arvensis L.) were associated with zero tillage but Canada thistle was associated with conventional tillage. Information will be utilized to implement more effective weed management programs in winter wheat production systems. Key words: Conservation tillage, fallow, multivariate analyses, weed populations, weed shifts, zero tillage

scholarly journals Signs of wildlife activity and Eucalyptus wandoo condition

2014 ◽  
Vol 36 (2) ◽  
pp. 146 ◽  
Author(s):  
T. L. Moore ◽  
M. D. Craig ◽  
L. E. Valentine ◽  
G. E. St J. Hardy ◽  
P. A. Fleming
Keyword(s):  
Western Australia ◽  
Mixed Model ◽  
Soil Health ◽  
Ground Cover ◽  
Soil Disturbance ◽  
Habitat Characteristics ◽  
Foraging Effort ◽  
Terrestrial Vertebrates ◽  
Eucalyptus Wandoo ◽  
Tree Condition

Soil disturbance by terrestrial vertebrates when foraging for food and shelter is not only a sign of activity but an ecosystem function required for soil health. Many forests and woodlands worldwide are currently showing signs of a decline in condition due to various causes. Eucalyptus wandoo, endemic to south-west Western Australia, has undergone a decline in condition over the last decade. This paper explores the influence of E. wandoo condition (e.g. loss of canopy) and the associated changes in the habitat (e.g. changes in leaf litter and bare ground cover) on the foraging activities and soil disturbance by vertebrates. The number of diggings and scats, a representation of the foraging effort by some vertebrates, were recorded in Dryandra Woodland and Wandoo Conservation Park, Western Australia. Mixed-model ANOVAs were used to explore the relationships between the number of scats and diggings with tree and habitat characteristics. More vertebrate diggings and scats were recorded beneath healthier E. wandoo trees. Diggings and scats were also correlated with time since last fire and seasonal differences, with more time since last fire and wetter months related to more diggings and scats. Changes in foraging effort, or turnover of soil by vertebrates, could be a result modification of the level of soil turnover and alter many ecosystem services such as tree recruitment and nutrient cycling, in turn altering the habitat quality and even tree condition itself.

scholarly journals Influence of crop rotation, tillage, and management inputs on weed seed production

Weed Science ◽  
1999 ◽  
Vol 47 (2) ◽  
pp. 175-183 ◽  
Author(s):  
George O. Kegode ◽  
Frank Forcella ◽  
Sharon Clay
Keyword(s):  
Seed Production ◽  
Crop Rotation ◽  
Crop Production ◽  
Conservation Tillage ◽  
Farming Systems ◽  
Crop Rotations ◽  
Weed Seed ◽  
Weed Species ◽  
Weed Seeds ◽  
Ridge Tillage

Approaches to crop production that successfully reduce weed seed production can benefit farming systems by reducing management inputs and costs. A 5-yr rotation study was conducted in order to determine the effects that interactions between crop rotation, tillage, and amount of herbicide and fertilizer (management inputs) have on annual grass and broad-leaved weed seed production and fecundity. There were 10 crop rotation and tillage system combinations and three levels of management inputs (high, medium, and low). Green and yellow foxtail were the major weed species, and together they yielded between 76 and 93% of collected weed seeds. From 1990 to 1994, average grass weed seed productions were 7.3 by 103, 3.7 by 1036.1 by 103and 5.7 by 103seeds m−-2, whereas average broad-leaved weed seed productions were 0.4 by 103, 0.4 by 103, 1.4 by 103, and 0.4 by 103seeds m−-2in crop rotations using conventional tillage (moldboard plow), conservation tillage, no tillage, and ridge tillage, respectively. Crop rotations using conventional or ridge tillage consistently produced more grass and broad-leaved weed seeds, especially in low-input plots. There was little difference in weed seed production among input levels for crop rotations using conservation tillage. Comparing rotations that began and ended with a corn crop revealed that by increasing crop diversity within a rotation while simultaneously reducing the amount of tillage, significantly fewer grass and broad-leaved weed seeds were produced. Among the rotations, grass and broad-leaved weed fecundity were highly variable, but fecundity declined from 1990 to 1994 within each rotation, with a concomitant increase in grass and broad-leaved weed density over the same period. Crop rotation in combination with reduced tillage is an effective way of limiting grass and broad-leaved weed seed production, regardless of the level of management input applied.

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