Weed Science Commons^™

Sequential Injection Analysis: A Powerful Tool For Routine Soil And Plant Laboratories, A. R. A. Nogueira, F. V. Silva, M. Y. Kamogawa, G. B. Souza, L. F. M. Ferraz

IGC Proceedings (1977-2023)

Sequential injection analysis (SIA) present attractive characteristics for analyses in large scale. In SIA the analytical determination can be performed automatically reducing the number of steps usually involved in a chemical analysis. In order to demonstrate the advantages found in the implementation of a SIA procedure in a laboratory dedicated to routine analyze, the determination of volatile nitrogen in silage and soil samples has been performed. The nitrogen content was determined after NH₃ on-line separation in alkaline conditions by using a gaseous diffusion or a pervaporation unit for liquid-liquid separation. An ammonium tubular selective electrode detector was used for …

A Chance-Constrained Linear Model For Beef Policy Analysis, Claudio F. Machado, S. T. Morris, C. Dake, A. Macdonald, I. M. Brookes, F. Di Croce, F. Gonzalez, N. J. Auza

IGC Proceedings (1977-2023)

A simple linear model to evaluate different bull beef policies (BBP) by incorporating the stochastic nature of pasture yield from a database with separate chance constraints (ChC) was developed. A 100 ha farm was used, and the model was run with five different BBP and set to different levels of pasture yield risk to maximise production.ha^-1.year^-1. Summer was the most risky season, and the optimum mix of policies changed at different levels of risk. Chance constraint represents an interesting and simple alternative to include pasture variation into a linear model.

Mapping Nitrogen Fixing Shrubs In Dry Unimproved Tussock Grassland, C. C. Boswell, W. L. Lowther, P. D. Espie

IGC Proceedings (1977-2023)

Global Positioning System (GPS) was used to both map the positions of individual nitrogen-fixing shrub plants and record individual plant height and breadth dimensions, within a small catchment of dry sub-humid unimproved short tussock grassland. The distributions of different species of shrubs varied with different landscape units within the catchment. The information will provide the base data for a first approximation of the role of the shrubs in the nitrogen balance of the ecosystem, which is pivotal to the sustainability of pastoral farming in the tussock grasslands.

Repeated Measurement Analyses Of Forages In Cropping Systems, A. R. De Freitas, O. Primavesi, L. De A. Corrêa, A. C. Primavesi, E. B. Pott, A. Dos S. Mascioli

IGC Proceedings (1977-2023)

Repeated measurements (RM) are common in forage experiments. The data used in this study were accumulated ammonia losses by volatilization (N) and dry matter production (DM) of Cynodon dactylon cv. Coastcross pasture from an experiment in blocks with five levels of urea: 0, 25, 50, 100 and 200 kg of N ha^-1, applied in five periods (cuttings). For N, RM were the averages of cuttings and nine days of observation. The F test for the hypothesis of no effect for Period and Level x Period interaction (DM) and for Days and Level x Days interaction was not affected …

Farmwi$E: A Flexible Decision Support Tool For Grazing Systems Management, A. D. Moore

IGC Proceedings (1977-2023)

CSIRO's new FarmWi$e decision support tool provides a framework that permits pasture-livestock systems and management policies of any level of complexity to be simulated. An underlying "modelling protocol" permits other simulation models to be added, further extending its domain of applicability. Management policies are specified in FarmWi$e by means of rules that govern when, whether and how management events take place. An example of the use of FarmWi$e to study lamb production is given.

Sward Height; Visual Estimate Compared With Plate Meter Height, W. B. Bryan, E. C. Prigge, E. L. Nestor, O. J. Gekara, M. A. Schettini

IGC Proceedings (1977-2023)

Sward height (SH) is widely used in pasture research and farm practice to evaluate pasture conditions. Visual estimates can take less time than actual measurements. This study compared visually estimated SH, of continuously grazed cool-season permanent pasture with plate meter height. Weekly estimates, by five people, were made on 12, 0.75 to 1 ha fields, grazed at two intensities. Paired data (visual estimate and plate meter height) were subjected to variance and covariance analyses and prediction equations were developed. Average visual height accounted for 86% of the variability in plate meter height. Inclusion of other sources of variability in the …

Sources Of Error For Ultrasonic Measurements Of Steer Compositional Traits In Grazing Studies, Glen E. Aiken, F. M. Rouquette Jr., A. H. Brown Jr.

IGC Proceedings (1977-2023)

Real-time ultrasound technology has potential use for measuring compositional traits in grazing studies. Sources of error with this application must be identified for designing experiments with adequate precision to determine treatment effects. A study was conducted to evaluate breed type (Angus x Brahman, AB; Simmental x [Angus x Brahman], SAB; Simmental x [Brahman x Hereford], SBH), initial body weight, and initial ultrasonic measures as sources of experimental error in the analyses of external fat (EF) depths and longissimus dorsi (ribeye) areas (LDA). Steers were ultrasonically scanned at the initiation and conclusion of a grazing study that examined stocking rate effects …

Grassland Management And Animal Product Quality, G. W. Sheath, J. B. Coulon, Q. A. Young

IGC Proceedings (1977-2023)

The expectations of consumers ultimately determine the specification of product quality; and grassland systems produce a wide range of animal-based products. Therefore, to provide focus, this paper deals only with food products that are destined for markets that exhibit strong discretionary choice. Quality expectations of consumers have traditionally been based on product attributes such as taste, freshness, nutritional value and appearance, but customer expectations are expanding to encompass food safety, environmental care, animal welfare and biotechnologies.

Grassland forages and their management influence the intrinsic sensory properties of food. A dairy products case study is presented, indicating that pasture species and …

Priority Setting And Funding Of Agricultural Research, M. Petit

IGC Proceedings (1977-2023)

Agricultural research funding amounts and modalities have been profoundly transformed in recent years in many countries. For instance, competitive funding has become the norm rather than the exception in most countries and funding sources have been greatly diversified. In addition, in some major countries, the private sector has become a major actor In agricultural research, both as a funder of research and as a provider research results. This poses a major challenge to public research institutions, which remain the major agricultural research actors and employers of researchers in most countries. With these changes in funding, formal procedures for research priority-setting …

Dilemma: Increase In Human Food Production Or Use Of Grasslands For Environmental And / Or Social Purposes, A. D. Meister

IGC Proceedings (1977-2023)

In the title for this paper we find three major objectives: to feed the world, sustain the environment and provide resources for social purposes, and a dilemma. Even though the word ‘dilemma’ usually implies choice between undesirable alternatives, it is obvious that the alternatives here are not undesirable. Is the dilemma then, that we can only do one at the time, or that the consequences of favouring one over the other can lead to undesirable outcomes? It is my opinion that we are talking about the latter interpretation. It is the foreclosing of options by allowing one objective to dominate …

The Development And Prospect Of Chinese Grassland Economic System, Fuzeng H.

IGC Proceedings (1977-2023)

China is a country with an old agriculture civilization of the world. The arrangement of the crop and pasture area had developed from Han and Tang dynasty. (From A.C 206.to AD 907). Chinese livestock economic had undergone the winding development for a thousand years of feudal society, however, It still belong to a phase of the loose private ownership. From 1949 when The People's Republic of China was founded, the pasture was nationalized and collective management. Since 1980s, the planned economic changed into the market economic gradually. The pasture was public ownership, but management by contract, paid utilization and unchanged …

Contextual Factors In The Management Of Common Grazing Lands: Lessons From Mongolia And Northwestern China, R. Mearns

IGC Proceedings (1977-2023)

Seen in a global perspective, pastoral development is now increasingly motivated by social and environmental objectives rather than by production- or output-orientated objectives. Attention is shifting towards a broader concern with sustainability, both of grasslands, and of the livelihoods of those who rely on them (de Haan et al, 1997, Fratkin and Mearns forthcoming). Quite how these twin sustainability objectives may be achieved in particular contexts, however, is an empirical question. Drawing on examples from a diverse range of natural grassland-based livestock production systems under economic transition in Mongolia and northwestern China, this summary paper aims to show how an …

De-Intensification Of Grasslands: Understanding The Processes To Find The Balance, K. C. Hodgkinson

IGC Proceedings (1977-2023)

There is a growing trend in Australia and other developed countries for deintensification of animal production from grasslands and for grasslands to be used for purposes other than livestock grazing. These shifts are occurring for a variety of reasons including unsustainable land management practices, environmental pollution, loss of conservation value, poor commodity prices and declining rural infra-structure and communities. In Australia, the shifts are under way in agricultural grasslands, where sown pastures occur in a matrix of semi-natural woodlands, but less so in the other three major natural grasslands that forms the arid and semi-arid rangelands.

The conversion of natural …

De-Intensification Of Grasslands: Current State And Trends, Michael Duru, Bernard Hubert

IGC Proceedings (1977-2023)

De-intensified use of grasslands, and more generally of the livestock systems they support, has been triggered by a growing sensitivity of citizens to environmental quality (nitrogen) and quality of animal products, and by the warnings addressed to political authorities by scientists about the environmental consequences of economic imbalances (decreasing biodiversity, drop in soil fertility, greenhouse effect), and in particular of food overproduction in Europe.

From an ecological standpoint, grassland de-intensification must be envisaged whenever the techniques implemented disrupt resource sustainability. The grassland resource itself may be at risk when a rate of vegetation offtake by herbivores that is incompatible with …

Cenchrus Setiger - Environmental Weed Risk Assessment 2022, Department Of Primary Industries And Regional Development, Western Australia

Environmental Weed Risk Assessments

Introducing new plants to an area may have both positive and negative effects on the environment, economy and community. To minimise the negative environmental impact of introducing new agricultural species, DPIRD conducts a risk assessment procedure based on widely accepted scientific standards. This report assesses Birdwood grass (Cenchrus setiger). Birdwood grass (Cenchrus setiger) is native to north Africa, India and Middle east. It arrived in Western Australia (WA) when seed was sent from India in the 1920s by Field Marshal Lord Birdwood to his son-in-law, a grazier, in northern WA (Petheram and Kok 1991). It is a tufted, perennial bunch …

Lotus Uliginosus - Environmental Weed Risk Assessment 2022, Department Of Primary Industries And Regional Development, Western Australia

Environmental Weed Risk Assessments

Introducing new plants to an area may have both positive and negative effects on the environment, economy and community. To minimise the negative environmental impact of introducing new agricultural species, DPIRD conducts a risk assessment procedure based on widely accepted scientific standards. This report assesses Greater lotus (Lotus uliginosus). Greater lotus (big trefoil, syn. Lotus pedunculatus) is a temperate perennial legume native to Europe, eastern Russia and northern Africa. It is used as a pasture species in New Zealand, the United States and Uruguay. In addition, there are about 100 000ha sown to greater lotus in coastal districts of New …

Macroptilium Bracteatum - Environmental Weed Risk Assessment 2022, Department Of Primary Industries And Regional Development, Western Australia

Environmental Weed Risk Assessments

Introducing new plants to an area may have both positive and negative effects on the environment, economy and community. To minimise the negative environmental impact of introducing new agricultural species, DPIRD conducts a risk assessment procedure based on widely accepted scientific standards. This report assesses Burgundy bean (Macroptilium bracteatum). Burgundy bean is a sub-tropical, short-lived perennial legume adapted to fertile, clay soils.

Prunus Persica - Environmental Weed Risk Assessment 2022, Department Of Primary Industries And Regional Development, Western Australia

Environmental Weed Risk Assessments

Introducing new plants to an area may have both positive and negative effects on the environment, economy and community. To minimise the negative environmental impact of introducing new agricultural species, DPIRD conducts a risk assessment procedure based on widely accepted scientific standards. This report assesses Peach (Prunus persica). The peach is a deciduous tree native to northwest China, where it was first domesticated and cultivated. Western Australia's stone fruit production of nectarines, peaches, plums and apricots is from the Perth Hills, Southwest and Gingin regions. The potential to grow low-chill stonefruit in the inland Pilbara is being evaluated.

Stylosanthes Scabra - Environmental Weed Risk Assessment 2022, Department Of Primary Industries And Regional Development, Western Australia

Environmental Weed Risk Assessments

Introducing new plants to an area may have both positive and negative effects on the environment, economy and community. To minimise the negative environmental impact of introducing new agricultural species, DPIRD conducts a risk assessment procedure based on widely accepted scientific standards. This report assesses Shrubby stylo (Stylosanthes scabra). Shrubby stylo (Stylosanthes scabra) is a shrubby, perennial legume, erect to suberect, with strong, woody stems, usually densely hairy and viscid, making them sticky under hot, dry conditions. It is a widespread and variable species, originating from South America and the Caribbean (Sousa Costa and Ferreira 1984) with two ecotypes identified …

Vicia Sativa - Environmental Weed Risk Assessment 2022, Department Of Primary Industries And Regional Development, Western Australia

Environmental Weed Risk Assessments

Introducing new plants to an area may have both positive and negative effects on the environment, economy and community. To minimise the negative environmental impact of introducing new agricultural species, DPIRD conducts a risk assessment procedure based on widely accepted scientific standards. This report assesses Vetch, common vetch (Vicia sativa). Common vetch is a sprawling, climbing annual legume which has been grown in the Middle east and Europe since ancient times. It is a versatile legume for pasture, green manure, hay/silage and grain. Two subspecies are recognized: narrow-leaved vetch (Vicia sativa subsp. nigra) and common vetch (Vicia sativa subsp. sativa). …

Avena Sativa - Environmental Weed Risk Assessment 2022, Department Of Primary Industries And Regional Development, Western Australia

Environmental Weed Risk Assessments

Introducing new plants to an area may have both positive and negative effects on the environment, economy and community. To minimise the negative environmental impact of introducing new agricultural species, DPIRD conducts a risk assessment procedure based on widely accepted scientific standards. This report assesses Avena sativa. Oats are a widely sown temperate cereal crop grown across the cereal growing areas of southern Australia and in temperate environments around the world. It is native to the Mediterranean Basin and Asia (Hussey et al. 2007) with the crop varieties most likely originating from wild types in the Middle East. Milled (rolled) …

Macroptilium Atropurpureum - Environmental Weed Risk Assessment 2022, Department Of Primary Industries And Regional Development, Western Australia

Environmental Weed Risk Assessments

Introducing new plants to an area may have both positive and negative effects on the environment, economy and community. To minimise the negative environmental impact of introducing new agricultural species, DPIRD conducts a risk assessment procedure based on widely accepted scientific standards. This report assesses Siratro, Atro (Macroptilium atropurpureum). Siratro (Atro) is a twining and climbing, perennial tropical legume.

Phoenix Dactylifera - Environmental Weed Risk Assessment 2022, Department Of Primary Industries And Regional Development, Western Australia

Environmental Weed Risk Assessments

Introducing new plants to an area may have both positive and negative effects on the environment, economy and community. To minimise the negative environmental impact of introducing new agricultural species, DPIRD conducts a risk assessment procedure based on widely accepted scientific standards. This report assesses Date palm (Phoenix dactylifera). The date Phoenix dactylifera is one of the oldest cultivated tree crops, thought to have been domesticated in Mesopotamia (now Iraq) more than 5000 years ago. The chief commercial production areas are in the Middle East and northern Africa. Date palm plants are diecious (i.e. either male or female), with only …

Lablab Purpureus - Environmental Weed Risk Assessment 2022, Department Of Primary Industries And Regional Development, Western Australia

Environmental Weed Risk Assessments

Introducing new plants to an area may have both positive and negative effects on the environment, economy and community. To minimise the negative environmental impact of introducing new agricultural species, DPIRD conducts a risk assessment procedure based on widely accepted scientific standards. This report assesses Lablab purpureus. Lablab purpureus is a herbaceous, forage annual legume with a vigorous trailing and twining habit used for grazing, forage conservation and as a break-crop.

Stylosanthes Hamata - Environmental Weed Risk Assessment 2022, Department Of Primary Industries And Regional Development, Western Australia

Environmental Weed Risk Assessments

Introducing new plants to an area may have both positive and negative effects on the environment, economy and community. To minimise the negative environmental impact of introducing new agricultural species, DPIRD conducts a risk assessment procedure based on widely accepted scientific standards. This report assesses Caribbean stylo (Stylosanthes hamata). Caribbean stylo (Stylosanthes hamata) is an annual or short-lived perennial herbaceous legume. Individual plants behave as self-regenerating annuals or biennials. In the Northern Territory up to 40% of plants persist from one wet season to the next (Cameron 2010), but this varies depending on the length of the dry season. It …

Triticum Aestivum - Environmental Weed Risk Assessment 2022, Department Of Primary Industries And Regional Development, Western Australia

Environmental Weed Risk Assessments

Introducing new plants to an area may have both positive and negative effects on the environment, economy and community. To minimise the negative environmental impact of introducing new agricultural species, DPIRD conducts a risk assessment procedure based on widely accepted scientific standards. This report assesses Wheat (Triticum aestivum). Wheat is an annual grass widely cultivated for its seed, a cereal grain which is a worldwide staple food. It is the major temperate cereal grown across the grain growing areas of southern Australia and in temperate and subtropical environments around the world. Wheat cultivation goes back to ancient times and seems …

Cenchrus Clandestinus - Environmental Weed Risk Assessment 2022, Department Of Primary Industries And Regional Development, Western Australia

Environmental Weed Risk Assessments

Introducing new plants to an area may have both positive and negative effects on the environment, economy and community. To minimise the negative environmental impact of introducing new agricultural species, DPIRD conducts a risk assessment procedure based on widely accepted scientific standards. This report assesses Kikuyu (Cenchrus clandestinus). Kikuyu (syn. Pennisetum clandestinum) is a creeping sub-tropical (C4) grass native to the highlands of east and central Africa (i.e. Kenya, Ethiopia) where it grows on deep, red loams of volcanic origin. Kikuyu forms a dense turf and is tolerant of heavy grazing and is widely used as a highly productive pasture …

Chamaecrista Rotundifolia - Environmental Weed Risk Assessment 2022, Department Of Primary Industries And Regional Development, Western Australia

Environmental Weed Risk Assessments

Introducing new plants to an area may have both positive and negative effects on the environment, economy and community. To minimise the negative environmental impact of introducing new agricultural species, DPIRD conducts a risk assessment procedure based on widely accepted scientific standards. This report assesses Wynn cassia, roundleaf cassia (Chamaecrista rotundifolia). Wynn cassis is an annual or short-lived, self-regenerating tropical legume.

Chloris Gayana - Environmental Weed Risk Assessment 2022, Department Of Primary Industries And Regional Development, Western Australia

Environmental Weed Risk Assessments

Introducing new plants to an area may have both positive and negative effects on the environment, economy and community. To minimise the negative environmental impact of introducing new agricultural species, DPIRD conducts a risk assessment procedure based on widely accepted scientific standards. This report assesses Rhodes grass (Chloris gayana). Rhodes grass (Chloris gayana) is a warm season or sub-tropical (C4) perennial grass which is both tufted and has stolons (runners). The degree of stoloniferous growth not only varies between varieties but can also vary between different environments and management practices. Vegetative growth is generally 30 to 100 cm in height, …

Citrus X Limon - Environmental Weed Risk Assessment 2022, Department Of Primary Industries And Regional Development, Western Australia

Environmental Weed Risk Assessments

Introducing new plants to an area may have both positive and negative effects on the environment, economy and community. To minimise the negative environmental impact of introducing new agricultural species, DPIRD conducts a risk assessment procedure based on widely accepted scientific standards. This report assesses Lemon (Citrus x limon). Lemons are part of the Citrus genus of small evergreen flowering trees and shrubs in the rue family, Rutaceae. They are native to Asia, primarily Northeast India (Assam), Northern Myanmar or China. Lemons are an important horticultural crop which is widely cultivated around the world. The Western Australian citrus industry primarily …