Weeds and weed management on arable land [Elektronisk resurs] an ecological approach / Sigurd Håkansson.

• Preface -- Background and Focus of the Book -- Guide to Central Topics Covered in Chapters 1–13 -- Acknowledgements -- 1. Introduction -- Comments on the book -- The concept of weeds -- Some definitions and descriptions -- 2. Classification of Plants Based on Traits of Ecological Significance -- Life Form, Growth Form, Lifespan -- Raunkiær´s Life-form System -- Classification Using the Term ‘Life Form’ in a Wide Sense -- Overview -- Seed banks and germination of weed seeds in the soil in different seasons -- Classification of weeds -- Annuals -- Biennials, monocarpic perennials (pluriennials) -- Stationary perennials -- Creeping perennials -- Perennials with other or modified regenerative structures -- Classification Problems with Species Distributed over Wide Geographical Areas -- 3. Annual and Perennial Crops -- 4. Weed Communities Looked Upon as Early Stages in Secondary Vegetation Succession -- 5. Weeds with Diverse Life Forms in Various Types of Crops -- Overview in a North-European Perspective -- Comments on crops and cropping systems in the Nordic countries -- Relationships of weeds to crops largely depend on times and types of tillage -- Changes in tillage and other measures selectively affecting weeds -- Scandinavia and Finland – Field Surveys and General Observations -- Summer annuals -- Winter annuals (facultative) -- Biennials (monocarpic perennials) -- Stationary perennials -- Creeping perennials with stolons or prostrate above-ground stems -- Creeping perennials with rhizomes sensitive to soil cultivation -- Creeping perennials with rhizomes tolerant to soil cultivation -- Creeping perennials with plagiotropic thickened roots -- Changes in weed flora after the 1940s -- Northern and Southern Europe -- Global Perspectives -- Life forms of weeds -- C4 plants among arable weeds -- Plants of different families as arable weeds -- Parasitic weeds -- Which Crops in a Crop Sequence Favour the Population of a Specified Weed? -- 6. Germination, Emergence and Establishment of Crop and Weed Plants -- Introduction -- Seed Dormancy and Germination and Soil Seed Banks -- From Seed Swelling to Plant Establishment -- Experiments Exemplifying Influences on Plant Emergence and Establishment -- Experimental conditions -- Dry matter losses before plant emergence -- Plant establishment -- Examples representing cultivated plants -- An example representing annual weeds -- Plant emergence and early mortality among emerged plants -- Overview of Factors Influencing Plant Emergence and Establishment -- Seed size and depth location in soil, light intensity and temperature -- Water conditions in the soil -- Soil Moisture Content – Seed Germination – Plant Growth -- Effects of the relative time of emergence of neighbouring plants in a cereal stand -- Sowing depth and growth of crop and weed plants -- Sowing depth – principles regarding crop and soil in the field -- Seedbed Preparation and Sowing Considering Relative Times of Crop and Weed Emergence -- Ordinary spring sowing – examples regarding different soils -- ‘Delayed’ spring sowing -- Autumn sowing -- Effects of rolling -- Late Emergence of Weeds – Consequences in Differently Competitive Crops -- Fertilizer Placement -- 7. Competition in Plant Stands of Short Duration -- The Concept of Competition -- General -- Impacts of allelochemicals – allelopathy -- Competition and Phenotypic Plasticity -- Intraspecific and Interspecific Competition -- Relative Competitiveness -- Competition as Influenced by Plant Spacing and Relative Time of Emergence -- Effects of Plant Density -- General characteristics of production–density relationships -- Production in crop stands -- Yield in different crops -- Plasticity of crop plants and quality of harvested products – examples -- Crop–weed interactions -- Effects of the Spatial Distribution of Plants -- Theory -- Row spacing and plant distribution in the row -- Effects of the Relative Time of Emergence -- General -- Experiments with cereals and weeds -- Competition Modifies the Response of Plants to Various Factors – Examples -- Response to nitrogen -- Growth of plants from seeds of different sizes placed at various depths in the soil -- Regrowth after breakage and burial of regenerative structures of perennial weeds with an example of nitrogen influences -- Response to temperature -- Response to infections – example, discussion -- 8. Weed Flora and Plant Adaptation to Environment and Competitive Conditions -- Extremely Complex Causalities -- Changes in the Weed Flora as Related to Increased Fertilizer Use – Some Scandinavian Examples -- Competitive Conditions in Different Crops -- Competitive Ability of Weeds -- The importance of plant traits -- Reasons for variation often hard to identify in the field -- Phenotypic Adaptation to Environments Exemplified by Weeds in Lawns -- 9. Measurements of Competition and Competitiveness in Plant Stands of Short Duration -- Introduction: Stands of Short and Long Duration -- Unit Production Ratio (UPR) -- UPR in Measuring the Relative Competitiveness of Plants -- Use of UPR and Percentage (or Relative) UPR – Examples -- Selective Effects of Competition within Heterogeneous Components in Mixed Stands -- Determination of Production–Density Relationships in Mixed Stands -- Reference Models -- Reference Models in Evaluating Relationships and Indices Aimed at Characterizing Relative Competitiveness – Examples -- Plant Growth as Influenced by Density and Relative Time of Emergence -- Growth Reduction Rate (RR) -- Changes in UPR and Percentage UPR Over Time – Comparing Growth Rates and Competitive Conditions in Mixed Stands -- The Relative Crowding Coefficient (k) and the Relative Yield Total (RYT) Observed Over Time -- ‘Critical Periods’ of Weed Control in a Crop Stand -- Early Predictions of Yield Loss Due to Weeds -- 10. Soil Tillage Effects on Weeds -- Introduction -- Uncultivated land brought into cultivation -- Selective effects of tillage -- No more tillage than necessary -- Tillage Effects on Weed Seeds in the Soil Seed Bank -- Tillage Effects on Seedlings -- Seedlings of annuals -- Seedlings of perennials -- Tillage Effects on Perennial Plants with Fully Developed Vegetative Structures -- General statements -- Plants with low tolerance to tillage -- Plants with higher tolerance to tillage -- Factors affecting the response of growing plants to tillage – an overview -- Perennials with rhizomes or plagiotropic roots -- Undisturbed growth and response to a single soil operation -- Response to repeated tillage -- A Cropping System Approach to Effects of Tillage -- Periods when the field is free of growing crops -- Seedbed preparation – effect on weed seeds in the soil -- Tillage considering the growth rhythm of Elymus repens -- Tillage between harvest and winter -- Tillage between harvest and autumn sowing -- Harrowing and hoeing in growing crops -- Reduced Tillage -- 11. Chemical Weed Control as an Element in the Cropping System -- Introductory Comments -- Intended Effects of Herbicides -- The importance of a uniform herbicide distribution -- Joint effects of herbicides and competition in a crop stand -- A reduced herbicide dose – a proportionally less reduced effect -- Herbicide application techniques -- Compounds mixed with herbicides in commercial formulations or added to the spray liquid -- Systemic and contact herbicides -- Pre-emergence soil application of herbicides -- The persistence of herbicides -- Measurements of herbicide effects -- Unintended Effects of Herbicides -- General -- Toxicity -- Persistence – movements -- Harm of pesticide pollution -- Problems in handling herbicides -- Resistance in response to recurrent use of similar herbicides -- Herbicide and Tillage Problems in Efforts to Develop Sustainable Cropping Systems -- 12. Special Management Measures -- Various Methods of Mechanical or Physical Weed Control -- Cover Crops and Mulches -- Harvesting – Timing and Methods -- Combine harvesting -- Harvesting of root crops -- Breeding for Increased Competitive Ability of Crops -- Biological Control -- 13. Important Points for Understanding the Occurrence and Rational Management of Weeds -- General Views -- Illustrations: Case Studies in Sweden -- Allium vineale – a bulb-forming perennial -- Introductory remarks -- The study and its results -- Morphology and reproduction (Fig. 66) -- Annual rhythm of growth and development (Fig. 67a) -- Population structure -- Sensitivity to tillage -- Occurrence in autumn-sown cereals -- Growth in years with and without spring tillage (Table 44) -- Occurrence on heavier and lighter soil and in winter rye and winter wheat -- Interpretation of results -- Effects of herbicides -- Occurrence and management of A. vineale discussed on the basis of the investigation -- Sinapis arvensis – a summer annual -- Avena fatua – a summer annual in the Nordic countries -- Elymus repens and Agrostis gigantea – perennial rhizomatous grasses -- Cirsium arvense – a perennial dicot with plagiotropic roots -- References -- Species Index -- Subject Index. 

• This book deals with the appearance and management of plants with different traits occurring as weeds on arable land. It describes and discusses matters and relationships that are important as a basis for understanding the varying occurrence of weeds in different crops and cropping systems and, at the same time, the response of different weeds to specified management measures for integrated weed management. The following topics are covered: ecological plant classification, annual and perennial crops, weed communities in vegetation succession, diverse life forms, germination, emergence and establishment, competition, plant adaptation to environmental conditions, soil tillage effects on weeds, chemical weed control, special management measures (including cover crops, mulches, biological control, plant breeding and physical weed control), and understanding the occurrence and rational management of weeds. This book will be of interest to teachers, postgraduate and undergraduate students and weed science researchers. 

Ämnesord

Ogräs  (sao)

Ekologi  (sao)

Weeds  (LCSH)

Weeds  -- Ecology (LCSH)

Weeds  -- Control (LCSH)

Weeds  -- Sweden (LCSH)

Weeds  -- Ecology -- Sweden (LCSH)

Weeds  -- Control -- Sweden (LCSH)

weeds  (agrovoc)

weed control  (agrovoc)

weeding  (agrovoc)

herbicides  (agrovoc)

tillage  (agrovoc)

environmental impact  (agrovoc)

scandinavia  (agrovoc)

Ecology  (LCSH)

Weeds  (LCSH)

Indexterm och SAB-rubrik

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Klassifikation

SB611 (LCC)

632/.5 (DDC)

Qdd/DR (kssb/7)

Qddb/DR (kssb/7)

Qdd (kssb/7)

Qddb (kssb/7)