File Name: 50 types of weeds and pests .zip
- Comparative Performance of Different Plastic Films for Soil Solarization and Weed Suppression
- Insect pests of vegetables
- 17 Common Types of Weeds
- Guide for Authors
Comparative Performance of Different Plastic Films for Soil Solarization and Weed Suppression
A pest is any animal or plant harmful to humans or human concerns. The term is particularly used for creatures that damage crops, livestock, and forestry or cause a nuisance to people, especially in their homes. Humans have modified the environment for their own purposes and are intolerant of other creatures occupying the same space when their activities impact adversely on human objectives.
Thus, an elephant is unobjectionable in its natural habitat but a pest when it tramples crops. Some animals are disliked because they bite or sting; snakes , wasps , ants , bed bugs , fleas and ticks belong in this category.
Others enter the home; these include houseflies, which land on and contaminate food, beetles, which tunnel into the woodwork, and other animals that scuttle about on the floor at night, like cockroaches , rats and mice , which are often associated with unsanitary conditions.
Agricultural and horticultural crops are attacked by a wide variety of pests, the most important being insects , mites , nematodes and gastropod molluscs. The damage they do results both from the direct injury they cause to the plants and from the indirect consequences of the fungal, bacterial or viral infections they transmit.
Plants have their own defences against these attacks but these may be overwhelmed, especially in habitats where the plants are already stressed, or where the pests have been accidentally introduced and may have no natural enemies. The pests affecting trees are predominantly insects, and many of these have also been introduced inadvertently and lack natural enemies, and some have transmitted novel fungal diseases with devastating results.
Humans have traditionally performed pest control in agriculture and forestry by the use of pesticides ; however, other methods exist such as mechanical control , trapping , and recently developed biological controls. A pest is any living thing, whether animal, plant, or fungus, which humans consider troublesome to themselves, their possessions, or the environment. Microorganisms , whether bacteria , microscopic fungi, protists , or viruses that cause trouble, on the other hand, are generally thought of as causes of disease pathogens rather than as pests.
In its broadest sense, a pest is a competitor to humanity. Animals are considered pests or vermin when they injure people or damage crops, forestry, or buildings. Elephants are regarded as pests by the farmers whose crops they raid and trample.
Mosquitoes and ticks are vectors that can transmit ailments but are also pests because of the distress caused by their bites.
Grasshoppers are usually solitary herbivores of little economic importance until the conditions are met for them to enter a swarming phase , become locusts and cause enormous damage. Flocks of starlings can consist of hundreds of thousands of individual birds, their roosts can be noisy and their droppings voluminous; the droppings are acidic and can cause corrosion of metals, stonework, and brickwork as well as being unsightly. Pigeons in urban settings may be a health hazard, and gulls near the coast can become a nuisance, especially if they become bold enough to snatch food from passers-by.
All birds are a risk at airfields where they can be sucked into aircraft engines. Many of the animals that we regard as pests live in our homes.
Before humans built dwellings, these creatures lived in the wider environment, but co-evolved with humans, adapting to the warm, sheltered conditions that a house provides, the wooden timbers, the furnishings, the food supplies and the rubbish dumps. Many no longer exist as free-living organisms in the outside world, and can therefore be considered to be domesticated. Plants may be considered pests, for example, if they are invasive species or weeds.
There is no universal definition of what makes a plant a pest. Some definitions encompass any hazardous or problematic organism, and so often include fungi , oomycetes , bacteria , and viruses. The term "plant pest", mainly applied to insect micropredators of plants, has a specific definition in terms of the International Plant Protection Convention and phytosanitary measures worldwide.
A pest is any species, strain or biotype of plant, animal, or pathogenic agent injurious to plants or plant products. Plants have developed strategies that they use in their own defence, be they thorns modified stems or spines modified leaves , stings, a thick cuticle or waxy deposits, with the second line of defence being toxic or distasteful secondary metabolites. Mechanical injury to the plant tissues allows the entry of pathogens and stimulates the plant to mobilise its chemical defences.
The plant soon seals off the wound to reduce further damage. Plants sometimes take active steps to reduce herbivory. Macaranga triloba for example has adapted its thin-walled stems to create ideal housing for an ant Crematogaster spp.
In addition to providing housing, the plant also provides the ant with its exclusive food source in the form of food bodies located on the leaf stipules. These Acacia trees also produce nectar in nectaries on their leaves as food for the ants. Insects are responsible for two major forms of damage to crops. First, there is the direct injury they cause to the plants as they feed on the tissues; a reduction in leaf surface available for photosynthesis, distortion of growing shoots, a diminution of the plant's growth and vigour, and the wilting of shoots and branches caused by the insects' tunneling activities.
Secondly there is the indirect damage, where the insects do little direct harm, but either transmit or allow entry of fungal, bacterial or viral infections.
In many cases it is the larva that feeds on the plant, building up a nutritional store that will be used by the short-lived adult; sawfly and lepidopteran larvae feed mainly on the aerial portions of plants while beetle larvae tend to live underground, feeding on roots, or tunnel into the stem or under the bark. The true bugs, Hemiptera , have piercing and sucking mouthparts and live by sucking sap from plants. These include aphids , whiteflies and scale insects.
Apart from weakening the plant, they encourage the growth of sooty mould on the honeydew the insects produce, which cuts out the light and reduces photosynthesis, stunting the plant's growth. They often transmit serious viral diseases between plants. The mites that cause most trouble in the field are the spider mites.
They mostly live on the underside of leaves and puncture the plant cells to feed, with some species forming webbing. They occur on nearly all important food crops and ornamental plants, both outdoors and under glass, and include some of the most economically important pests. They can feed on the roots or the aerial parts of plants and transmit viruses. The nematodes eelworms that attack plants are minute, often too small to be seen with the naked eye, but their presence is often apparent in the galls or "knots" they form in plant tissues.
Vast numbers of nematodes are found in soil and attack roots, but others affect stems, buds, leaves, flowers and fruits. High infestations cause stunting, deformation and retardation of plant growth, and the nematodes can transmit viral diseases from one plant to another. Slugs and snails are terrestrial gastropod molluscs which typically chew leaves, stems, flowers, fruit and vegetable debris. Slugs and snails differ little from each other and both do considerable damage to plants.
With novel crops being grown and with insect pests having been brought more under control by biological and other means, the damage done by molluscs becomes of greater significance. They devour seedlings, damage developing shoots and feed on salad crops and cabbages, and some species tunnel into potatoes and other tubers.
A weed is a plant considered undesirable in a particular situation; the term has no botanical significance. Often, weeds are simply those native plants that are adapted to grow in disturbed ground, the disturbance caused by ploughing and cultivation favouring them over other species.
Any plant is a weed if it appears in a location where it is unwanted; Bermuda grass makes a good lawn plant under hot dry conditions but become a bad weed when it out-competes cultivated plants.
A different group of weeds consists of those that are invasive, introduced, often unintentionally, to habitats to which they are not native but in which they thrive. Without their original competitors, herbivores, and diseases, they may increase and become a serious nuisance. In forestry, pests may affect various parts of the tree, from its roots and trunk to the canopy far overhead. The accessibility of the part of the tree affected may make detection difficult, so that a pest problem may already be far advanced before it is first observed from the ground.
The larch sawfly and spruce budworm are two insect pests prevalent in Alaska and aerial surveys can show which sections of forest are being defoliated in any given year so that appropriate remedial action can be taken.
Some pests may not be present on the tree all year round, either because of their life cycle or because they rotate between different host species at different times of the year. The import and export of timber has inadvertently assisted some insect pests to establish themselves far from their country of origin.
An insect may be of little importance in its native range, being kept under control by parasitoid wasps, predators, and the natural resistance of the host trees, but be a serious pest in a region into which it has been introduced.
Animals able to live in the dry conditions found in buildings include many arthropods such as beetles, cockroaches, moths, and mites. Another group, including termites , woodworm , longhorn beetles , and wood ants cause structural damage to buildings and furniture. The deathwatch beetle infests the structural timbers of old buildings, mostly attacking hardwood , especially oak. The initial attack usually follows the entry of water into a building and the subsequent decay of damp timber.
Furniture beetles mainly attack the sapwood of both hard and soft wood , only attacking the heartwood when it is modified by fungal decay. The presence of the beetles only becomes apparent when the larvae gnaw their way out, leaving small circular holes in the timber.
Carpet beetles and clothes moths cause non-structural damage to property such as clothing and carpets. The moth larvae live where they feed, but the beetle larvae may hide behind skirting boards or in other similar locations between meals.
They may be introduced to the home in any product containing animal fibres including upholstered furniture; the moths are feeble fliers but the carpet beetles may also enter houses through open windows. Constant vigilance is required to prevent an attack, and newly acquired items, and those that have been out on loan, may need quarantining before being added to the general collection. There are over four thousand species of cockroach worldwide, but only four species are commonly regarded as pests, having adapted to live permanently in buildings.
They can passively transport pathogenic microbes on their body surfaces, particularly in environments such as hospitals,  and are linked with allergic reactions in humans. Various insects attack dry food products, with flour beetles , the drugstore beetle , the sawtoothed grain beetle and the Indianmeal moth being found worldwide. The insects may be present in the warehouse or maybe introduced during shipping, in retail outlets, or in the home; they may enter packets through tiny cracks or may chew holes in the packaging.
The longer a product is stored, the more likely it is to become contaminated, with the insects often originating from dry pet foods. Some mites, too, infest foodstuffs and other stored products. Each substance has its own specific mite, and they multiply with great rapidity. One of the most damaging is the flour mite , which is found in grain and may become exceedingly abundant in poorly stored material. In time, predatory mites usually move in and control the flour mites.
The control of pests in crops is as old as civilisation. The earliest approach was mechanical, from ploughing to picking off insects by hand. Early methods included the use of sulphur compounds, before BC in Sumeria. In ancient China, insecticides derived from plants were in use by BC to treat seeds and to fumigate plants. Chinese agronomy recognised biological control by natural enemies of pests and the varying of planting time to reduce pests before the first century AD.
The agricultural revolution in Europe saw the introduction of effective plant-based insecticides such as pyrethrum , derris , quassia , and tobacco extract. The phylloxera a powdery mildew damage to the wine industry in the 19th century resulted in the development of resistant varieties and grafting , and the accidental discovery of effective chemical pesticides, Bordeaux mixture lime and copper sulphate and Paris Green an arsenic compound , both very widely used.
Biological control also became established as an effective measure in the second half of the 19th century, starting with the vedalia beetle against cottony cushion scale. All these methods have been refined and developed since their discovery. Forest pests inflict costly damage, but treating them is often unaffordable, given the relatively low value of forest products compared to agricultural crops.
It is also generally impossible to eradicate forest pests, given the difficulty of examining entire trees, and the certainty that pesticides would damage many forest organisms other than the intended pests.
Forest integrated pest management therefore aims to use a combination of prevention, cultural control measures, and direct control such as pesticide use. Cultural measures include choosing appropriate species, keeping competing vegetation under control, ensuring a suitable stocking density, and minimizing injury and stress to trees.
Pest control in buildings can be approached in several ways, depending on the type of pest and the area affected.
Insect pests of vegetables
Diseases of turf grasses result from infection by living organisms such as a fungus, bacteria, virus or nematode. A susceptible plant, favourable environment and a plant disease causal agent must be present over a period of time for a disease to occur. Most biotic or infectious diseases of turfgrass are caused by some kind of a fungus pathogen. Some diseases are turfgrass specific whereas others may attack multiple turfgrass types. There are very few important virus diseases of turf. Nematodes are often a problem on golf courses or other situations where turf is grown in sandy soil conditions. Other diseases can result from a stress imposed by non-living agents such as mechanical or chemical damage and adverse environmental conditions.
Pesticides are important. They help farmers grow more food on less land by protecting crops from pests, diseases and weeds as well as raising productivity per hectare. Production of major crops has more than tripled since , thanks in large part to pesticides. The amount of wheat has increased nearly percent. Without pesticides, more than half of our crops would be lost to pests and diseases. All farmers use pesticides, including organic farmers.
Once you've identified nuisance plants, you can more readily access information on eradication. In some cases, however, finding out more about the plants in question may persuade you to show more tolerance toward them. There are even some edible weeds. Some are worth your time to remove while others don't cause much harm and may even have beneficial aspects. Several of these weeds can cause rashes. Use proper clothing and gloves when working around these weeds, or enlist professional help to eradicate them. Here are 17 types of weeds you might encounter in your garden.
Yield reductions caused by weeds, pests and diseases are common in agri- cultural practice. crops of different height. hcand hwrepresent the height of the crop and of the weeds, Some manual weeding, no control of pests and diseases.
17 Common Types of Weeds
Once you've identified nuisance plants, you can more readily access information on eradication. In some cases, however, finding out more about the plants in question may persuade you to show more tolerance toward them. There are even some edible weeds.
The Editors of Crop Protection especially welcome papers describing an interdisciplinary approach showing how different control strategies can be integrated into practical pest management programs, covering high and low input agricultural systems worldwide. Crop Protection particularly emphasizes the practical aspects of control in the field and for protected crops , and includes work which may lead in the near future to more effective control. The journal does not duplicate the many existing excellent biological science journals, which deal mainly with the more fundamental aspects of plant pathology, applied zoology and weed science. Crop Protection covers all practical aspects of pest, disease and weed control , including the following topics:.
Guide for Authors
Soil solarization, also referred to as solar heating or solar pasteurization, is accomplished by passive heating of moist soil covered with transparent plastic film for more than 6 weeks McGovern and McSorley, Solarization is a useful nonchemical technique for controlling weeds, nematodes, and several soil-borne diseases Katan, ; McGovern and McSorley, ; Stapleton, Solarization has been shown to be most effective in regions that are cloudless and have hot weather Heald and Robinson, ; Katan, ; Stapleton and DeVay, This technique has also been applied in regions with humid climates, such as Florida Chase, ; Chellemi et al. Solarization was found to be a cost-effective Chellemi et al.
A pest is any animal or plant harmful to humans or human concerns. The term is particularly used for creatures that damage crops, livestock, and forestry or cause a nuisance to people, especially in their homes. Humans have modified the environment for their own purposes and are intolerant of other creatures occupying the same space when their activities impact adversely on human objectives. Thus, an elephant is unobjectionable in its natural habitat but a pest when it tramples crops. Some animals are disliked because they bite or sting; snakes , wasps , ants , bed bugs , fleas and ticks belong in this category. Others enter the home; these include houseflies, which land on and contaminate food, beetles, which tunnel into the woodwork, and other animals that scuttle about on the floor at night, like cockroaches , rats and mice , which are often associated with unsanitary conditions.
Topic PDF to print. Weed species are either broadleaf or grassy type. A few examples of broadleaf weeds are clover, dandelion, and purslane. Some examples of grassy type weeds are nutsedge, pampas grass, and bermuda grass. Weeds can be further divided into annuals, biennials, and perennials. Annuals complete their life cycle in one year. Summer annuals, such as crabgrass, germinate in the spring and die in the fall with the onset of colder weather.