Bøger af Magda Sabbour

Abiotic stress factors are environmental conditions that can negatively impact the growth, development, and productivity of plants, animals, and microorganisms. Unlike biotic stresses, which result from interactions with living organisms like pests and pathogens, abiotic stresses are non-living factors originating from the physical and chemical components of the environment. Abiotic stressors can include a wide range of conditions, such as temperature extremes, drought, salinity, heavy metals, radiation, and pollution. Understanding these abiotic stress factors is essential for mitigating their harmful effects on various ecosystems, agriculture, and human activities.

Die Effizienzgewinne in den Produktionsketten waren nur dank des Unternehmergeistes und des Managements der ländlichen Erzeuger möglich, die die modernsten Technologien, die der Wissenschaft zur Verfügung stehen, übernommen haben. Dazu gehören die Bodenbearbeitung, die Düngung und die Bodenverbesserung, die Techniken des integrierten Managements von invasiven Pflanzen, Krankheiten und Schädlingen sowie die zunehmende Verwendung von verbessertem Saatgut mit hoher Produktionskapazität. Es ist zu beobachten, dass die einfachen Maishybriden den Markt für Saatgut dominieren, das in Technologien eingebettet ist und von den Erzeugern leichter angenommen wird. Die Produktivitätssteigerungen in der Landwirtschaft sind mit dem Einsatz von gentechnisch veränderten Pflanzen zufriedenstellend und die Abhängigkeit von der Anwendung von Insektiziden auf die Kulturen wird im Laufe der Jahre geringer. Die Entwicklung und Vermarktung von gentechnisch verändertem Mais hatte weitreichende Folgen. 2011 betrug die Anbaufläche in den Vereinigten Staaten von Amerika (USA), die mindestens eine gentechnisch veränderte Eigenschaft aufwies, mehr als 88 % der gesamten Anbaufläche.

Chemical nematicides have been employed with varying degrees of success, but their implementation can be cumbersome, and furthermore they could potentially be neutralizing an otherwise positive effect from the entomopathogenic nematodes (EPN) that coexist with PPNs in soil environments and provide protection for plants against insect pests. Recent research has explored the potential of employing EPNs to protect plants from PPNs, while providing their standard degree of protection against insects. The interactions involved are highly complex, due to both the three-organism system and the assortment of variables present in a soil environment, but a strong collection of evidence has accumulated regarding the suppressive capacity of certain EPNs and their mutualistic bacteria, in the context of limiting the infectivity. Specific factors produced by certain EPN complexes during the process of insect infection appear to have a selectively nematicidal, or at least repellant, effect on PPNs. Using this information, an opportunity has formed to adapt this relationship to large-scale, field conditions and potentially relieve the agricultural industry of one of its most substantial burdens.

Pests are those species that attack some resource we human beings want to protect, and do it successfully enough to become either economically important or just a major annoyance. They are only a tiny fraction of the insect species around us. Even many of the species we would recognize as important pests only occasionally do significant damage to us or our resources.Natural enemies play an important role in limiting the densities of potential pests. This has been demonstrated repeatedly when pesticides have devastated the natural enemies of potential pests. Insects which were previously of little economic importance often become damaging pests when released from the control of their natural enemies. Conversely, when a non-toxic method is found to control a key pest, the reduced use of pesticides and increased survival of natural enemies frequently reduces the numbers and damage of formerly important secondary pest species.The three categories of natural enemies of insect pests are: predators, parasitoids, and pathogens.Predators: Many different kinds of predators feed on insects. Insects are an important part of the diet of many vertebrates.

Crop plants are affected by large number of pest species which have harmful effects on quality and yield. Chemical pesticides have affected these pests which become resistant and difficult to control . The need for biological control has increased, growers buy and release predatory mites on crops, but the predators disperse away or not reproduce making frequent releases necessary, which are expensive. Therefore, methods to enhance establishment and reproducing population of predators for pest inhibition for long time are needed. One of the effective methods is the use of biocontrol plants such as banker plants.

A protected plant that has been propagated and established through human intervention would not normally be considered to be ¿in the wild¿, especially where the plant receives regular management and maintenance (e.g. watering, protection from weeds or pests.) over a period of time. Typically this type of native vegetation is located within a tended garden or street-scaped or landscaped area. An exception to this circumstance could be where vegetation has been propagated and established through human intervention as part of a revegetation program, including but not limited to, a formal offset or mitigation requirement (e.g. a revegetation condition of an approval, an offset protected through a tenure mechanism). In this circumstance, artificially established vegetation may be considered to be ¿in the wild¿ and thereby protected under the Act, particularly if the revegetated area has reached a relatively self-sustaining state and no longer receives active management or maintenance through human intervention.

Phoenix dactylifera L. (Family: Arecaceae or Palmae), date palms are important species grown especially in arid regions around the world. It is permanent and heterogeneous with the growth of female plants (fruit carrier) and male (pollen) separately. Palm trees were planted six thousand years ago in Mesopotamia (present-day Iraq) (1, 2, 3). The palm weevil Rhynchophorus ferrugineus is one of two species of snout beetle known as the red palm weevil, Asian palm weevil or sago palm weevil. The adult beetles are relatively large, ranging between 2 and 4 centimetres (1 and 1+1¿2 inches) long, and are usually a rusty red colour¿but many colour variants exist and have often been classified as different species (e.g., Rhynchophorus vulneratus). Weevil larvae can excavate holes in the trunks of palm trees up to 1 metre (3.3 ft) long, thereby weakening and eventually killing the host plant. As a result, the weevil is considered a major pest in palm plantations, including the coconut palm, date palm and oil palm.

Synthetic chemical insecticides provide many benefits to food production and human health, but they also pose some hazards. In many instances, alternative methods of insect management offer adequate levels of pest control and pose fewer hazards. Insect pathogens are important components of the natural enemy complex of many insect species, including pest species. Some groups of pathogens, such as microsporidia, may not always maintain host insect densities below economic thresholds, but they suppress the rapid increase of pest populations and are often responsible for the decline of populations that have exceeded the economic threshold. In most cases the major goal for managing naturally occurring insect pathogens is to elicit an epizootic earlier in the season, before the host densities have exceeded the economic threshold. This can be accomplished by inoculative releases of the pathogen or by changing cultural practices to promote an epizootic Microorganisms and insects are associated in many different ways. These associations range from mutualistic associations to those where the microorganism causes fatal disease in the insect host. Infectious insect diseases, usually causing de

An insect is considered a pest if it threatens a resource valued by humans, including human health. Protection of a resource from a pest is usually achieved by poisoning the pest with a toxic pesticide, but it can also be achieved by manipulating a behavior of the pest. The manipulation of a pest¿s behavior to protect a resource is not a new concept. The practice of trap cropping, i.e. using a sacrificial resource for the pest to attack, in order to protect a valued resource, has been known for centuries (70). However, in the last 30 years or so, largely due to improvements in analytical techniques and an increased desire to reduce the reliance on broad-spectrum insecticides, there has been increased interest in behavioral manipulation for pest management. Virtually all methods of pest management involve some changes in pest behavior, whether intentional or not. In this review, we restrict our discussion to examples in which pest management is achieved through deliberate manipulation of a pest¿s behavior. For the purpose of this review, that manipulation is defined as the use of stimuli that either stimulate or inhibit a behavior and thereby change its expression.