The vertical pathosystem

Vertical resistance will not operate against a pathogen that has a virulent gene at the locus corresponding to the resistance gene of the host a matching allo-infection will occur. A host plant that has only one gene for vertical resistance can be matched by a pathogen having a corresponding single virulence gene at the appropriate locus however, a host plant having two resistant genes requires the pathogen to have two corresponding virulence genes at the appropriate loci. In such a situation a...

Models Information Technology and Communication Technology in IPM

Throughout this book reference has been made to and examples given of many different types of model. There have been examples of models used to forecast pest abundance (Chapter 2), models to simulate plant growth and pest damage (Chapter 3), models to explain the interactions between pests and their natural enemies (Chapter 6). These models have been of different types and forms but the fact that they are now used in most areas of insect pest management says something for their utility. Models...

The pathosystem concept

A system may be defined as a pattern of patterns, and a pattern within a pattern is called a subsystem (Robinson, 1976). A pathosystem is a subsystem of an ecosystem and is defined by the phenomenon of parasitism (Robinson, 1980a,b). As with an ecosystem the geographical, biological, conceptual and other boundaries of a pathosystem may be specified as convenient (Robinson, 1980b). The plant pathosystem involves plants used as hosts by parasites which includes fungi, bacteria, viruses, insects,...

Durable Crop Resistance to Insects

The primary goal of conventional (Mendelian) breeding is to produce a higher yielding, better quality crop and once that is achieved then resistance characters can be incorporated, provided the method for introducing the resistance can itself be readily integrated into the breeding programme. In this way, the breeding of pest resistant plant material is considered as an adjacent to the main breeding programme. Resistance, once it has been identified, is incorporated into plant material already...

Pest management in soybean

The soybean Glycine max is grown in at least 45 countries with a production of 113,069,000 tonnes. The major producers are the USA (44 ), Brazil (21 ), China (12 ) and Argentina (11 ) (Soyatech Inc, 1995). To produce a soybean crop that yields economically anywhere in the world farmers must control pathogens, insect pests and weeds (Sinclair et al., 1997). For many years from the 1940s onwards, pest control in soybean relied on chemical insecticides, but for the last two decades concerns about...

Evaluating antixenosis and antibiosis

During a breeding programme plants may be screened for resistance to insect pests but most experimental work on resistance mechanisms takes place either with released cultivars or with resistant culti-vars prior to release. Experiments to evaluate antixenosis and antibiosis are usually labour intensive and can only be carried out on relatively few cultivars and hence are rarely included in routine screening programmes although there are exceptions, e.g. screening in alfalfa and rice ....

The Stakeholders in Pest Management

Stakeholders are individuals and groups of individuals who have a vested interest in a particular issue, cause or enterprise. Their expectations are built on past experiences, assumptions and beliefs and will reflect specific organizational structures Collins, 1994 . Within pest management there are numerous stakeholders who can include, for instance, shareholders, managers, employees, suppliers, customers and communities who are all linked to different degrees to a commercial company that...

Sampling Monitoring and Forecasting

Monitoring in insect pest management can be used to determine the geographical distribution of pests or to assess the effectiveness of control measures, but in its widest sense monitoring is the process of measuring the variables required for the development and use of forecasts to predict pest outbreaks Conway, 1984b . Such forecasts are an important component of pest management strategies because a warning of the timing and extent of pest attack can improve the efficiency of control measures....

Brief History of Pest Management

The history of pest management dates back to the beginnings of agriculture and from that time it is a history that combines important events discoveries and defining moments , influential people, institutions, organizations and governments in ways that have led us to the current concept of integrated pest management IPM . IPM has been defined as a 'pest management system that in the context of the associated environment and population dynamics of the pest species, utilizes as suitable...

Types of pest damage

The presence of an insect pest in a crop is usually characterized by a particular type of damage. The damage may take the form of injuries caused by insect feeding, the presence of contaminants, such as frass, that reduce the market quality of the har-vestable product or indirect insect damage caused by the presence of bacteria or viruses transmitted by the insect. The type of pest damage will in turn influence both the likelihood and the extent of yield loss. Insects feed and consume plant...

Causes of Pest Outbreaks

The history of pest management is a subset of the history largely of agriculture and while pests have been a chronic problem in agriculture since the beginning, many of today's serious pest problems are the direct consequence of actions taken to improve crop production Waage, 1993 . The intensification of agriculture has created new or greater pest problems in a number of ways 1. The concentration of a single plant species variety in ever larger and more extensive monocultures increases its...