ABSTRACT
Recently most research has concentrated on the production of virus-resistant transgenic plants as the best way to keep crops free from viruses, avoid or minimize the use of pesticides and increase the yield and quality of the crop. e concept of ‘Management’, linking knowledge of virus ecology and epidemiology has been neglected or overlooked. e production and deployment of transgenic plants has much to o er, but is a laboratory process that only has its value when used in eld-gown crops. Whereas the development of a management process necessitates long-range eld studies and is a dynamic process involving virus, host, vector, volunteer sources of the virus and climate. e incidence of a virus disease depends upon the interaction of these components and this is true whether the host is a transgenic plant produced in the laboratory or one conventionally bred and selected. e International Committee for the Taxonomy of Viruses (ICTV) (Fauquet et al 2005) recognized a total of about 2000 species of viruses as of 2005 and 77% of these were initially isolated from cultivated plants (Wren et al 2006). Certain combination of conditions makes these viruses cause economic loss in one or more regions of the world. e primary objective of an agriculturist is to obtain cost-e ective economic yields. On many occasions, more than one virus may invade the same crop and this makes management more complex. In addition other pathogens, microorganisms and invertebrates will a ect the plant and may interact with any viruses that are present. us management of virus diseases necessitates a holistic approach to modulate all the relevant components and keep the incidence below the threshold level for economic damage. Economic globalization, competitive economies, demand-driven agriculture, swi change of cropping systems, the rapid increase of inter-country movement of planting materials, global warming, etc. are constantly changing disease incidences and damage in the world. is focusses the need for e ective ‘Integrated Management’ and designing appropriate ‘Cropping Systems’.
