The papers contained in this book were presented at a NATO Advanced Research Workshop (ARW) held at Cape Sounion, Athens, Greece, 19-24 May, 1991. The twenty-eight more comprehensive papers represent the key subjects of the ARW covered by invited speakers. The thirty-four short papers pre sented in a research format are contributions of those invited to participate in the ARW. There was a total of 70 participants from 21 countries. The objectives of the ARW were as follows: to review current knowledge of biological control of plant diseases and plant parasitic nematodes, with emphasis on mechanisms at the molecular, cellular, organismal, and ecosystem level; to examine and expand on current concepts and synthesize new concepts; to identify and prioritize limitations in the use of biological control for plant diseases and nematodes and the scientific research needed to overcome these limitations; and to develop strategies for biological control through management of resident agents or introduction of natural or modified agents."

The papers contained in this book were presented at a NATO Advanced Research Workshop (ARW) held at Cape Sounion, Athens, Greece, 19-24 May, 1991. The twenty-eight more comprehensive papers represent the key subjects of the ARW covered by invited speakers. The thirty-four short papers pre sented in a research format are contributions of those invited to participate in the ARW. There was a total of 70 participants from 21 countries. The objectives of the ARW were as follows: to review current knowledge of biological control of plant diseases and plant parasitic nematodes, with emphasis on mechanisms at the molecular, cellular, organismal, and ecosystem level; to examine and expand on current concepts and synthesize new concepts; to identify and prioritize limitations in the use of biological control for plant diseases and nematodes and the scientific research needed to overcome these limitations; and to develop strategies for biological control through management of resident agents or introduction of natural or modified agents."

From the beginning of agriculture until about 1950, increased food production came almost entirely from expanding the cropland base. Since 1950, however, the yield per unit of land area for major crops has increased dramatically. Much of the increase in yields was because of increased inputs of energy. Between 1950 and 1985, the farm tractor fleet quadrupled, world irrigated area tripled, and use of fertilizer increased ninefold. Between 1950 and 1985, the total energy used in world agriculture increased 6. 9 times. Irrigation played a particularly important role in the rapid increase in food production between 1950 and 1985. The world's irrigated land in 1950 totaled 94 million hectares but increased to 140 million by 1960, to 198 million by 1970, and to 271 million hectares in 1985. However, the current rate of expansion has slowed to less than 1 % per year. The world population continues to increase and agricultural production by the year 2000 will have to be 50 to 60% greater than in 1980 to meet demands. This continued demand for food and fiber, coupled with the sharp decline in the growth rate of irrigation development, means that much of the additional agricultural production in future years must come from cultivated land that is not irrigated. Agricultural production will be expanded in the arid and semiarid regions because these regions make up vast areas in developing countries where populations are rapidly rising.

Located mainly across Portsea Island on the south coast, the city of Portsmouth is best known for its maritime heritage and association with the Royal Navy. Its strategic location presented obvious importance in wartime, which saw Admiral Lord Nelson sailing from the harbour to his victory at Trafalgar and his doom. Today it is still a busy port, but the ships that set sail are for tourism, business and friendship, not war. In this book, authors R. J. Cook & K. C. Close provide a fascinating visual chronicle of how much the city has changed across the last century. Using sepia, black-and-white and colour photographs they show how the city expanded and developed across the decades. Readers will glimpse lost and forgotten scenes from the Victorian and Edwardian eras, through both world wars and right up to more recent times. In addition to the streets, buildings and industries, together with the naval and military connections, the book offers a fascinating record of the people of the city and their constantly changing way of life. Lost Portsmouth is an engrossing look back in time that will appeal to residents, visitors and all those with links to the city.

The railway route between Oxford and Cambridge – nicknamed the Varsity Line – was opened in stages in the nineteenth century. Running roughly east to west, it crossed several major trunk routes linking London with the North and Midlands, and became part of the LMS in 1923 Railway Grouping. Its strategic value was recognised during the Second World War as it allowed freight traffic to avoid London and several new connections to the line were built. Despite post-war plans to develop the line further, parts of the line were closed by BR in the 1960s. Since then, rising demand on the railways in general and recognition of the value of this through route have resulted in sections being reopened and a new company, East West Rail, has been founded to re-establish the entire line by 2030, linking Oxford, Bicester, Bletchley/Milton Keynes, Bedford and Cambridge, and also acting as a potential feeder route for HS2. This book surveys the history of this route and its operations, and looks at the campaign and plans to open it again, analysing both the benefits and downsides of such a large rail project today.