About the Book

This work summarises several decades of laboratory and field

research by specialists from the Tree Crops, Fruit and Horticultural

Crops, and Forestry Departments of CIRAD (Centre de Cooperation

Internationale en Recherche Agronomique pour le Développement).

Their results are the fruit of extensive laboratory and field research.

The authors have described about fifty often serious diseases that can

cause very substantial yield losses, thereby threatening and

sometimes even preventing the cultivation of several crops in

different parts of the world. In-depth knowledge of the biology,

genetic diversity and pathogenicity of the pathogen is essential for

the development of a control method. Breeding resistant planting

material is the most widely practised and often the only possible

method of control. It calls for extensive research by both plant

pathologists, for developing inoculation techniques, and breeders,

for producing resistant cultivars. Research on genetically modified

planting material is still in its infancy but appears to be very

promising. Plant pathologists still often resort to using pesticides,

particularly synthetic substances, whilst striving to reduce the dosage

and treatment frequency as part of a rational chemical control

strategy. In many cases, these methods are complemented by crop

techniques in order to reduce pathogen pressure and make the

environment less favourable for pathogen development. Viral

diseases-phytoplasmas and phytomonas-are generally

transmitted by insects of the hemipteran group. Lowering insect

population levels has proved to be a very effective control method in

several cases.

Drastic measures have to be taken to prevent the spread of

diseases or pathogens, especially through plant material exchanges,

which should be subjected to strict quarantine regulations.

Developing a control method often means integrating different

techniques, whose development must take the socio-economic

context of rural populations into consideration. Only close

collaboration between specialists and produce managers will enable

farmers to fully benefit from advances made in their research.