Nematodes.

The following review of the nematodes from cultivated guava is limited to the major problem caused by M. enterolobii, its idenfication and its management strategies. The synonymization of Meloidogyne enterolobii with Meloidogyne mayaguensis and the different methods of identifying Meloidogyne species are discussed. The life cycle, host-parasite relationships, symptoms, damage and dissemination of M. enterolobii are described. The host status of cover crops, maize and fruit plants for M. enterolobii is discussed, as well as the resistance in Psidium spp. to root-knot nematodes. New prospects using genetic resistance in Brazil and some control strategies that can be used in an integrated way are presented.

Psidium guajava L.: taxonomy, relatives and possible origin.

This chapter focuses on the taxonomy and geography of guava (Psidium guajava). Information is given on geography, morphological characteristics, chromosome number and genome size, phytochemistry and medicinal uses, closest relatives, and keys to species complexes.

Cultivars and plant improvement.

The major objectives of guava breeding are aimed at improving both plant and fruit characteristics such as to develop high-yielding, high-quality dwarf cultivars with fruits of uniform shape, good size, attractive skin and pulp colour, fewer and/or soft seeds, resistant to wilt, nematodes and long storage life. Selection of superior seedlings has resulted in the development of a number of cultivars in different countries. This chapter describes the Psidium species used in breeding (Psidium cattleyanum, P. guineense, P. acutangulum, P. friedrichsthalianum, P. angulatum and P. littorale), objectives of breeding programmes, introduction and selection, inheritance pattern, interspecific hybridization, polyploidy, mutation and molecular characterization. Guava cultivars growing in different countries (Brazil, China, Egypt, India, Israel, Malaysia, Mexico, Pakistan, South Africa, Taiwan, Thailand, USA and vietnam) are also described.

Flowering.

This chapter covers the various factors affecting the transformation of vegetative growth to reproductive phase of guava trees, and the phenology, anthesis and pollination in guava. The agricultural practices for regulating crop production are also discussed.

Fruit set, development and maturation.

This chapter describes the guava fruit as well as the fruit set, growth, drop, harvesting, yield and quality (total soluble solids, total acids and ascorbic acid). Understanding the phenological cycle of guava and the effect of management practices on yield and fruit quality allows management practices to be modified to develop strategies which should lead to productivity gains for different pruning or chemical application times. As the effects of various treatments and times of application on yield and fruit quality for different cultivars and climatic zones are known, it is possible to decide on the optimum time to apply treatments knowing what the quality of the fruit will be, the time that the fruit will be harvested, expected yield and the critical times to apply management practices.

Production and trade.

This chapter provides an overview of guava fruit world production, exports, imports and consumption trends, with the focus on US and European markets.

Propagation.

This chapter deals with various propagation methods used in the multiplication of guava and progress made so far in this field. Seeds, stem cuttings, root cuttings, air layering, stooling, grafting, budding, rootstock, and in vitro propagation are discussed.

Photosynthesis and productivity.

Knowledge on the responses of guava to environmental factors such as light, temperature, water availability and CO2 concentration is essential to determine the effect of suboptimal environmental conditions and to manage the crop for maximum productivity. This chapter aims to highlight the current understanding and the possible effects of environmental factors on the whole physiology of guava trees as expressed by growth, yield, fruit quality and photosynthetic features. Possible areas of future research are also suggested.

Diseases.

This chapter focuses on different diseases of guava. Information is given on losses, symptoms, causal organism, epidemiology, and disease management.

Orchard management.

Commercial production from a guava orchard begins on the third year after planting and cropping may continue for 40 years or more. The performance of an orchard depends on its management, which includes water and nutrient management, selection of the correct cultivars, planting technique, canopy management for flowering and fruiting, and improved light efficiency through pruning to optimize the quality of young and bearing trees. This chapter provides information on planting system, planting density, training and pruning, intercropping, and weed control in guava orchards.