Avocado Diseases of Major Importance Worldwide and their Management

Abstract

Avocado fruit has become one of the most sought after food sources worldwide. It is a nutritious source of food and is part of the staple diet of many people in third world countries where it is cultivated and where it is native. Avocado is a specialty fruit, produced on a large scale in more than 30 countries around the world and because of its appeal, it is an industry that continues to grow. It is a very lucrative industry, and with over production growers have been forced to develop overseas markets, however, the competition on these markets is very intense and growers have to ensure that their fruit are of the highest quality, unblemished and disease-free. Production costs are very high owing to the cultural requirements of the avocado tree and the presence of diseases, which can be major limiting factors to production. Phytophthora root rot, caused by Phytophthora cinnamomi, is such a disease. During the developmental stages of the fruit in the orchard and at harvesting, the fruit is also exposed to diseases such as scab (Sphaceloma persea), anthracnose (Colletotrichum gloeosporioides) and Cercospora spot (Pseudocercospora purpurea), which result in unsightly blemishes or the development of post-harvest decay; both of which are unacceptable on the export market. The objective of this chap-ter is two-fold: firstly, to describe the most important diseases of avocado which may be en-countered in different parts of the world, and secondly, to discuss current disease management strategies used to reduce the effects of these diseases, on tree health, longevity, fruit production and fruit quality.