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 diseasefree. 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 postharvest decay; both of which are unacceptable on the export market. The objective of this chapter is two-fold: firstly, to describe the most important diseases of avocado which may be encountered 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.

Commodity risk assessment of Persea americana from Israel

“…Quiescent infections can occur in fruits and leaves. The fungus infects young fruits but enters a dormant phase until fruit maturity (Marais, 2004). Confusion with other pathogens/pests Dothiorella aromatica (Sacc) Petr & Syd.…”

“…• Infected nursery stock, contaminated soil/substrate and fruits are the main pathways (PRA by the Australian Government). • The pathogen can be dispersed through spores on dead twigs, leaves and mummified fruit (Marais, 2004). • Rain and humidity facilitate the spore production and dispersal (Marais, 2004).…”

“…• The pathogen can be dispersed through spores on dead twigs, leaves and mummified fruit (Marais, 2004). • Rain and humidity facilitate the spore production and dispersal (Marais, 2004).…”

Criollo avocado of mexican race (Persea americana var. drymifolia): an underutilized species in horticulture

“…6 It is worth mentioning that although some CAMR genotypes are susceptible to damage caused by insects (e.g., Trioza anceps, Heilipus lauri, and Thysanoptera: Thripidae) and pathogenic fungi (e.g., Phytophthora cinnamomi, Colletotrichum gloeosporioides, and Sphaceloma perseae) that cause damage to avocado crops, the damage is less than in commercial varieties such as'Hass' and 'Fuerte'. 7 In addition, there are resistant genotypes, Sánchez-Gonzales et al 8 reported the resistance of CAMR rootstocks to Phytophthora cinnamomi; main pathogen that affect avocado production worldwide, causing root rot and secondary symptoms in the upper part of the plant, including dieback of branches, yellowing and wilting leaves, complete defoliation and death of the tree.…”

Identification of Soil Bacterial Isolates Suppressing Different Phytophthora spp. and Promoting Plant Growth

“…and crown canker of avocado. After P. cinnamomi , and this pathogen has been recorded in almost 90% of the avocado orchards in California ( Coffey, 1987 ; Marais, 2004 ). Furthermore, P. citricola has been reported as the second most destructive causal agent of root rot ( Schubert et al, 1999 ).…”