Dr. Guy Witney, project manager at Great Brak Avos in Mossel Bay, Western Cape, provides insights into the origins and cultivation of avocados in South Africa. Avocados likely originated from the mountainous rainforests of Mexico and Guatemala. Today, wild avocados are found in Central and South America's coastal tropical lowlands and mountainous highlands. The introduction of avocados to South Africa is attributed to Dutch settlers from the West Indies between 1652 and 1700.
Witney notes that "large, low-oil fruit from West Indian seedling trees, often referred to as 'butter avocados', are still common backyard trees and are preferred over higher-quality Mexican-Guatemalan hybrid avocado varieties introduced later from California."
Grafting is a key process in avocado cultivation, involving the connection of a branch of an avocado cultivar with the rootstock of a different tree. This method provides strong support and disease resistance, particularly against Phytophthora root rot.
Between 1932 and 1938, the first experimental avocado cultivar evaluation block was established near Mbombela. The success of California varieties in the region led to the first commercial plantings in 1938, primarily of the Fuerte variety in the Lowveld's mountainous areas near Tzaneen and Mbombela. Today, around 90% of international avocado trade involves the Hass variety, which is the main cultivated variety in South Africa, followed by Fuerte. Other varieties include GEM, Lamb Hass, Maluma, Carmen, Pinkerton, Ryan, and Reed.
The avocado industry in South Africa comprises approximately seven million trees across 20,000 hectares, with production ranging between 120,000 and 160,000 tons annually. Key production areas include the humid, subtropical foothills of Limpopo and Mpumalanga, the KwaZulu-Natal Midlands, the Southern Cape coast, and the interior valleys of the Amatole Mountain foothills in the Eastern Cape.
Avocados thrive in moderate temperatures, with optimal daytime highs of 24°C to 34°C and nighttime lows of 8°C to 20°C. Most varieties struggle at sustained temperatures above 35°C and are damaged below -1°C. New soil preparation technologies and clonal rootstock varieties have expanded suitable growing areas, even those with shallower soils and lower rainfall.
Witney emphasizes the importance of adequate high-quality water for avocado orchards, requiring 3,000m³ to 5,000m³ of water per hectare annually. Proper soil preparation, including deep ripping, cross-ripping, and adding ameliorants, is crucial for orchard success. Modern micro-irrigation systems, pioneered by Israeli companies, are highly efficient in delivering water to trees.
All commercial avocado trees are grafted to ensure superior fruit quality and disease resistance. The combination of top genetics and rootstock traits results in productive trees, although they are relatively expensive. Integrated pest management and Phytophthora root rot controls are essential for maintaining healthy orchards. Annual leaf and soil analysis, along with precise fertilization, support optimal growth and production.
Source: Farmer's Weekly
