Optimizing Planting Densities of Avocado on the Basis of Long-Term Canopy Growth and Development at Melkassa, Ethiopia

Abstract

There is a controversy regarding the spacing requirements of avocado varieties, different experts recommend varying planting densities for different varieties in different avocado growing countries, including Ethiopia. Each avocado variety has its own canopy stature, thus there is no spacing that fits all varieties. The canopy growth of different avocado varieties was recorded annually from a replicated plot of well-established trees, assuming that the tree canopy reached a maximum growth during the long-term experiment at Melkassa Research Centre. Measurements were made from six trees replicated three times. The data were averaged per plot and per replications. The results showed that each variety reached maximum canopy diameter that occupied its own area with adequate distance between trees and rows. Hass and Nabal grew to a maximum canopy diameter of 4.30 m, while Ettinger has grown to a maximum diameter of 5.50m; Fuerte and Bacon attained 5.0 m canopy diameter; Pinkerton developed to a maximum diameter of 3.10m. This suggests that with addition of small workspace the optimum spacing for Ettenger could be 5mx5m (400 trees/ha); Fuerte and Bacon at 5.0m x 5.50m (363 trees/ha); Hass and Nabal at 4.30m x 4.80m and Pinkerton at maximum of 3.50m x 3.50m (816 trees /ha). This spacing could give a high tree population per ha and allow enough workspace between trees with sufficient light penetration. Accordingly, these spacings provide higher tree population density per ha and could be used for new avocado plantations in the Melkassa area and other similar environment.