An avocado orchard should be profitable within seven to 10 years. If you space the trees so that no thinning is necessary in the orchard’s lifespan, you will utilise only slightly more than 50% of the land. This is clearly a a waste of space, so rather plant the trees close together initially and thin them out systematically and selectively at a later stage.
Arrange the trees in one of three patterns: square, diamond-shaped (both of which result in a change of direction of tree rows with every thinning) and rectangular (for hedge-type tree rows).
For the purpose of this article we focus on the rectangular pattern. Hedge-type tree rows are more suitable for a permanent irrigation system. If implements are used constantly, access to the rectangular type is possible for a longer period than in other layouts. In addition, traffic always moves in the same direction – an important factor in orchards planted on a slope.
Finally, the hedge-type tree-row layout minimises the effects of the loss of branches and trees in a row.
Take economic considerations and access for implements into consideration when determining inter-row spacing. Final distances of less than 10m will require thinning before the orchard is 10 years old.
Maximise early yield by planting trees close together in the row (at less than half the ‘final’ distance), as long as trees in the semi-permanent rows are removed timeously. If the soil has been well prepared, large planting pits are unnecessary, as is extra fertiliser.
Avocado trees bought from a nursery should already have been hardened off. Plant as soon as possible as deep as they were in the planting bags.
Support the young trees with props as soon as possible after planting and whitewash the stems (see box below). Irrigate young trees to ensure a uniform stand, but avoid overdoing the watering. Examine the soil moisture content of the subsoil regularly to prevent this.
Apply frequent light irrigations: 50l/tree/week and 100l as soon as the subsoil starts drying out, then resume watering at 50l/week/tree.
If the hardening off has been inadequate, provide temporary shade to protect the leaves. Tent-like shade-netting structures will also help to protect the trees against animals at night.
During the early years of an orchard, a cover crop restricted to the strips between the rows will protect and maintain the soil until the trees provide shade.
The following can be considered: soya, beans, cowpeas, medics, wheat, rye, barley, teff, vetches, and groundnuts.The drip area of the tree should be free of grass and weeds and, if possible, covered with organic mulch.
Sources: Directorate Communication, department of agriculture in co-operation with the ARC-Institute for Tropical and Subtropical Crops; gardena.com.