Hass Avocado Farming in Kenya will do well in areas with the following climatic requirements:
Climate: They are not frost-resistant even though plants of the Mexican race have been observed to overcome temperatures of between -4 to -50C without serious damage.
The best areas for production should have warm to cool climate, that is between 1,800 and 2,100m above sea level. Warm temperatures are essential for fruit set.
Rainfall: Avocados do well in areas with rainfall averages of 1,000-1,500mm per annum, well-distributed throughout the year. Irrigation is essential where rainfall is not sufficient.
Soils: Avocados can be grown in a wide range of soils provided that they are well drained and of at least 120cm depth. The soil should not be saline since avocados do not tolerate it. The best soils are medium sandy loams with pH of 5.5 — 6.5.
Wind: The avocado tree is easily damaged by winds due to its brittle branches. Moderately high winds can cause severe damage. Shelterbelts around orchards in strong wind areas are essential.
Establishment and maintenance
Site selection: The site for planting avocados should be free from anthills, be levelled or gentle-sloped and well sheltered from strong winds.
Site preparation: Land should be properly ploughed and harrowed to remove all perennial weeds. It is also advisable to plant maize or sunflower one year before planting the avocados.
Spacing: The square planting pattern is applied, that is, a spacing of 10mx10m or 10mx8m (rectangular) to give plant populations of 100 and 125 trees per hectare, respectively.
Planting: Planting holes are dug 45cmx45cmx45cm.
Holes are filled with top soil mixed with about 30kg of manure and 125g of DSP. The trees are delivered in polythene bags and carefully removed to cause very little disturbance to the roots.
The trees are usually planted at a higher level than they were in the nursery to allow for settling. After planting, they are watered and mulched. The best time to plant is when the long rains are starting.
Pruning: Normally, no pruning is required besides the removal of broken and diseased branches and trimming those touching the ground. Sucker growth is checked to remove shoots coming out of the rootstock.
Weeding: The orchard should be weed-free. It is recommended to have vegetables growing between the rows of young plantations. Beans have shown better results. Nothing should be planted closer than 2m from the tree. Higher crops such as maize and sunflower should not be intercropped with the avocado.
Irrigation: To have good production of avocados, irrigation is necessary, especially during the dry period. The quantity of water applied depends on the moisture characteristics of the soil and age of the trees. It, however, varies from 25-35 litres per tree per fortnight.
Since avocados are intolerant to salinity, the water used must be free from salts.
Manuring and fertilisation: For maximum growth and optimum yields, it is important to supply the avocado with the necessary nutrients.
It is, however, dangerous to give excessive amounts on any size of trees at a go as it may cause root damage, leaf burn and defoliation. The type of fertiliser to be used depends on soil pH.
In the planting year, it is advisable not to top-dress the orchard since this may retard root development during the first 4-5 months after planting.
After this period, 60g of 26 per cent N fertiliser should be applied after every three months when the soil is moist. In addition, about 25kg of well-rotten manure should be spread around the trees after each year.