Growing Avocado trees in Kenya (persea Americana)

Avocados fruits are grown for export and local market in Kenya. The plants are native to America but grows well in Kenya. Avocados are very nutritious with high protein and oil content. Climatic conditions requirements for growth of avocado fruits trees are altitudes of They perform well from 0-2100 m above sea level (asl). Varieties Tonnage and Simmonds  perform well in lowland with altitude  90 - 800 m. 'Hass' and 'Nabal varieties' are for 800-2100 m asl. 'Fuerte' and 'Puebla' do best at 1500-2100 m asl.  Well distributed annual rainfall of 1000-1200mm is required.The soils should be deep and free draining. Main varieties suitable for growing in Kenya  include:-   

Variety	Variety’s characteristics
Fuerte	Hybrid, Green, thin skinned pebbled fruits of very good flavor
Haas	Vigorously growing trees with black fruits. grows well in kenya
Nabal	Green fruits with good flavour.Bears in alternate years
Puebla	Dark green trees bearing round purple fruits. Used as rootstock

Avocado trees seedlings are grown in the nursery, from healthy egg sized seeds which are extracted from the fruits and planted in boxes, seedbed or 4kg containers. Grafting should be carried out when the seedlings reach pencil thickness. The wedge grafting method is the most successful. Grafting should be done when the root stock is still soft. The scion should be dormant at the time of grafting and should match the size of the rootstock. Wrap the grafting joint thoroughly to exclude water from the union. Planting of avocado trees is done at a spacing of 9m×9m.Dig planting holes 60cm ×60cm× 60cm separating top soil and subsoil. Mix the top soil with 20kg of well rotted manure, 120grams of double super phosphate fertilizer. Remove the seedling from the pot keeping the root and soil structure intact, and plant using the top soil mixture. The subsoil may be used to make a basin around the plant. Water and shade the avocado seedlings immediately after planting. Application of manure and fertilizer on growing avocado trees is done twice a year following soil analysis report, or the general guideline below:

Trees age	CAN	Double supers	Muriate of potash	manure
1-3  years	120 g	220 g	-------	15kg
4-5  years	220 g	450 g	-------	15kg
6-7  years	450 g	650 g	220gm	30kg
8-9  years	650 g	650 g	450gm	30kg
10-14years	900 g	1   kg	650gm	------
15 + years	1.3kg	1.2kg	650gm	------

Deficiencies in trace elements may occur in avocado fruits trees causing leaf discoloration. Leaf analysis can be done by agricultural laboratories for an accurate report.

Nutrient element	Deficiency symptoms	Control measures
Zink	Mottled leaves, light yellow patches between plant veins, abnormal Development of Growing shoots.	Application of 250g Zinc sulphate for each year of age up to 4.5kg along drip line
Manganese	--------------------	Spray manganese sulphate on Young plant leaves
Iron	Loss of green colour on tree leaves	Apply 360g iron chelate for Each year of age
Excess Chlorine	Avocado trees tip burns & plant root damages	Apply calcium, magnesium, Ammonium phosphate. Avoid chlorine fertilizers

Initial pruning of fruit trees can be done to give a good shape but latter pruning is limited to removal of of dead branches. It’s not easy to tell when fruits are ready for harvesting, and the recommendation is, pick a few fruits from the plant , keep at room temperature.Mature fruits  soften within ten days without shriveling. There are no major pests and diseases on growing avocado trees.For more information see http://www.journalofkenyanhorticulture.blogspot.com/2012/08/pruning-and-canopy-management-of.html