Avocado fertilization. Mkulilma today I received a question from a farmer through our #AskMKULIMATODAY service. How should I apply fertilizer to my avocado crops?

To obtain maximum growth potential for the plant and optimum yield, it is important to supply the avocado plant with nutrients.

It is however dangerous to give excessive amounts of fertilizer on any size of the tree at one time ass this may cause root damage, leaf burn, and defoliation. The type of fertilizer to be used depends on your soil pH.

read more

Top factors to consider and boost earnings in avocado farming.

KEPHIS on the export of immature avocados to the international market

Irish food processor Kerry Group expands to East African market

Avocado fertilization

In the planting year, it is advisable not to top-dress the orchard since this may reterd root development during the first four to five months after planting.

After this period 60g of 26 percent N fertilizer should be applied after every three months when the soil is moist.

In addition, about 25kg of well rotten manure should be used and spread around the trees after each year.

The following are for N and P fertilizers to be applied each year. (CAN and SSP)

  • Year 1                                    60g CAN and 250g SSP
  • Year 2                                    85g CAN and 500g SSP
  • Year 3                                    500g CAN and 750g SSP
  • Year 4                                    750g CAN and 750g SSP
  • Year 5                                    1kg   CAN and 750g SSP
  • Year 6                                    2kg   CAN and 1 kg  SSP
  • Year 7                                    3kg   CAN and 1.5 kg SSP
  • Year 8                                    4 kg CAN  and 2kg  SSP
  • Year 9                                    5 kg CAN and 2.5kg SSP
  • Year 10                                  6 kg CAN and 3 kg SSP

The use of farmyard manure in avocado fertilization is strongly recommended because it improves the physical condition of the soil and promotes the absorption in the soil and uptake by the plant of micronutrients.

The above-listed nitrogen levels should also be applied in splits.

Avocado trees also have a very high requirement for potassium, magnesium, and zinc.

Measures should therefore be taken to supplement these when they fall short.


The first yields come in the third year after planting. The avocado fruit does not soften on the trees when mature, therefore it is not easy to determine the time of harvest by external appearance.

Also, the fruits do not mature at the same time.

Maturity is determined by harvesting some fruits, which are assumed to be mature and stored at room temperature.

If they soften in 12 days without shriveling, then they are ready for picking.

Other indications of maturity are

  • the loss of a glossy sheen normally observed in immature fruits
  • when there is a yellowish tint on the skin and stem
  • the green fruit becomes smoother, especially at the end opposite the stem as small corky areas appear on the skin.
  • When the seed is examined in the ripe fruit, the coat appears dark brown and its tissue is very thin.

During harvesting, the fruit must be clipped with secateurs from the tree and stalk of about 1 cm left.

Never pull the fruits because this encourages rotting. It is recommended that cotton gloves be used during picking, grading, and packing to avoid bruising and leading to losses.

Avocado fertilization Pests and diseases

  1. Nematodes (Radophillus similies), attacks the roots and cause growth stunting of the plant


Fumigation of the soil before planting

  1. Fruit flies (Ceratis capitat and Ptendarus rosa) attack the ripening fruit


Spray with malathion or fenthion

  1. thrips attack young leaves


Spray with Rogor40 or any other systemic insecticide.

Other pests include mites, scale, and aphids.


1. Sunblotch (virus)

Shows very slight symptoms of yellow to brown areas on young branches, leaf petioles, and leaves. In severe cases, there can be dieback of branches, reduction of growth, grooves on stems and branches.

Fruits develop sunken areas and later become brown.


Use virus-free bud woods, cutdown infected trees to prevent the spread of the disease

  1. Phytophthera root rot (Phytophthera cinnamoni)

This is a root rot disease that is common under wet conditions


Spray trees with copper fungicides (copper oxychloride) and use resistant rootstocks.

  1. Armillaria root rot (Armillaria spp)

Root rot and the tree may be killed under severe infection


Spray copper fungicides


Credits carol Mutua

Department of crops, horticulture and soils

Egerton University

Have an agribusiness question? Do you know of a successful agribusiness venture or story that you wish to share? I would like to hear from you. Send me the TIP(s) at mkulimatoday@gmail.com

Like and follow MkulimaTODAY on Facebook | twitter | Pinterest | Instagram | Group share this article and leave comments or questions or WhatsApp me +254700761190 on what you would like me to answer in the next article.