Soursop Farming in Kenya

Soursop, known as “stafeli” in Swahili, is a tropical fruit that has increasingly gained popularity across Africa over the years. Soursop is mainly known for its medicinal properties and its distinctive taste that gives a combination of strawberry, pineapple and citrus. Soursop is part of the Annonaceae family, known for its spiny fruits that can weigh up to 4.5kg. While not native to Kenya, soursop farming has gained popularity due to its adaptability to the Kenyan climate, high market demand and potential for profit.

Soursop Fruit

Soursop thrives in relatively warm climates. In Kenya, the ideal regions for soursop farming include areas such as the coastal region, parts of Eastern and Nyanza, and the Lake Victoria basin. These are areas that experience the required temperatures, which range between 21 and 30 degrees Celsius, with minimal temperature fluctuations. Soursop grows well in well-drained slightly acidic soils with a pH range of 5.0 to 6.5. The plant thrives in loamy or sandy soils, but it can also adapt to clay soils if proper drainage is provided. Poorly drained soils may lead to root rot and stunted growth.

Before planting, farmers are advised to conduct soil tests to determine the pH and nutrient content of their soil and adjust accordingly by incorporating organic matter or appropriate fertilizers.

Propagation of Soursop

Soursop can be propagated through seeds or a vegetative method such as grafting.

When propagating from seed, select seeds from healthy, disease-free fruits and plant them. You can sow the seeds in nursery beds or directly into polybags that are filled with rich soil. The seeds take 20-30 days to germinate. The seedlings can then be transplanted after 6-months, once they are about 30-40cm tall.

When propagating from grafting, a soursop scion from a healthy, mature plant is grafted on to a compatible rootstock.

Planting and  Ideal spacing of soursop

It is advisable to transplant your soursop seedlings at the beginning of the rainy season. Soursop trees require adequate spacing to ensure proper air circulation and sunlight penetration and we therefore recommend a spacing of 5metres between trees and 5metres between rows. This results in a planting density of around 400 trees in an acre. The planting holes should be 60cm deep and 60cm wide to ensure the roots of your plants have enough space for establishment.

Young soursop trees should be watered regularly, especially during dry periods. Established trees can tolerate drought but benefit from supplemental irrigation during flowering and fruit development. Drip irrigation systems are ideal, as they conserve water while ensuring adequate moisture levels in the soil.

Regular fertilization is key to a productive soursop orchard. Organic compost, well-rotted manure, or commercially available fertilizers rich in Nitrogen, Phosphorus, and Potassium should be applied.

Common Soursop Pests and Diseases

 Soursop is susceptible to several pests and diseases which can negatively impact yield. Some of these are fruit flies, scale insects, and mealybugs. Neem oil or organic pesticides can be used to control pests. Diseases such as anthracnose and root rot may also occur, especially in poorly drained soils. You should ensure proper sanitation, regular pruning, and use of fungicides where necessary.

Harvesting and Post Harvest Handling.

Soursop trees typically start producing fruit 3-5 years after planting, depending on the propagation method used. The fruits are ready for harvesting when they are fully grown and slightly soft to the touch, usually about 4-5 days after the skin turns light green. Harvesting is usually done manually by cutting the fruit from the stem using something sharp to avoid bruising. The fruits are highly perishable and should be consumed, sold or processed within 3-5 days after harvesting. For extended shelf life, soursop can be processed into juices, purees, or frozen for export.

Market Potential and Uses of  Soursop

Soursop is a highly nutritious fruit, rich in vitamins, antioxidants, and dietary fibre. It has a unique sweet-sour flavor and is used in making fresh juices, smoothies, ice cream, and desserts. Soursop has also gained popularity for its medicinal properties, particularly in alternative medicine where it is believed to have anti-cancer, anti-inflammatory, and anti-parasitic properties.

In Kenya, there is growing demand for soursop in local markets, especially in health-conscious urban centres such as Nairobi and Mombasa.

Globally, soursop is considered a superfood due to its high vitamin C content and antioxidant properties. Kenya has the potential to tap into the growing international market particularly in Europe, Middle East and North America, where demand for exotic fruit is high. Exporting processed soursop products, such as juice and pulp, offers additional revenue streams for Kenyan farmers.

Challenges in Soursop Farming in Kenya

Despite its potential, several challenges hinder the widespread adoption of soursop farming, but I will only mention out one of the major challenges.

 Limited Knowledge – Many farmers are unfamiliar with the agronomic practices required to grow soursop.