The African star apple, also known as Agbalumo or Udara, is a popular tropical fruit native to Africa. Scientifically known as Chrysophyllum albidum, it belongs to the Sapotaceae family. The fruit is called the African star apple because when sliced horizontally it reveals a star-shaped pattern.
African star apples are highly nutritious, being rich sources of vitamin C, antioxidants, calcium, iron, and potassium. Both fruits and leaves have several medicinal uses in African traditional medicine, including treating infections, boosting fertility, and alleviating coughs. The fruits can be eaten raw, or made into juice or wine.
This guide will take you through the process of growing star apples from seeds, covering key aspects like land preparation, planting, care, fertilization, pest control, and harvesting your fruits. Let’s get started!
Selecting the African Star Apple Seeds
When growing African star apples from seed, it’s important to select ripe, healthy fruits for seed collection. Unripe or damaged fruit may produce weak seeds that fail to sprout or thrive. Healthy African star apple seeds are relatively large. Selecting only the biggest, robust seeds can help maximize germination rates.
The best fruits for seed selection are those that have turned entirely purple or bluish-purple on the outside. Cut the fruit open and the flesh should be yellowish-white. Avoid fruits with brown spots or other defects.
To extract the seeds, remove the pulp and juice from around the seeds. Rinse the seeds well under running water while gently rubbing to clean off any remaining pulp residue. Pick out any seeds that are undersized, discolored, or appear abnormal. Only large, plump, cream-colored seeds should be used for planting. Allow the cleaned seeds to air dry for 1-2 days before planting.
Growing star apples from seeds, instead of grafting, lets you preserve genetic diversity, as seedlings reflect natural cross-pollination. While grafting ensures predictability and uniformity, plants grown from seeds better adapt to local conditions.
Land Preparation
Before planting your African star apple seeds, the land needs to be prepared properly. This involves:
– Clearing the land: Remove any weeds, rocks, roots, or debris that could interfere with planting. Clear an area about twice the size of the intended planting area to allow sufficient space for pruning and harvesting.
– Tilling the soil: Use a hoe or cultivator to loosen the top 6-12 inches of soil. This allows the seedlings’ roots to easily penetrate the soil. Break up any clumps thoroughly.
– Adding compost or fertilizer: Mix in a 2-3 inch layer of compost or other organic material like well-rotted manure. You can also mix in a complete fertilizer at the recommended rate. This provides nutrients for strong seedling growth.
The prepared soil should be loose, weed-free, and enriched with organic matter. Create raised beds about 1 foot high and 3 feet wide if drainage is poor. Once the land is ready, you can start planting.
Planting African Star Apple Seeds
To plant an African star apple, start by digging holes that are 2 feet wide and 2 feet deep where you want to position the trees. Make sure the holes have plenty of loose soil at the bottom to allow good root growth.
Aim to space the holes around 25-30 feet apart, depending on the amount of room you have available. This gives enough space between trees for them to grow and spread without overcrowding each other.
When planting African star apple seeds, carefully place the seedling in the center of the hole. Make sure the soil level matches the nursery level on the stem where it meets the roots. Do not plant too deep. Gently fill in the hole with the loose soil, pressing down lightly around the base of the seedling to remove any air pockets.
After planting, water deeply until the soil is fully saturated. This helps the roots establish and grow properly. Check soil moisture regularly in the weeks after planting and water whenever the top few inches become dry. Proper watering is crucial while the trees are young to ensure strong root systems.
Watering
Newly planted African star apple seeds need consistent moisture to germinate and sprout. Water them daily, keeping the soil moist but not soaked. Create a watering basin around each seed and fill it with water, allowing it to fully drain before watering again.
Once seedlings are established, begin watering young trees every 2-3 days during dry periods, applying water slowly and deeply. Continue watering basin irrigation, gradually expanding basins as trees grow. Provide 5-10 gallons of water per tree at each watering.
Mature African star apple trees are drought tolerant when established but produce better fruit with regular watering. During fruiting season, water trees 1-2 times per week, applying 10-15 gallons of water. Soak the entire root zone area to a depth of 2 feet. Reduce watering during rainy periods.
Consistent moisture is critical while trees are flowering and fruit is growing. Dry spells can cause fruit drop. Monitor soil moisture and water as needed during dry periods to support developing fruit.
Weed Management
Weeding is an important part of caring for African star apple trees. Frequent weeding is necessary, especially when trees are young. Weeds compete with trees for water, nutrients, and sunlight. Allowing weeds to grow around young trees will stunt their growth.
Weeding should be done frequently, at least every 2-3 weeks. Check for weeds after rain or irrigation, as these conditions promote weed growth. It’s easiest to pull or hoe weeds when the soil is moist. Rake up and remove pulled weeds.
Use hand tools like hoes, rakes, and hand weeders for weeding. Take care not to damage the tree’s shallow roots when weeding close to the trunk. Long-handled tools allow weeding around the tree without stepping on the soil.
Applying mulch around trees is highly beneficial. A 3-4 inch layer of mulch prevents weed seeds from germinating and reduces the need for weeding. Organic mulches like wood chips, bark, straw, or compost improve the soil as they decompose.
Mulching retains soil moisture and regulates soil temperatures. Spread mulch out to the tree’s drip line, leaving 6 inches of space around the trunk. Replenish the mulch layer as needed.
Related: Types Of Weeds And Effective Methods Of Weed Control
Fertilizer Application
Proper fertilization is crucial for growing healthy African star apple trees and maximizing fruit production. Here are some recommendations:
– Recommended fertilizers: African star apple trees do well with organic fertilizers such as compost, manure, bone meal, or blood meal. These provide a slow, steady release of nutrients. You can also use a balanced 10-10-10 NPK fertilizer. Avoid high-nitrogen fertilizers.
– Application frequency: Fertilize young trees 2-3 times per year. Mature trees can be fertilized 1-2 times per year, preferably before flowering and fruiting. Spread the fertilizer evenly under the canopy.
– Signs of deficiency: Yellowing leaves, stunted growth, and lack of flowers or fruit can indicate a nutrient deficiency. Leaves turning brown at the edges or between veins may indicate potassium deficiency specifically. Address deficiencies promptly by applying the appropriate fertilizer.
Pruning of African star Apple Tree
Pruning is an essential practice when growing African star apples from seed. It helps regulate the shape and growth of the tree for optimal fruit production.
When to Start Pruning
– Pruning should begin after the plant is 1-2 years old or when it has reached about 1 meter in height.
– The best time is during the dry season when growth has slowed down. Pruning during wet seasons can encourage fungal diseases.
Pruning Method
– Use sharp, clean secateurs to make pruning cuts. Sterilize the tools before and after use to prevent spreading diseases.
– Prune off lower branches up to a height of 80 cm to allow you to cultivate under the tree.
– Also remove inward-growing branches, dead or diseased wood, and crossing or congested branches to open up the canopy.
– When the tree is older, contain its height by cutting back vertical shoots. Do not remove more than 30% of the canopy.
Benefits of Pruning
- It promotes branching and creates an open, spreading shape ideal for fruit production.
- Pruning improves air circulation and light penetration within the canopy.
- It makes harvesting easier and improves fruit quality.
- Removing diseased wood limits the spread of infections.
- It maintains tree health and vigor, extending its productive lifespan.
Pests and Diseases Control
African star apple trees can be affected by some pests and diseases if not properly managed. Here are some of the most common problems and how to address them:
Common pests
1) Fruit flies: These small flies lay eggs in the ripening fruits, causing them to rot. Monitor trees for infestations and pick fruits promptly when ripe. Remove fallen and infested fruits from the area.
2) Mealybugs: Mealybugs suck sap from leaves and stems. Look for white cottony masses on plant parts. Wipe off with cotton swabs dipped in alcohol or spray neem oil.
3) Scale insects: Like mealybugs, these insects attach to stems and leaves and feed on sap. Prune off heavily infested branches. Use horticultural oils or neem sprays.
Preventive measures
- Keep the area around trees free of weeds and fallen fruits which can harbor pests.
- Use row covers or netting to keep insect pests off young trees.
- Attract beneficial insects like ladybugs and lacewings which prey on pests. Plant nectar sources nearby.
- Rotate chemical pesticide applications to prevent resistance.
Organic treatments
- Apply Bacillus thuringiensis (Bt) for caterpillars and beetle larvae.
- Use spinosad, a natural bacterium, for thrips, beetles, and caterpillars.
- Apply kaolin clay sprays which deter feeding insects. The clay particles also act as a repellent.
- Introduce beneficial nematodes to soil to parasitize soil-dwelling pests.
- Spray plants with neem oil or insecticidal soap to smother and deter soft-bodied insects like aphids, mealybugs, and mites.
By monitoring for pests, maintaining tree health, and using organic sprays, African star apple trees can be protected from major damage. Prompt treatment when pests are first noticed is key to effective control.
Harvesting African star apple fruits
The African star apple fruits take 4-6 months after flowering to become mature and ready for harvesting. You’ll know the fruits are ripe and ready to pick when:
- The fruits turn yellow or orange-red in color
- The fruits feel slightly soft when pressed gently
- The skin has wrinkled a bit and looks loose
- The central cavity of the fruit sounds hollow when tapped
Picking Fruits
Use pruning shears or a sharp, clean knife to harvest the fruits. Cut the fruits carefully without damaging nearby growth. Pick the fruits by clipping the short fruit stalk close to the branch.
Handle the ripe fruits very gently to avoid bruising. Harvest regularly, at least every 2-3 days during peak season. This encourages the plant to continue producing fruits.
Pick fruits delicately and lower them into baskets or crates. Do not throw or drop the fruits, as they bruise easily. Harvest early in the day before the sun gets too hot.
Handling and Storage of African Star Apple Fruits
After picking, move the fruits to a shaded area for sorting and cleaning. Remove any damaged, bruised, or rotten fruits. Rinse the fruits gently in clean water to remove dirt and debris. Allow them to dry fully before packing or storing.
Pack the undamaged fruits carefully in crates or baskets lined with soft material. Cushioning between layers helps prevent bruising during transport and storage. The ripe fruits can be consumed fresh or processed into juice, jam, jelly, wine, or other products. Store only fresh, undamaged fruits for a shelf life of 2-3 weeks at room temperature.
Related: Best Fast Growing Apple Trees For Backyard Gardening
Final Notes
I hope this article provides sufficient information on the pre-planting and post-planting processes of growing African star apples. Do well to share with other botanists and agriculture enthusiasts.