Strawberry (Fragaria spp) is grown for its fruits which are widely appreciated for their bright red colour, aroma, sweetness and juicy texture. These fruits can be consumed fresh or in foods as pies, preserves, among others.
Although farmers have been quite reluctant in participating in strawberry farming stating that the industry is not very developed, those looking into venturing into the practice are highly encouraged because it has huge income potential.
Fruits are sold locally or exported. Their demand is readily available in major urban markets, supermarkets and in marketing companies like Brookside, Trufood, KCC, among others.
Strawberries are very easy to maintain.
Strawberry varieties grown in Kenya include:-
- Tioga Selva
Strawberry farming in Kenya is done outdoors. However, for better performance, greenhouses are recommended because protect the plants from drought and excess rain.
Strawberry farming does best in areas whose soil PH is 5.5 6-6.5. The soil should be well drained and weed-free. The crop thrives in hot climate and does not tolerate frost or extremely low temperatures.
They do well in levelled or slightly higher grounds and require 6-10 hours of direct sunlight each day.
Planting & Cultural Practices
It is however more difficult to start with seeds and thus runners are mostly used.
- Till the land and remove weeds. CLAMPDOWN 480SL 10-15 ml/L is a non-selective herbicide which kills all types of weeds.
- Add manure and fertilizer (DAP) in order to ensure adequate supply of nutrients to the crop. The fertilizer and/ or manure should be mixed with HUMIPOWER at the rate of 1 kg Humipower into 50 kg fertilizer or 1 ton manure. This helps in improving the crops’ nutrient uptake as well as stimulating growth.
- Construct raised beds.
- Prepare planting holes. These should be deep and enough to accommodate the entire root system of the crop, without bending it.
- Plant seedlings at a spacing of 20 inches apart and 4 feet between rows. The roots should be covered, but the crown should be right at the soil surface.
- Mulching-after planting the strawberry plants, mulching the beds with pine needles, shredded leaves or straw helps to keep the soil temperature down, mitigate the weed problem, and also keeps the fruit cleaner by keeping the strawberries off of the dirt. As the mulch breaks down, it also adds organic matter to the soil
- Weeding– weeds compete with the plants for nutrient, moisture, space and sunlight, as well as harbouring pathogens. Manual weeding is recommended. However, during critical growth periods, i.e., flowering, fruiting, daughter plant growth and establishment, weeding should not be done. This is in order to avoid any disturbances
- Training– strawberries are sprawling plants and the seedlings send out runners. These runners should be trained in order to follow a specific pattern for better performance.
- Irrigation- water is critically is very essential when growing strawberries. The plants need a lot of water especially when the runners and flowers are developing. Drip irrigation is highly recommended as it waters at the root.
- Pruning- this is majorly aimed at increasing fruit production. Flowers should be pruned off immediately they appear.
- Fertilization– application fertilizers and manure boost production. However, if too much fertilizer is applied, this promotes excessive leaf growth and poor production of flower stalks. Too much nitrogen results in soft and easily-damaged strawberries.
Besides basal fertilizers and manure, foliar feeds should be applied in order to help supply both micro and macro nutrient elements. These include OPTIMIZER, DIMIPHITE, ZINC GOLD, FERRARI GOLD, among others.
Pests & Diseases Management
- Strawberry bud weevil (Clipper) – infestation leads to creation of holes in flowers and petals. Stems are chewed or clipped through
- Tarnished plant bugs– these puncture the plant tissue and suck the sap leading to tissue distortion and premature leaf fall. Severely infested leaves become chlorotic. They also secrete honeydew which encourages the development of sooty mold as well as attracting other insects.
- Strawberry thrips– the adults and nymphs feed on the leaves and most preferably flowers by sucking the sap thus causing damages which may lead to flower damage/abortion thus production of reduced or malformed fruits.
- Nematodes– the affected plants are stunted, older leaves die and few runners are produced. Roots may be short and stubby, with swellings.
- Mites- their infestation reduces plant vigour and plants appear retarded, twisted, and distorted. Leaves turn yellow with whitish feeding marks and may eventually die with continued infestation. Silvery webbing on the leaves and stems can also be seen.
- Aphids-they feed through piercing and sucking the plant sap resulting into distorted growth. Severe cases of infestation reduces quality and quality of produce. They excrete honeydew which favors the growth of sooty mold.
Spray JAMBO CLEAN 100 ml/20l to clean the sooty mold.
- Leaf blight– this occurs on older strawberry leaves. Large circular to oval spots, which are reddish-purple form on the leaves. As infection advances, they develop brown centers bordered by purple zones. Black fungal growth may be seen in the center of the spot. Lesions may also develop on runners of susceptible cultivars.
- Leaf spot- symptoms begin as round purple spots on upper leaf surfaces. As infection continues, the center of the spot becomes tan or gray, then almost white with a purple border. The disease can attack immature petioles, fruit stalks, runners and caps of susceptible cultivars.
- Leak– the symptoms are so distinct that they cannot be easily confused with those of other fruits rots. The color of the infected ripe berry remains unchanged at first but changes to light brown. The berry becomes soft and watery and collapses flat with the juice running out, hence name leak. The rotted fruit and especially the packaged one soon becomes covered with white fluffy cottony fungal growth with black spore producing structures.
- Leaf blotch– infection is characterized by purplish to brown blotches and in later stages by large necrotic spots. These spots often occur on the end of a leaflet and are wedge shaped. This fungus can also attack the fruit stalk, cap and fruit.
- Gray mold (Botrytis) – it is the major fruit rot disease of strawberries. Infection usually starts early in the season as a blossom blight, blighting of the buds and blooms and rotting of the green or ripe berries. It progresses downwards infecting the berries, stems and leaves. In damp weather, the affected plant parts are covered with gray masses of spores.
- Leathery rot – occurs on either green or ripe fruits. The rotted area is light brown in the center and shades into purple at the edge. In the late stages of decay, the fruit becomes tough and leathery.
- Anthracnose fruit rot– symptoms appear as soft to firm brown to black spots on green fruits and dark purple spots on ripe fruits. The spots enlarge rapidly on the ripe fruits until the fruits rot. The surface of lesion can become covered with pink to orange masses of spores.
- Powdery mildew– although whitish fungal growth is not very common on strawberry leaves as on many other plants infected by powdery mildews, infection causes the infected leaflets to curl upwards along the margins. The lower leaf surface may turn reddish on heavily infected leaflets. Fruit infection occurs during bloom and shows up at harvest as a tan to rusty pink berry surface that often cracks as the fruit expands.
NOTE; whenever doing foliar sprays, it is advisable to ALWAYS USE INTEGRA 3 ml/20l. This is a sticker, wetter, spreader and penetrant which helps in improving the efficacy of the product.
Maturity, Harvesting & Post-Harvest Handling
The crop takes about 70 days to maturity. Usually, fruits are ready for harvesting 4–6 weeks after blossoming and only the fully ripened (red) berries should be picked because they do not ripen after harvesting.
Harvesting can be done up to 3 weeks and this should produce a lot of berries, depending on the variety and the management practices employed. For instance; if well managed, a 1/8th piece of land can produce 30-50 kg of strawberries per week.
Strawberries are fragile and are easily damaged/bruised and should thus be handled carefully, for instance, when picking them from the strawberry plants.
Strawberries should picked in the morning when the fruits are cool and while dry because when wet, they mold quickly. Soon after harvesting, the berries should be stored unwashed in cool, dry place like in a refrigerator, where they can last for 5-7 days.
They can also be dried, frozen or made into jam or preserves.