The strawberry (Fragaria × ananassa) is a perennial plant belonging to the Rosaceae family, known for its nutritious fruit, widely cultivated in Morocco. Strawberries are particularly rich in vitamins C, B1, P, and PP, as well as minerals, making them an ideal food for the elderly or those following a specific diet. Strawberry cultivation plays a major economic role in Morocco, especially in the Souss, Gharb, and Loukkos regions, which are the main production areas.
1. Botany and Importance of Strawberry Cultivation
Strawberries are a member of the Rosaceae family, valued for their nutritional qualities. They provide essential vitamins like vitamin C, which is crucial for boosting the immune system, and are also beneficial for those following a weight loss diet due to their low calorie content. In Morocco, the most suitable areas for strawberry cultivation are regions with moderate climates and well-drained soils.
2. Pedoclimatic Preferences
Strawberry plants require specific climatic conditions to thrive. They prefer cooler climates, but some varieties are suited to warmer regions. For example, southern varieties (adapted to hot or temperate zones) need less cold to initiate their flowering, while others, like Gorella, require prolonged periods of cold for optimal development.
- Temperature: Temperature requirements vary during different growth phases. For floral initiation, an average temperature of 10 to 15°C is ideal, while fertilization occurs best at 20°C with a relative humidity below 60%. The optimal fruit growth temperature is around 25°C.
- Light and Photoperiod: Strawberries also respond to the photoperiod, producing runners during long summer days and initiating flowering during the shorter days of autumn. However, excessive short days can lead to dormancy, which can be reversed by exposing the plants to cold temperatures.
3. Varieties and Propagation Techniques
The three main types of strawberry varieties used in Morocco are:
- Remontant varieties: These varieties produce two harvests per year, such as Rappella, Marastil, and Brighton.
- Non-remontant varieties: These varieties yield one harvest per year, often with larger fruits.
- Semi-remontant varieties: These offer an intermediate level of production, providing some additional fruit, but not as much as remontant varieties.
Early varieties, such as Chandler and Guariguette, are also popular. Strawberry plants are mainly propagated vegetatively, either through fresh plants (produced in high-altitude nurseries) or frigo plants (stored cold for several months before planting).
4. Soil Conditions and Planting Techniques
Strawberries are adaptable to various soil types but prefer light, well-drained soils. Compact soils or those rich in chlorides should be avoided. The optimal soil pH ranges from 5.7 to 6.5.
Before planting, thorough soil preparation is required, including medium plowing, cross harrowing, and sometimes rolling. Planting is typically done on raised beds or mounds that are 10 to 20 cm high to ensure good drainage.
Planting dates vary depending on the type of plant and the region, but for fresh plants, the best time is from late October to December, while frigo plants should be planted between July and August.
5. Irrigation and Fertilization
Irrigation is essential to ensure optimal growth, especially in regions with insufficient rainfall. The drip irrigation system is most commonly used as it allows precise water distribution without wetting the leaves or flowers.
Fertilization is crucial for high yields. A base fertilization consisting of manure, nitrogen, phosphorus, and potassium is recommended. For cover fertilization, regular applications of potash nitrate and ammonium nitrate are used, often through fertigation, to nourish the plants throughout their growth cycle.
6. Cultural Practices
Cultural practices include cutting the runners, removing leaves, and weeding to keep the plants healthy. Ventilation within the tunnels is also necessary to prevent diseases and promote proper fruit development.
7. Pests and Diseases
Strawberry plants are susceptible to several diseases, including:
- Rhizome rot (Phytophthora cactorum)
- Powdery mildew (Sphaerotheca macularis)
- Gray mold (Botrytis cinerea)
Pests such as nematodes, mites, and aphids are also a threat. Viruses can attack the plants at various stages, with common ones like Strawberry mosaic virus (SMV) and Strawberry yellow edge virus (SWYE). Preventative measures, including controlling weeds and virus vectors (mainly aphids), crop rotation, and using virus-free planting material, are essential.
8. Harvesting, Handling, and Storage
Strawberry harvesting in Morocco is done manually, typically every 3 to 4 days, to ensure the fruits are collected at their peak of ripeness. To minimize damage to the fruits, it is recommended to use scissors to cut the stem, avoiding direct contact with the fruit.
For proper storage, the ideal temperature depends on how long the strawberries are to be kept. For short-term storage, they should be kept at 12–15°C. For longer storage, they should be kept at around 0°C. Techniques like modified atmosphere (with reduced CO2 levels of 10–15% and low oxygen) and ionization (exposing the fruits to gamma rays or accelerated electrons to delay ripening) are also used to extend shelf life, allowing strawberries to be stored for up to 10 days, even at higher temperatures like 13–15°C.
Strawberry cultivation in Morocco is a dynamic sector that requires careful management of climatic conditions, soil types, and cultural practices to ensure high yields and optimal fruit quality. By employing modern techniques for irrigation, fertilization, pest control, and storage, the strawberry industry in Morocco has become an important economic driver, providing both local and export markets with a reliable supply of high-quality fruit.
