Strawberries belong to the Rosaceae family and the Fragaria genus . While the common strawberry is a wild plant that grows in forests, gardens, and orchards, the wild strawberry originated in the 18th century as a hybrid created by French botanists. The common strawberry is smaller and less intensely colored, and is also white inside, while the wild strawberry, on the other hand, has a red interior as well . Regarding taste differences, the wild strawberry has a sweeter flavor , while the common strawberry is more acidic. Among their properties, both fruits are rich in water, fructose, glucose, and xylitol, but above all, they stand out for their high content of polyphenols, natural antioxidants, especially vitamin C. Having provided this brief overview and highlighted the differences between the two fruits, in this Cultinews article we will focus specifically on strawberry cultivation.

 

Spain is the world's third largest producer of strawberries, behind China and the United States, with a total of 344.679 tons in just over 7.000 hectares (Statistical Yearbook 2019. Ministry of Agriculture, Fisheries and Food), and the largest exporter worldwide, mainly supplying the European Union.

 

The economic importance of this crop has led to a high degree of refinement in its cultivation, both in terms of genetics and production management, as well as post-harvest handling. We have already addressed some related topics in previous Cultinews , specifically mitigating post-transplant stress , controlling rot, and managing post-harvest life . In this Cultinews, we will focus precisely on production management and, more specifically, on fruit ripening.

 

 

From an agronomic perspective, strawberry cultivars can be classified into three groups: everbearing or long-day, non-everbearing or short-day, and everbearing or day-neutral. Flowering in the first two cases is induced by a specific photoperiod , while this factor does not play a role in the third. In any case, not only the photoperiod influences flowering, but also the temperatures or chilling hours the plant endures.

 

The varieties typically cultivated in Huelva are non-re-flowering , primarily due to the mild winter temperatures, which promote almost uninterrupted vegetative activity throughout the year. In this case, the limiting factor for growth is the high summer temperatures.

 

The chilling hour requirements , with temperatures below 7°C , for proper vegetative development and subsequent fruiting are not met under the climatic conditions of Huelva. This necessitates cultivating the plants at higher latitudes, so that once the required chilling hours for each cultivar have accumulated, these plants are then transplanted to the Huelva coast to fruit and produce. Insufficient chilling hours result in weak plant development , producing soft fruit with a short shelf life. Excessive chilling , on the other hand, leads to lower yields , excessive vegetative growth, and the development of premature runners.

 

After the first flowering and once the plant begins to bear fruit, temperatures below 12°C are detrimental to proper fruit ripening, resulting in misshapen fruit. The optimal temperature for producing quality strawberries is between 14 and 21°C . Above this range, fruit ripening and coloring occur very rapidly, preventing it from reaching a commercially viable size.

 

Regarding photoperiod , to ensure proper fruit ripening, the plants need between 8 and 10 hours of sunlight per day , or even more. This is because strawberries are plants that continuously mobilize sugars, therefore requiring energy from sunlight to power the complex process of photosynthesis.

From the technical department of Cultifort , we recommend weekly applications of BVC EVOLUTION (formerly BVC 2021) and FERKOLOR during the fruit ripening period, provided that the conditions are suitable.

 

  • BVC EVOLUTION (Before BVC 2021) It is a combination of seaweed, amino acids, nitrogen and reducing sugars, which promotes the start of physiological activity of the plant, stimulates the formation of leaves and flowers, delays leaf senescence, improves the quality of the fruits and advances ripening. It is a powerful metabolic activator of the plant, even when conditions are adverse. And now its formula has been improved by the CULTITEK Activating Biotechnology, further reinforcing its effect on the chlorophyll biosynthesis and photosynthetic activity.
  • FERKOLOR It is a liquid formulation of potassium, calcium, boron and nitrogen that promotes the formation of Fruits with greater size, color, firmness and quality. It helps the fruits to ripen in a uniform and staggered, improving sugar accumulation and preventing blossom end rot and softening of the fruit.

However, when temperature and photoperiod conditions are not as described in previous paragraphs, such as on winter days or cloudy days, which are shorter, with fewer hours of daylight and colder temperatures , the fruit will ripen more slowly, sometimes even struggling to reach its optimal commercial color. In this case, applying BVC EVOLUTION is practically essential, and should be done in conjunction with FASKOLOR . This product is a liquid formulation with potassium, organic acids, and peptide complexes selected to accelerate anthocyanin synthesis, thus improving the fruit's color, quality, and post-harvest life . As mentioned, its application is crucial when the days are shorter, with fewer hours of daylight and colder temperatures, providing a final boost to fruit ripening. It is also recommended when the plant is under a heavy crop load , preventing the most advanced fruit from fully ripening.