Boron is a crucial micronutrient for the growth and development of plants, including the olive tree. Recent studies have shown how it active growth regulatory genes e promotes the accumulation of essential metabolites, such as carbohydrates and amino acids, which are essential for the formation and ripening of fruits.
Its action is concentrated above all in critical periods such as flowering and fruit setting, moments in which the plant has a greater need for nutritional support.
Among its main functions, boron:
- regulates nitrogen absorption, optimizing the plant's metabolism;
- stimulates the elongation of plant tissues, essential for structural growth;
- supports the vitality of pollen, improving the quality of flowering and fruit setting;
- optimizes sugar transport, ensuring sufficient energy for the development of the olives.
These benefits highlight the importance of providing the plant with adequate amounts of boron at the right time.
Apply boron before flowering
The application of boron should take place approximately one month before flowering, a strategic period to ensure that the plant has this nutrient available during critical phases. Boron enters plant cells mainly in the form of boric acid (H₃BO₃), a small, neutral molecule that crosses cell membranes by passive diffusion. This process requires no energy and allows boron to move from tissues with a higher concentration to those with a lower amount.
The one-month period before flowering allows the plant to absorb and distribute boron in good time, preparing it for the nutritional needs of subsequent stages, such as pollen fertility and fruit formation.
Boron absorption problems
Although boron is naturally present in soils, its availability for the olive tree can be limited by several factors:
1. calcareous soils: in soils rich in limestone, boron is immobilized, reducing its bioavailability;
2. drought: lack of moisture hinders the movement of boron towards the roots;
3. leaching: In sandy or over-watered soils, boron may be leached out before the plant can absorb it.
To overcome these difficulties, fertilizers have been developed that contain boron in more easily absorbable forms.
Technological innovations: boron and ethanolamine
A recent innovation in the field of fertilization is theassociation of boron with ethanolamine. This organic substance is produced by the reaction between ethylene oxide, a gas that becomes liquid at temperatures below 10°C, and ammonia, which chemically binds to boron forming a stable and water-soluble complex.
This complex:
- prevents the precipitation of boron, keeping it available for the plant;
- overcomes the barriers of the leaf cuticle, facilitating its absorption;
- stabilizes nutrient solutions, improving the effectiveness of fertilization.
Once absorbed, boron complexed with ethanolamine is rapidly translocated into plant tissues, where it performs fundamental functions such as stabilizing cell membranes and transporting sugars.
Ultimately, the ethanolamine itself can be used by the plant as a source of organic nitrogen or degraded in plant tissues.
Examples of products that use this technology include:
- Boroplus (Syngenta): recommended with doses of 100-200 mL/hl in pre-flowering and post-fruit setting.
- Boltrac 150 (Yara Italia): applied in doses of 1-1,5 litres per hectare in pre-flowering.
- Boro Axibor (Scam): indicated for foliar application with dosages of 1-1,2 kg per hectare, to be applied every 10 days during flowering.
- Borosprint (The Green Country): recommended to improve fruit setting, with doses of 200-250 g per 100 litres of water.
- Boro (Serbia): to be applied by foliar application in 2-3 treatments with doses of 150-350 g/hl or through fertigation with 7-10 kg/ha.
Boron Absorption and Functions
When applied by foliar application, boron is absorbed by the olive tree within 24 hours. Once inside, it binds to the pectins present in the cell walls, contributing to the structural stability of the tissues.
This cellular strengthening is important for:
- leaves, which improve resistance to environmental stress;
- the flowers and the pollen, which increase fertility and reproductive quality;
- the pollen tubes, essential for the transport of male genetic material to the egg.
During fruit formation, boron maintains the cohesion of cells in the mesocarp, contributing to the final quality of olives. In addition, boron participates in critical metabolic processes, such as sugar transport and protein synthesis for cell division.
Synergies with boron, zinc and wood distillate
The combined use of boron, zinc and wood distillate represents an innovative approach to improve the health and productivity of olive trees. This synergy is particularly effective thanks to the complementary properties of the two micronutrients and is part of the BioDea protocol, where boron strengthens cell walls, stabilizes membranes and optimizes the transport of sugars, which are essential for the growth and formation of fruit.
Lo Zinc supports the synthesis of plant hormones, such as auxins, promotes the formation of young tissue and acts as a catalyst in numerous enzymatic reactions, including protein synthesis.
Il wood distillate due to the presence of acetic acid and alcohols, low molecular weight compounds, they easily penetrate the leaf cuticle and cell membranes, facilitating the absorption of boron and zinc and their distribution in plant tissues.
Boron Calcium and Amino Acids
Combinations of boron with calcium or amino acids represent solutions that improve nutrition and, here too, exploit synergistic properties such as calcium, essential for cell structure, contributes to the formation of robust cell walls, amino acids, facilitate the absorption of nutrients, including boron and calcium, stimulate plant metabolism, promoting protein synthesis and cell growth, act as biostimulants.
On the market we find products such as:
- Glibor Ca (Biolchim), which combines boron with calcium to strengthen cell structure.
- Ilsamin Boro (Ilsa), enriched with amino acids to facilitate the absorption of boron and enhance metabolic processes.
Conclusion
In conclusion, boron is an important micronutrient for olive trees, its application pre-flowering and post-fruit setting, together with the support of synergies such as that with zinc and other technological products, represents a step forward for efficient and sustainable agricultural management. Technological innovations, such as the use of boron complexed with ethanolamine, have already improved the efficiency of absorption and application of this element.
Nanofertilizers are also being studied, which could be able to release boron in a controlled way and optimize its absorption by plants.
