The importance of nutrition in olive flowering

The olive tree is a crop of great importance throughout the Mediterranean basin and the Spanish territory. Being Spain one of the main producing countries, nowadays we are at the forefront of cultivation techniques, varieties and nutrition of the olive grove. Due to the great importance of this crop, we talk about nutrition in olive flowering.

The intensive olive grove area is becoming increasingly important, with very reduced planting frames and higher production. However, it is also more dependent on the management and cultural techniques used.

Regarding the olive grove and its nutrition, flowering and fruit set is one of the most critical and important phenological stages of the whole cycle, significantly influencing the productivity of the olive tree, flowering and fruit set. When the flower bud emerges, flowering treatments are initiated to provide the nutritional resources that the olive grove needs at this stage.

This nutritional balance of the olive grove, which begins with the fruit filling of the previous season, leads to a significant increase in the number of fruit set. In this regard, although the olive grove produces a very high number of flowers, only between 1 and 2% of them reach fruit set.

Nutritional needs of the olive grove in bloom

The availability of nutrients in the olive orchard can condition the number of viable flowers and fruit at the fruit set stage. Flowers are consumers of sugars and carbohydrates, so it is important to haveprevious reserves in the tree to achieve remarkable productive results. Therefore, we say that the relationships between mineral nutrition of the olive tree, flowering and productivity are complex and depend on environmental factors such as water availability and winter cold.

In addition, a sustainable and balanced fertilization program is vital to achieve proper flowering and fruit set. This results in optimal yields once the oil production process (lipogenesis) is initiated.

Therefore, an adequate and available nutrition will favor the fruit formation during its development, mainly increasing the olive yield. Thus, the 3 main nutrients in olive orchard nutrition are nitrogen, phosphorus and potassium. Both nitrogen and phosphorus are important for the formation of plant mass and for correct root development, especially in young seedlings. On the other hand, potassium is important from the beginning of fruit set, fundamental to achieve adequate water mobility, reduce summer stress and favor fat accumulation.

Among the micronutrients, boron has a special role in olive trees, especially during the fruiting period. This element is important in the formation of pollen for good fertilization, and is a fundamental nutrient in the development and maturation of pollen. In addition, it accumulates mainly in the reproductive tissues and to a lesser extent in the vegetative organs. It also influencesprotein synthesis and phosphorus assimilation.

During the flowering season, the nutritional needs for boron and phosphorus increase and with an adequate supply of these nutrients, a more uniform flowering and a higher percentage of viable flowers are achieved.

Recommended nutrients in this phase

Together with mulch or fertigation nutrition, olive orchards are a crop that favors foliar applications of nutrients and biostimulants. Flowering, being a sensitive and critical phase, is a very favorable time for this type of treatment. In addition to the preventive products for repyllication, stimulants for rapid energy supply or phytohormones that regulate the flowering and cellular differentiation processes are usually applied.

Amino acids: Amino acids in pre-flowering and flowering provide an energetic stimulus necessary to give viability to flowers and boost the fruit set process. However, they are not very important in the physiological processes related to phytohormones. It is important that the amino acid contains a complete aminogram to satisfy the demand for each of them. This is because there are special formulations adapted to olive flowering.

Seaweed extracts: Seaweed extracts provide nutrients that are not present in the fertilizers commonly used, such as different oligosaccharides, enzymes, vitamins and phytohormones. In particular, the flowering and fruit set of the olive grove is favored when these types of products are used, as they manage to balance the physiology of the olive grove to increase its receptivity to flower fertilization. One of the most recommended seaweed extracts for this phase, especially for its auxin and cytokinin ratio, is Ecklonia Maxima, from the South African coasts.

Amino acids (Agran Amino): contains natural enzymatic hydrolysis and is rich in organic nitrogen.