Calcium is an essential nutrient for fruit quality, since it is part of the cell wall and plays a key role in membrane integrity. Low calcium levels affect the selective permeability of membranes and lead to cell damage, necrosis and splitting in fruits. A deficiency of this mineral triggers characteristic symptoms known as: bitter pit in apples, cork spot in pears, blossom end rot in tomatoes…
Calcium is a low-mobility element and tends to accumulate in older organs, while tissues with greater metabolic activity (growing leaves, flowers, fruits and apical meristems) require a greater supply. Therefore, the deficiency of this macronutrient mainly affects parts that are forming as well as growing meristems, where calcium remains fixed and immobile in the cell walls. Given this immobility, old leaves may have normal calcium concentrations, whereas young leaves, fruits, or other organs may have levels that are below normal.
The concentration of calcium in fruits is the highest at the beginning of the season, when water and solutes are supplied mainly via the xylem. As the season progresses, the transpiration capacity of fruits decreases and they begin to depend on the phloem for nutrition. In this tissue, calcium solubility is very low and, therefore, the concentration of the nutrient is diluted as the fruits grow (Figure 1 – in Spanish).
Source Monge et al., 1994.
Furthermore, most of the calcium contained in plants is found in the central vacuoles and in the cell walls, said calcium being bound to certain polysaccharides called pectates. In the vacuoles, calcium usually precipitates as insoluble oxalate crystals.
Calcium pectates, present in the cell walls, are called bound calcium and they have a structural function; therefore, they are responsible for the firmness of fruit and maintaining its useful life (Figure 2 – in Spanish). Studies on fruit senescence have demonstrated that it depends on the level of calcium in the tissues. Increased levels of this element alter parameters such as respiration, protein content and membrane fluidity.
Improving calcium absorption, especially that intended for bound calcium, increases fruit quality and prevents certain physiopathies that reduce crop yields.
CITOMASTIC® is an enzymatic catalyst particularly suited to increase the photosynthetic rate and metabolic activity of crops. Applying CITOMASTIC® enables us to increase the translocation of essential macro and micro nutrients to reserve organs, as is the case with fruit.
In trials conducted under controlled conditions on the “sweet Italian” pepper variety, we successfully increased the presence of bound calcium in fruits, increasing the translocation of said element by 48% (T-student p<0.01), thanks to the application of CITOMASTIC® along with foliar calcium fertilisation.
We thus optimised calcium intake in times of greatest need, increasing the quality of the harvest and its useful life and reducing the possible emergence of physiopathies.
Source T-student p<0,01
Sources:
- Álvarez-Herrera, J. G., Fischer, G., & Vélez-Sánchez, J. E. (2015). Producción de frutos de uchuva (Physalis peruviana L.) bajo diferentes láminas de riego, frecuencias de riego y dosis de calcio. Revista Colombiana de Ciencias Hortícolas, 9(2), 222-233.
- Curetti, M., Raffo Benegas, M. D., Calvo, G., Rodriguez, A. B., & De Rossi, R. P. (2022). Importancia del calcio en el fruto y su relación con la calidad. EEA Alto Valle, INTA.
- Quinones, A., Martínez-Alcántara, B., Legaz, F., & Bermejo, A. (2015). Fraccionamiento del calcio en los distintos órganos de plantas jóvenes de cítricos cultivadas en distintas condiciones de aporte de calcio. Levante Agrícola, (425), 41-46.
- Bonomelli, C., Arias, M. I., & Villalobos, L. (2018). Adaptation and validation of a methodology for the measurement of calcium fractions in fruits. Communications in soil science and plant analysis, 49(6), 735-744.
- Dong, C. X., Zhou, J. M., Fan, X. H., Wang, H. Y., Duan, Z. Q., & Tang, C. (2005). Application methods of calcium supplements affect nutrient levels and calcium forms in mature tomato fruits. Journal of plant nutrition, 27(8), 1443-1455.
• Monge, E., Val, J., Sanz, M., Blanco, A., & Montañés, L. (1994). El calcio nutriente para las plantas. Bitter pit en manzano. INSTITUCIÓN “FERNANDO EL CATÓLICO”, 189.
