Optimizing postharvest quality and structural strength in roses through Foliar Calcium and Potassium applications

By: Eng. Christian Molina G.

Technical and Commercial Manager – Crop Protection Division

Agrocelhone del Ecuador Cía. Ltda.

Introduction

In today's highly competitive floriculture industry, maximizing yield and commercial quality is essential for accessing international markets. Achieving this goal requires efficient and strategic plant nutrition management. Calcium (Ca) and Potassium (K) are two indispensable nutrients in this process; however, their uptake through the root system is often limited by ionic antagonisms and adverse environmental conditions.

To address this challenge, Agrocelhone del Ecuador Cía. Ltda. offers CALCIO 24, a high-technology foliar fertilizer formulated with an optimal balance of Calcium (24%) and Potassium (7.81%). Direct foliar application provides the fastest and most efficient strategy to correct latent deficiencies, enhancing structural integrity and biological competitiveness in rose crops.

Physiological Synergy: The Role of Calcium and Potassium

Calcium (Ca – 24%)

Calcium is the primary structural component of cell walls, where it binds pectin chains to provide rigidity and stability to plant tissues. It also functions as a secondary messenger in plant signaling and defense mechanisms, increasing the plant's natural resistance to opportunistic pathogens and environmental stress factors.

Potassium (K – 7.81%)

Potassium acts as the plant's main osmotic regulator, controlling stomatal opening and closure, water balance, and photosynthesis. Additionally, it activates more than 60 enzymatic systems and is responsible for transporting sugars and starches to flower buds, directly influencing flower size, coloration, and vase life.

Methodology and Field Trial (Efficiency Evaluation)

To evaluate the biological impact of CALCIO 24, a field trial was conducted in a commercial plantation of the Freedom rose variety located in Pichincha Province, Ecuador.

Treatment 1

CALCIO 24, applied as a foliar spray every two weeks at a rate of 1.0 g/L.

Farm Control

The farm's standard calcium foliar fertilization program using a conventional commercial calcium source.

Evaluated Variables

The following parameters were measured:

• Flower bud size at harvest

• Vase life

• Incidence of Botrytis cinerea

• Calcium concentration fixed within bud tissues, expressed as a percentage of dry matter

Field Results

1. Flower Bud Size

Thanks to the translocation effect of the potassium (7.81%) contained in the formulation, roses treated with CALCIO 24 showed an average increase of 11% in bud diameter compared to the control. Visually, the flowers displayed more intense and uniform coloration due to enhanced sugar and anthocyanin synthesis and transport.

2. Vase Life

Commercial stems treated with CALCIO 24 maintained cellular turgidity and firmness for an additional 3.5 days compared to the control, effectively delaying cellular senescence during transportation and postharvest handling.

3. Tolerance to Phytopathogens (Botrytis cinerea)

The strengthening of cell walls reduced petal tissue susceptibility to fungal enzymatic penetration. Evaluations showed a 30% reduction in Botrytis incidence in plots treated with CALCIO 24 compared to the control.

4. Calcium Concentration

Tissue analysis revealed that plants treated with CALCIO 24 reached a calcium concentration of 0.38% in flower buds, compared to 0.24% in the control. This increase demonstrates the product's superior penetration and translocation capabilities, overcoming calcium's natural immobility toward low-transpiration organs.

Comparison of Commercial Quality and Nutritional Parameters

Variable Evaluada	Testigo	Tratamiento CALCIO 24	Resultado
Diámetro del Botón (cm)	5.3	5.9	(+11.0%)
Incidencia de Botrytis (%)	12.4	8.7	(-30.0%)
Vida en florero (Días)	11.2	14.7	(+3.5 días)
Calcio en Botón (% materia seca)	0.24	0.38	(+58.3%)

Conclusions

• The collected data demonstrated that the advanced formulation, solubility, and nutritional balance of CALCIO 24 generated statistically significant differences and superior performance compared to the control treatment.

• The combination of Calcium and Potassium in CALCIO 24 functions as a highly assimilable biotechnological tool for foliar nutrition, showing significantly greater physiological efficiency than the control by correcting critical deficiencies and promoting sugar translocation to flower buds during key developmental stages.

• Analytical and mechanical results confirm that the systematic use of this product significantly improves both physical and nutritional quality parameters of cut flowers compared to conventional management practices, reducing losses caused by culling and Botrytis infection.

Recommendations for use

Preventive Program

It is recommended to replace traditional low-translocation calcium sources with CALCIO 24, incorporating it consistently into foliar nutrition programs at a rate of 1.0 g/L with weekly or biweekly applications during periods of active stem elongation.

Application Versatility

Thanks to the high purity and solubility of its raw materials, CALCIO 24 can be safely applied not only as a foliar spray but also through fertigation systems, drip injection, or directed soil applications (drench).

CALCIO 24

"The strategic ally of Ecuadorian flower growers for superior plant vigor, reduced losses, and export-quality production. Innovation and nutritional precision within your reach."