Optimization of Postharvest Quality and Structural Resistance in Roses through Foliar Application of Calcium and Potassium

By: Eng. Christian Molina G.

Technical and Commercial Manager “Crop Protection” – Agrocelhone del Ecuador Cía. Ltda.

Introduction

In modern, highly competitive floriculture, maximizing yield and commercial quality is essential for accessing international markets. Achieving this requires efficient and strategic management of plant nutrition. Calcium (Ca) and Potassium (K) are two essential elements in this process; however, their assimilation from the soil is often limited by ionic antagonisms or climatic conditions.

To address this challenge, Agrocelhone del Ecuador Cía. Ltda. presents CALCIO 24 in its high-tech portfolio , a foliar fertilizer designed with an optimal balance of Calcium (24%) and Potassium (7.81%). Its direct foliar application is the fastest and most efficient strategy for correcting latent deficiencies, enhancing the structural health and biological competitiveness of rose crops.

Physiological Synergy: The Role of Calcium and Potassium

• Calcium (Ca - 24%): It is the main structural component of cell walls, where it acts by binding pectin chains to provide rigidity and stability to tissues. It also participates as a secondary messenger in plant signaling and defense mechanisms, increasing the plant's natural resistance against opportunistic pathogens and environmental stressors.

• Potassium (K - 7.81%): Acts as the plant's main osmotic regulator, controlling stomatal opening and closing, water balance, and photosynthesis. It also catalyzes the activation of more than 60 enzyme systems and is responsible for mobilizing sugars and starches to flower buds, directly influencing their size, color, and vase life.

Methodology and Field Trial (Efficiency Evaluation)

With the aim of evaluating the biological impact of CALCIO 24 , a field trial was carried out in a commercial plantation of Freedom variety roses, located in the province of Pichincha, Ecuador.

Treatment 1: CALCIUM 24 , with bi-weekly foliar application at a dose of 1.0 g/l.

Control Farm: Corresponding to the standard program of foliar calcium fertilization of the farm using a commercial product from traditional sources.

Variables evaluated

The size of the flower bud at harvest, vase life, incidence of Botrytis cinerea , and concentration of calcium fixed in the bud tissue, expressed as a percentage of dry matter, were measured.

Field Results

1. Flower Bud Size: Thanks to the translocating action of potassium (7.81%) in the formula, roses treated with CALCIO 24 showed an average increase of 11% in bud diameter compared to the control. Visually, the flowers exhibited a more intense and homogeneous color due to the optimal synthesis and transport of sugars and anthocyanins.

2. Vase Life: Commercial stems evaluated under the CALCIUM 24 treatment maintained their cell turgor and firmness for an additional 3.5 days compared to the control, efficiently delaying cell senescence processes during the transport stage.

3. 3. Tolerance to Phytopathogens ( Botrytis cinerea ): Strengthening the cell walls decreased the susceptibility of the petal tissue to enzymatic penetration by fungi. Evaluations reflected a 30% reduction in the incidence of Botrytis in the blocks treated with CALCIO 24 compared to the control.

4. Calcium Concentration: Chemical tissue analysis revealed that plants treated with CALCIO 24 reached a calcium concentration of 0.38% in the flower bud, exceeding the 0.24% obtained with the control. This increase demonstrates the product's superior penetration and translocation capacity, overcoming the natural immobility barrier of calcium to organs with low transpiration rates.

Comparison of commercial and nutritional quality parameters

Variable Evaluated	Witness	Calcium 24 Treatment	Result
Button Diameter (cm)	5.3	5.9	(+11.0%)
Incidence of Botrytis (%)	12.4	8.7	(-30.0%)
Life in a Vase (Days)	11.2	14.7	(+3.5 days)
Calcium in Bud (% dry matter)	0.24	0.38	(+58.3%)

Conclusions

• The data collected showed that the advanced formulation, solubility and nutritional balance of CALCIO 24 generated statistically significant differences and a notable superiority over the Control.

• The combination of Calcium and Potassium in CALCIO 24 acts as a biotechnological tool of high foliar assimilation, demonstrating a physiological efficiency far superior to the Control by correcting critical deficiencies and mobilizing sugars towards the bud at key stages.

• The analytical and mechanical results confirm that the systematic use of this product significantly raises the physical and nutritional quality parameters of the flower compared to conventional management, reducing losses due to discarding and Botrytis .

Usage Recommendations

• Preventive Program: It is recommended to replace traditional sources of low translocation calcium with CALCIUM 24 , incorporating it constantly into the foliar program at a dose of 1.0 g/l with weekly or bi-weekly frequencies during the phases of greatest elongation.

• Application Versatility: Thanks to the high purity and solubility properties of its raw material, CALCIO 24 can be applied with absolute safety not only via foliar application, but also through fertigation systems, drip injection or directed applications (drench).

"CALCIO 24 : The strategic ally of the Ecuadorian flower grower for superior vigor, loss-free production with export quality. Innovation and nutritional precision within your reach."