Copper, Sulfur and Silicon: Nutrients That Strengthen the Plant's Natural Defenses

Q: Is complexed copper better than traditional copper?

As a fertilizer, yes: it's absorbed and moves better in the plant, with lower doses and a lower risk of phytotoxicity.

Q: What is silicon used for in plants?

It strengthens cell walls, gives rigidity to leaves and stems, and improves tolerance to external damage and stress.

Q: Are copper, sulfur and silicon fertilizers plant protection products?

No. They are fertilizers; for pest and disease control, authorized plant protection products must be used.

Quick answer: copper is a micronutrient that activates enzymes and stimulates the plant's own production of defensive compounds (polyphenols and phytoalexins). Sulfur and silicon harden cell walls and make tissues more resistant. Applied as fertilizers, mainly as a preventive measure, they help the crop arrive better prepared for high-risk periods. They do not replace authorized plant protection treatments.

What each nutrient provides

Copper (Cu): involved in photosynthesis and lignin formation; its deficiency causes weak shoots and misshapen leaves.
Sulfur (S): needed to form proteins and defense compounds.
Silicon (Si): deposits in the cell wall and gives mechanical rigidity to leaves and stems.

Which product to choose

Product	Composition	Recommended for	Recommended dose
Cuprea	5% soluble copper (4% complexed) with wetting and sticking adjuvants	Vegetables, fruit trees and citrus, at the start of the cycle and during peak vegetative activity	Fertigation 6-10 L/ha · Foliar 1-1.5 L/ha
Cuprea Vital	Liquid fertilizer rich in copper	Correcting copper deficiencies	Ask our team
Raíz Fuerte	Copper complexed with amino acids and organic molecules of marine origin	Woody crops and vegetables: strengthens vigor and defenses in roots and crown	Foliar 1.5-2 L/ha
Brotalia	1.7% copper with systemic action	Stone and pome fruit trees: breaking winter dormancy, budbreak and fruit set	Fertigation 7 L/ha · Foliar 1.5-2 L/ha
Argenta	30% sulfur, 7% soluble silica, 6% K₂O, 0.2% iron	Grapevine, vegetables and fruit trees susceptible to powdery mildew, applied preventively	Foliar 1.5-3 L/ha

For humid periods, Fluvia combines boron and silica with a water-repellent effect that reduces moisture on the leaf.

When to apply them

End of winter and budbreak in fruit trees (Brotalia).
Before high-risk periods (humidity, sudden temperature changes): Cuprea or Argenta applied preventively.
Crops with recurring root and crown problems: Raíz Fuerte to improve root system vigor.

Precautions

Respect the recommended doses: excess copper can be phytotoxic, especially in sensitive crops or at high temperatures.
Don't mix sulfur-based products with mineral oils, and don't apply sulfur at temperatures above 28-30°C.
Run a mixing test before combining with other products.

Frequently asked questions

Is complexed copper better than traditional copper?

As a fertilizer, yes: complexed copper is absorbed and moves better within the plant, so a lower dose achieves better nutrition and a lower risk of phytotoxicity.

What is silicon used for in plants?

It strengthens cell walls, makes leaves and stems more rigid, and improves the plant's tolerance to external damage and stress.

Are these plant protection products?

No. They are fertilizers that improve plant nutrition and overall condition. For pest and disease control, authorized plant protection products for each crop must be used.

Questions about compatibility or timing? Ask our technical team. Also see: iron, zinc and manganese correctors.