Ultrasol K and Ultrasol SOP 52 have a positive effect on mango flower induction

During September 2008, Steve Oosthuyse (SQM Africa) and Claudio Vicencio (SQM Latin America) visited the mango-producing regions of Ecuador, Peru, and northern Brazil.

In regions close to the equator, such as Ecuador, northern Peru, and northern Brazil, floral induction in mangoes is essential to ensure the economic viability of the crop.

Since these regions do not have distinct seasons, the success of flowering depends on rigorous and well-scheduled technical management.

The importance of floral induction in mango

The foliar application of Ultrasol® K at the appropriate stage of terminal bud maturation is a key measure to stimulate mango flowering.

Successful floral induction is achieved through a precise sequence of post-harvest treatments during the vegetative sprouting phase.

The role of stress in florigen production

Mango trees require environmental stress (such as drought and low temperatures) to induce the production of florigen, the hormone responsible for initiating the flowering process.

Although florigen has not yet been chemically identified, its existence is supported by numerous studies.
Ideal conditions for florigen production:

• Night temperatures below 20 °C
• Moderate water stress during terminal bud development
• Synchronization between stress and the early stages of sprouting

When these conditions are met, latent buds can transform into inflorescences if florigen is produced in adequate quantities during their development.

Growth inhibitors: Gibberellic acid and Paclobutrazol

Gibberellic acid (GA) acts as a natural inhibitor of floral development in mango. High GA levels are associated with vegetative budding, so reducing its concentration is necessary to stimulate flowering.

How is GA reduced in mangoes?

• Post-harvest pruning to induce synchronized sprouting.
• Application of paclobutrazol to the soil around the trunk. This compound:
• Inhibits GA synthesis.
• It is absorbed by the roots.
• It is transported to terminal buds through the xylem.

Once the terminal bud leaves mature (dark green color), a foliar application of:

• Ethephon
• Ultrasol® SOP 52

These products help prevent early bud break and create a hormonal environment conducive to flowering.

Integrated strategy for successful flowering

The proper combination of controlled stress, hormonal inhibitors, and foliar nutrition is key to achieving intense and uniform flowering.

Recommended products for mango floral induction:

• Ultrasol® K: Stimulates florigen production during bud maturation.
• Paclobutrazol: Inhibits gibberellic acid production, promoting floral induction.
• Ultrasol® SOP 52: Strengthens terminal buds and prevents premature sprouting.
• Ethephon: Complements the hormonal environment for successful flowering.

Managing floral induction in mango trees in equatorial zones requires a technical and precise approach.

Coordination between pruning, hormone control, water stress, and foliar nutrition maximizes flowering and ensures crop profitability. Products such as Ultrasol® K, paclobutrazol, and ethephon play a fundamental role in this strategy.