Zereno Application Verification on Mexican White Onions: Stability Under Extreme High-Humidity Conditions and Optimized Product Structure Performance

In agricultural production, climate uncertainty often presents more challenges than the technology itself. This is especially true during seasons of prolonged rainfall and high soil moisture, where yield reduction, deformed crops, and root diseases become “normal risks.” In the 2025 growing season, a collaboration with a major white onion grower in Mexico’s largest planting region allowed us to conduct a real-world, quantifiable test under these extreme conditions.

Note: Zereno is the local brand name for Max's Youmai Shi in Mexico.

An Unfavorable Test Environment: A Test of Resilience

Crop: White Onions

Climate Conditions: Significantly higher than usual rainfall during the growing season

Primary Risks: Increased occurrence of pink root; root function damage; uneven plant growth; severe product specification variation

In such a scenario, the test was not about achieving high yields under ideal conditions, but about answering a more practical question: How can crops perform more stably and with higher commercial value in adverse environments?

Technical Approach: A Coordinated Treatment Strategy with Zereno

The trial utilized a combination of Zereno and microbial inoculants and compared the results with conventional control treatments. From the start, the focus of this trial was not on a single indicator, but on three key areas:

• Root Health
• Overall Plant Growth
• Final Product Specification and Structure

Key Results: Structural Optimization Rather Than Just Yield Increase

During the challenging year with heavy rainfall, the trial fields presented a set of highly valuable data points:

• Overall Yield: Increased by 8% compared to the control
• Large-sized Onions: Increased by 27%
• Medium-sized Onions: Increased by 2%
• Small-sized Onions: Decreased by 10%

This data shows that the yield increase was not only due to an increase in the number of onions, but rather a clear optimization of the product structure.

Root Health: The Critical Difference in High-Humidity Conditions

A key observation in the high-humidity environment was the significantly lower incidence of pink root in the onions treated with Zereno compared to the control. Furthermore, the synergistic effect of Zereno amplified this advantage:

• Longer Root Vitality
• Higher Nutrient Absorption Efficiency
• More Balanced Growth Above Ground

As a result, even under unfavorable climatic conditions, the plants maintained robust growth and uniformity.

From Trial Results to Economic Impact: A Positive Shift in Profit Structure

While an 8% yield increase is already impressive, what truly convinced the customer and grower was the shift in profit structure. After using the Zereno + microbial inoculants treatment, calculations based on the market prices of different sized onions showed an additional net profit of approximately 50,000 pesos.

This further validates a key point: The value of agricultural inputs is not only reflected in “how much more you can harvest,” but in “how well you can sell it.”

Core Value of the Case: Beyond One Season’s Data

This is not a story of Zereno’s success in “ideal conditions.” In fact, it’s the opposite: it was carried out in a year with excessive rainfall and under the pressures of root diseases and growth imbalances. What was tested here was the stability and reliability of the product in adverse conditions.

Zereno’s value to customers is not a short-term growth stimulant, but rather:

• Helping crops maintain growth rhythm under harsh conditions
• Optimizing product specification structure and reducing low-value output
• Turning uncontrollable climatic risks into manageable differences in results

In an Uncertain Environment, Verifying Truly Reliable Solutions

The most valuable products often don’t stand out during favorable conditions, but instead demonstrate consistent results during difficult years of heavy rainfall, high humidity, and compounded stress. This is why Zereno is consistently tested and proven in different countries and on various crops.