In an industry of blueberry which increasingly incorporates biostimulants, physical protectants, regulators and nutritional alternatives, testing well before scaling helps to make more accurate management decisions that are better suited to the reality of the field.

During Blueberries Mexico 2026, Daniel Díaz, Reinaldo Campos and Gerardo Arias agreed on a practical criterion for producers, advisors and exporters: measure in the field before taking a technical decision to a commercial scale.

Public inquiries about biostimulants, kaolin, titanium, nitrogen, brassinosteroids, zinc, and boron led to this approach being applied to specific management situations. blueberriesThe specialists emphasized observing the plant, testing with a method, comparing results, and evaluating each alternative according to the crop, phenological stage, and desired productive outcome.

Daniel Díaz, Reinaldo Campos and Gerardo Arias at the XLI International Blueberries Seminar Mexico 2026 © Blueberries Consulting

Test on a small scale before scaling up

The question about titanium during flowering and its potential effect on pollen viability opened one of the most cross-cutting topics of the conversation. Daniel Díaz pointed out that the available evidence is still limited and that the background information comes from a few studies, under specific conditions and species.

Reinaldo Campos reinforced this view from a practical perspective. Faced with products that still had partial evidence, he proposed a concrete path: test in limited areas, measure, compare, and scale up when the measurements support it.

Campos also drew attention to products that generate striking visual responses in the plant, but which need to demonstrate an effect on weight, firmness, diameter, or fruit quality. This distinction is especially relevant in an industry that is constantly evaluating new nutritional, biostimulant, or regulatory alternatives.

For producers and exporters, the key point is operational: a technology must demonstrate measurable results before allocating land and influencing program decisions. Field experience gains value when it is built upon data and allows for distinguishing between a visual response and a verifiable productive outcome.

Reinaldo Campos at the XLI International Blueberries Seminar Mexico 2026 © Blueberries Consulting

Anticipating stress from plant signals

In the section on biostimulants, Daniel Díaz steered the discussion towards physiological anticipation. In response to a question about glycine betaine, he explained that the strategy must consider the type of stress and the advance signals the plant provides.

In heat waves, he noted that there is a window of opportunity to intervene before the stress reaches its peak. Indicators such as slower growth or shorter internodes can signal that the plant is entering a critical condition.

Díaz further differentiated the active ingredients according to the type of environmental pressure. For drought or salinity, he mentioned compounds such as glycine betaine or proline, which are more closely associated with those responses. In the case of heat, the choice may include other components, always depending on the specific condition and the expected effect.

The choice of biostimulant becomes more precise when it responds to a signal from the plant, the type of condition that is being addressed, and the moment when the intervention can best support the physiological response of the crop.

Daniel Díaz at the XLI International Blueberries Seminar Mexico 2026 © Blueberries Consulting

Nutrition and vigor within the productive objective

The relationship between excess nitrogen, ascorbic acid, and reactive oxygen species shifted the conversation towards vigor, succulence, and physiological balance.

Daniel Díaz suggested that nitrogen levels exceeding the plant's metabolic capacity can lead to increased succulence and, consequently, greater susceptibility to certain stress conditions. From this perspective, nitrogen management should maintain vegetative growth within the target production range.

Reinaldo Campos elaborated on the answer, explaining that reactive oxygen species perform normal functions in the plant when kept at low levels. When faced with heat and stomatal closure, the plant continues to receive light energy, but its capacity to use it for photosynthesis is reduced; this is where maintaining physiological balance and active antioxidant systems becomes increasingly important.

For growers and technical teams, the key is to connect nutrition, vegetative balance, and physiological response before the problem manifests in the fruit. In this sense, nitrogen requires a dosage aligned with the growth objective and the anticipated stress conditions.

Kaolin: actual coverage, conductance, and permanence

Gerardo Arias answered several questions about kaolin, including color formulations, comparison with diatomaceous earth, coverage, rain, and possible effects on the leaf.

Regarding colored kaolin, he explained that this alternative is also used to reduce solar radiation stress. When that is the goal, the color can affect its ability to reflect light. For thrips management, however, the critical point remains coverage, especially on the underside of the leaf, where much of the oviposition occurs.

Given concerns about potential hardening of the wood, Arias shifted the evaluation to a more precise indicator: stomatal conductance. He explained that in his measurements, kaolin showed no significant negative effect on this parameter, while diatomaceous earth showed a slight impact.

He also clarified that both kaolin and diatomaceous earth act as physical barriers, not insecticides. Their function is to hinder feeding and egg-laying, thus delaying the establishment of the pest. In his assessments, he also observed that diatomaceous earth tends to decompose more quickly than kaolin.

Arias emphasized the importance of checking the actual deposit on the plant, observing the underside of the leaf, using appropriate adjuvants, and evaluating production variables such as flowering, yield, and crop response. In rainy areas, the product's persistence on the plant should guide the application frequency.

Gerardo Arias at the XLI International Blueberries Seminar Mexico 2026 © Blueberries Consulting

Dose, species, and evidence before extrapolating

Questions about brassinosteroids, zinc, and boron reinforced the importance of adjusting each intervention to the species, dose, physiological event, and crop stage.

Regarding brassinosteroids, Daniel Díaz explained that they can interact with ethylene, although this relationship changes depending on the concentration and physiological process. At high doses, even small amounts can alter the expected response. Reinaldo Campos added that hormones work at very low concentrations and that when the dosage is taken to an extreme, ethylene can become involved.

Regarding zinc and boron, Díaz used the pecan tree as a reference, where zinc has a well-documented role in early growth stages and flower quality. Based on this example, he cautioned that evidence from one species should be carefully interpreted before being applied to other crops.

En blueberriesThe decision should consider available information, the element's mobility, the phenological stage, and the management goal. The value of these alternatives depends on the species, the dose, the stage, and the available evidence.

XLI International Blueberries Seminar Mexico 2026 © Blueberries Consulting

From visual effect to measurable result

For producers, consultants, and exporters, the conversation reinforced an operational criterion: test on a limited scale, measure with relevant variables, and scale up what demonstrates an effect on the plant, fruit, and commercial performance.

In biostimulants, kaolin, nutrition, regulators, or micronutrients, each alternative must be linked to the type of stress, the phenological stage, the plant's response, and the desired commercial outcome. This work allows for the separation of visual effect, physiological response, and measurable productive result.

For an industry of blueberry Increasingly demanding, measuring before scaling allows for better-informed technical decisions. The criterion has been established: test methodically, observe with data, and scale only what demonstrates a measurable effect on the plant, fruit, and commercial performance.

Check out the summary of the 41st International Blueberries Seminar Mexico 2026 on our channel. Youtube Blueberries TV

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