Impact of Available N on Yield Determination

Tillering is a stage of high physiological plasticity. When nitrogen is available from the beginning, the crop can sustain growth, leaf area development, and fertile tillers—three decisive factors for building yield potential early in the cycle.

In wheat, nitrogen use efficiency is not determined solely by the applied rate. Above all, it depends on the ability to synchronize nutrient supply with the stages in which the crop has the greatest plasticity to convert that availability into productive structures. In Argentine wheat production systems, where yield depends on early management decisions, environment, genetics, available water, and nutrition, tillering becomes a strategic stage: it is the moment when the crop still has the capacity to build a significant portion of its yield potential.

From a physiological standpoint, the crop is not only producing more leaves or increasing ground cover; it is defining how many secondary stems will survive, become fertile tillers, and ultimately contribute spikes per square meter. This component is one of the foundations of grain number per unit area, which is often the main determinant of final yield. Therefore, nitrogen availability at this stage should not be interpreted as a simple nutritional reinforcement, but as an intervention in the crop’s productive architecture.

Tillering: the Stage When the Crop Builds Its Potential

Available nitrogen first impacts canopy growth rate. A well-supplied plant sustains higher chlorophyll synthesis, greater photosynthetic activity, and improved leaf expansion. This increases leaf area index, allows the crop to intercept more radiation, and supports greater biomass production at a stage when the plant is forming the structure that will sustain reproductive demand later in the cycle.

When nitrogen is limiting, the plant reduces leaf expansion, accelerates senescence of basal tissues, and shifts into a resource-saving strategy, prioritizing the main stem and sacrificing tillers. This early loss is often not fully recovered with later applications.

Therefore, without available nitrogen, the plant captures less carbon, builds less tissue, and sustains fewer structures. During tillering, this restriction occurs precisely when the crop needs to convert vegetative growth into reproductive potential.

Nitrogen availability also has hormonal and signaling effects. An adequate nitrate supply promotes signals that stimulate tiller growth and nodal root development. In contrast, when the crop detects low nitrogen availability, internal competition among stems increases. Weaker tillers lose priority as sinks for photoassimilates and eventually abort. This is a key point: not all tillers that emerge become spikes. To a large extent, the difference is determined by the nutrition available at the time when those tillers are competing for resources.

NUE: Converting Applied Nitrogen into Spikes, Biomass, and Grain

For this reason, tillering—especially its early stages—is a period of high agronomic efficiency for intervention. The crop still has plasticity to adjust the number of fertile tillers, while already having enough leaf surface to respond to complementary strategies. Basal fertilization with phosphorus and nitrogen remains essential to ensure crop establishment, root development, and early growth, but nitrogen refertilization during tillering helps correct imbalances, support high-potential environments, and prevent the crop from entering a deficit during a critical stage.

Foliar fertilization adds a precision tool within this strategy. It does not replace diagnosis or basal fertilization, but it can improve the synchrony between nutrient supply and crop demand. During tillering, the crop has high metabolic activity and functional leaves capable of intercepting and absorbing nutrients.

If the formulation is efficient, stable, and high quality, foliar nutrition can complement available nitrogen without depending exclusively on nutrient movement through the soil.

Nanoparticle-based technologies provide an additional advantage within this approach. By working with small-sized mineral particles, high dispersion, and high purity, they support a more precise application, better contact with the leaf surface, and faster nutrient availability for the crop. In foliar fertilization, efficiency is not measured only by nutrient concentration, but by the formulation’s ability to reach, remain on, enter, and be used by the plant at the right physiological stage.

MIST N® by Kioshi Stone fits within this logic. It is a nitrogen foliar fertilizer developed with high-purity nanoparticle technology, supplying nitrogen together with calcium, magnesium, and sulfur. This combination supports processes related to photosynthesis, nitrogen metabolism, tissue stability, and enzymatic activity. Applied at the beginning of tillering, its technical role is to complement nitrogen nutrition when the crop is defining tillers, canopy development, and spike potential.

Impact and Field Results

The trial conducted by the Faculty of Agricultural Sciences of the National University of Lomas de Zamora during the 2025 season provides concrete field evidence of this concept. In wheat, using the DM Alerce variety under field conditions in Lobos, Buenos Aires province, the unfertilized T1 reached 3,580 kg/ha. T2, with 70 kg/ha of MAP at planting and 100 kg/ha of urea at Z2–Z3, achieved 3,931 kg/ha. However, T3, which maintained the same base of 70 kg/ha of MAP and 100 kg/ha of urea while also incorporating 2 L/ha of MIST N, reached 5,062 kg/ha.

The difference is agronomically relevant because it compares a complementary foliar strategy against a system that already included conventional fertilization. The treatment with MIST N outperformed the unfertilized control by 1,482 kg/ha and exceeded the MAP plus urea treatment by 1,131 kg/ha. This shows that efficiency does not depend only on adding more nitrogen to the system, but on improving timing, delivery method, and the crop’s ability to use nitrogen during a highly sensitive stage.

The central message is that a large portion of yield is conditioned from the beginning of tillering. If the crop reaches tillering with adequate nitrogen supply, it has a greater chance of sustaining fertile tillers, forming an efficient canopy, and building a solid foundation for grain number. If it reaches this stage under limitation, later applications may improve aspects such as greenness, grain filling, or protein content, but they are unlikely to fully compensate for lost tillers and reduced reproductive structure.