Wheat tillering: how to reach the optimal number of tillers?
Tillering: the first and decisive yield component in wheat
Tillering is the first yield component established during the wheat cycle. It has a strong genetic determinism, but field conditions often prevent crops from reaching the optimal number of tillers by the end of winter. When tillering is not optimal, yield losses can reach up to 70%, making this stage a strategic lever for performance.
The objective at the end of winter is clear: secure a sufficient and homogeneous number of fertile tillers per square meter to prepare stem elongation and grain formation under the best possible conditions.
Root development: the hidden driver of tiller formation
While genetics define the potential, root system development plays a decisive role in expressing that potential.
There is a clear relationship between primary root development and tiller number, with approximately one additional tiller for every three additional adventitious roots. This highlights the strong physiological link between below-ground growth and above-ground architecture.
An efficient secondary root system, which develops from the tillering stage onwards, is essential to:
A well-developed root system limits tiller regression during stem elongation and secures the conversion of tillers into productive ears.
Nitrogen efficiency and tiller survival
Tillering is closely linked to nitrogen availability and plant nitrogen use efficiency. Insufficient nitrogen uptake at this stage leads to weak tillers and increases the risk of regression before stem elongation.
Field trials on winter wheat have demonstrated that stimulating root development at tillering improves nitrogen use efficiency by around 8% on average. This improvement translates into better nutrient valorisation and more stable tiller survival.
In addition, optimized root systems have shown increases of 0.4 to 0.5 t/ha compared to untreated controls under similar conditions. These gains confirm that working on root functionality during tillering directly impacts final yield.
Strengthening wheat resilience during tillering
Wheat is particularly sensitive to stress during tillering, especially hydric stress. Climate variability has increased the frequency of water deficits occurring earlier in the cycle, including at vegetative stages.
Promoting secondary root development between tillering and the second node stage enhances water absorption capacity and reduces the risk of tiller abortion under stress conditions.
Phosphorus nutrition at tillering, as a complement to base fertilization, has shown positive effects on maintaining tiller numbers under both vegetative and reproductive water stress scenarios. Improved nutrient uptake and root exploration capacity are key to stabilizing yield components.
Agronomic strategies to reach the optimal number of tillers
Reaching the optimal number of tillers requires a comprehensive approach combining:
- appropriate sowing density and variety choice
- early root stimulation
- targeted nutrition at BBCH 21–25
- efficient nitrogen management
Applying biostimulant or phosphorus-based solutions at tillering can enhance root growth, stimulate tiller formation and improve nitrogen absorption, while also increasing cold tolerance.
By securing root functionality at this early stage, growers can reinforce wheat structure before stem elongation and safeguard yield potential.
From tiller number to grain performance
Optimizing tillering is not an isolated objective. It conditions the number of ears per square meter, which remains one of the main determinants of final yield.
Beyond tillering, supporting grain filling through enhanced photosynthetic activity and late nitrogen availability contributes to higher thousand kernel weight and improved protein content.
Securing the optimal number of tillers at the end of winter therefore represents a strategic milestone in wheat crop management, linking early root performance to final grain quality and yield stability.
