Tillering

Tillering is the process by which new shoots, or tillers, arise from the base of a grass or cereal plant, increasing the number of stems per plant. Tillers typically originate from axillary buds located at or near the crown and may develop into flowering stems (reproductive tillers) or remain vegetative.

In cereals and grasses, tillers add to leaf area and photosynthetic capacity and can contribute to grain yield when they mature and bear panicles or ears. The tillering pattern is influenced by genetics and environment, and it can occur in waves during early vegetative growth. Some tillers remain small and abort, while others develop fully and produce reproductive organs.

Factors affecting tillering include temperature, light intensity, photoperiod, and planting density. Hormonal signals, such as auxins, cytokinins, and gibberellins, interact to regulate axillary bud outgrowth and apical dominance. Nutrient status, especially nitrogen, strongly affects tiller number: adequate nitrogen often promotes more tillers up to an optimum, while deficiency reduces tillering. Water availability and stress conditions can also suppress tiller formation or cause tiller loss. Crowded stands with limited resources tend to have fewer productive tillers due to competition.

Significance in agriculture centers on tiller number as a component of yield in cereals. Producers manage tillering through sowing density, cultivar choice, and nutrient and water management to balance the potential advantages of more tillers with the risks of reduced panicle size or lodging.