Modulating tiller formation in cereal crops by the signalling function of fertilizer nitrogen forms

This study investigates the hypothesis that different nitrogen (N) fertilizer forms can manipulate tiller number in cereal crops. Hydroponically grown barley showed increased tiller numbers with exclusive nitrate supply compared to urea or ammonium. This correlated with higher root-to-shoot translocation of cytokinins. External cytokinin application further stimulated tillering in nitrate, but not urea treatments. Nitrate also increased the translocation of a synthetic cytokinin analog. Field trials with winter wheat confirmed that nitrate fertilization dose-dependently increased tiller number, with significant genotypic variation observed across cultivars. The findings suggest that cytokinin-mediated signaling from fertilizer N forms can be used to regulate tiller number in cereal crops.

Bernhard Bauer, Nicolaus von Wirén