title: Topology of a maize field: distinguishing the influence of end-of-day far-red light and shade avoidance syndrome on plant height.
abstract: Correlations were established between plant height and Cartesian position in a field of diverse maize (Zea mays) germplasm. The influence of the shade avoidance syndrome (SAS), a series of responses to lower photosynthetically active radiation (PAR) and red to far-red light ratio (R:FR) at high planting density, was detected by a steep increase of plant height from the edge to interior rows of the field. In addition, a gradual increase in height was observed across the field from east to west. We attribute this result to a R:FR gradient caused by sunlight laterally penetrating the stand at dusk. Furthermore, we hypothesize that the increased height of west-positioned plants may be analogous to responses induced by end-of-day FR (EOD-FR) treatments used by photobiologists to induce SAS in controlled environments. While preliminary, these results nevertheless suggest that a plant's position in a field will influence the impact of daily fluctuations in PAR and R:FR in modulating plant height and, potentially, other agronomically relevant traits.
authors.affiliation: Department of Plant Breeding and Genetics, Cornell University, Ithaca, NY, USA. patrice.g.dubois@gmail.com
authors.forename: Patrice G
authors.initials: PG
authors.lastname: Dubois
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Brutnell
mesh_terms: D008027:Light; D003313:Zea mays / Q000254:growth & development / Q000378:metabolism* / Q000528:radiation effects*