title: Assessment of plant biomass and nitrogen nutrition with plant height in early-to mid-season corn.
abstract: BACKGROUND
  The physiological basis for using non-destructive high-resolution measurements of plant height through plant height sensing to guide variable-rate nitrogen (N) applications on corn (Zea mays L.) during early (six-leaf growth stage, V6) to mid (V12) season is largely unknown. This study was conducted to assess the relationships of plant biomass and leaf N with plant height in early- to mid-season corn under six different N rate treatments.
  
  
  RESULTS
  Corn plant biomass was significantly and positively related to plant height under an exponential model when both were measured at V6. This relationship explained 62-78% of the variations in corn biomass production. Leaf N concentration was, in general, significantly and positively related to plant height when both were measured at V6, V8, V10 and V12. This relationship became stronger as the growing season progressed from V6 to V12. The relationship of leaf N with plant height in early- to mid-season corn was affected by initial soil N fertility and abnormal weather conditions.
  
  
  CONCLUSIONS
  The relationship of leaf N concentration with plant height may provide a physiological basis for using plant height sensing to guide variable-rate N applications on corn.
authors.affiliation: Department of Plant Sciences, The University of Tennessee, Jackson, TN 38301, USA. xyin2@utk.edu
authors.forename: Xinhua
authors.initials: X
authors.lastname: Yin
authors.forename: Robert M
authors.initials: RM
authors.lastname: Hayes
authors.forename: M Angela
authors.initials: MA
authors.lastname: McClure
authors.forename: Hubert J
authors.initials: HJ
authors.lastname: Savoy
mesh_terms: D018533:Biomass; D005308:Fertilizers; D009584:Nitrogen / Q000378:metabolism*; D018515:Plant Leaves / Q000378:metabolism*; D018547:Plant Stems / Q000033:anatomy & histology*; D012621:Seasons; D012987:Soil / Q000737:chemistry; D014887:Weather; D003313:Zea mays / Q000254:growth & development / Q000378:metabolism
chemical_list: D005308:Fertilizers; D012987:Soil; D009584:Nitrogen