Plant growth analysis

• Classical plant growth analysis made easy
  Many studies have only one, or very few, harvest intervals and must therefore use the classical (non-curve-fitting) form of plant growth analysis. However, most studies of this type neglect the rigorous, but necessary, mathematical and statistical calculations that this approach involves. A 2002 Annals of Botany paper describes a state-of-the-art spreadsheet tool which does all of the hard work for users who paste-in appropriate raw data.
  

• You can download a .pdf version of the paper here (size 129kB), and the Excel spreadsheet tool here Warning: these items are both copyright material for personal and private study only.

• Functional plant growth analysis made easy
  If you have a series of successive harvests in your growth experiment there are good reasons for using fitted plant growth curves to derive your growth parameters.  
  

• If you have a moderate number of harvests (perhaps five to ten) you should consider using stepwise polynomial growth curves. A 1974 paper in the Journal of Applied Ecology described a method which has been successfully used hundreds of times. There is now a Windows-based tool which you can use to apply this method. Go here to download all the necessary files.

• If you have more than about ten harvests you should consider using splined polynomial growth curves. There is a DOS-type application available for obtaining plant growth parameters from spline curves: go here to download all the necessary files. This application also delivers second derivatives from the fitted splines (the rates of change of the rates of change).