Wheat Plant Tissue Interpreter
  Wheat Plant Tissue Interpreter is designed to help with the interpretation of  crop nutrition status according to its nutrient content of various plant parts and its phenological growth stage.  Most currently available systems have a single critical range for a wide window of growth stages which  can introduce error particularly  through growth stages 20 - 37 when crop drymatter is rapidly increasing therby diluting nutient content. The algorithms relating plant part,  decimal growth stage and  nutrient status have been derived from a wide range of data sources including Reuter and Robinson (1997), Weier and Creswell (1994) and a range of other sources publised since the 2000.
If you like what you see, let us know. A more complete version  containinig all 16 essential nutrients is avaible by  contacting 
  Back Paddock Support
  1. Input the Zadoks growth stage number for the majority of the plants in the crop. The calculator will then provide a description of the Zadoks growth stage and a Feekes scale equivalent.

2. Enter the laboratory values in the appropriate "Lab Input Value" column for either  "Whole Shoots" or "YEBS (Youngest Expanded Blades).  The critical ranges and status will then be displayed in to the right of the  Lab value.
Growth stage range indicates  the growth stages that were included in the calibation. Interpretion for individual elements may be associated with increase error for growth stages outside those defined due to interpolation and extrpolation outside the measured data set used in the calibration.
Less than optimum is where the laboratory value is  in the range  critical value and critical value minus the standard error of the calibration  line.
n= number of observation obtained from references used to build relationships.
Sufficiency Index = Relative % actual of critical value
  The evaluation and recommendation reports provided here are a guide only, and depend on representative samples being analysed. Additionally environmental and managerial factors influence performannce therefore as suppliers of this decision support we do not accept any liability whatsoever arising from the application of recommendations, for any damage, loss or injury of any nature and the user takes these evaluations and recommendations on these terms. This recommendation is made in good faith, based on the best technical information available.
  © Back Paddock Company 2015
SPRING WHEAT   DESCRIPTION                  
Input Zadoks Growth Stage            
Feekes Scale Approximation              
Plant Part Whole Tops  
  Input Lab Value Status   Low Satisfactory  High Standard Error Growth Stage Range for Data  n Sufficiency Index    
Nitrogen % < 12 - 75 28  
Phosphorus % < 12 - 60 18  
Potassium % < 14 - 73 17  
Sulphur % < 21 - 49 11  
  Calculated Value                    
Nitrogen/sulphur ratio < 8 15          
Plant Part Youngest Expanded Blade  
  Input Lab Value Status   Low Satisfactory  High          
Nitrogen % < 12 - 60 6  
Phosphorus % < 15 - 30 4  
Potassium % < 12 - 44 3  
Sulphur % < 26 - 35 1    
  Calculated Value                    
Nitrogen/sulphur ratio   0 15