Michigan State University - Wheat Performance Trials


Measure photosynthetic efficiency of Michigan wheat varieties at four growth stagesĀ under conventional and high management treatments at two distinct locations.


The One Protocol (Phi2, PSI, NPQ) II

The One Protocol to rule them all! Phi2, PSI, NPQt, combined!

Changes from previous The One protocol: - no longer outputs signal from the far red period, which simplifies the signal output for the user - changed distance between measuring pulses from 10,000 to 2,000 which improves measurement resolution - has an initial stabilization period, so Fs has a chance to adjust to the actinic. - the measuring lights are used only when actually needed (before lights 15 and 10 were always pulsed, even when the values were not used in the macro outputs) - removed light 2 (650) on add-on board during the actinic periods so now actinic is just light 20 (650) on the main boards. This was causing the actinic to not match ambient, as the combination of two 650 lights was greater than the ambient value.

Chlorophyll content (SPAD) III

REQUIREMENTS: Firmware v0.41 or higher. Measures transmission at 940nm and 650nm in order to determine the 'greenness' of a leaf, an indicator of chlorophyll content and nitrogen content. The 940 is used to account for leaf thickness. Improvements over Chlorophyll content (SPAD): - performs 3 different spads at 3 intensities for thin and thick leaves - auto-chooses appropriate intensity - is calibrated to a Minolta SPAD device from factory.

Improvements over previous version -

  • Compatible with firmware v0.41 or higher.


  1. Plot Number
  2. Leaf Number


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By Greg Austic, almost 2 years ago
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By Anne Stanton, almost 2 years ago
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