CIRAS-3 Operation Manual V. 1.09 130 support@ppsystems.com
NO
ϕ
NO
=
(
)
=
NPQ-K
Φ
NPQ-K
=
(
)
Note: ϕ
PSII
+ ϕ
NPQ
+ ϕ
NO
=1
f,D
ϕ
f,D
=
NPQ-G
ϕ
NPQ-G
=
Chlorophyll Fluorescence Measurements – Setup and
Operation
With CIRAS-3 there is a new option available to record complete fluorescence measurement sequences
with or without combining simultaneous photosynthesis measurements. We have also included updated
calculated fluorescence parameters, representing both lake and puddle models of PSII reaction centers -
their detailed descriptions and calculations are provided above. ФNPQ-K (Kramer et al. 2004 calculation)
and ФNPQ-G (Genty et al. 1996 calculation) are reviewed in Hendrickson et al. 2004. ФNO (Kramer et
al. 2004) and Фf,D (Genty et al. 1996) are significantly different between 500-1500 PAR at 25 °C, and
under lower light (250-500 PAR) at 10 °C, respectively. Presenting both values allows for greater
flexibility in searching for correlations based on unique plant and treatment considerations.
Also new is the use of calculated Fo’ (Oxborough and Baker 1997) in the absence of Fo’ measured
immediately following the application of far-red light. Here, the justification is that precise determination of
F
o
' in far-red light may be questionable, due to inevitable relaxation of non-photochemical quenching, in
addition to the desired reoxidation of PSII reaction centers (with concomitant reduction of PSI). As an
alternative, Oxborough and Baker offer the calculation (versus measurement) of F
o
’. Incorporated into
CIRAS-3 software-level calculations, F
o
’, F
v
’, F
v
’/F
m
’, qP, qNP, qL, ϕNO, ϕNPQ parameters will be
returned with each repeated ϕPSII measurement, assuming the initial measurement was F
v
/F
m
. Without
an initial F
v
/F
m
, these calculations are dependent upon the far-red sequence, F
o
’ (measured), and they
are returned for a single record only. In the absence of dark adaptation, several variables cannot be
returned because they require F
o
, F
m
, or both. Those variables are F
v,
F
v
/F
m
, qNP, NPQ, ϕNO, ϕNPQ
(Kramer calculation), ϕf,D, ϕNPQ (Genty calculation).
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