Table 1.

Leaf greenness estimated using a colorimeter (Chlorophyll Meter Konica-Minolta SPAD 502), and chlorophyll a and b content determined by extraction in acetone and spectrophotometer lecture in plants of soybean cv. ‘PR91M10’ grown in closed-loop hydroponics (vegetative phase; n = 6).

	SPAD (SPAD units)	Chl a (mg ml-1)	Chl b (mg ml-1)	Chl a/Chl b (ratio)	Tot Chl (mg ml-1)
C	33.33	6.94	1.72	4.0	8.66
I	34.33	6.78	1.64	4.1	8.42
	ns	ns	ns	ns	ns