Table 2.

Total nitrogen content of 0.1 g oven-dried samples from one-yr.-old containerized tree seedlings fumigated with 0.1 ppm SO₂, 0.1 ppm NO₂ or a combination of 0.1 ppm SO₂ + 0.1 ppm NO₂ 7 hr daily for 8 weeks.^¹

	Nitrogen content (%)^²
Fumigation treatment	Black locust	Black cherry	Siberian elm	Yellow-popla
SO₂	3.537^a	2.504^a	2.882^ab	2.097^b
NO₂	3.831^b	2.660^a	2.771^a	1.691^a
SO₂ + NO₂	3.520^a	3.323^b	2.951^b	1.695^a
Control	3.917^b	2.582^a	2.852^ab	1.774^a

↵1,2 See footnotes for Table 1.