Glufosinate Effects on Nitrogen Nutrition, Growth, Yield, and Seed Composition in Glufosinate-Resistant and Glufosinate-Sensitive Soybean

Table 5

Effect of glufosinate application on leaf and seed nitrogen content and delta ¹⁵N in glufosinate-resistant, glyphosate-resistant, and conventional soybean in a field study at Stoneville, MS, 2009 and 2010^a.

Herbicide	Rate (g/ha)	Application timing	Nitrogen content (%)			Delta ^15N^b
			Leaf at V5	Leaf at R4	Seed
Glufosinate-resistant soybean
No glufosinate	0		4.84^b	5.64^a	6.22^b	0.20^a
Glufosinate fb	450	EPOST	5.23^a	5.87^a	6.38^a	0.21^a
glufosinate	450	LPOST
Glyphosate-resistant soybean
No glufosinate	0		5.17^a	5.85^b	6.49^a	0.83^a
Glufosinate	45	EPOST	5.13^a	6.05^a	6.64^a	0.76^a
Conventional soybean
No glufosinate	0		5.31^b	5.06^b	6.30^a	0.55^a
Glufosinate	45	EPOST	5.78^a	5.39^a	6.25^a	0.69^a

Abbreviations: fb: followed by; EPOST: early postemergence applied at 3 wk after planting; LPOST: late postemergence applied at 6 wk after planting.
^aMeans within a column for each soybean type followed by the same letter are not statistically significant at the 5% level as determined by Fisher’s LSD test.
^b Delta ¹⁵N was determined in leaf samples taken at R4 soybean growth stage.