Author
Reddy, Krishna | |
Zablotowicz, Robert | |
Bellaloui, Nacer | |
DING, WEI - Northeast Agricultural University |
Submitted to: International Journal of Agronomy
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 6/6/2011 Publication Date: 8/8/2011 Citation: Reddy, K.N., Zablotowicz, R.M., Bellaloui, N., Ding, W. 2011. Glufosinate effects on nitrogen nutrition, growth, yield, and seed composition in glufosinate-resistant and glufosinate-sensitive soybean. International Journal of Agronomy. 2011:1-9. Interpretive Summary: When glufosinate is applied to glufosinate-resistant crops, drift to non-glufosinate-resistant crops may cause injury, disrupt nitrogen metabolism, and reduce yields. Herbicide drift complaints from ground or aerial applications are common in the Mississippi Delta. Scientists at Crop Production Systems Research Unit and Crop genetics Research Unit, Stoneville, Mississippi have conducted a 2-yr field study to determine effects of glufosinate on plant injury, chlorophyll content, nodulation, nitrogenase activity, leaf nitrogen, yield, and seed composition in glufosinate-resistant and –susceptible soybean. Glufosinate-sensitive (glyphosate-resistant and conventional) soybean exposed to glufosinate drift may exhibit transient injury (speckling, necrosis, and chlorosis) and soybean can recover from injury over time. Glufosinate had no effect on yield; increased leaf nitrogen at R4 growth stage, seed protein, and oleic acid; and decreased oil content, linoleic, and linolenic acid in glufosinate-sensitive soybean. In glufosinate-resistant soybean, chlorophyll content, nitrogenase activity, root respiration, plant biomass, soybean yield were not affected while seed nitrogen and protein were increased and seed oil content decreased. These results indicate that Glufosinate-sensitive soybean exposed to glufosinate drift may exhibit transient injury but soybean could recover over time without a yield penalty. Glufosinate altered seed composition in all soybean types. Technical Abstract: Glufosinate applied to glufosinate-resistant crops may drift and injure non-glufosinate-resistant crops. A 2-yr field study examined glufosinate effects on plant injury, chlorophyll content, nodulation, nitrogenase activity, leaf nitrogen, yield, and seed composition in soybean. Glufosinate drift was simulated by application at 45 g ha-1 to glyphosate-resistant and conventional (glufosinate-sensitive) soybean at 3 weeks after planting (WAP). Glufosinate effects were also evaluated in glufosinate-resistant soybean at 450 g ha-1 applied twice at 3 and 6 WAP. In glufosinate-resistant soybean, chlorophyll, nitrogenase activity, root respiration, plant biomass, and yield were not affected; seed nitrogen and protein were increased; and seed oil content decreased. In glufosinate-sensitive soybean, glufosinate caused 28-32% injury and decreased 35-42% chlorophyll content within 3 d after treatment (DAT) but soybean completely recovered by 14 DAT. Glufosinate had no effect on plant biomass, nitrogenase activity, and root respiration in 2009 and inconsistent effect in 2010. Glufosinate had no effect on yield; increased leaf nitrogen, seed protein, and oleic acid; and decreased oil content, linoleic, and linolenic acid in glufosinate-sensitive soybean. Glufosinate-sensitive soybean exposed to glufosinate drift may exhibit transient injury but soybean could recover over time without a yield penalty. Glufosinate altered seed composition in all soybean types. |