Glufosinate Rate and Timing for Control of Glyphosate-Resistant Rhizomatous Johnsongrass (Sorghum halepense) in Glufosinate-Resistant Soybean

Table 1

Significance of the main effects of initial glufosinate application rate (POST1), sequential glufosinate application rate, and sequential glufosinate application timing (POST2 or POST3) and interactions among main effects pooled across environments 20 and 28 d after treatment (DAT) and at harvest for glyphosate-resistant rhizomatous johnsongrass control and height as a percent of the nontreated and soybean grain yield.

Parameter	Data collection	IR	SR	ST	IT × SR	IT × ST	SR × ST	IT × SR × ST
		value
Control	20 DAT	0.0002	0.3073	0.2284	0.1628	0.0853	0.4139	0.6861
	28 DAT	0.0541	0.0575	0.0094	0.2399	0.4606	0.3473	0.6594
	At harvest	0.0107	0.5275	0.0014	0.2678	0.7232	0.1330	0.4546
Height	20 DAT	0.0397	0.4905	0.0041	0.5300	0.3473	0.1703	0.0931
	28 DAT	0.2998	0.0358	0.0253	0.1106	0.3439	0.7247	0.6855
	At harvest	0.4725	0.0042	0.0191	0.8517	0.6954	0.9213	0.9310
Soybean grain yield		0.0076	0.0346	0.5869	0.2337	0.2896	0.7770	0.7820

IR: initial glufosinate application rate (POST1); SR: sequential glufosinate application rate; ST: sequential glufosinate application timing (POST2 or POST3).
Main effects and interactions considered significant if .