Weed Control and Grain Sorghum (Sorghum bicolor) Tolerance to Pyrasulfotole plus Bromoxynil

Table 1

Weed control at Lubbock and Yoakum as influenced by pyrasulfotole plus bromoxynil combinations in 2008, 4 weeks after MPOST applications.

			Weed control^4
Herbicide^1,2	Dose	Timing^3	A. palmeri	U. texana	P. louisianica
	Kg ai/ha			%
Untreated	—	—	0	0	0
Pyrasulfotole (P)	0.03
+Bromoxynil (B)	0.20	EP	100	33	100
+Atrazine (A)	0.58
P	0.04
+B	0.24	EP	100	23	100
+A	0.58
P	0.03
+B	0.20	EP	100	33	100
+A	0.58
+2, 4-D	0.27
P	0.03
+B	0.20	EP	100	33	100
+A	0.58
+dicamba	0.13
Atrazine	0.58	EP	98	20	100
P	0.03
+B	0.20	MP	100	47	100
+A	0.58
P	0.04
+B	0.24	MP	100	50	100
+A	0.58
P	0.03
+B	0.20	MP	100	33	100
+A	0.58
+2,4-D	0.27
P	0.03
+B	0.20	MP	100	55	100
+A	0.58
+dicamba	0.13
Atrazine	0.58	MP	100	30	100
P	0.03
+B	0.18	EP + MP	100	45	100
+A	0.58
P	0.03
+B	0.21	EP
+A	0.58		100	47	100
P	0.03	MP
+B	0.18
P	0.04
+B	0.26	EP
+A	0.58		100	33	100
P	0.03	MP
+B	0.18
P	0.03
+B	0.26	EP
+A	0.58		100	50	100
P	0.03	MP
+B	0.26
LSD (0.05)			1	12	NS

¹ At Yoakum, all herbicide treatments with the exception of the untreated check included S-metolachlor at 1.11 kg ai/ha applied preemergemce. At both locations, all herbicide treatments with the exception of atrazine alone include ammonium sulfate at the rate of 3.9 kg/378 L.  
²Agridex at 1.0% v/v added to all treatments at Yoakum while R-11at 0.25% was added to all treatments at Lubbock with the exception of the atrazine only treatments which included Agridex at 1.0% v/v.  
³Abbreviations: EP (early postemergence), weeds 5 to 10 cm tall; MP (mid postemergence), weeds 10 to 20 cm tall; A. palmeri, Amaranthus palmeri, S. Wats; P. louisianica, Proboscidea louisianica (Mill.) Thellung; U. texana, Urochloa texana L.  
⁴Weed rating scale: 0: no control; 100: complete control. A. palmeri was present at both locations while U. texana was present at Yoakum and P. louisianica was present at Lubbock. A. palmeri ratings were combined over locations due to a lack of interaction.