Table 3. Weed control effectiveness, weed control costs, corn yields, and gross margins.

Conventional	Treatments	ANGR	CHEAL	AMARE	AMBEL	ABUTH	All Weeds (≥ 90%)	Cost^1($/A)	Yield (bu/A)	Gross Margin^2 ($/A)
PRE	GuardsMax + Prowl	81	85	96	55	65	No	31.89	208	332.11
	GuardsMax + Python	78	91	94	67	96	No	32.03	212	338.97*
	Axiom + Atr + Prowl^3	87	90	94	60	67	No	31.33	170	266.17
	Key + Python	79	98	99	64	99	No	30.53	212	340.47*
	Key + Hornet	72	93	94	60	97	No	32.62	214*	341.88*
	KeyLA + Hornet	74	98	98	65	98	No	33.48	212	337.52*
	CinchATZ + Basis	90	88	99	74	85	No	33.61	215*	342.64*
	Lumax	85	78	93	61	88	No	32.05	219*	351.20*
PRE/POST	GuardsMax fb. Clarity + Aim^3	90	93	99	98	98	Yes	36.37	202	317.13
	Outlook fb. Distinct	96	67	93	65	83	No	39.70	206	320.80
	Define fb. Buct/Atr	84	100	100	90	100	No	34.95	204	322.05
	Atr fb. Option + Distinct	91	89	99	86	93	No	36.59	221*	350.16*
	Cinch fb. SteadATZ + Distinct	99	100	100	100	100	Yes	43.53	221*	343.22*
	BicepIIMag fb. Callisto + Atr	96	100	100	99	100	Yes	45.24	216*	332.76
Total POST	Atr + Callisto + Option	96	100	100	100	99	Yes	31.48	220*	353.52*
	SteadATZ + Distinct	95	100	100	97	100	Yes	29.35	221*	357.40*
Roundup Ready
PRE/POST	Key + GlyphoPlus	86	79	94	76	94	No	37.28	215*	338.97*
	CinchATZ fb. RoundupWM	93	82	91	74	99	No	39.21	222*	349.29*
	HarnXtra fb. RoundupWM	86	75	93	75	98	No	41.50	221*	345.25*
	BicepIIMag fb. Touchdown	95	78	96	77	99	No	49.40	224*	342.60*
POST	RoundupOM + Atr	91	100	100	98	98	Yes	24.14	217*	355.61*
(1-Pass)	DegXtra + RoundupWM	99	100	100	100	99	Yes	33.91	222*	354.59*
POST (2-Pass)	RoundupWM fb. RoundupWM	99	100	99	100	100	Yes	39.83	229*	360.92*
	Touchdown fb.Touchdown	100	100	100	100	100	Yes	39.77	218*	341.73*
Untreated	Weedy	0	0	0	0	0	na	0	87	152.25

Abbreviations: ANGR= annual grass, CHEAL= common lambsquarters, AMARE= redroot pigweed, AMBEL= common ragweed, ABUTH= velvetleaf, fb.= followed by.

¹Herbicide and additive costs = avg. of price lists (April 2004); Application cost = $6.00/A; Roundup Ready seed premium = $20.50/bag; seeding rate = 30,000 seeds/A. Weed control costs = Herbicide $ + Additive $ + Application $ + seed premium $ (where applicable).

²Crop selling price = $1.75/bu (December 2004). Gross Margin = (Yield x Price) – Weed Control Costs.

³Corn injury was 15% and 10% for Axiom + Atrazine + Prowl and Guardsman Max fb. Clarity + Aim, respectively. All other treatments showed no corn injury.

*Values are not significantly different from the highest value within that column.

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