Evaluation of Preemergence Herbicide Programs for Control of Protoporphyrinogen Oxidase-Resistant Amaranthus palmeri in Soybean

Table 3

Palmer amaranth density reduction following PRE herbicide application in soybean from 12 trials conducted near Crawfordsville and Marion, Arkansas, in 2016 and 2017^a,b,c.

Herbicide	Rate	WSSA group	28 DAT
			Density^d
			2016		2017
	g ai ha^−1		%
Saflufenacil + dimethenamid-p + pyroxasulfone + metribuzin	25; 219; 149; 314	14; 15; 15; 5	95	a	98	a
Flumioxazin + pyroxasulfone	88; 111	14; 15	93	a	98	a
S-metolachlor + metribuzin	1,105; 242	15; 5	92	a	85	ab
Flumioxazin + metribuzin + chlorimuron-ethyl + pyroxasulfone	70; 250; 22; 90	14; 5; 2; 15	91	a	97	a
Pyroxasulfone + metribuzin	149; 314	15; 5	90	a	98	a
Metribuzin + chlorimuron-ethyl + S-metolachlor	343; 17; 1,105	5; 2; 15	90	a	96	a
Metribuzin + chlorimuron-ethyl + S-metolachlor	269; 45; 1,070	5; 2; 15	88	ab	67	cd
Flumioxazin + pyroxasulfone + chlorimuron-ethyl	78; 98; 21	14; 15; 2	86	ab	98	a
S-metolachlor + metribuzin	1,389; 420	15; 5	86	ab	94	ab
Metribuzin + chlorimuron-ethyl + pyroxasulfone	269; 45; 90	5; 2; 15	85	ab	92	ab
Flumioxazin + cloransulam	106; 35	14; 2	84	a-c	88	ab
Flumioxazin + metribuzin + chlorimuron-ethyl	70; 250; 22	14; 5; 2	80	a-c	92	ab
Sulfentrazone + S-metolachlor	134; 1,210	14; 15	78	a-c	86	ab
Flumioxazin + cloransulam	71; 24	14; 2	74	a-c	79	a-c
Flumioxazin + chlorimuron-ethyl + thifensulfuron + pyroxasulfone	76; 13; 4; 90	14; 2; 2; 15	73	a-c	93	ab
Metribuzin	420	5	73	a-c	74	a-c
Flumioxazin + chlorimuron-ethyl + thifensulfuron + pyroxasulfone	72; 23; 7; 90	14; 2; 2; 15	67	a-c	94	ab
Flumioxazin + chlorimuron-ethyl + thifensulfuron	76; 13; 4	14; 2; 2	61	a-c	73	a-c
Flumioxazin + chlorimuron-ethyl	63; 22	14; 2	56	a-c	77	a-c
S-metolachlor	1,064	15	55	a-c	79	a-c
Flumioxazin + chlorimuron-ethyl + thifensulfuron	72; 23; 7	14; 2; 2	53	a-c	87	ab
Sulfentrazone + metribuzin	188; 282	14; 5	51	a-c	77	a-c
Sulfentrazone + cloransulam	130; 17	14; 2	47	a-c	31	d
Flumioxazin	72	14	35	bc	77	a-c
Sulfentrazone + cloransulam	196; 25	14; 2	30	c	54	cd
Herbicide (-value)			<0.0001		<0.0001

^aAbbreviations: DAT, days after treatment; WSSA, Weed Science Society of America. ^bMeans within a column followed by the same lowercase letter are not different based on Tukey’s HSD . ^cAverage Palmer amaranth density for the nontreated control was 217 per m² in 2016 and 37 per m² in 2017. ^dGregory not included as density data are not available.