Management Options and Factors Affecting Control of a Common Waterhemp (Amaranthus rudis) Biotype Resistant to Protoporphyrinogen Oxidase-Inhibiting Herbicides

Table 3

Visual control and fresh weight reduction of common waterhemp population resistant to protox-inhibiting herbicides. Data were collected 21 days after treatment.

Treatmenta	Rate	2002		2003
		Control	Fresh weight reduction	Control	Fresh weight reduction
			%
Nontreated		0	0	0	0
Flumiclorac-pentyl + COC	30 g ai/ha + 2.3 L/ha	26	64	0	34
Carfentrazone-methyl + NIS	9 g ai/ha + 0.25% v/v	14	57	8	37
Lactofen + COC + DAS	220 + 1.2 L/ha + 2.8 kg/ha	34	49	45	14
Acifluorfen + COC + DAS	420 + 2.3 L/ha + 1.7 kg/ha	46	90	18	17
Fomesafen + COC + UAN	330 + 1% v/v + 2.5% v/v	57	89	20	39
Mesotrione + COC + DAS	110 + 1% v/v + 9.5 kg/ha	99	99	68	72
Dicamba/diflufenzopyr + NIS + DAS	290 + 0.25% v/v + 2.8 kg/ha	72	78	87	83
Atrazine + COC	1680 g ai/ha + 2.3 L/ha	56	100	37	42
LSD (𝑃=0.05)		23	28	12	42

aAbbreviations: DAS: diammonium sulfate ((NH₄)₂SO₄); COC: crop oil concentrate; and NIS: nonionic surfactant; UAN: 28% urea ammonium nitrate.