Fusilade DX / fluazifop-p-butyl

WSSA Resistance Group: 1

Crop/non-crop registration: Broadleaf crops: forage legumes (alfalfa, red clover, bird'sfoot trefoil), soybeans, cotton, cabbage, tomatoes, cucumber, sugarbeets, stone fruits

Sensitive weeds: Annual grass species; volunteer corn, wheat, barley; quackgrass, johnsongrass.

Application method: POST- when grasses actively growing 2-5 leaf stage, quackgrass 3-5 leaf stage.

Absorption & Translocation: Absorbed primarily by foliage and translocated primarily via the symplasm (including the phloem) to meristematic regions of roots, rhizomes and shoots where it accumulates;however, translocation is relatively slow.

Mode of Action: Inhibition of lipid formation.

Metabolic pathway inhibited: Inhibits acetyl-CoA carboxylase (ACCase), the enzyme catalyzing the first step in de novo fatty acid synthesis; inhibition of fatty acid synthesis presumably blocks the production of phospholipids which are essential components of cell membranes.

Basis of Selectivity: Metabolized by tolerant species (and/or insensitivity of ACCase).

Symptoms: Cessation of growth within 2-3 days of application; growing tissue in the nodes and buds become necrotic, young leaves are first affected and turn yellow (within 1 wk) and then brown; leaf sheaths become brown and mushy at or just above their point of attachment to the node; older leaves show yellowing, light purpling and browning; susceptible plants are typically dead within 3-4 weeks and those not completely dead may show excessive tillering.

Residuality: Essentially none; short (< 1month).

Toxicity: Oral LD50 = 4096 mg/kg - slightly toxic (FUSILADE DX = >5000 mg/kg - practically non-toxic).

Additional comments: Preplant tillage to break up rhizomes will improve control of quackgrass; when plants stressed (lack of moisture, excessive humidity, low temperature and/or very low relative humidity), fluazifop-p-butyl is less effective; since there is no residual activity, a new flush of weeds may emerge after the first flush has been controlled; follow label instructions as to when and how to apply broadleaf herbicides on same area; an oil adjuvant or nonionic surfactant is required for maximum efficacy.

Images above: Fluazifop-p-butyl (POST) on corn. Note: the brown and mushy leaf sheaths. Stems break off at the soil surface when pulling on plants (left). Fluazifop-p-butyl (POST) on broadleaf and grass crops and weeds (right). 

Images above: Fluazifop-p-butyl (POST) on grasses including barnyardgrass, yellow foxtail and large crabgrass (left). Fluazifop-p-butyl (POST) on tomatoes (right). 

Image above: Fluazifop-p-butyl (POST) on broadleaf weeds velvetleaf, redroot pigweed, common lambsquarters and wild mustard. Note: healthy appearance of plants.