Spinach Seed

asulam (Asulox)

Oregon and Washington only

Rate 0.62 to 1.25 lb ai/a (1.5 to 3 pints/a Asulox)

Time Apply postemergence; works best if weeds are small. If applied once per season, use 1.5 pints/a on spinach with two to four leaves, or 3 pints/a on spinach with four to six true leaves. If applied twice per season, use 3 pints/a on spinach with four to eight true leaves and 3 pints/a seven days later (typically 8 to 12 true leaves).

Remarks SLN labels OR-070016 and OR-100008, and WA-080001 and WA-110003. A nonionic surfactant at 0.25% v/v may be added to the spray to increase efficacy. Crop oils and other adjuvants such as urea ammonium nitrate are not recommended. Suggested dilution rate is 20 gal/a water. Spinach may be somewhat stunted, especially with two applications at 3 pints/a.

Caution No pesticide residue tolerance has been established for this crop, and so no portion of this seed crop (including screenings) may be used or distributed for food or feed. Grazing the crop field or stubble is not permitted. Asulam is known to leach through soil into ground water under certain conditions. Using asulam where soils are permeable, particularly where the water table is shallow, may contaminate ground water. Avoid surface water contamination.

Site of action Group 18: inhibits DHP synthase step

Chemical family Carbamate

clopyralid (Stinger)

Rate 0.064 to 0.125 lb ae/a (0.17 to 0.33 pints/a Stinger)

Time Apply in 10 gal or more total spray volume when seed crop has at least two true leaves. Spot applications up to 0.66 pint/a may be applied to Canada thistle. Apply after most thistle basal leaves emerge but before buds form.

Remarks Use above rates for annual weeds 1 to 2 inches high. Re-treat as necessary up to eight-leaf stage of crop growth, but do not exceed 0.5 pint/a Stinger per growing season. Crop safety data are limited, so use only if crop injury is acceptable. Follow rotational crop restrictions on label. Avoid spray drift to sensitive crops.

Caution Do not use any part of the treated field, including seed, seed screenings, hay forage, and stubble, for human or animal consumption.

Site of action Group 4: synthetic auxin

Chemical family Pyridine

cycloate (Ro-Neet)

Western Washington only

Rate 3 to 4 lb ai/a (4 to 5.4 pints/a Ro-Neet)

Time Apply preplant to soil dry enough to thoroughly mix; incorporate immediately by cross-disking or using a rotary tiller.

Remarks Use on mineral soils only. Seed may be planted immediately. Inhibits shoot growth.

Site of action Group 8: lipid synthesis inhibitor but not an ACCase inhibitor

Chemical family Thiocarbamate

ethofumesate (Nortron SC)

Western Washington and Oregon only

Rate 0.75 to 1 lb ai/a (24 to 32 oz/a Nortron SC)

Time Apply preemergence at or shortly after planting but before weeds germinate.

Remarks SLN labels OR-160003 and WA-010001. Soon after treatment, 0.5 inch of rain or irrigation is important to activate herbicide. If rain is marginal, incorporate ethofumesate 1 to 2 inches before planting.

Caution Do not apply through any type of irrigation system. Do not rotate with any crops other than sugar beets or ryegrass for 12 months. Do not cultivate deeper than 2 inches; this may reduce effectiveness of ethofumesate.

Site of action Group 16: unknown

Chemical family Benzofuran

fluazifop (Fusilade DX)

Washington only

Rate 0.063 to 0.25 lb ai/a (4 to 16 oz/a)

Time Apply to actively growing grasses. Results often are erratic on grass stressed from lack of vigor, drought, high temperature, or low fertility.

Remarks SLN label WA-040006. Identify grasses and adjust rates for stage of weed growth and susceptibility as label instructs. More mature grasses and quackgrass can be controlled but may require two applications. Annual bluegrass and all fine fescues resist treatment.

Caution Do not exceed 32 oz/a per season. Do not apply if rain is expected within 1 hour. Do not plant rotation grass crops such as corn and cereals within 60 days of the last application. Grazing any plant product or residue is prohibited.

Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor

Chemical family Aryloxyphenoxypropionate

phenmedipham (Spin-Aid)

Rate 0.5 to 1 lb ai/a (3 to 6 pints/a Spin-Aid)

Time Apply when seedling weeds have germinated and spinach has four to six true leaves.

Remarks Temperature must be below 75°F, and spinach should not be stressed. Avoid applying when weather changes rapidly from cool and cloudy to warm and sunny. Tip burn or temporary growth retardation and chlorosis may occur, but plants usually resume normal growth within 10 days. Do not exceed 7 gal water per quart of herbicide, to prevent precipitating the herbicide.

Site of action Group 5: photosystem II inhibitor

Chemical family Phenylcarbamate

quizalofop (Assure II)

Rate 0.069 to 0.17 lb ai/a (5 to 12 oz/a Assure II)

Time Apply at optimum growth stage listed on label.

Remarks Identify susceptible grasses, and add 4 quarts crop oil concentrate or 1 quart nonionic surfactant/100 gal spray mix. Grass control may be reduced if applied immediately before or after applying a broadleaf herbicide.

Caution Do not mix with, or apply with, any other pesticide except as label specifies. Do not apply to plants stressed by drought, cold, or injury from herbicides, insects, or disease. Do not use any treated part of crop for food or feed. Do not exceed 25 oz/a per season.

Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor

Chemical family Aryloxyphenoxypropionate

sethoxydim (Poast)

Rate 0.28 to 0.47 lb ai/a (1.5 to 2.5 pints/a Poast)

Time Apply at optimum growth stage listed on label.

Remarks Identify susceptible grasses and add 2 pints/a nonphytotoxic crop oil concentrate to improve leaf absorption. Control often is erratic on grasses stunted or stressed by drought, heat, or low fertility. Resistant grasses include annual bluegrass and all fine fescues, but quackgrass can be suppressed.

Caution Do not exceed 3 pints/a per season.

Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor

Chemical family Cyclohexanedione

S-metolachlor (Dual Magnum)

Oregon and Washington only

Rate 0.32 to 0.64 lb ai/a (0.33 to 0.67 pints/a Dual Magnum)

Time Apply preemergence at or shortly after planting, but before weeds germinate.

Remarks SLN labels OR-040010 and WA-990005. This indemnified label is available only through the Syngenta Indemnified Labels website (https://www.syngenta-us.com/labels/indemnified-label-search)). Follow the steps listed in "Beet seed" section of this chapter to acquire the indemnified label. Apply in at least 15 gal/a water with ground equipment; 0.5 inch of rain or irrigation soon after treatment is important to activate herbicide. Use lower rate on coarse soil and higher rate on medium- or fine-textured soils.

Caution Restricted-use herbicide in Washington to protect surface and groundwater. Do not mechanically incorporate. Do not apply through any type of irrigation system. Crop may be damaged if excess rain after seeding washes Dual Magnum into the root zone.

Site of action Group 15: Inhibits very long chain fatty acid synthesis

Chemical family Chloroacetamide