Postemergence

bentazon (Basagran 5L)

Rate 0.5 to 1 lb ai/a (1.2 to 1.6 pints/a Basagran 5L)

Time Apply to small, rapidly growing annual broadleaf weeds after first trifoliate bean leaf is fully expanded. Not effective if temperature drops below 50°F at night and in daytime does not exceed 70°F. Adjust rate depending on expected weather conditions: more for cold days, less for hot days.

Remarks Controls some broadleaf weeds, including smartweed; suppresses nutsedge. Leaves may be temporarily yellow, bronzed, speckled, or burned, but beans usually continue growth with minimal delay in pod maturity. Add nonionic surfactant/crop oil concentrate/methylated seed oil and urea ammonium nitrate/ammonium sulfate. Refer to label for approved bean types. Apply to beans after first trifoliate has expanded, but before flower bud formation. Apply when weeds are small and actively growing. Rainfast in 4 hr.

Caution Do not tank mix with other pesticides except Raptor herbicide. Do not exceed 4 pints/a per season. Preharvest interval is 30 days. Applying with crop oil concentrate may increase potential of injury, particularly in hot weather.

Site of action Group 6: photosystem II inhibitor

Chemical family Benzothiadiazole

clethodim (Select Max and others)

Rate 0.068 to 0.12 lb ai/a (9 to 16 oz/a on annual grasses; 12 to 16 oz/a on perennial grass weeds)

Time Apply to actively growing grasses at recommended weed heights.

Remarks Recommended surfactant is nonionic surfactant at 0.25%; do not add ammonium sulfate. Can be tank mixed with bentazon (Basagran) at 9 to 16 oz/a and with imazamox at 9 to 12 fl oz/a, but expect reduced grass control. Use crop oil concentrate (1%) plus AMS (2.5 lb/a) with bentazon and NIS (0.25%) plus AMS (2.5 lb/a) with imazamox.

Caution Do not exceed 16 fl oz/a per year. One application allowed per year. Allow at least 14 days between applications. Preharvest interval is 21 days.

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

Chemical family Cyclohexanedione

imazamox (Raptor) + bentazon (Basagran 5L)

Rate 0.031 lb ae/a (4 oz/a) Raptor; 0.188 to 0.50 lb ai/a (4.8 to 12.8 oz/a) Basagran

Time Apply to snap beans in the first to second trifoliate leaf stage when most weeds are growing actively and less than 3 inches tall.

Remarks Label requires application of imazamox with 4.8 to 12 oz/a of Basagran 5L. Tankmixing imazamox with more bentazon than the recommended amount will reduce grass control. Adding Basagran as a tank-mix reduces the potential for crop injury. Follow label carefully for best results. Add a nonionic surfactant or crop oil. Use of a nitrogen-based fertilizer to improve weed control will improve grass control but must be measured against the potential for increased crop injury. If applying during very hot weather, it is best to eliminate nitrogen-based adjuvants and to use nonionic surfactant rather than crop oil concentrate. Avoid repeat applications to minimize chances of developing resistance to this family of herbicides. Do not apply to drought-stressed bean plants or plants with poor root development. Varisto is a premix of Raptor and Basagran applied at 16 to 21 fl oz/A (0.023 to 0.03 lb ai/a imazamox and 0.5 to 0.66 lb ai/a bentazon)

Caution Injury symptoms such as shortened internodes and/or temporary yellowing may appear soon after treatment but disappear within several days as long as plants are not stressed. Do not tank mix with any insecticide or fungicide. Avoid tank-mixes with other herbicides, such as Select and Poast, in most cases. Consult label for rotational crops and food or feed restrictions; this herbicide may persist for 26 months. Moldboard plowing may slow breakdown of imazamox and increase chance or carryover.

Site of action Group 2: acetolactate synthase (ALS) inhibitor (imazamox); Group 6: photosystem II inhibitor (bentazon)

Chemical family Imidazolinone and benzothiadiazole

quizalofop P-ethyl (Assure II)

Rate 0.04 to 0.08 lb ai/a (6 to 12 fl oz/a Assure II)

Time Apply to annual or perennial grasses listed on label at optimum use rates based on weed size.

Remarks Always use either a nonionic surfactant at 0.25% (1 quart/100 gal), or a petroleum-based crop oil at 1% (1 gal/100 gal of water). Grass control may be reduced if applied with Basagran. Increase Assure rate by 2 oz/a if tank mixing with Basagran to compensate for expected loss of grass control. Wait 7 days between applications.

Caution Do not exceed 14 fl oz/a per season. Preharvest interval is 15 days. Do not graze livestock in treated areas or feed forage or hay to livestock.

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

Chemical family Aryloxyphenoxy propionate

sethoxydim (Poast)

Rate Consult label; do not exceed 0.47 lb ai/a (2.5 pints/a) per application or 0.75 lb ai/a (4 pints/a) per year.

Time Apply at optimum growth stage listed on the 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 from drought, high temperatures, or low fertility. Resistant grasses include annual bluegrass and all fine fescues; quackgrass can be suppressed. Grass control may be reduced if applied with Basagran. Inhibits fatty acid production, cell membranes, and new growth.

Caution Preharvest interval is 15 days.

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

Chemical family Cyclohexanedione