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Chemical selector

Crop type: Corn
Application type: Preplant or Preemergence

Pounds of active ingredient per acre
S-Metolachlor + Atrazine 0.78 to 1.56 + 1 to 2
Product quantity per acre
1.3 to 2.6 qt Bicep II Magnum/Charger Max ATZ
Comments and limitations

These are formulated mixtures of 3.1 lb atrazine (a restricted-use pesticide) and 2.4 lb S-metolachlor/gal. Use the lower rate for expected light weed infestations and the higher rate for heavy weed infestations. Use with shallow preplant incorporation or surface apply after planting and before grasses and broadleaf weeds are at 2-leaf stage and corn is 5 inches tall. For sensitive watersheds, see K-State Research and Extension publication MF-2208 for atrazine best management practices. Follow atrazine rate limits and label directions.

Pounds of active ingredient per acre
S-Metolachlor + Atrazine 0.8 to 1.58 + 0.63 to 1.27
Product quantity per acre
0.95 to 1.9 qt Bicep Lite II Magnum/Charger Max ATZ Lite
Comments and limitations

These are formulated mixtures of 2.67 lb atrazine (a restricted-use pesticide) and 3.33 lb S-metolachlor/gal for use by growers wanting to reduce rates of soil-applied atrazine. Follow label directions.

Pounds of active ingredient per acre
S-Metolachlor 1 to 1.9
Product quantity per acre
1 to 2 pt Dual II Magnum/EvarpreX/Charger Max/Moccasin II Plus, or 6 to 16 lb Dual II Magnum
Comments and limitations

Controls many annual grass and small-seeded broadleaf weeds. Preplant surface apply up to 45 days before planting corn, apply preplant and shallowly incorporate into the top 2 inches of soil within 14 days before planting, or apply before corn emerges. Small grains can be planted 4.5 months after treatment. Follow label directions.

The Pesticide Selector includes suggestions for chemical control of pests in Kansas crops, which are provided by K-State Research and Extension, and may not be relevant for states other than Kansas. We will continue to expand this tool for help in selecting other types of agricultural chemicals, and for other states. Contact the myFields Team if you are interested in contributing content!

The herbicide performance ratings are taken from: C.R. Thompson, D.E. Peterson, W.H. Fink, P.W. Stahlman, and J.W. Slocombe. 2020. Chemical Weed Control for Field Crops, Pastures, Rangeland, and Noncropland, Kansas State University, January 2016. Contribution no. 16-029-S from the Kansas Agricultural Experiment Station. Find it online at the bookstore.

The insecticide recommendations are taken from: B.P. McCornack, S. Zukoff, R.J. Whitworth, J.P. Michaud, and H.N. Schwarting. 2019. Insect Management Guides. March 2018. Kansas State University Agricultural Experiment Station and Cooperative Extension Service. PDF formats are available here.

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