Weed Management with Engenia™ in Bollgard II Xtendflex™ Cotton.

WEED MANAGEMENT WITH ENGENIAª IN BOLLGARD II XTENDFLEXª COTTON.

E.M. Keeling, A.T. Koonce, J.W. Keeling; Texas Tech University and Texas A&M AgriLife Research, Lubbock, TX

ABSTRACT

Engeniaª is a new dicamba formulation under development by BASF for use in Bollgard II Xtendflexª cotton, which could improve control of a wide range of annual and perennial weeds. Resistant Palmer amaranth (Amaranthus palmeri), ivyleaf morningglory (Ipomoea hederacaea), woollyleaf bursage (Ambrosia grayi), kochia (Kochia scoparia), field bindweed (Convolvulus arvensis), and Texas blueweed (Helianthus ciliaris) could be more effectively controlled with Engeniaª when applied post emergence (POST) compared to Roundup PowerMax (RUPM) applied alone. Field studies were conducted in 2013 and 2014 at Lubbock, TX to evaluate Palmer amaranth, devil's-claw, and Russian thistle control with various applications of Engeniaª and other residual herbicides, including Prowl H2O and Outlook.

The objectives of these studies were to evaluate Palmer amaranth, Russian thistle, and devil's-claw control with Engenia applied pre- or postemergence in Bollgard II Xtendflexª cotton. Efficacy of Prowl H2O applied preplant incorporated (PPI) or preemergence (PRE) and Outlook (POST) with Engeniaª for residual weed control was determined.

Field trials compared Prowl alone and Prowl + Engeniaª (PRE) followed by Roundup PowerMax (RUPM) alone, RUPM + Engeniaª + Outlook mid-postemergence (MPOST). POST only treatments include RUPM + Outlook, RUPM + Outlook + Engeniaª, RUPM + Engeniaª, or RUPM only. Treatments were applied using a CO₂-pressurized backpack sprayer calibrated to deliver 15 gallons per acre. Percentage of weed control was estimated visually 17-21 and 60 days after planting (DAP).