In-Crop Applications of XtendiMax® Herbicide with VaporGrip® Technology

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Growers using XtendiMax® herbicide with VaporGrip® Technology have options for timing this year. Window of application for in-crop use of XtendiMax® herbicide with VaporGrip® Technology depends on weed height, soybean stage, and daily conditions.

Weed Control Window

Many factors affect herbicide efficacy including rate and environment. Control of small weeds -

1) reduces risk of yield loss from competition

2) helps create uniform coverage with typical carrier volumes, especially with high weed densities

3) makes secondary weed control simpler in the case of escaped weeds.1

It is best to plant into clean fields and use multiple herbicide Modes of Action (MOA) for weed resistance management and to facilitate in-crop weed control. Environmental conditions can prevent application or inhibit performance of pre-plant and pre-emergence herbicides. Fields without a successful pre-emergent herbicide program should have priority for in-crop herbicide applications.

Soybean Growth Stage.

Establishing a robust weed management program is essential to maintaining farm productivity and reducing weed populations and weed proliferation. Starting the growing season clean and applying herbicides when weeds are actively growing and less than 4 inches tall significantly improves efficacy.

Roundup Ready 2 Xtend® soybeans are tolerant to applications of XtendiMax® herbicide with VaporGrip® technology -

  • In minimum tillage situations, apply XtendiMax® herbicide with VaporGrip® technology (22 or 44 oz/acre) + Roundup PowerMAX® herbicide (32 oz/acre) + an approved drift reduction agent (DRA) with a soil residual herbicide (Group 14 or 15) early in the season for burndown/at planting.
  • In conventional tillage situations, especially under dry conditions, apply XtendiMax® herbicide with VaporGrip® technology (22 or 44 oz/acre) tank mixed with a soil residual herbicide (Group 14 or 15) early in the season at planting.
  • When weeds are less than 4 inches and within 20 to 30 days after planting, a POST application of XtendiMax® herbicide with VaporGrip® technology (22 oz/acre) + Roundup PowerMAX® herbicide (32 oz/acre) + an approved DRA with Warrant® Herbicide (3 pts/acre) or Warrant® Ultra Herbicide (50 oz/acre) is recommended to control continuous germination of problematic weed species like Palmer amaranth, marestail, and waterhemp.
 

Figure 1. Spray from emergence up to and including beginning bloom (R1 stage). Photo courtesy: Shaun Casteel – Purdue University

The RRXtend Spray App is a farmer- and applicator-focused digital tool that provides location-specific weather forecasts, digital record-keeping capabilities and education resources related to the Roundup Ready® Xtend Crop System. Follow http://www.roundupreadyxtend.com/stewardship/spray-app/ for more information.

Iowa applicators must attend training approved by Iowa Department of Ag & Land Stewardship. Label requirements at www.xtendimaxapplicationrequirements.com should be reviewed by applicators within 24 hours prior to spraying.

Sources: 1 Hartzler, B. 2003. Effect of application timing on herbicide efficacy. Iowa State University. Web source verified 4/8/18 180414003739

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