|NICHOLS, R - Cotton, Inc|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/28/2014
Publication Date: 2/28/2014
Citation: Price, A.J., Nichols, R.L. 2014. Herbicide application volume effects on weed control in conservation tillage cotton [abstract]. Southern Weed Science Society Meeting. CDROM.
Technical Abstract: Currently, glyphosate-resistant weeds have become a serious threat to conservation tillage cotton production. However, integrating herbicide systems and high residue covers crops in a conservation tillage systems is are increasingly being recommended to combat resistant and hard to control weeds. An experiment was established in fall 2011 and 2012 at the Wiregrass Research and Extension Center near Headland, AL and contained an augmented factorial treatments arranged in a complete block, with a split block restriction on randomization, containing eighteen treatments and three replications. Treatments included two preemergence herbicides: pendimethalin (Prowl 3.8 H2O) applied at 0.84 kg ai ha-1 or fomesafen (Reflex 2EC) applied at 0.28 kg ha-1. Herbicides were broadcast applied at 10, 15, 20, 25, 30, and 60 GPA immediately after planting in a high-residue conservation tillage system. A non-treated check high residue was included for comparison. Palmer amaranth control was not significantly influenced by application volume in row in 2011 or 2012 although amaranth control with Prowl was negatively numerically influenced by increasing volume in 2012. Relex application at any volume resulted in excellent control in 2011 and 2012 in row. Prowl performed similarly in 2013; however in 2012, control in row was inadequate when volume exceeded 15 gpa. Results revealed excellent between row amaranth control provided by the integration of residual herbicides and a high residue rye cover crop. The use of a high-residue cereal cover crop in cotton production potentially can aid in early-season Amaranthus suppression. The ongoing evaluation of weed management options suggests that control of herbicide resistant Palmer amaranth might be achieved while protecting soil resources; however, it will require the use of diverse management tactics.