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MANAGING LARGE MORNINGGLORY IN ROUNDUP – READY COTTON WITH LAY-BY HERBICIDES. S.G. Wilson, A.S. Culpepper, and A.C. York University of Georgia and N. C. State University. STUDY OBJECTIVE:. To Evaluate Lay-By Herbicide Options For Controlling Large Pitted Morningglories
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MANAGING LARGE MORNINGGLORY IN ROUNDUP – READY COTTON WITH LAY-BY HERBICIDES S.G. Wilson, A.S. Culpepper, and A.C. York University of Georgia and N. C. State University
STUDY OBJECTIVE: To Evaluate Lay-By Herbicide Options For Controlling Large Pitted Morningglories And Evaluate Plant Injury
Locations * Ocilla * Moultrie
Materials & Methods • RR Variety Sprayed at 4-Leaf Stage w/ Commercial Broadcast Sprayer • Plots Sprayed At Lay-By w/ Backpack Sprayer @19psi & 14.8 GPA
Materials & Methods • Randomized Complete Block Design • Four Replications
Materials & Methods • Treatments Evaluated At ~ Two And Four Weeks For Efficacy • Treatments Evaluated At ~ One And Two Weeks For Injury
RU + Aim RU + MSMA Caparol + MSMA Direx + MSMA Valor + MSMA RU RU + Direx RU + Harvade + COC RU + Staple RU + Valor Treatments: *RU abbreviated for various brands of Monsanto’s glyphosate products at 1 lb ai/A, Staple 0.6 to 0.8/A oz, Direx 1.0-1.5 pt/A when mixed with RUand 2 pt/A when mixed with MSMA, Harvade 6-8 oz/A, Aim 0.8-1 oz/A, MSMA 2 lb ai/A Valor 1 oz/A when mixed with RU and 2 oz/A when mixed with MSMA, Caparol 2 pt/A, and COC 1 pt/A.
Morningglory Response to Lay-By Herbicides. 2001. * Values followed by the same letter within a column are not different at P=0.05
No Directed Application No Directed Application
No Directed Application Roundup UltraMax 1.6 pt
No Directed Application Roundup UltraMax 1.6 pt + Valor 1 oz
No Directed Application Valor 2 oz + MSMA 2 lb
No Directed Application Roundup UltraMax 1.6 pt + Harvade 6 oz
Morningglory Re-growth • Treatments including Aim looked excellent initially, but MG’s suckered back out by 14 DAT (right)
Morningglory Response to Lay-By Herbicides. 2002. * Values followed by the same letter within a column are not different at P=0.05
Large Pitted Morningglory Response to Lay-By Herbicides. 2003. * Values followed by the same letter within a column are not different at P=0.05
Cotton Response to Lay-By Herbicides* * Values followed by the same letter within a column are not different at P=0.05
Non-treated Control Soil Uptake of Harvade
Herbicide Injury • Cotton was extremely green (no woody material) at time of application • At 5 DAT, injury ranged from 16-25% for Aim or Valor Mixtures
Summary • On 3-4’Mg, RU + Valor or Valor + MSMA were the most effective treatments • On 2’ MG, RU + Staple, Valor, or Aim as well as Valor + MSMA were the most effective treatments • On 9” Mg, the most effective treatments were Direx, Harvade, Valor, Aim or MSMA when mixed with RU
Summary • Tank mixes including Aim and Valor were more injurious • Injury was worse on green cotton • Harvade injury appeared as leaf chlorosis • Injury was short-lived
Summary • No differences in yield were noted • Early season weed competition was similar across the trial