Fungicide Placement and Control of Target Spot in Cotton

Tuesday, January 7, 2014: 3:00 PM
Galerie 1 (New Orleans Marriott)
Austin Hagan , Department of Plant Pathology Extension
Randy Akridge , Brewton Agricultural Research Unit
Shawn Scott , E.V. Smith Research Center
Fungicide Placement and Control of Target Spot in Cotton

With over-the-top broadcast fungicide applications, much of the fungicide is intercepted by the upper leaf canopy and fails to reach the lower leaves in the inner canopy where target spot infections often begin.  Improved control may be obtained with drop nozzles that improve coverage of lower leaves.  At Brewton Agricultural Research Unit, better target spot control was obtained with Headline and Quadris applied with a drop nozzle than broadcast rig on Phytogen 499 and DPL 1252.  While Headline and Quadris proved equally effective in controlling target spot on Phytogen 499, the former fungicide gave better disease control on DPL 1252.  In a similar study at EV Smith Research Center, similar disease control was obtained with the broadcast and drop nozzle rigs.  As was noted in the previous study, Headline gave better target spot control than Quadris.  Disease ratings in both studies were significantly lower for DPL 1252 than for Phytogen 499.