Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: March 30, 2009
Publication Date: April 27, 2009
Citation: Matocha, J.E., Gentry, T., Greenberg, S.M., Bradford, J.M., Yang, C., Wilborn, J., Nichols, R. 2009. Controlled release fungicide, soil amendments and biofumigation effects on cotton root rot suppression. National Cotton Council Beltwide Cotton Conference. 1245-1248. CDROM.
The cotton root rot pathogen (Phymatotrichopsis ominora) causes major losses in cotton produced in the Southwest. Granular controlled release formulations (CRF) of the fungicide, Propiconazole, developed to be soil applied at planting were studied at 1.0 and 3.0 lb a.i./ac. applications and with two rates of release. Elemental S for soil pH reduction and trace elements (Zn and Fe) were also evaluated for disease suppression in additional studies not reported here. Stem drenches with fungicides and biofumigation methods using winter cover Brasica plants were also included in this study. Four sites ranging from the Lower Rio Grande Valley through the Coastal Bend and Southwest Texas regions with histories of moderate to severe root rot disease pressure were used for most treatments. Results indicate granular CRF of Propiconazole suppressed the disease to varying degrees at all four locations. Stem drenching with a new Prothioconazole fungicide was about 90% as effective as similar treatment with Propiconazole, which produced the most impressive disease suppression. Biofumigation with winter cover crop Brassica platns showed disease suppression in 2007, but produced less consistent results in 2008.