Skip to main content Accessibility help

Efficacy of Pyrithiobac and Bromoxynil Applied with Low-Volume Spray Systems

  • Joyce A. Tredaway (a1), Michael G. Patterson (a1) and Glen R. Wehtje (a1)


Field experiments were conducted in 1994 and 1995 to determine if the sodium salt of pyrithiobac or bromoxynil applied in a low-volume, air-assist spray system controlled entireleaf morningglory, pitted morningglory, and smallflower morningglory as well as treatments applied with a conventional hydraulic fan spraying system, and to determine if herbicide rates could be reduced when using the low-volume spraying system. Pyrithiobac at 0.035 and 0.071 kg ai/ha and bromoxynil at 0.56 and 1.12 kg ai/ha were applied alone and in combination with DSMA at 1.7 kg ai/ha or MSMA at 1.7 kg ai/ha. Spraying systems were calibrated to deliver 26 L/ha and 140 L/ha for the low-volume and conventional systems, respectively. No significant differences in control were noted between low-volume and conventional spray systems when herbicides were applied at the suggested use rates of 0.071 and 1.12 kg ai/ha for pyrithiobac and bromoxynil, respectively. Morningglory control was reduced when pyrithiobac and bromoxynil were applied at one-half the suggested use rate regardless of the spraying systems. Bromoxynil alone generally controlled pitted and entireleaf morningglory better than pyrithiobac alone regardless of rate and application method. However, pyrithiobac generally provided better control of smallflower morningglory than bromoxynil. Adding MSMA or DSMA to bromoxynil and pyrithiobac increased control of both weed species.



Hide All
Ahrens, W. H., ed. 1994. Herbicide Handbook. 7th ed. Champaign, IL: Weed Science Society of America. pp. 230233.
Dotray, P. A., Keeling, J. W., Henniger, C. G., and Abernathy, J. R. 1996. Palmer Amaranth (Amaranthus palmeri) and Devil's claw (Proboscidea louisianica) control in cotton (Gossypium hirsutum) with pyrithiobac. Weed Sci. 10:712.
Fehringer, R. J. and Cavaletto, R. A. 1991. Comparison of Drift from Hooded and Open-boom Agricultural Ground Sprayers. American Society of Abricultural Engineers Technical Paper No. 90–6510. St. Joseph, Ml: American Society of Agricultural Engineers. pp. 113.
Hanks, J. E. and McWhorter, C. G. 1991. Variables affecting the use of positive displacement pumps to apply herbicides in ultralow volume. Weed Technol. 5:111116.
Harrison, M. A., Hayes, R. M., and Mueller, T. C. 1996. Environment affects cotton and velvetleaf response to pyrithiobac. Weed Sci. 44:241247.
Jordan, D. L., Frans, R. E., and McClelland, M. R. 1993a. Factors associated with DPX-PE350 applied postemergence. Proc. Beltwide Cotton Conf. 17:1526.
Jordan, T. N., Berry, C. W., and Ritter, D. D. 1993b. The Performance of Selected Postemergence Herbicides with Ultra-low Volume Application Using Different Diluents. Station Bulletin No. 666. West Lafayette, IN: Department of Botany and Plant Pathology, Purdue University. 13 p.
Keeton, A., Murdock, E. C., Stapleton, G. S., and Toler, J. E. 1994. Response of broadleaf weeds to Staple (DPX-PE350), bromoxynil, and glyphosate. Proc. Beltwide Cotton Conf. 18:1705.
Kepner, R. A., Bainer, R., and Barger, E. L. 1978. Principles of Farm Machinery. 3rd ed. Westport, CT: Avi. pp. 301303.
Legg, B. J. and Miller, P.C.H. 1990. Drift assessment using measurements and mathematical models. American Society of Agricultural Engineers Technical Paper No. 90–1593. St. Joseph, MI: American Society of Agricultural Engineers. pp. 11.
McWhorter, C. G., Barrentine, W. L., and Hanks, J. E. 1992. Postemergence grass control with herbicides applied at ULV in paraffinic oil. Weed Technol. 6:262268.
McWhorter, C. G., Fulghum, F. E., and Barrentine, W. L. 1988. An air-assist spray nozzle for applying herbicides in ultralow volume. Weed Sci. 36:118121.
Murdock, E. C. 1994. Weed control in bromoxynil-tolerant cotton. Proc. Beltwide Cotton Conf. 18:1700.
Patterson, M. G. and Norris, B. E. 1993. Transgenic cotton allows Over-the-top Weed Control. Highlights of Agricultural Research 40:13. Auburn AL: Alabama Agricultural Experiment Station, Auburn University.
[SAS] Statistical Analysis Systems. 1989. SAS software, SAS Institute, Raleigh, NC.
Smith, M. C., Jordan, D. L., Frans, R. E., and McClelland, M. R. 1993. Influence of application rate and timing on efficacy of bromoxynil. Proc. Beltwide Cotton Conf. 17:1519.
Snipes, C. E. and Allen, R. L. 1992. Broadleaf weed control in cotton with DPX-PE350. Proc. South. Weed Sci. Soc. 45:26.
Steel, R.G.D. and Torrie, J. H. 1980. Principles and Procedures of Statistics. a Biometrical Approach. 2nd ed. New York: McGraw-Hill. pp. 173, 187–188.
Vidrine, P. R., Crawford, S. H., and Girlinghouse, J. M. 1993. DPX-PE350 interactions in cotton. Proc. South. Weed Sci. Soc. 46:26.
Wilcut, J. W., Eastin, E. F., and Richburg, J. S. III. 1993. Buctril systems and efficacy for transgenic cotton in Georgia. Proc. Beltwide Cotton Conf. 17:1524.
Williford, J. R. and Fulgham, F. E. 1989. The Teemizer—a new air-atomizing spray system. American Society of Agricultural Engineers Technical Paper No. 89–1522. St. Joseph, MI: American Society of Agricultural Engineers. pp. 15.


Efficacy of Pyrithiobac and Bromoxynil Applied with Low-Volume Spray Systems

  • Joyce A. Tredaway (a1), Michael G. Patterson (a1) and Glen R. Wehtje (a1)


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed