AS  Vol.6 No.11 , November 2015
Broadleaf Weed Control in Sunflower (Helianthus annuus) with Preemergence-Applied Pyroxasulfone with and without Sulfentrazone
A field study was conducted at two locations in Kansas, USA in 2011 and 2012 to test weed control efficacy and crop response to preemergence-applied pyroxasulfone alone and in combination with sulfentrazone in sunflower. Treatments included three rates of pyroxasulfone (100, 200 and 400 g·ha-1) applied alone and tank-mixed with sulfentrazone at 70, 140 and 280 g·ha-1. Commercial standards sulfentrazone at 140 g·ha-1 + pendimethalin at 1390 g·ha-1 and sulfentrazone at 140 g·ha-1 + S-metolachlor at 1280 g·ha-1 were also included. Pyroxasulfone at 100 g·ha-1 controlled Palmer amaranth 87% at 3 weeks after application (WAA), but control decreased to 76% at 6 WAA. Increasing pyroxasulfone rate to ≥200 g·ha-1 or tank mixing with sulfentazone at 140 g·ha-1 provided ≥90% Palmer amaranth control for at least 6 WAA. Sulfentrazone alone at 70 g·ha-1 controlled Palmer amaranth 77% at 3 WAA, but control dropped to 69% at 6 WAA. Increasing sulfentrazone rate from 70 to 140 or 280 g·ha-1 increased control to >90% at 3 WAA, but did not maintain acceptable control at 6 WAA. Tank mixing sulfentrazone at 140 g·ha-1 with pendimethalin at 1390 g·ha-1 or S-metolachlor at 1280 g·ha-1 controlled Palmer amaranth ≥90 and 84% at 3 WAA and 6 WAA, respectively. The lowest rate of pyroxasulfone (100 g·ha-1) controlled kochia 98% and the control was complete with all other treatments. However, no treatment provided as much as 90% puncturevine control at 3 WAA and the control was commercially unacceptable (<75%) at 6 WAA. No treatment visibly injured sunflower anytime during the season or reduced sunflower plant population.

Cite this paper
S. Reddy, S. , Stahlman, P. and Geier, P. (2015) Broadleaf Weed Control in Sunflower (Helianthus annuus) with Preemergence-Applied Pyroxasulfone with and without Sulfentrazone. Agricultural Sciences, 6, 1309-1316. doi: 10.4236/as.2015.611125.
[1]   USDA-NASS (United States Department of Agriculture National Agricultural Statistics Service) (2014) Data and Statistics/Quick Stats. USDA-NASS, Washington DC.

[2]   Thompson, C.R., Peterson, D.E., Lyon, D.J., Olson, B.L.S., Kniss, A.R. and Falk, J.S. (2009) Weed Control. In: Meyer, R., Belshe, D., O’Brien, D. and Darling, R., Eds., High Plains Sunflower Production Handbook. MF-2384, Kansas State University Agricultural Experiment Station and Cooperative Extension Service, Manhattan, 8-10.

[3]   Johnson, B.J. (1971) Effect of Weed Competition on Sunflower. Weed Science, 19, 378-380.

[4]   Kandel, H. (2014) 2013 National Sunflower Association Survey.

[5]   Chubb, W.O. and Friesen, G.H. (1985) Wild Oat Interference in Sunflower. Canadian Journal of Plant Science, 65, 219-222.

[6]   Durgan, B.R., Dexter, A.G. and Miller, S.D. (1990) Kochia (Kochia scoparia) Interference in Sunflower (Helianthus annuus). Weed Technology, 4, 52-56.

[7]   Lewis, D.W. and Gulden, R.H. (2014) Effect of Kochia (Kochia scoparia) Interference on Sunflower (Helianthus annuus) Yield. Weed Science, 62, 158-165.

[8]   Tanetani, Y., Kaku, K., Kawae, K., Fujioka, T. and Shimizu, T. (2009) Action Mechanism of a Novel Herbicide Pyroxasulfone. Pesticide Biochemistry and Physiology, 95, 47-55.

[9]   Geier, P.W., Stahlman, P.W. and Frihauf, J.C. (2006) KIH-485 and S-Metolachlor Efficacy Comparisons in Conventional and No-Tillage Corn. Weed Technology, 20, 622-626.

[10]   Kurtz, M.E. (2011) Pyroxasulfone for Use in Southern States Soybean Production. Proceedings of Southern Weed Science Society, 64, 57.

[11]   King, S.R. and Garcia, J.O. (2008) Annual Broadleaf Control with KIH-485 in Glyphosate-Resistant Furrow Irrigated Corn. Weed Technology, 22, 420-424.

[12]   Hardwick, J.M. (2013) Evaluation of Pyroxasulfone in Corn (Zea mays L.) and Soybean (Glycine max L. MERR.) Weed Management Programs. Thesis Submitted to Louisiana State University, Baton Rouge.

[13]   Knezevic, S.Z., Datta, A., Scott, J. and Porpiglia, P.J. (2009) Dose-Response Curves of KIH-485 for Preemergence Weed Control in Corn. Weed Technology, 23, 34-39.

[14]   Stahlman, P.W., Olson, B.L.S., Thompson, C.R. and Zollinger, R.K. (2010) Pyroxasulfone (KIH-485) for Weed Control in Sunflower. Proceedings of the 1st Australian Summer Grains Conference, Gold Coast, 21-24 June 2010, 1-7.

[15]   Olson, B.L., Zollinger, R.K., Thompson, C.R., Peterson, D.E., Jenks, B., Moechnig, M. and Stahlman, P.W. (2011) Pyroxasulfone with and without Sulfentrazone in Sunflower (Helianthus annuus). Weed Technology, 25, 217-221.

[16]   Robertson, G.P., Sollins, P., Ellis, B.G. and Lajtha, K. (1999) Exchangeable Ions, pH, and Cation Exchange Capacity. In: Robertson, G.P., Coleman, D.C., Bledsoe, C.S. and Sollins, P., Eds., Standard Soil Methods for Long-Term Ecological Research, Oxford University Press, Oxford, 106-114.

[17]   Combs, S.M. and Nathan, M.V. (1998) Soil Organic Matter. In: Brown, J.R., Ed., Recommended Chemical Soil Test Procedures for the North Central Region, North Central Regional Research Publication No. 221 (Revised), SB 1001, Missouri Agriculture Experiment Station, Columbia, 53-58.

[18]   Gregory, L.S., Porpiglia, P.J. and Chandler, J.M. (2005) Efficacy of KIH-485 on Texas Panicum (Panicum texanum) and Selected Broadleaf Weeds in Corn. Weed Technology, 19, 866-869.

[19]   Anonymous (2006) KIH-485 Experimental Herbicide. Kumiai Chemical Industry Co., Ltd., White Plains, 8 p.

[20]   Reddy, S.S., Stahlman, P.W., Geier, P.W. and Thompson, C.R. (2012) Weed Control and Crop Safety with Premixed S-Metolachlor and Sulfentrazone in Sunflower. American Journal of Plant Sciences, 11, 1625-1631.