Hostname: page-component-78c5997874-ndw9j Total loading time: 0 Render date: 2024-11-08T07:19:01.871Z Has data issue: false hasContentIssue false

Critical time of weed removal in glyphosate-resistant Glycine max

Published online by Cambridge University Press:  20 January 2017

Chris M. Boerboom
Affiliation:
Department of Agronomy, University of Wisconsin, Madison, WI 53706

Abstract

Field experiments were conducted in 1996 and 1997 to determine the effect of the rate and time of glyphosate application on weed emergence, survival, biomass, and Glycine max yield in reduced-tillage (RT) and no-tillage (NT) glyphosate-resistant G. max planted in rows spaced 18 (narrow-row) and 76 cm (wide-row). Glyphosate was applied at 0.42, 0.63, and 0.84 kg ae ha−1 at V2, V4, R1, and R4 growth stages. On separate plots, 0.84 kg ha−1 glyphosate was applied at each growth stage with hand weeding. A weed-free check was maintained with preemergence imazethapyr plus metolachlor supplemented with hand weeding, and a nontreated check was included. Weed population density before glyphosate application ranged from 239 to 606 plants m−2 in RT and 33 to 500 plants m−2 in NT systems. Setaria faberi and Chenopodium album were the predominant species. Weed control efficacy and crop yield were influenced more by application time than by glyphosate rate. Glyphosate applied at V2, V4, and R1 gave season-long control of weeds in 18-cm rows. In 76-cm rows, glyphosate applied at V2, V4, and R1 gave almost complete control of weeds, but broadleaf weeds emerged after application at V2. The critical time of weed removal, the time beyond which weed competition reduced G. max yield by 3% or more compared to the weed-free check, was at R1 and V4 in 18-cm RT G. max in 1996 and 1997, respectively, and at V2 in 76-cm RT G. max in both years. The predicted critical time of weed removal in 18- and 76-cm NT G. max was R1 and V4, respectively, in 1996 and R1 in 1997. This research showed that there was variation in the onset of the critical time of weed removal between tillage systems, as well as within tillage systems across years. The results indicate a single glyphosate application can prevent yield loss in narrow-row, glyphosate-resistant G. max under favorable conditions, but application timing becomes more critical in wide rows because the critical period of weed removal occurs earlier. Late-emerging weeds may warrant a second glyphosate application in wide-row G. max.

Type
Research Article
Copyright
Copyright © Weed Science Society of America 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Literature Cited

Banks, P. A., Tripp, T. N., Wells, J. W., and Hammel, J. E. 1985. Effects of tillage on sicklepod (Cassia obtusifolia) interference with soybeans (Glycine max) and soil water use. Weed Sci. 34:143149.Google Scholar
Baysinger, J. A. and Sims, B. D. 1991. Giant ragweed (Ambrosia trifida) interference in soybeans (Glycine max) . Weed Sci. 39:358362.CrossRefGoogle Scholar
Burnside, O. C. 1979. Soybean (Glycine max) growth as affected by weed removal, cultivar and row spacing. Weed Sci. 27:562565.Google Scholar
Burnside, O. C. and Colville, W. L. 1964. Soybean and weed yields as affected by irrigation, row spacing, tillage, and amiben. Weeds 12:109112.Google Scholar
Burnside, O. C. and Moomaw, R. S. 1977. Control of weeds in narrow row soybeans. Agron. J. 69:793796.Google Scholar
Burnside, O. C. and Wicks, G. A. 1969. Influence of weed competition on soybean growth. Weed Sci. 17:332334.Google Scholar
Bussan, A. J., Burnside, O. C., Orf, J. H., Ristau, E. A., and Puettmann, K. J. 1997. Field evaluation of soybean (Glycine max) genotypes for weed competitiveness. Weed Sci. 45:3137.CrossRefGoogle Scholar
Coble, H. D. and Ritter, R. L. 1978. Pennsylvania smartweed (Polygonum pennsylvanicum) interference in soybeans (Glycine max) . Weed Sci. 26:556559.CrossRefGoogle Scholar
Fellows, G. M. and Roeth, F. W. 1992. Shattercane (Sorghum bicolor) interference in soybean (Glycine max) . Weed Sci. 40:6873.Google Scholar
Gebhardt, M. R., Daniel, T. C., Schweizer, E. E., and Allmaras, R. R. 1985. Conservation tillage. Science 230:625630.Google Scholar
Harper, J. L., Williams, J. T., and Sager, G. R. 1965. The behavior of seeds in soil. I. The heterogeneity of soil surfaces and its role in determining the establishment of plants from seed. J. Ecol. 53:273286.Google Scholar
Hartwig, R. O. and Laflen, J. M. 1978. A meterstick method for measuring crop residue cover. J. Soil Water Conserv. 33:9091.Google Scholar
Howe, O. W. and Oliver, L. R. 1987. Influence of soybean (Glycine max) row spacing on pitted morningglory (Ipomoea lacunosa) interference. Weed Sci. 35:185193.CrossRefGoogle Scholar
Lal, R., Logan, T. J., Eckert, D. J., and Dick, W. A. 1994. Conservation tillage in the corn belt of the United States. Pages 76113 In Carter, N. R., ed. Conservation Tillage in Temperate Agroecosystems. Boca Raton, FL: Lewis Publishers.Google Scholar
McWhorter, C. G. and Sciumbato, G. L. 1988. Effects of row spacing, benomyl, and duration of sicklepod (Cassia obtusifolia) interference on soybean (Glycine max) yields. Weed Sci. 36:254259.CrossRefGoogle Scholar
Mulugeta, D. and Boerboom, C. M. 1999. Seasonal abundance and spatial pattern of Setaria faberi, Chenopodium album, and Abutilon theophrasti in reduced tillage soybeans Weed Sci. 47:95106.Google Scholar
Oliver, L. R. 1979. Influence of soybean (Glycine max) planting date on velvetleaf (Abutilon theophrasti) competition. Weed Sci. 27:183188.Google Scholar
Padgette, S. R., Re, D. B., Barry, G. F., Eichholtz, D. E., Delannay, X., Fuchs, R. L., Kishore, G. M., and Fraley, R. T. 1996. New weed control opportunities: Development of soybean with a Roundup Ready gene. Pages 5384 In Duke, S. O., ed. Herbicide-Resistant Crops: Agricultural Economic, Environmental, Regulatory, and Technological Aspects. Boca Raton, FL: CRC Press.Google Scholar
Ratkowsky, D. D. 1990. Handbook of Nonlinear Regression Models. New York: Dekker.Google Scholar
[SAS] Statistical Analysis Systems. 1990. SAS/STAT Users Guide. Version 6, 4th ed. Cary, NC: Statistical Analysis Systems Institute, pp 120.Google Scholar
Shurtleff, J. L. and Coble, H. D. 1985. Interference of certain broadleaf weed species in soybeans (Glycine max) . Weed Sci. 33:654657.Google Scholar
Staniforth, D. W. and Weber, C. R. 1966. Effects of annual weeds on growth and yield of soybeans. Agron. J. 48:467471.Google Scholar
Thurlow, D. L. and Buchanan, G. A. 1972. Competition of sicklepod with soybeans. Weed Sci. 20:379384.Google Scholar
Van Acker, R. C., Swanton, C. J., and Weise, S. F. 1993. The critical period of weed control in soybean [Glycine max (L.) Merr.]. Weed Sci. 41:194200.Google Scholar
Wax, L. M. and Pendleton, J. W. 1968. Effects of row spacing on weed control in soybeans. Weed Sci. 16:462465.Google Scholar
Wax, L. M., Nave, W. R., and Looper, R. L. 1977. Weed control in narrow- and wide-row soybeans. Weed Sci. 25:7378.CrossRefGoogle Scholar
Wilson, H. P. and Cole, R. H. 1966. Morningglory competition in soybeans. Weeds 14:4951.CrossRefGoogle Scholar
Wyse, D. L., Young, F. L., and Jones, R. I. 1986. Influence of Jerusalem artichoke (Helianthus tuberosus) density and duration of interference on soybean (Glycine max) growth and yield. Weed Sci. 34:243247.Google Scholar
Zimdahl, R. L. 1980. Weed Crop Competition: A Review. Corvallis, OR: International Plant Protection Center. 196 p.Google Scholar