Hostname: page-component-77c89778f8-fv566 Total loading time: 0 Render date: 2024-07-24T22:48:31.275Z Has data issue: false hasContentIssue false
  • English
  • Français

A Bioassay Technique Detects Imazethapyr Leaching and Liming-Dependent Activity

Published online by Cambridge University Press:  20 January 2017

Leon J. Van Wyk  and
Carl F. Reinhardt
Leon J. Van Wyk
Affiliation:
University of Pretoria, Department of Plant Production and Soil Science, Pretoria 0002, Republic of South Africa
Carl F. Reinhardt*
Affiliation:
University of Pretoria, Department of Plant Production and Soil Science, Pretoria 0002, Republic of South Africa
*
Corresponding author's E-mail: creinhard@postino.up.ac.za.
Get access Rights & Permissions [Opens in a new window]

Abstract

Excessive persistence of imazethapyr has been responsible for injury to corn grown after soybean. Factors implicated in corn injury reported from certain parts of the main corn-producing region in South Africa were: leaching of herbicide to deep soil layers during the season of application, followed in the next season by capillary movement to the root zone of corn, and increased bioactivity of herbicide residues following liming of fields. Bioassays were employed to determine to what extent imazethapyr leached in a soil that typically contains less than 10% total clay and 0.1% organic C in the 0- to 300-mm zone and to assess the role of pH and liming in the bioactivity of the herbicide. Undisturbed soil columns were collected in polyvinyl chloride pipe for the leaching experiment. In the greenhouse, the equivalent of 40 g ai/ha imazethapyr was applied on the column surface, followed by leaching with simulated rain of 25 or 50 mm. Leaf area measurements of the test species rapeseed showed that the herbicide was readily leached to at least 30 cm at both water regimes and that it subsequently moved upward in the soil, with evaporation as the driving force. In the other bioassay, the soil was ameliorated with different amounts of Ca(OH)2 or CaCO3 to adjust pH levels to between 5.7 and 7.1 These soil samples were each treated with imazethapyr at rates equivalent to 1.8, 3.75, 7.5, 15, and 30 g ai/ha. The growth response of the test species indicated that where Ca(OH)2 was applied, the bioactivity of imazethapyr in most instances was significantly greater than where CaCO3 was used. At all the imazethapyr rates, the activity of the herbicide increased significantly with an increase in pH from 5.6 to 6.5 where Ca(OH)2 was used, but with CaCO3, activity was significant only at 15 and 30 g ai/ha. Changes in imazethapyr adsorption and in the organic matter in the soil were not monitored, but it is suggested that the increase in herbicide activity caused by Ca(OH)2 may be due to the degradation of organic matter in the soil or to desorption of the herbicide, which would render the herbicide more available for uptake. These effects, if they do occur, are likely to be of significance for herbicide adsorption only in soil with very low organic matter content. Results indicate that imazethapyr could leach easily in coarse-textured soils low in clay and organic matter content and that the type of lime used on those soils may influence the bioactivity of the herbicide.

Keywords

Atrazineimazamethabenzimazaquinimazethapyrcorn, Zea mays L.rapeseed, Brassica rapa L. ‘Salusia’soybean, Glycine max (L.) MerrAdsorptionbioactivityherbicide mobilitysoil pHFC, field capacityOM, organic matterPVC, polyvinyl chloride
Type
Research
Information
Weed Technology , Volume 15 , Issue 1 , March 2001 , pp. 1 - 6
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

Anonymous. 1991. Technical information report on imazethapyr. Princeton, NJ: American Cynamid. Agricultural Research Division. 29 p.Google Scholar
Ashton, F. M. and Monaco, T. J. 1991. Weed Science: Principles and Practices. 3rd ed. New York: J. Wiley. 466 p.Google Scholar
Basham, G. W., Lavy, T. L., Oliver, L. R., and Scott, H. H. 1987. Imazaquin persistence in three Arkansas soils. Weed Sci. 35: 576–582.Google Scholar
Beckie, H. J. and McKercher, R. B. 1990. Mobility of two sulfonylurea herbicides in soil. J. Agric. Food Chem. 38: 310–315.Google Scholar
Buys, A. J. 1988. FSSA Fertilizer handbook. 2nd ed. Pretoria, South Africa: Fertilizer Association of South Africa. 331 p.Google Scholar
Enfield, C. G. and Yates, S. R. 1990. Organic chemical transport to groundwater. In Cheng, H. H., ed. Pesticides in the Soil Environment: Processes, Impact, and Modeling. Number 2. SSSA Book Series. Madison, WI: Soil Science Society of America Inc. pp. 271–302.Google Scholar
Gan, J., Weimer, M. R., Koskinen, W. C., Buhler, D. D., Wyse, D. L., and Becker, R. L. 1994. Sorption and desorption of imazethapyr and 5-hydroxyimazethapyr in Minnesota soils. Weed Sci. 42: 92–97.Google Scholar
Goetz, A. J., Wehtje, G., Walker, R. H., and Hajek, B. 1986. Soil solution and mobility characterization of imazaquin. Weed Sci. 34: 788–793.Google Scholar
Goetz, A. J., Lavy, T. L., and Gbur, E. E. 1990. Degradation and field persistence of imazethapyr. Weed Sci. 38: 421–428.CrossRefGoogle Scholar
Günther, P., Rahman, A., and Pestemer, W. 1989. Quantitative bioassays for determining residues and availability to plants of sulphonylurea herbicides. Weed Res. 29: 141–146.Google Scholar
Henning, J.A.G. and von M. Harmse, H. J. 1993. The effect of soil characteristics and rainfall on the presence and seasonal fluctuations of water tables in aeolian sand of the north-western Orange Free State. S. Afr. J. Plant Soil 10: 105–109.CrossRefGoogle Scholar
Henning, J.A.G. and Stoffberg, D. J. 1992. Effect of internal forces, associated with water tables, on consolidation of tillaged sand from the north-western Free State. Appl. Plant Sci. 6:47.Google Scholar
Koskinen, W. C. and Harper, S. S. 1990. The retention process: mechanisms. In Cheng, H. H., ed. Pesticides in the Soil Environment: Processes, Impact, and Modeling. Number 2. SSSA Book Series. Madison, WI: Soil Science Society of America. pp. 51–78.Google Scholar
Loux, M. M. and Reese, K. D. 1993. Effect of soil type and pH on persistence and carryover of imidazolinone herbicides. Weed Technol. 7: 452–458.Google Scholar
Loux, M. M., Liebl, R. A., and Slife, F. W. 1989. Adsorption of imazaquin and imazethapyr on soils, sediments and selected adsorbents. Weed Sci. 37: 712–718.CrossRefGoogle Scholar
Mangels, G. 1991. Behavior of the imidazolinone herbicides in soil—a review of the literature. In Shaner, D. L. and O'Connor, S. L., eds. The Imidazolinone Herbicides. New York: CRC Press. pp. 191–209.Google Scholar
Nitsch, J. P. 1972. Phytotrons: past achievements and future needs. In Rees, A. R., Cockshull, K. E., Hand, D. W., and Hurd, R. G., eds. Crop Processes in Controlled Environments. London: Academic Press. pp. 33–55.Google Scholar
O'Dell, J. D., Wolt, J. D., and Jardine, P. M. 1992. Transport of imazethapyr in undisturbed soil columns. Soil Sci. Soc. Am. J. 56: 1711–1715.Google Scholar
Oppong, F. K. and Sagar, R. 1992. The activity and mobility of triasulfuron in soil as influenced by organic matter, duration, amount and frequency of rain. Weed Res. 32: 157–165.Google Scholar
Renner, K. A., Meggitt, W. F., and Penner, D. 1988. Effect of soil pH on imazaquin and imazethapyr adsorption to soil and phytotoxicity to corn (Zea mays). Weed Sci. 36: 78–83.Google Scholar
Riley, D. and Eagle, D. 1990. Herbicides in soil and water. In Hance, R. J. and Holly, K., eds. Weed Control Handbook: Principles. 8th ed. London: Blackwell Scientific. pp. 243–259.Google Scholar
Santlemann, P. W. 1977. Herbicide bioassay. In Truelove, B., ed. Research Methods in Weed Science. 2nd ed. Auburn, AL: Southern Weed Science Society. pp. 79–87.Google Scholar
Sigua, G. C., Isensee, A. R., and Sadeghi, A. M. 1993. Influence of rainfall intensity and crop residue on leaching of atrazine through intact no-till soil columns. Soil Sci. 156: 225–232.CrossRefGoogle Scholar
Stougaard, R. N., Shea, P. J., and Martin, A. R. 1990. Effect of soil type and pH on adsorption, mobility and efficacy of imazaquin and imazethapyr. Weed Sci. 38: 67–73.Google Scholar
Streibig, J. C. 1988. Herbicide bioassay. Weed Res. 28: 479–484.Google Scholar
Walsh, J. D., Defelice, M. S., and Sims, B. D. 1993. Soybean (Glycine max) herbicide carryover to grain and fiber crops. Weed Technol. 7: 625–632.CrossRefGoogle Scholar