Improving the Efficiency of EPTC Herbicide in Tobacco Weed Control by Microcapsule Formulation and Herbicide Extender

Document Type : Research Article

Authors

1 Department of Agrotechnology, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran

2 Ferdowsi University of Mashhad

3 Professor of weed science, Iranian Research Institute of Plant Protection, Tehran, Iran

Abstract

Introduction
The effectiveness of herbicides is influenced not only by the active ingredients and their toxicity but also by the formulation of the herbicide. Conventional herbicide formulations include wettable powder and emulsifiable concentrate (EC). EC formulations are prepared by mixing the active ingredient with solvents and surfactants. However, these formulations can have negative phytotoxic effects due to hazardous solvents and can be unsafe for operators during application. As an alternative to EC formulations, capsule suspension (CS) formulation has been considered. EPTC is a thiocarbamate herbicide used to control the growth of germinating annual weeds, including broadleaves, grasses, and sedges, in crops such as tobacco in Iran. EPTC acts by inhibiting cuticle formation during the early stages of seedling growth. It is available in formulated products such as emulsifiable concentrate (EC) liquids containing up to 87.8% active ingredient and granular (G) formulations containing up to 25% active ingredient. However, there have been few studies on the production of microcapsule formulations of this herbicide. This experiment aimed to evaluate the weed control effectiveness of EPTC microcapsule formulation, which was synthesized for the first time in Iran. Additionally, the study examined the effect of the herbicide extender, Ammonium thiosulfate, at different doses and application methods.
Materials and Methods
To investigate the effectiveness of different herbicide formulations and application methods, a three-way factorial experiment was conducted in Tirtash Research and Education Center in Mazandaran province, Iran, during the 2014 growing season. The experiment followed a randomized complete design (CRD) with three replications.
The factors studied in the experiment were:

Herbicide formulation:

Emulsifiable concentrate formulation (Eradicane® EC 82%)
Emulsifiable concentrate formulation with Ammonium thiosulfate
Microcapsule formulation

Herbicide dose:

50% of the recommended active ingredient (2.46 kg a.i. ha-1)
75% of the recommended active ingredient (3.69 kg a.i. ha-1)
100% of the recommended active ingredient (4.92 kg a.i. ha-1)

Herbicide application method:

Soil-incorporated pre-planting
Pre-planting


A control plot with no herbicide application was also included. Throughout the growing season, weed density, weed dry weight, and tobacco yield were measured. The relative weed control compared to the control treatment was used to evaluate the efficiency of the different treatments. The collected data was subjected to analysis of variance using Minitab (Version 18), and mean comparisons were performed using the honestly significant difference (HSD) test at a significance level of 0.05.
Results and Discussion
Based on the relative frequency of weeds, Setaria viridis L. and Amaranthus retroflexus L. were dominant species. The experimental results show the effects of formulation type, application dose and method of application on weed density and weed dry weight and tobacco yield were statistically significant difference. The microcapsule formulation increased weed control efficiency and tobacco yield significantly compared to EC formulation and the highest weed control performance and tobacco yield belong to the soil incorporated of microcapsule formulation with recommended dose.
Conclusions
The results indicated that the utilization of a microcapsule formulation allows for a 25% reduction in the application dose of the EPTC herbicide, without compromising weed control or tobacco yield. Consequently, there were no significant differences observed between applying 75% of the recommended dose using the microcapsule formulation and applying 100% of the recommended dose using the EC formulation, with or without the extender. Based on these findings, it is crucial to promptly mix the herbicide with the soil immediately after spraying in order to maintain the efficiency of EPTC. Furthermore, it was discovered that employing two-thirds of the recommended dose of the microcapsule formulation yields the same level of effectiveness as the recommended dose of other formulations. Additionally, incorporating the EPTC herbicide with soil in all formulations enhanced weed control efficacy. In contrast to previous research suggesting the positive impact of extender adjuvants such as ammonium thiosulfate on herbicide efficiency, this study did not observe similar effects. This discrepancy may be attributed to the varying soil and climatic conditions at the test site.

Keywords

Main Subjects

References

  1. Bean, B.W., Roeth, F.W., Martin, A.R., & Wilson, R.G. (1990). Rotation and continuous use of dietholate, fonofos and SC-0058 on EPTC persistence in soil. Weed Science 38: 179-185. https://www.jstor.org/stable/4045048.
  2. Bernards, M.L., Simmons, J.T., Guza, C.J., Schulz, C.R., Penner, D., & Kells, J.J. (2006). Inbred corn response to acetamide herbicides as affected by safeners and microencapsulation. Weed Technology 20: 458-465. https://doi.org/10.1614/WT-05-130R.1.
  3. Buelk, S., Vendy, W.B., Colin, D.B., Mattew, M., & Allan, W. (2005). Evaluation of simplifying assumption on pesticide degradation in soil. Journal of Environmental Quality 34: 1933-1943. https://doi.org/10.2134/jeq2004.0460.
  4. Cobb, A.H., & Reade, P.H. (2010). Herbicide and plant physiology. Blackwell Science. https://doi.org/10.1002/9781444327793
  5. Coffman, C.B., & Gentner, W.A. (1984). Herbicidal activity of controlled release formulations of trifluralin. Indian Journal of Agricultural Science 54(2): 117-122. http://www.jstor.org/stable/4044606.
  6. Danielson, L.L., Gentner, W.A., & Jansen, L.L. (1961). Persistence of soil-incorporated EPTC and other carbamates. Weeds 9(3): 463-476. https://www.jstor.org/stable/i386849.
  7. Doub, J.P., Wilson, H.P., & Hatzios, K.K. (1988). Comparative efficacy of two formulations of alachlor and metolachlor. Weed Science 36: 221-226. https://www.jstor.org/stable/3989325.
  8. Ghorbani, R., Seel, W., & Leifert, C. (1999). Effects of environmental factors on germination and emergence of Amaranthus retroflexus. Weed Science 47: 505-510. https://doi.org/10.1017/S0043174500092183.
  9. Goos, R.J., & Ahrens, W.H. (1991). Ammonium thiosulfate as herbicide extender. Patent No.: EP0431863.
  10. Gray, R.A. (1965). A vapor trapping apparatus for determining the loss of EPTC and other herbicides from soils. Weed Science 13(2): 138-141. https://doi.org/10.2307/4041155.
  11. Harvey, R.G. (1990a). Biodegradation of butylate, EPTC and extenders in previously treated soils. Weed Science 38: 237-242. https://doi.org/10.1017/S0043174500056460.
  12. Harvey, R.G. (1990b). Systems allowing continued use of carbamothioate herbicides despite enhanced biodegradation. p. 214-221. In K. Racke (ed.) Enhanced biodegradation of pesticides in the environment. ACS Symposium Series, American Chemical Socity, Washington DC. https://doi.org/10.1021/BK-1990-0426.
  13. Harvey, R.G., Mcnevin, G.R., Albright, J.W., & Kozak, M.E. (1986). Wild proso millet (Panicum miliaceum) control with thiocarbamate herbicides on previously treated soils. Weed Science 34: 773-780. https://www.jstor.org/stable/3987102.
  14. Hyzak, D.L. (1983). N-methylcarbamoyloxy anilides as herbicide extenders. Patent No.: US 4381195A.
  15. Hyzak, D.L. (1984). Iminophenyl n-methylcarbamates as herbicide extenders. :US 4490166A.
  16. Kotoula-Syka, E., Matsi, T., & Georgoulas, L. (1999). Alachlor and acetochlor toxicity to corn and cotton seedlings and residual activity of the herbicides. Proceedings of the 11th European Weed Research Society Symposium, 28 June - 1 July 1999. Basel – Switzerland.
  17. Mandumbu, R., Twomlow, S.J., Jowah, P., Mashingaidze, N., Hove, L., & Karavina, C. (2012). Weed seed bank response to tillage and residue management in semi-arid Zimbabwe. Archives of Phytopathology and Plant Protection 1: 1-12. https://doi.org/10.1080/03235408.2012.722842.
  18. Matthews, G.A. (2000). Pesticide application methods. Blackwell Science. Ltd. https://doi.org/1002/9780470760130.
  19. Nichols, V., Verhulst, N., Cox, R., & Govaerts, B. (2015). Weed dynamics and conservation agriculture principles:A review. Field Crops Research 183: 56-68. https://doi.org/10.1016/j.fcr.2015.07.012.
  20. Obrigawitch, T., Roeth, F.W., Martin, A.R., & Wilson, R.G. (1982). Addition of R-33865 to EPTC for extended herbicide activity. Weed Science 30(4): 417-422. https://etd.ohiolink.edu/apexprod/rws_etd/send_file/send?accession=osu148759630735724&disposition=inline.
  21. Petersen, B.B., & Shea, P.J. (1989). Microencapsulated alachlor and its behavior on wheat (Triticum aestivum) straw. Weed Science 37(5): 719-723. https://www.jstor.org/stable/4045135.
  22. Rashed Mohassel, M.H., & Mousavi, S.K. (2007). Weed management principles. Ferdowsi University of Mashhad press. (In Persian)
  23. Sabahi, G. (2009). Optimising pesticide use. University of Tehran press. (In Persian)
  24. Schneider, M., Endo, S., & Goss, K.U. (2013). Volatilization of pesticides from the bare soil surface: Evaluation of the humidity effect. Journal of Environmental Quality 42: 844-851. https://doi.org/10.2134/jeq2012.0320.
  25. Schreiber, M.M., Shasha, S., Ross, M.A., Orwick, P.L., & Edgecomb, D.W. (1978). Efficacy and rate of release of EPTC and butylate from starch encapsulated formulations under greenhouse conditions. Weed Science 26: 679-686. https://doi.org/10.1017/S0043174500064821.
  26. Somani, L.L. (1992). Dictionary of weed science. Agrotech Publishing Academy (India).
  27. Sopeña, F., Maqueda, C., & Morillo, E. (2009). Controlled release formulations of herbicides based on micro-encapsulation. Ciencia eInvestigacion Agraria 35(1): 27-42. http://dx.doi.org/10.4067/S0718-16202009000100002.
  28. Ueji, M., & Inao, K. (2001). Rice paddy field herbicides and their effects on the environment and ecosystems. Weed Biology and Management 1: 71-79. http://doi.org/10.1046/j.1445-6664.2001.00002.x.
  29. Vasilakoglou, I.B., Eleftherohorinos, I.G., & Dhima, K.B. (2001). Activity, adsorption and mobility of three acetanilide and two new amide herbicides. Weed Research 41: 535-546. https://doi.org/10.1046/j.1365-3180.2001.00256.x.
  30. Wilkins, R. (2003). Controlled release formulations of pesticides. In Encyclopedia of agrochemicals Eds Plimmer J.R., Gammon D.W. and Ragsdale N.N., Wiley-Interscience. https://doi.org/10.1002/047126363X
  31. Williams, A. (1984). The controlled release of bioactive agents. Chemical in Britain 221-224. https://doi.org/10.1016/0167-7799(84)90007-6.
  32. Wilson, M. (2003). Optimising pesticide use. John Wiley & Sons Ltd. https://doi.org/10.1002/0470871792
  33. Zand, E., Baghestani, M.A., Mousavi, S.K., Oveisi, M., Ebrahimi, M., Rastgoo, M., & Labafi Hosseinabadi, M.R. (2008). Weed management guide. Jahad Daneshgahi of Mashhad press. (In Persian)

Zhang, Y., & Rochefort, D. (2012). Characterisation and applications of microcapsules obtained by interfacial polycondensation. Journal of Microencapsulation 1-14. https://doi.org/10.3109/02652048.2012.676092

Send comment about this article
CAPTCHA Image

Files

Share

How to cite

Statistics