Epoxiconazole Explained

Epoxiconazole is a fungicide active ingredient from the class of azoles developed to protect crops. In particular, the substance inhibits the metabolism of fungi cells infesting useful plants, and thereby prevents the growth of the mycelia (fungal cells). Epoxiconazole also limits the production of conidia (mitospores). Epoxiconazole was introduced to the market by BASF SE in 1993 and can be found in many products and product mixtures targeting a large number of pathogens in various crops. Crops are, for example, cereals (mainly wheat, barley, rye and triticale), soybeans, banana, rice, coffee, turnips, and red as well as sugar beets.

Use

Epoxiconazole is used against, amongst others, cereal diseases, two of which, namely leaf blotch (Septoria tritici) and rust (Puccinia triticina), are responsible for up to 30% yield losses.[1] Although not used commercially for insect control, epoxiconazole exhibits a strong anti-feeding effect on the keratin-digesting common clothes moth larvae Tineola bisselliella.[2]

Resistance

Certain plant pathogens develop resistance to fungicides. In contrast to the relatively rapid development of resistance to strobilurins, azole fungicides like Epoxiconazole have maintained their effectiveness controlling key wheat diseases for over two decades.[3] According to a study conducted by the Home Grown Cereals Authority (HGCA), Epoxiconazole was one of two triazole fungicides (the other being prothioconazole) reported to still provide a high level of eradicative and protective control of Septoria tritici.[4] Additional classes of fungicides like contact fungicides, strobilurins or carboxamides are available to farmers. In the latter case, the best activity rates are achieved in mixtures with triazoles.[5]

Mode of Action

As an azole, Epoxiconazole, actively stops the production of new fungi spores and inhibits the biosynthesis of existing hostile cells. Epoxiconazole works as an eradicant by encapsulating fungal haustoria, which are then cut off from their nutrient supply and therefore die. Some fungicide interactions can actually lead to increased production of mycotoxins, which are normal metabolic products of fungi, and it has been found that the inclusion of triazoles, like Epoxiconazole, in the fungicide mix may be necessary to limit mycotoxin levels.[6]

Regulation

In Europe, the active substance epoxiconazole has been withdrawn by industry from the approval process under Regulation (EC) No 1107/2009. The effect of that withdrawal is that epoxiconazole is banned from all use in the category ‘pesticides’, due to the fact that it has not been approved for any other use in that category.

In addition, the harmonised classification of epoxiconazole under Regulation (EC) No 1272/2008 of the European Parliament and of the Council [7] is sufficient evidence that the substance raises concerns for human health and the environment.

According to the European Chemicals Agency, Epoxiconazole is very toxic to aquatic life with long lasting effects, may damage fertility or the unborn child, and is suspected of causing cancer.[8]

Notes and References

  1. Zhang XY, Loyce C, Meynard JM, Savary S: Characterization of multiple disease systems and cultivar susceptibilities for the analysis of yield losses in winter wheat. In: Crop Protection. Nr. 25, 2006, pg. 1013-1023.
  2. Sunderland, M. R.. Cruickshank, R. H.. Leighs, S. J.. 2014. The efficacy of antifungal azole and antiprotozoal compounds in protection of wool from keratin-digesting insect larvae. Textile Research Journal. 84. 9. 924–931. 10.1177/0040517513515312 . 135799368 .
  3. Web site: New Challenges for Triazoles. Farmers Journal, Crop Protection . 2004 . McCabe T . dead . https://web.archive.org/web/20110722042613/http://www.farmersjournal.ie/cp2004/triazoles.pdf . 2011-07-22 .
  4. Web site: Research and Development, Annual Project Report. Project number: RD-2004-3025. Fungicide performance network. Up to date information on fungicide performance for wheat growers. . https://web.archive.org/web/20070606220906/http://www.hgca.com/document.aspx?fn=load&media_id=3281&publicationId=3644 . dead . 2007-06-06 . 2007 . HGCA (Home Grown Cereals Authority) .
  5. Web site: The wheat disease management guide . https://web.archive.org/web/20110711165404/http://www.hgca.com/document.aspx?fn=load&media_id=5975&publicationId=4406 . dead . 2011-07-11 . 2010 . HGCA (Home Grown Cereals Authority) McCabe T .
  6. Xu X, Nicholson P and Ritieni A.: Effects of fungal interactions among Fusarium head blight pathogens on disease development and mycotoxin accumulation. In: International Journal of Food Microbiology Nr. 119 (1-2), 2007, pg. 67-71.
  7. Web site: Regulation (EC) No 1272/2008 of the European Parliament and of the Council of 16 December 2008 on classification, labelling and packaging of substances and mixtures, amending and repealing Directives 67/548/EEC and 1999/45/EC, and amending Regulation (EC) No 1907/2006. 2008-12-31.
  8. Web site: ECHA Epoxiconazole Substance Infocard.