• allelochemical;
  • biphasic;
  • crop enhancement;
  • dose–response;
  • growth stimulation;
  • phytotoxin

Belz RG, Cedergreen N & Duke SO (2011). Herbicide hormesis – can it be useful in crop production? Weed Research51, 321–332.


The yield-enhancing effects of some pesticides may change the focus of their use in crop production, from crop protection to crop enhancement. While such beneficial uses of pesticides are specifically en vogue for fungicides and seed treatments, the use of herbicides for crop enhancement has not yet been realised. The potential for improving crop production by low-dose, stimulatory effects of herbicides has been proposed, and reports of 10–25% efficiency of improving certain plant traits under field conditions seem promising. However, past attempts to make use of herbicide hormesis, the term for this effect, have been largely unsuccessful. The reasons for this may be manifold, but the lack of understanding of the principles and mechanisms of this low-dose phenomenon in plants may have contributed to the often claimed lack of adequate predictability for commercial use. Thanks to the research progress recently made in this area, we are now better able to understand the principles of herbicide hormesis and its potential for crop enhancement. Therefore, this review highlights the potential of phytotoxins to induce plant hormesis and the factors influencing its expression. Based on this, possible practical constraints and consequences for the portfolio of uses for herbicides are discussed, along with undesired but apparent hormetic side effects of herbicides.