Why farmers deviate from recommended pesticide timing: the role of uncertainty and information.
BACKGROUND
Precise timing of pesticide applications, as recommended by decision-support systems, can ensure crop protection, while maintaining efficient use of pesticides, yet farmers often deviate from recommended timing strategies. Here, we assess and explain farmers' choices to follow or not follow recommendations for the timing of fungicide applications against potato late blight in Switzerland.


RESULT
Based on daily fungicide application records as well as regional application recommendations and disease pressure, we found that 36% of applications took place earlier than recommended. Using regression analysis, we identified the exposure to economic risks of infection, susceptibility of the planted potato varieties to late blight infections, as well as yearly differences in disease occurrence as the most important determinants of farmers' application decision.


CONCLUSION
Our results indicate that decisions to not follow application recommendations and apply early are linked to available information and uncertainty with respect to disease predictions. Based on our results, we make recommendations on how to account for farmers' uncertainty with regard to the timing of pesticide applications in the design of pesticide policies and agricultural decision-support systems. These include the use of new technologies and data, mandatory reporting and tailor-made taxes and insurance solutions. Although the focus of this article is on late blight in Switzerland, our analysis can easily be extended to other countries and important plant diseases like powdery mildew in grapevines or Fusarium head blight in winter wheat. © 2020 Society of Chemical Industry.
['Möhring|Niklas|N|https://orcid.org/0000-0003-0292-4402', 'Wuepper|David|D|', 'Musa|Tomke|T|', 'Finger|Robert|R|']
D000383:Agriculture D000067565:Farmers D007722:Health Knowledge, Attitudes, Practice D006801:Humans D016273:Occupational Exposure D010575:Pesticides D013557:Switzerland D035501:Uncertainty
timing uncertainty information pesticide application late blight plant diseases decision support systems