Members of the oomycete phylum represent highly problematic crop pathogens and a threat for global food security. For instance, P. infestans is the agent of potato late blight, and P. viticola of grapevine downy mildew. Oomycete infections are currently controlled by frequent applications of copper-based compounds, but the massive use of these compounds leads to pollution, residual toxicity and adverse effects on human health. The discovery of innocuous and reliable alternatives to traditional inorganic fungicides remains challenging and has been set as a high priority by EU and other countries. NoPest aims to develop an environmentally friendly approach for crop protection as an alternative to conventional chemical pesticides. The strategy, inspired by medical and pharmaceutical research, relies on peptide aptamers to counteract oomycetes infections by i) identifying small peptides (linear/cyclic peptide aptamers) that inhibit vital enzymes involved in oomycete cell wall formation and cell stability; ii) optimizing aptamer efficiency through peptidomimetics designed for field applications; iii) searching, using chemo-informatics approaches, for non-peptide small molecules that mimic the activity of aptamers. These objectives will be addressed by selecting peptide aptamers from combinatorial libraries, based on their affinity and specificity for selected protein targets. Key benefits will be i) low probability to select resistant oomycete strains and no risk of co-selection of bacteria resistant to heavy metals; ii) no impact on animal and human health; iii) low environmental impact, as the approach is based on peptides that consist of natural amino-acids; iv) potential to develop additional products that confer antimicrobial resistance to any crop pathogen. Furthermore, in order to make the new molecules competitive in the pesticide market, precision farming non-invasive sensing tools will be developed, leading to reduced pesticide usage for field treatments.