Nature-based solutions: the potential of bryophytes for snail repellency in lettuce crop production

Damage in lettuce production caused by burgundy snails has led to an increased use of molluscicidal chemicals, which persist in both the lettuce and the substrate, and accumulate over time with undesirable outcomes in terms of mollusk pest control. Moreover, these chemicals also harm natural snail populations. In this study, the effects of selected bryophyte species extracts and their application concentrations were tested as natural snail repellents. Twelve bryophyte species, eight mosses, and four liverworts were randomly selected, and their ethanolic extracts were applied as burgundy snail repellents in lettuce. Significant antifeeding effects were observed for the liverworts Bazzania trilobata, Plagiochila asplenioides, and Porella platyphylla, as well as for the mosses Fontinalis antipyretica, Mnium stellare, and Neckera crispa. Among these, B. trilobata exhibited the strongest antifeeding effect without negatively impacting lettuce growth and development, as assessed through seed germination, hypocotyl length, and seedling total chlorophyll content. All bryophyte species with significant antifeeding i.e. repellent potential shared similar chemical profiles, characterized by high phenolic and triterpenoid contents and strong antioxidant capacity. The results obtained offer a nature-based solution in lettuce crop protection as well as an eco-friendly alternative in food production.