Agricultural and Biological Research

Production and evaluation of eco-friendly and non-toxic herbal pest repellent chalk

A.M. Ananda Kumar*, K. Kavipriya, R. Rakkimuthu, P. Sathishkumar, D. Sowmiya

This study presents the development of an eco-friendly herbal chalk to repel pests in stored food grains, addressing significant economic and psychological losses caused by infestations in warehouses and homes. Various plant extracts, including Vitex negundo, Ocimum tenuiflorum, Origanum vulgare, Chrysanthemum indicum and Eucalyptus species, were combined to create five formulations, which were applied to chalks through repeated soaking. The repellent activity was tested using maze studies, where formulations F5 (12.5 cm) and F3 (12.1 cm) were most effective in repelling ants, with F5 and F3 repelling 80% and 76% of ants, respectively. Phytochemical analysis revealed the presence of terpenoids, flavonoids, saponins and other compounds, while ash content tests indicated high values in Origanum vulgare and Chrysanthemum indicum (14.54% and 12.16%, respectively). The formulations were stable, with minimal reaction to most solvents and demonstrated low toxicity to humans and animals. These herbal chalks, with long-lasting aroma and bitterness, provide a sustainable, cost-effective solution for pest control and are adaptable for use in various environments. The study suggests the potential for future commercial production of non-toxic insect repellent chalk for widespread applications in food storage.