Keywords: Farmers’ field experiment, indigenous knowledge, plant resource use, botanical pesticides

Tharu ethnic community is rich in ethno-botanical knowledge on the utilization, distribution, abundance, and conservation of plants to fulfill their daily needs of food, medicine, fodder, timber, fuel wood, etc. The faith healers (Gurau) and elderly people of Tharu community have precise knowledge on plants for their use in health care and pest management. Information on twenty-four locally available plants having pesticidal values have been recorded from the Tharu community of Dibya Nagar and Meghauli VDCs of western Chitwan. An experiment was conducted to test the efficacy of neem (Azadirachta indica A. Juss.), asuro (Justicia adhatoda L.), bisundari {Persicaria barbata (L.) Hara} and titepati (Artemisia indica Willd.) against the pests of Cucurbita pepo L. cv. Zucchini under farmers’ field condition in Sisai of Dibya Nagar–4 during the summer season of 2006. Plant extract of concentration 1:5 of the fresh green leaves of selected plants were sprayed at seven days interval on the plants to control insect pests of Zucchini. It is found that neem possessed most promising effect on insect pests of Zucchini plants followed by bisundari. However, all other treatments showed some sort of positive effect for suppression of insect pests of Zucchini. Similarly, the result indicated that both concentration of plant extract and spraying intervals are equally important for effective pest management indicating the possibility of using locally available botanical materials towards the development of organic pest management.