Ecological Engineering for the Management of Fruit Borers in Okra Ecosystem by Encouraging Natural Enemies
S. Gopi *
Department of Entomology, College of Horticulture, Bagalkot, Karnataka, India.
J. B. Gopali
Regional Horticultural Research Extension Center, Kumbhapur Farm Dharwad, University of Horticultural Sciences, Bagalkot, Karnataka, India.
T. B. Allolli
Department of Vegetable Science, University of Horticultural Sciences, Bagalkot, Karnataka, India.
Venkateshalu
University of Horticultural Sciences, Bagalkot, Karnataka, India.
M. A. Waseem
University of Horticultural Sciences, Bagalkot, Karnataka, India.
Mallikarjun G. Awati
Horticulture Research Extension Centre, Thidagundi, Bijapur, University of Horticultural Sciences, Bagalkot, Karnataka, India.
*Author to whom correspondence should be addressed.
Abstract
An experiment was conducted under field conditions at the University of Horticultural Sciences, Bagalkot, to evaluate ecological engineering approaches for managing fruit borers in okra and their influence on natural enemies. Four treatments were assessed: T1, okra as the main crop without ecological engineering; T2, okra with two rows of 25-day-old maize seedlings as a barrier crop and one row of 25-day-old marigold seedlings as a trap crop; T3, okra with two rows of cowpea as a border crop and coriander intercropped with okra in a 5:1 ratio; and T4, okra with maize, marigold, cowpea and coriander in the same arrangement. The experiment was laid out in a randomised complete block design with five replications. Observations were recorded on shoot damage, fruit damage, coccinellids and spiders. T4 recorded the lowest mean shoot damage by Earias vittella (5.11%), the lowest mean fruit damage by E. vittella (7.40%) and reduced fruit damage by Helicoverpa armigera (17.68%). The same treatment supported the highest mean populations of coccinellids (1.95 per plant) and spiders (0.61 per plant). These findings indicate that the combined use of barrier, trap, border and intercrops can reduce fruit borer damage and support natural enemy activity in okra. The T4 treatment may be considered a useful component of integrated pest management, subject to validation across seasons and locations.
Keywords: Okra, ecological engineering, Earias vittella, Helicoverpa armigera, barrier crop, trap crop, cowpea, coriander, natural enemies, integrated pest management.