Efficacy of Different Rates of Formulated Neem Seed Oil and Frequency of Application on the Control of Flower Thrips Infesting Early Maturing Pigeonpea Cultivar in Owerri, Imo State, Nigeria

Abstract

Thrips (Megalurothrips usitatus Bagnall) population dynamics on early maturing pigeonpea flowers was carried out in the Postgraduate Teaching and Research Farm, Department of Crop Science and Technology, Federal University of Technology, Owerri Imo State beginning from May 2009, 2010 and July 2010. In this study, thrips (M. usitatus) population management using formulated neem seed oil (F-NSO) at different doses and spraying frequencies was examined. The experiment was laid out in 3 x 5 factorial comprising three rates of neem seed oil, 2 ml (4.2l ha^-1), 4 ml (8.3l ha^-1), 6 ml (12.5l ha^-1) with 0ml (0l ha^-1), and synthetic pyrethroid (cypermethrin) 0.72 ml (1.5l ha^-1) as check plots and three intervals of application: once a week, once in two weeks, and once in three weeks. Results from formulated neem seed (F-NSO) control measures showed non-significant (p<0.05) effect on the population of M. usitatus even at higher dosage of once a week 2 or 3 weeks of spraying in a four spraying regime. The application of synthetic pyrethroid (SPY) at once a week in a four spraying regime affected significantly (p<0.05) the population of M. usitatus on the flowers of early maturing pigeonpea.

Keywords: Improved pigeonpea, Thrips, flowers, population, formulated neem seed oil, rates, and frequencies.