Abstract

T. T. Epidi, A. E. Bassey and K. Zuofa

We conducted a 3 x 4 factorial experiment fitted into a randomized complete block design, using three intercrops: cowpea ( Vigna unguiculata L. Walp) at 0, 50,000, 100,000, 150,000 plants/ha; groundnut (Arachis hypogea L.) at 100,000, 200,000, 300,000 plants/ha; and egusi- melon (Colocynthis vulgaris L.) at 10,000, 20,000, and 30,000 plants/ha to evaluate their influence on incidence of stem borer (Chilo zacconius) (Blesz) and the green stink bug (Nezara viridula (L.)) in upland rice ( Oryza sativa L.) .The experiment was conducted during the wet and dry seasons of 2004. Rice/cowpea recorded the highest incidence of N. viridula (3.1, 3.3%) compared to rice/groundnut (1.3, 1.3%) and rice/egusi, (1.8, 1.8%) during the wet and dry seasons respectively. Intercrop with groundnut significantly (p 0.05) reduced stem borer (C. zacconius) incidence to 7.4 and 13.2% respectively for wet and dry season cultivation compared with the control (12.0 and 18.0%). Rice and groundnut (100,000 - 200,000 plants/ha) intercrop is recommended for reduced incidence of C. zacconius and N. viridula. This result demonstrates that a careful selection of crop combination and plant population could lead to reduced insect pests’ incidence in upland rice.