Effects of intercropping sesame, Sesamum indicum and false sesame, Ceratotheca sesamoides on infestation by the sesame leafroller, Antigastra catalaunalis, the green semilooper, Chrysodeixis acuta and the parasitiod, Apanteles syleptae

Abstract

Full Title: Effects of intercropping sesame, Sesamum indicum and false sesame, Ceratotheca sesamoides on infestation by the sesame leafroller, Antigastra catalaunalis, the green semilooper, Chrysodeixis acuta and the parasitiod, Apanteles syleptae

Field plot experiments were conducted in 2009-2010 to study the effects of intercropping sesame Sesamum indicum L. (Lamiales: Pedaliaceae) and false sesame Ceratotheca sesamoides (Lamiales: Pedaliaceae) on infestation by the sesame leafroller, Antigastra catalaunalis (Duponchel)( Lepidoptera: Crambidae), the green semilooper, Chrysodeixis acuta (Walker)(Noctuidae) and the parasitiod, Apanteles syleptae F. (Hymenoptera: Braconidae). The experiment was carried out in a randomized complete block design. There were five treatments namely sole crop S. indicum, sole crop C. sesamoides, intercrop 1 (1 row of S. indicum: 1 row of C. sesamoides), intercrop 2 (2 rows of S. indicum: 1 row of C. sesamoides) and intercrop 3 (1 row of S. indicum: 2 rows of C. sesamoides). The treatments were each replicated three times. There was no application of insecticide on the treatments. Counting of insects was done three times a week. The crops were harvested 8 weeks after planting for the yield analysis using the land equivalent ratio. The highest mean number of A. catalaunalis was recorded on sole crop S. indicum while the  least population was recorded on C. sesamoides. Intercrop 1 had the highest reduction in pest numbers among the three different intercropping patterns, while the highest yield was recorded on intercrop 2 which also had the highest land equivalent ratio value of 2.16. This value implies that the intercropped area would produce twice as much as the monocrop.

Key words: insect damage, abundance, yield and land equivalent ratio