ISSN: 0041-3216 (Online), 0041-3216 (Print)
Volume 71 Number 3
The influence of weeds on insect- related mortality of intercropped sorghum and maize in southern Honduras
Partial crop life tables were constructed during 1988 and 1989 to determine plant mortality factors in intercropped sorghum and maize in southern Honduras. Whole plant samples of sorghum and maize were taken from plots without weed control and those with weed control. Seed viability, wireworms, and cutworms were the most important factors in stand establishment. Other insects like Listronotus dietrichi (Stockton) and Diatraea spp. played a minor role in plant mortality and were habitat specific. Once plant stands were established, insects had little effect on reducing plant densities; however, a mid-season drought significantly reduced maize stands; the presence of weeds exacerbated the effect of drought on maize. Sorghum, which was still in its vegetative phase, was not affected by drought. An enhanced maicillo cultivar with antibiosis to fall army worm suffered significantly less cutworm damage than maize. The results indicate that good sorghum stands could be established in normal rainfall conditions by deployment of enhanced cultivars with good seed viability and insect resistance.
Keywords: Crop life tables; Sorghum; Maize; lntercropping; Non-crop vegetation; Insect damage