Variations in Stem Borer Infestation and Damage in Three Maize (Zea mays L.) Types in Southern Guinea Savanna and Rainforest Zones of Nigeria

摘要

The effects of location, maize types and borer control with carbofuran (Furadan 3G) on the severity of maize stem borer infestation and damage was investigated in the late maize planting season of 2011. Treatments were laid out in randomized complete block design using a split-slip-plot factorial arrangement. Whole plot factor consisted of two locations (Southern Guinea Savanna and Rainforest agro-ecological zones of Nigeria), subplot factor consisted of 1.5 kg a.i.ha~(-1) and 0.0 kg a.i.ha~(-1) of carbofuran, while the sub-sub-plot factor comprised of three endosperm types of maize (flint, pop and sweet corn). Stem borer infestation (quantified by dead heart count and larval population per plant) and damage (quantified by %lodged stem, %bored internodes, %bored ears, number of exit holes, number of stem borer cavities and number of damaged seeds per plant) as well as yield were compared. Results revealed that borer infestation and damage were significantly higher (P < 0.05) in the Rainforest compared with the Savanna. Single dose application of carbofuran (1.5 kg a.i. ha~(-1)) also significantly (P < 0.05) increased grain yield in all the maize types at both locations. For all parameters, no significant (P > 0.05) location × carbofuran × maize type and location × maize type effect was detected. However, significant (P < 0.05) location × carbofuran and carbofuran × maize type interaction effects were observed. We conclude that in both agro ecologies, flint corn was more tolerant of borer attack while sweet corn was more susceptible compared to either flint or popcorn. In addition, carbofuran at 1.5 kg a.i.ha~(-1) can significantly reduce stem borer population in the three maize types.