Articles
Evaluation of amaranth lines for insect pest incidence and severity under field conditions in Ibadan, southwestern Nigeria
Article number
1378_48
Pages
365 – 370
Language
English
Abstract
Studies were conducted to evaluate the incidence and severity of major insect pests observed on 12 amaranth lines at the vegetable experimental field of the National Horticultural Research Institute (NIHORT), Ibadan (7°25N; 3°52E), rain forest ecological zone of Nigeria, in 2018 and 2019 cropping seasons.
The amaranth lines were raised in the nursery and transplanted to the field at 3 weeks after planting (3 WAP). The seedlings were spaced 20 cm apart with a 1-m border and arranged in a randomized complete block design (RCBD) with three replicates.
Major insect pests observed on the amaranth species in both years of the study were: whitefly (Bemisia tabaci), variegated grasshopper (Zonocerus variegatus), true bugs (Coreus marginatus) and Hypolixus truncatulus (amaranth weevil). High whitefly and grasshopper incidence was observed on all the lines in 2018 while the pests incidence was low in 2019. However, the occurrence of Coreus marginatus and Hypolixus truncatulus was relatively low and negligible in both years of the study.
The incidence of whitefly and grasshopper on amaranth was significantly higher on lines Am6 and Am10 relative to other lines in 2018 while Am10 recorded higher incidence of the whitefly in 2019. Higher incidence of Coreus marginatus and Hypolixus truncatulus was observed on Am10 in both years.
However, lower incidence of the insect pests was observed on lines Am2 and Am5. The severity of the observed insects was mild on all the amaranth lines used in the study.
The amaranth lines were raised in the nursery and transplanted to the field at 3 weeks after planting (3 WAP). The seedlings were spaced 20 cm apart with a 1-m border and arranged in a randomized complete block design (RCBD) with three replicates.
Major insect pests observed on the amaranth species in both years of the study were: whitefly (Bemisia tabaci), variegated grasshopper (Zonocerus variegatus), true bugs (Coreus marginatus) and Hypolixus truncatulus (amaranth weevil). High whitefly and grasshopper incidence was observed on all the lines in 2018 while the pests incidence was low in 2019. However, the occurrence of Coreus marginatus and Hypolixus truncatulus was relatively low and negligible in both years of the study.
The incidence of whitefly and grasshopper on amaranth was significantly higher on lines Am6 and Am10 relative to other lines in 2018 while Am10 recorded higher incidence of the whitefly in 2019. Higher incidence of Coreus marginatus and Hypolixus truncatulus was observed on Am10 in both years.
However, lower incidence of the insect pests was observed on lines Am2 and Am5. The severity of the observed insects was mild on all the amaranth lines used in the study.
Authors
O.Y. Akinkunmi, H.A. Akintoye, A.O. Shokalu, M.T. Olatunji, A.G. Adebayo
Keywords
amaranth lines, insect pest, vegetable, grasshopper, true bug
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