Genetic Variability and Seasonal Influence of Fall Armyworm (Spodoptera Frugiperda (J. E. Smith)) Damage to Early Vegetative Growth of African Maize Accessions in the Humid Tropics of South-Eastern Nigeria

Abstract

Fall armyworm (Spodoptera frugiperda (J. E. Smith)) (FAW) is a petrifying invasive pest of maize (Zea mays L.) in Africa. Ten tropical maize accessions from the International Plant Genetic Resources Institute (IPGRI) collections and a check (Ikom White variety) were studied, under rainfed conditions, in a multi-environment trial (MET) to assess their responses to natural infestation of FAW. The study was conducted in the 2018 first and second maize cropping seasons in Cross River State, Nigeria using a genotype x season interaction (GSI) model. The combined analyses of variance showed non-significant difference (p > 0.05) for genotypes and significant (p ≤ 0.05) genotype x season interactions for seedling emergence, plant height, number of leaves, leaf area and FAW infestation. The most FAW-damaged maize accession in this study was TZm-304 while TZm-1427 was the least FAW-damaged maize accession. Overall, FAW infestation was significantly (p ≤ 0.01) higher in the second maize cropping season (Akpabuyo) than in first maize cropping season (Calabar). This subsequently led to corresponding decreases in early vegetative growth in the second maize cropping season. The IPGRI African maize accessions evaluated in this study were all susceptible to FAW damage at their early vegetative growth stages. However, the infestation dynamics of FAW on maize in Africa is presently being understudied. Thus, there is a dire need for the adoption of a genotype x location x year (GLY) model in subsequent MET studies on FAW across all maize-growing States in Nigeria and selection for maize genotypes in breeding for resistance to FAW should consider early vegetative growth stage and initial establishments in the field as useful aids to selection.

Estimation of Genetic Variability in Maize Genotypes under Infestation by the Maize Storage Weevil, Sitophilus zeamais Using Multivariate Analysis

“…The kernel contains 72% starch, 10% protein, 4.80% oil, 8.50% fiber, 3.0% sugar, and 1.70% ash [3]. In spite of the importance of maize as a means of feeding the ever-growing population of the world, its production and yield is greatly affected by biotic stresses such as pest and diseases among other environmental factors [4,5]. Sitophilus zeamais is a major insect pest that affects maize production and reduces its yield adversely both on the field and in the store.…”

Aptitud combinatoria y efectos recíprocos de la precocidad en poblaciones nativas de maíz de Tamaulipas

“…Lo cual favorece que este cultivo sea atacado por una amplia diversidad de insectos plaga en las regiones tropicales y subtropicales como el noreste de México, en donde destaca Spodoptera frugiperda (J. E. Smith) o gusano cogollero (Fernández et al, 2013;Yáñez et al, 2019). Este insecto, en estado larval consume principalmente tejido foliar en desarrollo, lo que disminuye el área fotosintética de la planta y en consecuencia el rendimiento de grano (Neves et al, 2020;Obok et al, 2021).…”