ISSN: 0041-3216 (Online), 0041-3216 (Print)
Volume 77 Number 4
Field evaluation of kenaf, mesta, and related genera for their reactions to spiral borer. (232)
Out of 10 kenaf (Hibiscus cannabinus L.) cultivars assessed under field conditions against spiral borer (Agrilus acutus Thumb.), one was rated resistant, one was moderately resistant, one was moderately susceptible, five were susceptible, and two were highly susceptible. Levels of resistance expressed in two cultivars of mesta (H. sabdariffa L.), one of deshi jute (Corchorus capsularis L.), two of tossa jute (C. olitorius L.), one of okra [Abelmoschus esculentus (L.) Moen.], one accession of H. radiatus Cav., two of H. acetosella Welw. ex. Hiern, and one of ban-dheras (Malachra capitata L.) ranged from resistant to highly resistant. Among the resistant materials, there were no significant differences in the amount of plant damage. However, where per cent infestation was considered, PI 343128 (one cultivar of kenaf) was found to be significantly different from the other resistant materials. The cultivar CVL-1 (C. capsularis) was found to be completely free from borer attack (0% infestation and 0% damage). The presence of significantly high levels of resistance observed in mesta (H. sabdariffa) and other related species (H. radiatus and H. acetosella) indicate a potential use in breeding programmes for developing resistant cultivars. High levels of resistance in related genera (C. capsularis, C. olitorius, A. esculentus, and M. capitata) indicate that these genera would not act as alternate hosts of A. acutus.
Keywords: Kenaf; Mesta; Spiral borer; Resistance