Resistance of Ivy Geraniums to the Twospotted Spider Mite1
1982; American Society for Horticultural Science; Volume: 107; Issue: 6 Linguagem: Inglês
10.21273/jashs.107.6.1089
ISSN2327-9788
Autores Tópico(s)Plant Disease Management Techniques
ResumoAbstract Resistance to the twospotted spider mite ( Tetranychus urticae Koch) of 18 cultivars of ivy geranium [ Pelargonium peltatum (L.) L’Her ex Ait.] was evaluated under greenhouse conditions by mass screening, by measuring fecundity on isolated leaves, and by paired leaf tests for selected cultivars. ‘Sybil Holmes’, ‘Yale’, and ‘Cornell’ were among the most susceptible, whereas ‘Double Lilac White’, ‘Sunset’, and ‘Salmon Queen’ were relatively mite-free. ‘Madeline Crozy’ and ‘Cornell’ were preferred for oviposition over the resistant ‘Double Lilac White’. Mite resistance was not related to density of simple or glandular leaf trichomes, but there was an apparent relationship between mite susceptibility and severity of oedema.
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