Navegando por Autor "Silva, B. N."

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    Infecção de cafeeiros com vírus de vira-cabeça
    (Instituto Agronômico (IAC), 1960-03) Costa, A. S.; Silva, B. N.; Carvalho, Ana Maria B.
    Coffee plants inoculated by rubbing with the tomato spotted wilt virus were highly resistant. Plants that were preconditioned in the dark for 4-8 days and inoculated in a similar manner developed concentric local lesions 10-25 days after inoculation. No systemic invasion of the plants followed. Recovery of the tomato spotted wilt virus from the lesions onto tobacco test plants was positive when the inoculum was prepared from lesions on coffee leaves 18 and 90 days after inoculation, but not after 210 days. When lesions from leaves that were showing the coffee ring spot disease were similarly treated and used to inoculate tobacco and other test plants no symptoms ensued, although these attempts were repeated a number ot times. This is considered evidence thot coffee ring spot is not caused by any of the common strains of the tomato spotted wilt virus complex used in the tests. Coffee plants exposed to a white fly population (Bemisia tabaci Genn.) bred on Sida micrantha plants affected with abutilan mosaic did not develop ring spot symptoms.