Distribution, host range and some properties of a virus disease of sunflower in Kenya.
Apparently similar viruses were associated with 2 different disease symptoms of sunflower in Kenya, one a yellow blotch and the other a leaf crinkle. The virus occurred in all sunflower-growing regions, but the crinkle disease was confined to areas east of the Rift Valley. Disease incidence varied with locality and season. Mechanical transmission of virus from plants with either disease was possible, but the yellow blotch virus was also transmissible from an alternative field host (Tridax procumbens) by Aphis gossypii to 23 species in 3 families. Partially purified preparations of virus made from mechanically inoculated seedlings affected with either type of symptom contained 26-nm virus particles which, in immunosorbent electron microscope tests reacted with antisera prepared against 6 members of the luteovirus group.