Abstract
The effects of α-naphthalen acetic acid and 2-4-D on the infection of tobacco by ordinary mosaic virus were studied. Detached leaves of Nicotiana glutinosa were inoculated and placed on Curt Leben's agar plates supplied with a plant hormone. The results indicated that the numbers of necrotic spots on the half leaves treated with both plant hormones were less than on untreated halves.
The numbers of necrotic spots on the leaves inoculated with the mixture of plant hormone solutions and virus juice differed from the ones inoculated with virus juice only.
These plant hormones presumably effected not on the activity of virus but on the susceptibility of the host plant.
