Fig 4. The inhibitory effect of oxathiapiprolin on development of downy mildew in cucumber depends on time of application.

Detached leaves were inoculated on lower leaf surface with sporangial suspension (25 droplets/leaf) and oxathiapiprolin was applied as a spray at 0, 1, 2 or 3dpi. A—No lesions developed when oxathiapiprolin was applied at 0 dpi. Lesions appeared when oxathiapiprolin was applied at 1 or 2dpi, but became smaller as its dose increased. B—Oxathiapiprolin was applied at 3dpi. Note no effect on lesion size. Photos were taken at 6 dpi.