Papaya ringspot virus
A viral disease spread by aphids that causes mottled, distorted papaya leaves and ring-shaped spots on the fruit.
Also known as: PRSV, Papaya mosaic
Symptoms and identification
Young leaves show yellow and green mosaic patterns and become narrow, curled and strap-like. Dark green streaks appear on stems and leaf stalks, and fruit has rings and spots. Growth and yields fall sharply.
Causes
The virus is carried from plant to plant by aphids feeding briefly. It also infects cucumber, pumpkin and other cucurbits, which act as a source.
Organic treatment
There is no cure. Remove and destroy infected plants promptly so they do not infect healthy ones, and replant with fresh seedlings.
Prevention
Raise seedlings under insect netting, plant papaya away from gourds and pumpkins, and control aphids. Grow a few border rows of maize as a barrier.
Chemical treatment (use with care)
Chemicals do not cure viral diseases. Aphid control can slow the spread.