A number of mosaic viruses infect cucurbits including cucumber mosaic, papaya ringspot, watermelon mosaic, zucchini yellow mosaic.
Identification
Infected leaves become mottled yellow/green and take on a puckered (drawstring) effect
If infected at an early growth stage, the plant will become stunted and malformed; it may also fail to produce fruit
Plants infected later in the season will produce mottled, misshapen fruit that often fail to ripen
Often Confused With
Nutrient Deficiencies
Period of Activity
Viruses can be present at any time, although they are most common during periods of heavy aphid infestations.
Scouting Notes
While scouting for other diseases, take note of any mottled, stunted or puckered plants. Record the scope and location of any infected areas.
Thresholds
None. There are no effective controls for viruses in cucurbits.