What plants are affected?
CGMMV affects cucurbit crops, including watermelon, cucumber, melons, zucchini, pumpkin, squash, bitter gourd, and bottle gourd.
What do I look for?
CGMMV can cause severe symptoms including fruit abortion, rotting, yellowing or dirty red discolouring of the internal fruit, or fruit malformation. It can appear as mosaic-like mottling on leaves, and can give a bleached appearance.
Symptoms on young seedlings may be indistinct or difficult to recognise as being caused by a virus, and may not be apparent until more mature leaves emerge.
Fruit may also be symptomless externally. In some cases, fruit showing no external symptoms may be internally discoloured or necrotic. This can be especially pronounced in watermelon.
There are at least five strains of CGMMV, whose symptoms can vary between hosts. Additionally, there are other mosaic diseases caused by potyviruses which are known to occur in northern Australia, which cause similar symptoms.
This makes it difficult to visually identify CGMMV. The virus must be conclusively established by laboratory testing, which can be undertaken by the AGWEST Plant Laboratories.