Q How do I know my courgette or squash plants have been affected by virus?
A Courgettes, squash and their relatives are very prone to virus infections and symptoms include yellowing, poor growth, stunting and mosaicing, ring-spotting and streaking of the foliage, usually combined with a very poor or nonexistent yield. The most commonly seen virus is cucumber mosaic. Viruses are usually spread by handling, or by sap-sucking pests, such as greenfly, as they feed.
Caption: Courgette foliage shows the signs of virus damage
Q Is there anything I can do if my courgette or squash plants are affected by virus?
A Unfortunately, any fruits which do form on virus-affected plants tend to be small, pitted and very unpleasant to eat. If suspect plants appear, remove and dispose of them promptly, but always wash your hands thoroughly after handling virusy or suspect plants.
Q How can I prevent virus problems on courgettes and squash?
A There are no controls available for virus infections, so avoidance is the key. Check plants regularly and control any pests found. The following year, try to grow virus-resistant varieties, such as courgette 'Defender'