Mosaic Virus

This is probably one the most common and devastating viruses to affect capsicum. It is common as it has so many different plant hosts in the garden. It infects other types of vegetables as well as weeds. Each virus has a name based on the host and looks slightly different. There are literally hundreds types of Mosaic Virus, Tomato Mosaic Virus, Tobacco Mosaic Virus, Cucumber Mosaic Virus, Alfalafa Mosaic Virus… There are so many different types of Mosaic Virus, we are just going to keep things simple at this point and call this Mosaic Virus. The Solanaceae family of plants are highly vulnerable to Mosaic Virus.

This virus is highly transmissible (Contact, Water, Soil), but the main vector for the transmission of this virus is Sap sucking insects (Mites, Thrips, Whitefly, Aphids, Mealybugs). Sap suckers can transmit the virus from one plant directly to your chilli plant. Depending on the type of Mosaic Virus infecting your plant, the look may be slightly different. But, in essence the basic visual tell tale with Mosaic Viruses are pretty much similar and quite easy to spot. When we talk about Mosaic Viruses there is usually a general distortion of the leaves and a very obvious patterning on the leaf surface. This pattern is commonly a very contrasty patterning of yellow and dark green. The patterns may vary and may even be more subtle (Cucumber Mosaic Virus), but it is usually quite distinctive. There is no visible furriness like with molds, but a very obvious bold rash across the leaf. Much like we humans can get red blotches (rashes) on our skin with viral infections.

Mosaic Virus’ can be transmitted on infected seed stock. There are capsicum cultivars that are Mosaic Virus resistant. All cultivars respond to the Virus differently. Some are less affected than others. The virus is mostly transmitted to plants by sap sucking insects, but can also be transmitted by contact, water and soil/plant material. Once infected, there is no cure. There are fungicides that can help stabilize infected plants, but there is no known cure.

Sadly the prognosis for infected plants is not good and given the highly transmissible nature of this virus, it is most advisable to remove the infected plant before transmission to neighboring plants can take place. Once a plant has been infected by sap sucking insects carrying the virus, the plant itself can become a vector to uninfected sap suckers, who will in turn transmit the virus to other plants.

As previously stated, Mosaic Virus affects all plants in the Solanaceae family of plants. These are all the cousins of the Capsicum family (Potatoes, Gooseberry, Tobacco, Eggplant (Aubergine), Tomatillo. These are all common co-habitors in the vegetable garden. For those of you who are smokers – another word of warning (apologies). Commercial Cigarette Tobacco is known to carry the Tobacco Mosaic Virus (TMV). This means when you touch your Capsicum plants in the garden, your hands can very easily transmit the TMV virus to your healthy capsicum plants. Please ensure you wash your hands or wear gloves when working in the garden. Unknowingly, you may be the vector at the centre of your garden woes!

Here are some tips to help you manage Mosaic Virus in your pepper patch:

• Prevention is better than the cure. Be prepared.
  • Look out for Mosaic Virus Resistant Cultivars when buying your seeds.
  • Regularly spray your plants in the rainy season with fungicides that are sulphur (Kumulus™) or copper (Bordeaux Mix) based. These can help prevent your plants getting infected in the first place and will deter sap suckers from setting up camp on your plants.
• It is advisable to cut your losses on Mosaic Virus infected plants. Get rid of them as soon as you know. The virus will spread and you run the chance of loosing your entire crop.
• Dispose of all infected plant material in the refuse. Do not add infected plant material into your compost.
• Avoid contacting other plants.
  • Wash hands regularly or wear gloves.
  • Clean tools that have been in contact withe infected plants.
  • Dispose of infected containers and soil.
• Keep ontop of sap sucking insects by spraying with insecticides regularly.
• Keep other vegetables (in particularly Tomatoes, Tobacco, Eggplants, Gooseberrys, Tomatillos & Potatoes) away from your peppers.
• Avoid using home DIY liquid vertilisers or insecticides that contain plant material which may be infected with Mosaic Virus.
• Keep weeds under control, these can also infect plants with Mosaic Virus.

If you are not sure about whether or not your plant has Mosaic Virus, consult a expert. Nurserys can also give advice on your plants if you can show them a picture.