Tomato Leaf Curl Virus also known as leaf roll affects more than just tomato plants but a whole host of plants.
This virus plant disease can be quite deadly for plants and halt the production of fruit altogether – especially if the plants get infected when they are young.
Tomato leaf curl virus affects a total of forty-four plant families across 300 species. It is most common in locations with an arid or semi-arid climate.
NOTE: The tomato mosaic virus is another virus which causes downward leaf curling leaves and leaf rolling along with leaf spot and mottled colored foliage.
What is the Tomato Leaf Virus?
Tomato leaf virus is among a number of viral diseases that infects plants and stunts their growth eventually leading to their death.
It spreads to other plants physically through the silverleaf whitefly (Bemisia tabaci). (Read our article on Whitefly Control)
This insect picks up the virus while feeding on an infected plant.
Once the whitefly is infected, it retains the virus for almost two weeks and transfers viral infections to any other tomato plants it feeds on during that time.
The virus will leave their body after ten to twelve days and require them to get infected again in order to spread.
However, it is still long enough to infect a good number of plants.
What Damage Does the Tomato Yellow Leaf Curl Virus Cause?
Leaf rolling or leaf curling can result from a variety of conditions including:
- Viral infection
- Herbicide damage
- Environmental stress
- Insect infestations
The Cooperative Extension Service At Rutgers suggests asking these questions:
- Is the leaf curling on older leaves, lower leaves, new leaves, or all of the leaves?
- Is the leaf curling upward or downward?
- Are there any other abnormal symptoms such as yellowing or distorted leaves?
Tomatoes affected by tomato curl virus will appear to have a number of symptoms such as:
- Leaf curling – known as “physiological leaf” roll
- Stunting of plant growth
- Flower/fruit drop
- Low fruit production
It can be difficult to identify this virus because the symptoms are similar to other common diseases.
Tomato yellow leaf curl can happen at any time during the growing season but the late spring to early summer appears the most common.
The first signs of the virus will begin to show when the lower leaves of diseased plants start to thicken and either curl upwards or droop downwards.
The virus infection usually followed by the leaves changing color to reflect a faded yellow with tints of purple in the leave’s veins. The change in color looks a bit like herbicide damage.
Another common symptom of this virus is flower or fruit drop as the virus spreads.
Tomato plants with the virus will stop bearing fruit altogether.
However, if the plant has borne any fruit prior to getting infected, the fruit will likely appear small, crinkled and dried out and will ripen before it’s supposed to.
Once you destroy the infected diseased plants, plant any new plants far away from the area to avoid the risk of infected whiteflies still alive.
How to Control Tomato Leaf Virus
- Look for disease-resistant varieties to prevent problems with tomato plants.
- Plant tomato cultivars less susceptible to yellow leaf virus
- Mulch to maintain consistent soil moisture
- Avoid heavy pruning fo tomatoes
- Water as necessary
Given that this virus is spread by silverleaf whiteflies, controlling the spread of the virus has to do mainly with controlling the spread of these insects.
Try and prevent whiteflies from attacking your plants by creating a trap for them.
A 12”x12” board painted in yellow will attract the whiteflies.
Spread petroleum jelly on this board, to catch the whiteflies before they attack your plants.
However, this may not be an effective preventive measure and will not work once plants become infected.
An alternative organic option is to spray an insecticidal soap every two to three weeks.
If a plant has been affected by the tomato yellow leaf curl virus, take steps to ensure it can be spread to other plants.
This requires covering the infected plant in a bag to trap any potential whiteflies inside and burn the plant to keep others from feeding on it and catching the infection.