Understanding Tomato Spotted Wilt Virus: Causes, Prevention And Effective Management

Are you not able to sell your tomato fruits in the market due to their deformed shape and presence of ringspots on their surface? The frustration of such a situation is understandable, but we’re here to get you out of it. 

Are you still wondering how to solve this problem and what could be causing it?  

Look no further, as we have the answers you’ve been seeking. Tomato spotted wilt virus (TOSPOW) is the one causing trouble to your tomato field. If you want to understand its causes, learn how to identify it, and most importantly, discover effective strategies for tackling it head-on, then your search ends here. Dive into the content thoroughly to equip yourself with the knowledge to minimize your losses.  

Symptoms of Tomato Spotted Wilt Virus

• Dark brown, bronze or black circular spots can appear on the leaves, starting as small lesions and gradually enlarging. 
• Infected leaves may show a yellowing or bronzing discoloration, starting from the edges and progressing inward. 
• Infected leaves may exhibit distortion, curling or crinkling. They may appear twisted or deformed compared to healthy leaves. 
• Affected plants may exhibit a wilted or drooping appearance, even when adequately watered. 
• The stems may display dark brown or black streaks, which may extend from the base to the upper parts of the plant.  
• Infected plants often exhibit stunted growth and show overall reduced vigor. 
• Circular or irregularly shaped ringspots appear on the surface of infected fruits, usually with a lighter or darker coloration compared to the surrounding healthy tissue. 
• Infected fruits may have a bumpy or rough texture on the surface. 
• Affected fruits may be deformed and ripen unevenly. 
• If the plant is affected at an earlier stage, it does not bear any fruit at all.    

What causes it? 

• TOSPO is primarily transmitted by thrips. These insects feed on infected plants and acquire the virus. They then spread the virus to healthy plants as they feed on them. 
• High temperatures, especially above 27°C, can enhance thrips activity and virus replication. Dry conditions can also lead to increased thrips movement, promoting virus transmission.  
• Use of more quantities of ammoniacal nitrogen to the crops. 
• The virus can infect several weed species, including pigweed, lambsquarters and nightshades. These weeds can serve as reservoirs for the virus and provide a constant source of infection for nearby tomato plants. 
• Tomato plants grown in close proximity to infected plants, whether they are tomatoes or other susceptible hosts, are at a higher risk of contracting TOSPO.  

Ways to Prevent TOSPO Virus 

• Use tolerant varieties. 
• Use virus free planting material for planting.  
• Remove all the infected plants and destroy (burn) them at early infection stages to avoid the spread of virus. 
• Avoid excessive use of nitrogen fertilizers. 
• Eliminate weed species that can act as alternative hosts for virus and thrips. Regularly remove weeds from your field to reduce the reservoir of the virus. 
• Avoid planting tomato plants near alternate hosts such as pepper and potato. 
• Avoid planting near infected crops.  
• Grow 2 – 3 rows of sorghum, maize or bajra as barrier crop around the field to reduce the movement of thrips from adjacent field.  
• Install sticky traps to monitor the thrips population. 
• Spray neem oil (1 – 2 ml/lit of water) at regular intervals from seedling stage of the crop to prevent feeding of thrips. 
• Give foliar spray of Magnum Mn (0.5 gm/lit of water) and V-Bind Bio viricide (2 – 3 ml/lit of water) to enhance the plant’s resistance to TOSPO virus and reduce the incidence of the disease.  

Management of Vector, Thrips 

As the virus is transmitted by vector i.e., thrips, controlling them can help to reduce the spread of disease in tomato crops. 

(Note: Check and follow the instructions given in product’s label to know the right time o application) 

Further, click here to know the “Easy ways to get rid of TOSPO virus (Tomato Spotted Wilt Virus)”