Tomato Leaf Curl Virus
Tomato Leaf Curl Virus (TLCV): This disease is transmitted by whitefly (Bemisia tabaci). It is one of the most devastating diseases of tomato. Leaf curl disease is characterized by severe stunting of the plants with downward rolling and crinkling of the leaves. The newly emerging leaves exhibit slight yellow colouration and later they also show curling symptoms. Older leaves become leathery and brittle. The nodes and internodes are significantly reduced in size. The infected plants look pale and produce more lateral branches giving a bushy appearance. The infected plants remain stunted.
Control: The affected plants should be removed and destroyed. Alternate or collateral hosts harboring the virus causing this disease is removed at the time of weeding or earthing up operations to minimize the spread of the disease. Checking the white fly population can reduce the disease incidence. Soil application of granular insecticide like Furadan (1 kg a.i./ha) at the time of sowing seeds in the nursery bed checks whitefly population. Another dose of Furadan (1.5 kg a.i./ha) is given one week after transplanting. 2-3 foliar sprays with Dimethoate (0.05%) or Monocrotophos (0.05%) at 10 days intervals controls the white fly population.
The disease spread can be minimized by cultural practices like use of border or barrier cropping. Barrier crops like maize, jowar, bajra are good to protect the crop from TLCV infection. Five or six rows of these crops all around the main tomato plot should be sown at least 50-60 days before transplanting of tomato. These crops check incoming viruliferous whiteflies from entering into tomato crop. TLCV incidence can be reduced drastically by the use of polythene mulching in the soil just before transplanting of tomato. Polythene sheets of white, blue, grey and black colours are effective. Combined application of polythene mulching and Furadan application in the soil is recommended.
