Yellow Mottled Tomato Leaves

Disease Identification

• Tomatoes are susceptible to infection from the tomato mosaic virus, also referred to as tobacco mosaic virus. The disease is caused by the tobacco etch virus or the potato Y virus within the potyvirus group. The virus is present in all the tomato growing regions around the world. Other host plants of the virus include more than 150 types of plants including flowers, weeds and a variety of other vegetables.

Symptoms

• A distinct sign of the disease includes a yellow and green mottling of foliage. Mottling refers to alternating shades of green and yellow. The foliage grows sharply pointed and almost fernlike in appearance. Fruit quantity is reduced in younger plants with distorted, blemished fruit. Foliage areas that are dark green have a thicker texture. Overall plant growth is stunted and dwarfed. Affected plants produce discolored flowers.

Favorable Conditions

• The virus is rapidly transmitted between plants by aphid species. Plants are most prone to infection during high aphid activity periods. Other likely pest vectors include chewing pests like beetles and grasshoppers. The use of contaminated tools and hands is the most frequent cause of spread. Growing plants from infected seed leads to infected plants. Plants that are growing in poorly maintained sites with leftover root and leaf debris from prior planting are also prone to the infection.

Control

• Since no chemicals are available for the control of the disease once plants are infected, the main control strategy is to maintain good sanitation in the planting area and use insecticides to control insect vectors. The virus has the highest persistence level among all plant viruses with its ability to live in dried plants for nearly 50 years. Buy healthy seeds from reliable sources. Use silver reflective mulches around plants to repel aphids and reduce chances of infection.