Watch out for tomato spotted wilt virus

Submitted by: Juli Hughes, County Director MSU Extension Service – Choctaw County

Reports are coming in from all over Mississippi concerning Tomato Spotted Wilt Virus (TSWV) symptoms on tomatoes and peppers. Symptoms include a downward cupping of the upper leaves, a purple to black discoloration on petioles and stems, and eventually a rough feel and appearance of the leaf surface. Affected plants should be removed from the garden and destroyed.

The virus is spread by thrips and leaving a diseased plant in the garden serves as a source to infect the rest of the plants. Replace diseased plant with varieties that are tolerant of the virus. Tomato growers may want to replant with Bella Rosa since it is both heat and TSWV tolerant.

Southern peas Thrips are attacking emerging Southern peas causing the leaves to be discolored and crinkled. Flea beetles have also attacked emerging peas and butter beans causing small circular holes in the leaves. Treat with an appropriate insecticide if more than fifty percent of the plants are damaged.

Pumpkins Pumpkin growers should be arranging seed for late June to early July planting. Anyone trying to grow very large pumpkins for Halloween should be planted by the end of June since the very large varieties can take 120 days to mature. Remember that pumpkins take a lot of space in the garden and the plants do not tolerate shade.

Virginia Buttonweed Virginia buttonweed once established in a lawn is very difficult to control since it reproduces by seed, fleshy roots and from stem fragments. It is a spreading perennial broadleaf weed with opposite, lance shaped leaves producing small, four-lobed white flowers when in bloom that eventually develop tiny football shaped seed pods. This past winter’s milder temperatures and an early spring has given Virginia buttonweed a furious start in invading many lawns already this year.

Virginia buttonweed favors moist to wet areas, but can spread throughout the lawn. Pre-emergent herbicides provide only fair control of new seedlings and are ineffective from spreading by vegetative plant parts. Therefore, post-emergent herbicide applications are the most effective means of management.

Products containing phenoxy (hormonal) type chemicals such as 2,4-D, mecoprop, dicamba, fluroxypyr, etc. are effective if applied several times during the growing season. The sulfonyl-urea type chemicals including chlorsulfuron, metsulfuron, trifloxysulfuron, sulfosulfuron, etc. are also very effective at extremely low use rates.

Caution should always be taken to calibrate application equipment and apply herbicides accurately to prevent turf injury. Read product labels carefully and completely as not all products can be applied to all warm-season turf species. More specific information on controlling weeds in home lawns can be found in the turf section of Extension publication Weed Control Guidelines for Mississippi.

This publication can be downloaded from the Extension web at www.MSUcares.com.