Tomato Spotted Wilt Virus: TSWV in Vegetable Crops: Tospoviruses

Tospoviruses In Solanaceae and Other Crops in The Coastal Plain of Georgia

Tospovirus Summary and Outlook

Alex Csinos

Tospovirus have become some of the greatest concerns in tobacco, peanut and vegetable production in the southeast. Some headway has been made over the past 15 years in management of the diseases in particular where disease resistance can be incorporated into the management plans. This is particularly the case for peanut, tomato and pepper where traditional breeding programs have developed cultivars that have at least partial resistance. These cultivars have become central to the management programs and have been very effective in reducing TSWV losses.

Crops such as tobacco and onion do not have cultivars with resistance and thus management programs are dependent on cultural techniques and chemicals. Although transgenic tobacco lines, immune to TSWV, have been developed, GMO crops are not well accepted in the world market and thus are unacceptable to tobacco companies. The susceptibility and resultant crop damage on onion has just recently been brought to light and thus impact of TSWV on the onion industry in Georgia is yet uncertain.

Tospoviruses are a great concern world wide, but little information is available on managing these viruses. The Coastal Plain of Georgia has become the center of TSWV damage on crops grown in the southeast. We suspect that environment and hosts play an important role on the severity of the virus in Georgia. Many crops and weeds are susceptible to TSWV infection and the vector thrips also use those same plants as hosts. With the virus, hosts and the vector all present during the entire year, epidemics of TSWV will occur each year the environment is suitable.

Host resistance, and critical biological aspects of the disease may be the only forseeable management areas we may be able to capitalize on. Insecticides such as imidacloprid (Admire), and phorate (Thimet) are used primarily to target the insect vectors of TSWV. acibenzolar-S-methyl (Actigard) is a plant activator and induces systemic acquired resistance (SAR) in plants to protect against infections. These materials are currently recommended and are being used with limited success, but alone may not provide acceptable control of the disease.

Management of tospoviruses and other similar viruses vectored by insects will continue to be serious threats to southeast agriculture since both the viruses and the thrips vectors are endemic. Both traditional breeding programs and transgenic breeding programs (if accepted) will provide the best input into management programs for tospoviruses.

Understanding the biology of both the virus and its thrips vector and their relationship to environmental conditions favorable for epidemics continues to be a priority in research programs.

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