Researchers Identify Cause of Watermelon Vine
Decline By Alfredo Flores November 8, 2007
With popular and nutritious watermelon now battling a new plague
called watermelon vine decline, Agricultural Research Service (ARS) scientists in Fort Pierce, Fla., are
trying to pinpoint the cause of the disease and find ways to control it.
A crippling plant disease, watermelon vine decline (WVD) has made a
serious economic impact since first being seen in Florida in May 2003. So far,
it has been limited to the Sunshine State, but growers fear it could spread
anywhere watermelons are commercially grown. Research efforts are being led by
Adkins, who's in the
Subtropical Plant Pathology Research Unit at Fort Pierce.
Symptoms of WVD include interior browning of the fruit rind, rapid
vine collapse and death just before harvest. Yield losses totaled more than $60
million in 2005, relegating Florida watermelon producers to the No. 2 spot,
Bruton has worked with Adkins since the initial stages of WVD research, and
Kousik joined the effort in November 2005. Bruton is at the
South Central Agricultural Research Laboratory in Lane, Okla., while Kousik
is at the
U.S. Vegetable Laboratory in Charleston, S.C.
Bacteria, fungi and non-biological factors had been previously
eliminated as the cause of WVD by other researchers. Then Adkinsin
collaboration with Susan Webb, a University of
Florida entomologist, and Carlye Baker, a plant pathologist with the
Florida Department of Agriculture and
Consumer Services, Division of
Plant Industrydetermined that the novel ipomovirus named squash vein
yellowing virus is the causal agent. The host range of squash vein yellowing
virus appears to be limited to the Cucurbitaceae family, with the most dramatic
symptoms occurring on squash and watermelon.
It had been known for some time that the principal insect pests on
watermelons in Florida were aphids, rindworms, whiteflies and thrips, but it
took two years of research to determine that squash vein yellowing virus,
transmitted by the silverleaf whitefly, was responsible for WVD.
Screening of watermelon germplasm for resistance to squash vein
yellowing virus in greenhouse trials in Fort Pierce and field trials with
University of Florida scientists has yielded promising results.
about this research in the November/December 2007 issue of Agricultural
ARS is the U.S. Department of
Agricultures chief scientific research agency.