WASHINGTON, Oct. 9, 2002--The U.S. Department of Agriculture's Animal and Plant
Health Inspection Service today announced plans to conduct a national survey
for potato mop top virus, the results of which will represent every certified
seed lot in the United States.
PMTV was confirmed for the first time in the United States in Maine in August
2002. In order to determine the distribution of PMTV in seed-producing states,
APHIS will test approximately 3,000 tubers per state. The samples will include
tubers from all certified seed lots grown in the 17 states that produce
certified seed potatoes.
The results of the PMTV survey, which will be available in late 2002, will form
the basis for any future regulatory action that may be taken by APHIS. If PMTV
is determined to have limited distribution, APHIS will consider regulatory steps
to prevent the interstate movement of infected seed.
PMTV, which does not affect humans, is a soilborne virus in the pomovirus group
and is transmitted by the fungus that causes potato powdery scab disease.
PMTV may cause discoloration or necrotic rings on lines in infected tubers.
Above ground portions of infected plants may show various types of mottling
and stunting. Losses of up to 20 percent have been reported in sensitive
cultivars as a result of reduced tuber production and loss of tuber quality.