I. The Control of Potato Virus Y on Pepper and Tomato

 J. N. Simonsi/


 This past growing season, 1958-59, has seen the occurrence of what may have
been the most destructive outbreak of virus infection of peppers and tomatoes
in the history of the Lower East Coast farming area. Because of the severe
losses suffered this year, and since it is almost certain that this disease
will be a serious problem next year, the research and extension workers of the
area are making an intensive effort to avoid repetition of this year's disaster.
It is the aim of this report to point out in detail what is involved in the
spread of this disease, the important factors that influence its destructiveness,
and the procedures that are useful in a control program.


 History of the Disease

 The first case of a pepper or tomato plant infected with potato virus Y
in eastern Palm Beach County was observed in the Spring of 1957. The disease
had been destructive to pepper crops planted along the shore of Lake Okeechobee
for many years but was restricted to tha part of the County. The discovery of
the disease along the East Coast was not unexpected.

 It had been observed that this virus occurred in south Florida only where
potatoes had been grown commercially; i.e., Homestead, Belle Glade, Bradenton.
Both the East Coast and Immokalee sections were free of the disease and neither
had a history of commercial potato production. Since seed potatoes carry a
low percentage of this virus it seem reasonable that: 1) the distribution of
the disease was correlated with potato culture; and 2) with the advent of
potato growing in either the East Coast or Immokalee sections virus Y should
be introduced into those areas. Thus, when the virus was found in pepper on
the East Coast the year following the introduction of potatoes, the expected
had happened.

 Losses in the Spring of 1957 were negligible, but the virus became firmly
established in certain weeds (mainly nightshade) where it was carried over
during the summer. During the 1957-58 season the virus appeared over a large
area of the East Coast. Losses were generally moderate but a few late pepper
and tomato growers and one hydroponics tomato grower suffered heavy yield reduc-
tions. We all know only too well what happened during this past 1958-59 season.


 How Does the Disease Spread?

 Like most plant viruses this virus can only spread when certain factors
are present. These include:

 1. A source of virus must be available.
 2. An insect capable of transmitting the virus (a vector) must be present
 and moving.
 3. A susceptible crop must be growing.


I/ Assistant Virologist, Everglades Experiment Station, Belle Glade.