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SOME STRAWBERRY DISEASES
W. D Armstrong
B§12.f2~E
The red stele root rot disease has long been a serious problem in the
strawberry producing sections of Illinois, New jersey, and a number of other
states. Kentucky growers have been very fortunate in that losses from this
disease have been relatively light, to date. The writer first saw the disease in
an Aroma patch near Paducah in the spring of 1939. Another strawberry crop
was planted on this sarne field in 1944 and was again virtually ruined by red
stele in 1945. It was seen in a few other berry fields in the Paducah section and
I at Lexington in 1947 and it is suspected to be spread more generally than is
realized. In 1948 additional evidence of the disease causing injury around
Louisville and Covington was seen.
The disease is caused by a fungus that thrives in poorly drained soils
and causes most injury in cool, wet seasons. The disease is often carried to
1 the new field on the roots of the newly set plants and can be spread by surface
water run~off, as well as by cultivation tools that have been used in diseased
spots. If set in high, well —drained soil, infected plants mg develop healthy
‘ runner plants and grow into a productive field. However, if the soil is low,
poorly drained or of a tight, wet nature or if a wet, cool spring follows, the new
i patch may grow nicely the first season and then go to pieces early the following
Q spring The disease is inactive during the warm part of the year. Hence, in-
] fected patches often arc- vigorous and liealtliy looking during the suninier. This
  condition prevailed in a three-acre ficlcl of Blakenwores in the Pac1ucah—l{evi1
section in 1947 and the entire crop was lost except. on a high ridge down the
center of the field.
Symptoms: The trouble usually becomes noticeable just before harvest.
The sympt_o_rris_a_1Te low, small, light foliage that often wilts as the berries try
to ripen. These symptoms usually occur first in the lower parts of fields. in
little draws. dips or depressions. Most of the foliage scorches on seriously
infected plants and the berries do not mature or are seedy and of very low
quality. I\/lost of the infected plants continue to lose vigor and die out. The
disease can be identified easiest by carefully digging suspected plants and
splitting the roots lengthwise. In diseased plants the central core (or stele) of
the roots is a dark red or copper color. This corresponds to the appearance
of the lead in a pencil split lengthwise.
Control measures: At present the best control seems to be to avoid the
disease, if possible, This can be done, to a large extent by setting only clean
plants that have come from inspected fields. Use higher, well-drained soil
V as far as possible, especially after the disease has become established on the l
farm. Setting berry plants on small ridges has proven helpful in infected areas. _
Lay out the berry rows so as to encourage good surface water drainage but,
of course, still attempt to reduce erosion. Keep new settings of berries out of
infected fields for at least five years, since the disease remains in the soil for