Control Plant Disease
in yard and garden
Mimeo BP 4-4
Revised

STRAWBERRY ROOT ROTS

Every year Indiana strawberry grow-
ers are puzzled by areas of dead plants in
their strawberry plantings. These areas
vary from a few plants to, occasionally, the
entire planting. Usually this is the result
of strawberry root rot--either the black
root rot or the red stele type.

BLACK ROOT ROT

The specific cause of black root rot
is not known. But one or more of the follow-
ing may be wholly or partly responsible--
soil fungi, nematodes, winter injury, drought
or nutritional deficiencies.

Symptoms

This disease usually occurs in the
spring. Around picking time, plants suffer-
ing from root rot start to wilt, the leaves
turn yellow then brown, and the plant dies.
Affected plants show brown to nearly black
roots which dry out and die. These roots
are much smaller than normal.

Control

Black root rot damage may be greatly
reduced by following these suggestions:

1.	Plant strawberries in well-drained
and preferably sandy soils.

2.	Select transplants with bright white
roots from healthy mother plants.

3.	Plant root rot-resistant varieties,
such as Midway, Blakemore, Premier,
Tennessee Beauty, Temple, Sparkle, etc.
Use virus-free plants, if possible.

4.	In the spring apply 600 to 1, 000
pounds of 3-12-12 or equivalent fertilizer
per acre. This will help offset loss of vigor
that may result from spring infections of
root rot.

5.	Treat the soil with zineb (Parzate
or Dithane Z-78) to reduce the root rot.

Using Zineb

In established strawberry patches,
when the first signs of root rot appear, dig
a V-shaped furrow 4 inches wide and 4 inch-
es deep on each side of the row and as close
as possible to the roots without injuring them.
Then apply a zineb solution (2 heaping table-
spoonsful per gallon of water) to the furrow
at the rate of 1 gallon per 7 feet. Finally,
refill the drenched furrow.

For treating soil before planting
strawberries, prepare the plant bed so the
soil is reasonably loose and dry. Then
thoroughly mix 1/4 to 1/2 ounce of zineb
dry powder with every cubic foot of soil (24
inches x 12 inches.x 6 inches deep). Dip the
roots and crowns of all transplants in a solu-
tion of zineb (2 tablespoonsful per gallon of
water), and plant immediately. Finally,
irrigate the patch right after planting.

RED STELE DISEASE

In the past few years, red stele has
become economically important in Indiana.
It is the most serious fungus disease of
strawberries in the U. S.

Cooperative Extension Service PURDUE UNIVERSITY Lafayette, Indiana
Department of Botany and Plant Pathology, Life Science Building