\m    19    4   92    2  1 'Anthracnose'
\m    42   11  117    2  1 'Helminthosporium Leaf Spots'
\m    69   22   76    3  1 'Rust'
\m    86   27   26    3  1 'Pythium Root Rot'
\m   108   34   57    3  1 'Seedling Blight'
\m   128   40   53    4  1 'Common Root Rot'
\t'October 1987'                                               'IV H-'page
\a                 Dr. Tom Kucharek, Extension Plant Pathologist
\a
\a                             DISEASE CONTROL IN RYE

                 Dr. Tom Kucharek, Extension Plant Pathologist



                             DISEASE CONTROL IN RYE


\h 1 'Anthracnose'
                                  Anthracnose


CAUSE:  Fungus (Colletotrichum graminicola)

SYMPTOMS:  Often found on lower part of plant during the first two weeks of
March.  Stem bases become bleached and later turn brown.  Purplish-brown,
water-soaked blotches are formed at or near nodes.  Toward maturity of rye
plant, elongated, black, raised, spore bearing pustules, smaller than a
pinhead appear on stems and leaf sheaths and blades or even floral parts.
Root rot, culm deterioration, lodging, sterility and premature ripening occur.

HOST RANGE:  Rye, oats, barley, timothy, red top, certain wheats, corn,
sorghum, Johnson grass, sudan Barnyard grass, quack grass, cheat (chess), and
wild barley.

CONTROL:  Crop rotation with non-grasses.  This disease is associated with low
pH and low phosphorus soils.  The presence of broom sedge is an indicator of
such soils.



\h 1 'Helminthosporium Leaf Spots'
                          Helminthosporium Leaf Spots

CAUSE:  Fungus (Helminthosporium sativum)

SYMPTOMS:  This fungus is seedborne, causing discolored shriveled seed.  If
such seed is planted, germination will be low with pre and postemergence
damping-off (seedling blight).  It may cause root and crown rot.  Crown rot
will appear as a low vigor plant with dark brown-green-black lesions on leaf
sheaths.  Lesions on leaves and leaf sheaths are usually elongated, football
shape, reddish-brown in color and often accompanied by a yellow halo.  When
sporulation occurs the lesion will have a greenish cast.  Flower and head
parts (glumes, etc.) are also susceptible.

HOST RANGE:  Wheat, barley, rye and numerous other crop and weed species.

CONTROL:  Use disease free seed.  Treat seed with fungicide.  Such a treatment
has increased germination of infected seed.  See section on Seed Treatment.
The use of a fungicide spray program with Dithane M-45 or Manzate 200 at 2
lbs/A will be beneficial in increasing yield and vigor or rye seed.  Begin the
first of 3 spray applications when rye is about 18 inches tall (growth stage
7).  Do not apply fungicide within 26 days of harvest or do not graze treated
area within 24 days after application.  Not recommended unless crop grown for
seed.
\b\v
\v
\v
\h 1 'Rust'
                                      Rust

CAUSE:  Puccinia rubigovera f. sp. secalis

SYMPTOMS:  Similar to leaf rust of wheat:  a) 1-2 mm round or oblong raised,
orange-red pustules (uredia) on leaf blades, leaf sheaths and sometimes on
glumes and awns.  They are found beginning in late winter to early spring up
though the heading stage.  b) Black pustules (telia) covered by leaf surface.
This stage is usually formed around heading time.

HOST RANGE:  Anchusa sp., Secale sp., possibly other small grain crops.

CONTROL:  None necessary at this time.



\h 1 'Pythium Root Rot'
                                Pythium Root Rot

CAUSE:  Fungus (Pythium sp.)

SYMPTOMS:  Preemergence damping-off.  Postemergence damping-off.  Plants that
emerge successfully are stunted, and rot at base of stem.  Root tips appear
water-soaked.  Occurs most frequently in the fall.  Lower leaves become
yellow.  Laboratory diagnosis should be used for this disease.  Can be
confused with or occur with nitrogen deficiency.

HOST RANGE:  Wheat, rye, barley, oats, ryegrass, peanuts, corn, sorghum,
soybeans, tobacco, rice, bermudagrass, and many other plant species.

CONTROL:  Seed treatment aids in control up to emergence.  Avoid planting
before the first of October with wheat, barley and rye and first of September
with oats.  Cool temperatures will reduce the activity of this fungus.
Serious losses may require replanting.  Seed treatment with Apron may be
beneficial.



\h 1 'Seedling Blight'
                                Seedling Blight

CAUSE:  Fungi (Pythium sp., Rhizoctonia sp., Helminthosporium sp., Fusarium
sp.)

SYMPTOMS:  Pre or postemergence stunting, distortion or death of seedling.
Rotting of young roots and culms present.  Water-soaking of roots, reddish or
brown lesions on young plant parts.  May mimic nitrogen deficiency (yellowing
of lower leaves).

HOST RANGE:  Wheat, rye, barley, oats, corn and many crop and weed species.

CONTROL:  Avoid deep planting of seed.  Crop rotation with non-cereal crops.
Bury stubble.  Seed treatment (see section on Seed Treatment).  Avoid planting
before the first of October.  Cool soil temperatures reduce Pythium seedling
blight in Florida.
\b\v
\v
\v
\h 1 'Common Root Rot'
                                Common Root Rot

CAUSE:  Several fungi (Helminthosporium sp., Fusarium sp., Rhizoctonia sp.)

SYMPTOMS:  Stunted plants which may be accompanied by purpled leaves.
Purplish coloration of leaves may also occur due to cold damage or some other
stress factor.  It may occur in patches or where small grains have been grown
on same land for several years, it may be more general in field.  Tan-brown
lesions on roots and basal leaf sheaths.  Inner tissues of crown may be brown.
May follow drought, nematode or insect damage.

HOST RANGE:  Wheat, barley, rye, oats, corn and many crop and weed species.

CONTROL:  Crop rotation with non-cereal crops.  Bury stubble.  Use seed
treatment (see section on Seed Treatment).