Transcript Review - Columbus, Georgia

Review
Disease Triangle
Host
Describe the Disease Triangle
Disease
Environment
Pathogen
• Name the 4 biotic
disease pathogens
we deal with and at
least one identifying
factor for each.
• Name abiotic factors
in plant death.
• Can you id these diseases in the
landscape?
Seridium Canker
• This disease is particularly
prevalent on drought stressed
Leyland Cypress trees during
hot weather.
• Fungus Seiridium unicorne.
• Symptoms: Yellowing and
browning of old foliage
precedes fading and death of
twigs and branches. Sunken,
long cankers with a reddish
tinge develop at wounds on
bark, bark is darkened and
resin exudes from margins of
cankers. Infection can occur on
any part of the plant and stage
of the tree. Infected trees look
thinly branched.
Leaf Rusts
• Leaf rust diseases are
common on roses,
snapdragons, hollyhocks,
crabapple, and most
recently, daylilies. The
most diagnostic sign of
the disease are the raised
pustules that rupture to
release powdery, orange
to rust-colored spores on
the underside of the
affected leaf.
Rhizoctonia Root Rot
• They occur in wet soils
with limited soil drainage
(porosity) or in areas that
are over-watered or
remain wet due to
location of gutters and
downspouts, air
conditioning units and
slopes, etc. All landscape
plants (trees, shrubs and
flowers) are susceptible
to root rot.
Damping Off
Pythium Root Rot
Brown, necrotic roots
• Plants attacked by soil-borne
pathogens may be stunted,
develop lesions at the soil line,
or wilt and collapse. When
larger plants become infected
with root rot pathogens,
aboveground symptoms
include poor growth, off-color
foliage, yellowing and dropping
of lower leaves, wilting and
death. Infected roots are
usually brown, soft and
decayed. Some root rot
pathogens invade the lower
stem as well, causing tan, dry
cankers or a soft, dark-brown,
watery stem rot
Powdery Mildew
• Powdery mildew is
characterized by the
presence of whitish
fungal growth on the
surfaces of leaves,
stems, and flowers.
Infection of young,
expanding leaves or
shoots can result in
severe distortion.
• Very common on
pruned crapemyrtles.
Leaf Gall, Exobasidium
• Common on azalea,
rhododendron,
mountain laurel
(Kalmia) and camellia
in the spring during
wet, humid, cool
weather. Infection
only occurs at leaf or
flower bud break if
favorable
environmental
conditions exist.
Fire Blight
• Fireblight is a
destructive, highly
infectious and
widespread disease
caused by the
bacterium Erwinia
amylovora. Fireblight
affects plants in the
Rosaceae family such
as pear, crabapple,
cotonoaster, photinia,
pyracantha, quince,
etc.
Botrytis Blight
• The fungus commonly
invades wounded or
senescent tissue, such as
fallen flower petals or
other fresh plant
residues. It can also
invade healthy tissue in
contact with infected
residues. Masses of
fuzzy, grayish-brown
spores on thin black
stalks develop on infected
plant tissues under cool,
moist, humid, cloudy
Sooty Mold
• Fungus that grows on
the secretions of
piercing sucking
insects such as
aphids, whitefly.
• Remove the food
sources, the fungus
will go away.
Bacterial Diseases
• Leaf spots are initially
water-soaked or
greasy in
appearance, often
angular, and
concentrated along
leaf veins or margins
• Requires water to
enter leaf
• Fungus gnat larvae
can spread soft rot
bacteria
Viral Diseases
• Virus symptoms are
often quite striking
and distinctive.
Chlorotic mottling,
ringspots and line
patterns on the
foliage or stems may
occur.
• Stunting is commonly
observed.
• Destoy plants, rid
area of vectors.
Yellow Ringspot
Pattern on Lily
Brown Patch
• Brown patch symptoms appear
as circular patterns or rings of
dead grass. The turf turns
brown, individual leaves exhibit
irregular spots, and grass
blades rot off. If observed
closely, blighted areas initially
show a dark purplish-green,
which quickly fades to a light
brown.
• Brown patch infection on the
crown area promotes rotting of
tissue, therefore leaves and
runners pull out easily. Circular
or irregular patches of blighted
grass develop rapidly.
• What is an annual?-name 3
• What is a perennial?-name 3
Soil Composititon
Air
25%
Organic
Matter
5%
Water
25%
Mineral Matter
45%
What does organic matter do for
soils?
•
•
•
•
•
•
Improves soil physical condition
Reduces erosion
Improves water infiltration
Improves water holding capacity
Increases soil cation exchange capacity
Source of nutrients
Warm-season
Turfgrasses
• Bermudagrass
•
•
•
•
Centipedegrass
Zoysiagrass
St Augustinegrass
Bahiagrass
Soil Prep
Sample soil
Clean planting site
Rough grading
Replace topsoil
Organic matter
Tilling 6-8 inches
Fertilizer & lime
Final grading
Methods of Turf Planting
Vegetative Methods
 Sodding
 Sprigging
 Plugging
Seeding
Mowing Info
 1/3 rule
 Gradually change height
 Recycle (leave or compost)
 Change directions
 Keep mower in good working
order
Mowing: Blade
Sharpness
Nebraska – Steinegger &
Shearman, 2001
Dull blades
 increased disease
 water use decreased
Sharp blades
 33% more water used
 22% reduction in fuel
Rotary Mowers
Disadvantages
Advantages
 Low quality of
cut
 Fewer man-hours
 Lower maintenance

Grasscycling
 No low heights
• 1-inch
minimum
 No striping
Reel Mowers
Disadvantages
Reel Mowers
 Higher
maintenance
 High quality of cut
 More man-hours
 Lower heights
 Infinitely adjustable
 Minimal scalping
 Striping
Mowing a new lawn
After Establishment
 Mowing
 1st mow at 130 to 150%
 Proper Mowing Height
 Avoid mowing when
wet
Proper Mowing Height
Species
Mower
Height
(in)
Frequency
(days)
Bermuda
Common
Rotary or
Reel
1 to 2
5 to 7
0.5 to 1.5
3 to 4
Centipede
Either
1 to 2
5 to 10
St. Augustine
Rotary
2 to 3
5 to 7
Reel
0.5 to 2
3 to 7
Rotary
1.5 to 3
5 to 7
Hybrid
Zoysia
Tall Fescue
Irrigation Guidance
 Water application based on
soil or plant moisture status is
more efficient than applying water
based on a set schedule
So--When should you irrigate?
1st signs of water stres
Visual Symptoms:
 Dull bluish green color
 Footprints remain
 Leaf blades roll
Q: When is the best
time to irrigate?
A: After the dew falls and before
it dries Water losses lowest
(Less wind and lower temps)
 Does not promote disease
How Much to Irrigate?
Wet 6 to 8 inch depth
 clay soils (1 to 1¾ inches
week)
 sandy soils (½ inch, 3
times a week)
per
Proper Irrigation
Cultural Practices
Only wets the turfgrass
rootzone
 Does not saturate the soil
 Does not allow water to run off
Weed Life Cycle
• Annual: Completes growth cycle in a
single growing season (crabgrass).
• Perennial: A plant that can persist
more than two years, and reproduce
through roots or seeds (clover).
• Biennial: A plant that normally requires
two growing seasons to complete its
life cycle, flowering and fruiting in its
second year (wild carrot).
Herbicide
Classification
Preemergence: Applied before
weed seed germination
(trifluralin). Generally no
control of emerged weeds.
Postemergence: Applied after
weed emergence. Generally no
control of unemerged weeds.
• Selective: Kills some plant species, but
does not damage others (2,4-D)
• Nonselective: Generally kills all plant
species (glyphosate)
Veggies?
Landscape Planting and
Maintenance
Composting
• Why compost?
• What are the ingredients of successful
composting?
• What are some factors that might make it
all go wrong?
BUGS!
• Good bug, bad bug?