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 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 Brown, necrotic roots
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 conditions.
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
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
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 Low quality of cut No low heights 1-inch minimum No striping Advantages Fewer man-hours Lower maintenance Grasscycling
Reel Mowers Disadvantages Higher maintenance More man-hours Reel Mowers High quality of cut Infinitely adjustable Lower heights Minimal scalping Striping
Mowing a new lawn After Establishment Mowing 1 st mow at 130 to 150% Proper Mowing Height Avoid mowing when wet
Proper Mowing Height SpeciesMower Height (in) Frequency (days) Bermuda Common Rotary or Reel 1 to 25 to 7 Hybrid0.5 to 1.53 to 4 CentipedeEither1 to 25 to 10 St. AugustineRotary2 to 35 to 7 ZoysiaReel0.5 to 23 to 7 Tall FescueRotary1.5 to 35 to 7
Irrigation Guidance Water application based on soil or plant moisture status is more efficient than applying water based on a set schedule
1 st signs of water stres Visual Symptoms: Dull bluish green color Footprints remain Leaf blades roll So--When should you irrigate?
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 per week) sandy soils (½ inch, 3 times a week)
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)
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?