Common Turf Problems Drought
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Chinch Bugs
Chinch bug damage is usually first detected when irregular patches of turf begin to turn yellow then straw colored. The straw colored areas may be completely dead. These patches continue to enlarge in spite of watering.
Apparently, feeding by chinch bugs blocks the water and food conducting vessels of grass stems. By blocking the water, the leaves wither as in drought and the manufactured food doesn't reach the roots and the plant dies. Damage is especially severe during hot, dry weather from June into September and is often mistaken for drought dormancy.
Japanese Beetle
The adults are skeletonizers, that is, they eat the leaf tissue between the leaf veins but leave the veins behind. Attacked leaves look like lace, which soon withers and dies. The adults will often attack flower buds and fruit. The grubs can kill small seedling plants but most commonly damage turf. The turf first appears off color as if under water stress. Irrigating often masks infestations, but when withdrawn, severe damage soon appears. The turf feels spongy under foot and can be easily pulled back like old carpet to reveal the grubs. Large populations of grubs kill the turf in irregular patches.
Dollar Spot
Dollar spot is a common and persistent disease that occurs on most turfgrass species throughout the world. On closely mowed grasses (such as golf greens) the overall symptom of dollar spot is small, circular, sunken patches that rarely exceed 2-3 in. (6 cm) in diameter. These patches coalesce into larger, irregular patches if the disease becomes severe. Residential lawns and other taller turfs may exhibit irregularly shaped, bleached patches of blighted grass 1-6 in. (2-15 cm) or more across.
Under favorable conditions, patches may coalesce to cover large areas of turf.
Dark stromatic tissue forms on infected leaves, and serves an important role in survival of the fungus during periods of unfavorable environment.
Individual infected leaves develop a lesion that is first chlorotic, then water-soaked, and finally a bleached color. Dollar spot lesions are characteristically bounded by a tan to reddish brown margin, and they generally enlarge to extend across the entire leaf, except on grasses with coarse leaves (such as Paspalum). Lesions often appear hourglass-shaped. Dieback from leaf tips is also common. Individual leaf blades may have a single lesion, have many small lesions, or be entirely blighted. Leaf symptoms may be confused with those caused by red thread, copper spot, brown patch, and Pythium blight. When dew is present on grass blades and the pathogen is active, a white cottony or cobwebby growth of fungal mycelium may be seen on diseased turf.
Pink Patch
Patches of affected turf may be up to 2 feet (60 cm) across. Pink patch spreads much more slowly than red thread and is much less severe, because it damages only a comparatively small number of leaves in the patch and does not significantly reduce the growth rate of the grass. Thus, patches generally retain their green color.
Individual leaves become covered with a pink, gelatinous growth of mycelium. The mycelium initially forms along leaf margins and later may cover the entire width. The leaf dies from the tip downward. Pink patch lacks two of the distinguishing characteristics of red thread: the red, threadlike growths of mycelium on leaf tips and the pink, cottony flocks of arthroconidia.
Snow Mold
Receding snow reveals the presence of circular or irregularly shaped snow mold patches with white to gray, woolly or appressed mycelium. Slight variations in symptoms are produced by the sclerotial and nonsclerotial strains of this pathogen. The nonsclerotial strain tends to grow faster and with more cottony growth than the sclerotial strain. Thus, the nonsclerotial strain often produces patches that are somewhat larger and whiter than those formed by the sclerotial strain. The nonsclerotial strain often forms patches 6-12 in. (15-30 cm) in diameter.
Sclerotia are initially seen as conspicuous white hyphal knots, up to 3 mm wide, on leaf surfaces. These white knots later turn light brown and mature into brownish black, elliptical or flattened, irregularly shaped sclerotia 1-3 mm wide. Infected plants have rotted, water-soaked leaves or leaf lesions. The lesions, or leaves, become pale brown when dry and have dark, red-brown margins.
Spring Dead Spot
Circular patches of bleached, dead grass appear in the spring as the dormant grass resumes growth. In Australia, the patches are also visible in autumn and winter after a series of unusually cool days or wet, cold weather. Patches are a few inches to 3 ft (few centimeters to 1 m) in diameter and tend to reappear and expand in the same spot for three or more years. After 2-3 years, the centers of active patches may remain alive, and in this stage the patch takes on a ringlike appearance. Rings that coalesce can appear as serpentine arcs. Frequently, patches coalesce and the damage is nonuniform and appears similar to winterkill or winter desiccation.
The roots and stolons of bermudagrass plants in affected areas are severly rotted. Regrowth of grass into the patches is generally slow, and in some areas the patches remain barren or fill with weeds. When the grass recolonizes affected areas, it remains stunted. The presence of a persistant toxin in soil has been demonstrated in North America. Casual fungi produce dark brown, septate mycelia stolons and roots. Ascocarps (pseudothecia or perithecia) of casual fungi are also observed occasionally on dead tissues.
Red Thread
Circular or irregularly shaped, small to large patches 2-20 inches in diameter (5-50 cm) of infected grass become water-soaked and die rapidly. The tan color of dead leaves may be the first symptom observed. Dead leaves are generally interspersed among infected leaves, which gives an overall diffuse, scorched, or ragged appearance to the patch. The patches may be widely scattered or close together and may coalesce to form large areas of infected turf. Several other diseases, including dollar spot and pin patch, can be easily confused with red thread.
Inspection of individual plants reveals that only the foliage is infected, and death usually proceeds from the leaf tip downward. When the air is saturated with moisture, the pathogen produces colorful mycelial structures that are of diagnostic value. Pink to pale red or orange fungal growths called red threads, may extend beyond the end of the leaf tip.
Pink, cottony flocks of mycelium may also be produced. When the red threads or flocks are present, following humid weather, the patches of blighted grass take on a reddish, pink, or tan cast that is easily detected. Red thread may occur at different times of the year at different sites, and symptoms may be highly variable. The disease is particularly difficult to diagnose when red threads or cottony flocks are not present.
Brown Patch
Symptoms of brown patch may vary greatly with the type of grass and soil conditions. The disease usually causes thinned patches of light brown grass that are roughly circular in shape. These areas range in diameter from a few inches to several feet. Often the center of the patch will recover, resulting in a doughnut-shaped pattern.
When disease conditions are favorable, large areas of the lawn may be uniformly thinned and eventually killed with no circular patch being evident. This type of pattern is commonly seen on infected St. Augustinegrass grown in shady, moist locations.
Close inspection of cool-season grass blades reveals small, irregular, tan leaf spots with dark-brown borders. Bentgrass may not show individual lesions, but leaves will turn brown and shrivel. Infected warm-season grasses rarely have leaf spots but instead have rotted leaf sheaths near the soil surface.
Wild Violet
Wild violet is a winter perennial, growing 2 - 5 inches tall. It can have a tap root or a fibrous root system, and also can produce rooting stolons and rhizomes. The leaves can vary but usually are heart shaped, on long petioles with scalloped to shallow rounded margins.
The flowers of wild violet range from white to blue to purple and appear from March to June. Wild violet flowers are pansy-like with three lower petals and two lateral petals on long single flower stalks. Wild violets are found throughout the United States, except for the Rocky Mountains. Wild violets are more common where they are sold as ornamental ground covers.
Dandelion
Dandelion is a winter perennial. The dandelion has thick fleshy tap root which often branches. New plants come from the root and root segments. Leaves form in a rosette, are deeply lobed, with the lobes pointing toward the base. Both the leaves and flower stems contain a white milky fluid.
The flowers are yellow and are individual stems. The seeds are brown with tip containing white hairs. The yellow flower will turn to a white globular puff ball. The seeds are disseminated by wind. Dandelions spread by both seed and stems from the root.
Ground Ivy
Ground Ivy is a creeping winter perennial. The leaves are round to kidney shaped with round toothed edges. The leaves are opposite on long petiole attached to square stems that root at the nodes. It is usually found in moist shaded areas, but also tolerate sun very well. Ground ivy will form dense mats which can take over areas of turfgrass.
The flowers of ground ivy are blue to lavender and grow in clusters. It usually flowers in the spring. The flowers are funnel shaped and are located at the leaf axis or near the tip of the stem. Ground ivy spreads by stolons and sometimes by seed.
Bentgrass
A very fine-textured bright green grass. The leaves are flat, narrow, and rolled in the bud. There are no auricles and a long, tapered ligule is present. Creeping bentgrass is a low-growing grass with a shallow root system. It spreads by stolons to form a mat or thatch layer above the soil line.
This intel first appeared on: http://Common Turf Problems
