Cough cough , Sneeze sneeze , My Lawn has turf disease.

With all the wet, cool, humid weather we have been having not to mention flooding Turf disease is on the rise. There are somewhere in the neighborhood of 100 different diseases that affect turfgrasses. Just like human illnesses, each turf disease has a specific prescription for its cure and prevention. Some diseases can be suppressed by the application of nitrogen fertilizer, whereas others are encouraged by more nitrogen. Some diseases are suppressed by high soil pH, whereas others are encouraged by low pH. A long list of other turf management practices can be used to control disease, but the most effective prescription is specific for each disease.

As the older, broad-spectrum fungicides are removed from the market due to environmental concerns, they are being replaced with a new generation of products with narrow control-spectrums. These new products are very effective, and safe to the environment, but they are effective against a small number of diseases. Because of this change in the turfgrass industry, accurate diagnosis of turfgrass diseases is becoming even more important.Diagnostic Methods
Turfgrass diseases are very difficult to identify. Grass plants are very small, and most diseases are caused my microorganisms that can't be seen without a microscope. However, with some basic knowledge and a lot of practice, you can vastly improve your diagnostic skills. By learning how to diagnose just a few common diseases, you will be able to diagnose most of the disease problems that you encounter during the season.

The first thing to remember is that disease diagnosis is much like detective work. A detective rarely looks at a situation and solves the mystery on the spot. Rather, a detective develops a list of possibilities, gathers evidence by careful observation, and then arrives at a conclusion by a process of elimination. When you see a disease on your turf, first develop a list of possible diseases. This list can be developed based on the turfgrass species that is being affected and the time of year the disease developed. Then, closely observe and make note of the symptoms and signs that you see on the turf. Also, make note of recent weather conditions and major cultural practices
that were performed recently.

What are symptoms and signs?

Most diseases leave a unique and reliable pattern on the turf. These patterns are expressed as either symptoms or signs, and are very useful for disease
diagnosis. Symptoms are the evidence of disease on the turf plants. Two types of symptoms are produced in turf: stand symptoms and plant symptoms.

Stand symptoms are most easily observed by standing and looking across the turf area. There are several different types of stand symptoms, which basically describe the pattern of the disease on the lawn or landscape. Diseases may produce spots, circles, patches, rings, or an irregular stand symptom. A spot
is an area of diseased turf less than 4 inches in diameter (Figure 1).

A circle is a perfectly circular area of diseased turf greater than 4 inches in diameter (Figure 2).

A patch is an irregularly shaped area of diseased turf greater than 4 inches in diameter (Figure 3).

As the name implies, a ring is circular area of diseased turf with healthy turf to the inside and outside, leaving a ring-like pattern on the turf stand (Figure 4).

Rather than producing a regular pattern of symptoms on the turf, some diseases produce an irregular or non-patterned symptom across the turf stand (Figure 5).

Most diseases produce a very specific stand symptom, but some diseases can produce more than one of the above symptoms. Nevertheless, the stand symptoms are very useful for narrowing the list of possible diseases.

Far too many turfgrass managers attempt to diagnose diseases just by looking at the problem from a distance. However, there is another important set of clues available on the individual plants, called the plant symptoms. Plant symptoms describe the location and pattern of symptoms on the individual plants. It is important, however, to look for plant symptoms in the right spot. Generally, the best plant symptoms can be observed along the border between healthy and diseased turf. The plants in severely affected areas that are already dead are not very useful for diagnosis of turfgrass diseases.

Symptoms observed on individual plants include leaf spots, foliar lesions, stem lesions, foliar
blight, foliar dieback, crown
rot, and root rot . A leaf spot
is a round or oval area on the leaf with a distinct border, which is usually a different color than the center of the spot (Figure 6).

A foliar lesion
is irregular in shape and is typically larger than a leaf spot, but still has a distinct border that is usually a different color (Figure 7).

A stem lesion is very similar to a foliar lesion, but is present on the stem or leaf sheath of the grass plant rather than on the leaves (Figure 8).

Foliar blight and foliar dieback produce symptoms on whole leaves or entire plants (Figure 9);

the two are distinguished in that a foliar
blight produces a distinct border between healthy and diseased turf, whereas a foliar dieback does not. Crown rot is observed as a dark and rotten area at the base of the turfgrass plant (Figure 10).

Root rots produce a visibly dark and rotten root system, and also a noticeable reduction in root depth in affected areas (Figure 11).

Crown rots and root rots often occur together, and may also include rotting of stolons and rhizomes if present (Figure 12).

Signs are the visible evidence of the presence of a pathogen. Most turfgrass diseases are caused by fungi, and even though fungi are microscopic organisms, some produce larger structures at certain times in their life cycle that can be seen with the naked eye. Mycelium is a cottony or spider-web-like mass of fungal growth that certain fungi produce when the turf is wet or humidity is high (Figure 13).

Spore masses are fuzzy or jelly-like growths produced on the diseased tissue by certain fungi, again usually when the turf is wet or humidity is high (Figure 14).

Sporophores are enclosed structures that contain fungal spores. If present, sporophores are often seen as small, dark specks on the diseased tissue (Figure 15).

Sclerotia are small, round, hard structures produced on the diseased turf or in the thatch layer by certain fungi (Figure 16).

Sclerotia are actually survival structures that some fungi use to survive through periods of unfavorable weather conditions. Most people are familiar with mushrooms, which are the large spore-producing structures produced above-ground by Basidiomycete fungi. Some turfgrass pathogens, most notably the fairy ring fungi, produce mushrooms as a sign of their presence (Figure 17).

What other clues can be used to diagnose diseases?

Is the disease limited to or more severe in a particular microclimate on the turf stand? Some diseases are more severe in low-lying, wet areas, whereas others are worse in high and dry locations. Some diseases are encouraged by shade, whereas others are more severe in open areas. Take a few minutes to carefully look at the distribution of the disease and see if you can come up with any consistent relationships - the power of observation is very valuable when diagnosing a turfgrass disease.

The development of disease is highly dependent on weather conditions, so recent weather conditions are important clues for disease diagnosis. In order to grow and cause disease, fungi need moisture, either in the form of rain, irrigation, or atmospheric humidity. Fungi are also very sensitive to changes in temperature; each fungus has a narrow range of temperatures in which it is able to grow and cause disease. Since most disease development occurs at night when the turf is wet from dew, nighttime low temperatures are the most important parameter influencing the development of foliar diseases. The development of root diseases is determined by soil temperature rather than air temperatures.

Consider any cultural practices that were (or were not) conducted on the turf in the last month. If a pound of nitrogen fertilizer per 1000 sq ft was applied two weeks ago, then your turf probably has a disease that is encouraged by high nitrogen levels. If you recently aerified and topdressed the turf, then it is possible that the turf is affected with a stress-related disease like anthracnose basal rot.

Distinguishing diseases from other problems


There are many other problems that occur in turfgrasses that can be confused with disease. These include cultural problems, environmental problems, nutrient deficiency or toxicity, chemical spills, or a myriad of other problems. There are a few rules of thumb that can be used to distinguish these problems from disease. The first rule of thumb is that diseases progress. Disease symptoms are initially mild and localized in a small area, then the symptoms gradually become more severe and widespread over time. The rate at which a disease progresses depends on the disease, the host, weather conditions, and cultural factors, but this generally occurs over a period of several days to several weeks. In addition, there is usually not a sharp, well-defined line between healthy and affected turf, but this transition occurs very gradually. If large areas of turf die overnight or during the course of one day, or if there is a sharp line between healthy and diseased turf, then the damage was probably not caused by a disease (Figure 18).

One simple way to determine if a problem is actively spreading is to mark the edge of the affected area with a surveying flag or stake. Monitor the area over a course of several days and determine if the problem is spreading in relation to the flag or stake.


Another rule of thumb is that diseases never occur in straight lines or other regular patterns. Instead, disease symptoms are randomly distributed across a turf stand. If the symptoms of a problem are in straight lines or some other recognizable pattern, then this damage was not likely caused by a disease. In most cases, management-related errors, such as misapplication of a fertilizer or chemical, are responsible for these types of symptoms (Figure 19).

Finally, diseases typically do not kill large areas of turf and leave adjacent areas of the same turfgrass species untouched. A disease may be more severe in a certain microclimate, such as a compacted area, but some symptoms of the disease will also be evident in adjacent, less compacted areas. Environmental, cultural, or management-related issues should be investigated when large areas of severe damage are surrounded by large areas of completely healthy turf.

Diagnosis is a process of elimination. First, start with a list of possible diseases based on time of year and the species of grass that is being affected. Second, look for stand symptoms, plant symptoms, signs, and other clues. Based on the evidence that you collect, narrow the list of possibilities. Repeat these two steps if necessary. If you can narrow the list down to one disease, then you have diagnosed the problem and can now develop a management program for its control. If you can only narrow the list down to two or three diseases, then you have two choices. First, you can design a management program that will control all of the possible diseases. This is a reasonable choice when the diseases can be controlled by similar cultural practices or fungicides

What are grubs? Can they damage my lawn? When do I protect my lawn? NOW!

White grubs, sometimes called grubworms, are small, white, C-shaped larvae of a group of beetles known as scarabs. The most common grubs that we encounter in lawn care are: Japanese beetles, northern and southern masked chafers, European chafers, Oriental beetles and Phyllophaga (May-June beetles).

White grubs feed on the roots of plants. The first sign of damage is that the grass wilts easily despite watering. Damage symptoms mimic drought stress.

feeding will cause the turf to die in irregular patches. The turf will feel spongy underfoot and birds may begin to feed in the area. With heavy infestations, the turf can be rolled back like a carpet. Animals, such as raccoons, skunks and moles, may tear up the turf while looking for grubs and other insects.

Occurrence

White grubs attack all the cool season and transition zone turfgrasses. Masked chafers and Phyllophaga occur throughout the United States. Japanese beetles occur primarily in states east of

the Mississippi river; however, localized infestations have been found in plains and western states. The European chafer and the Oriental beetles are found mainly in the Northeast and in the

Great Lakes region.

Description

Most white grubs develop from egg to adult in one year. Adults lay eggs in late spring to early summer. The eggs hatch within 10-14 days as long as there is adequate soil moisture. Grubs feed throughout the summer and fall. Cool soil temperatures in the fall force the grubs to go down deep into the soil to survive the winter. The grubs return to the surface in the spring. Japanese beetle and European chafer grubs may feed and cause some damage in the spring. All pupate in the spring and the new adults emerge 6-10 weeks later.

Phyllophaga beetles (May- June beetles) take several years to develop from eggs to adults. The adults emerge in early spring and begin to lay eggs. The larvae may feed for 2 or 3 summers before pupating.

Control

Because white grubs live below the thatch layer in the soil, grubs are somewhat difficult to control. The typical method is to apply a pesticide as close to egg hatch as possible to control young first instar grubs. The timing of this varies across the country but typically occurs from late-May to mid-August. Because the grubs reside in the root zone, the treatment should be watered in to move the pesticide into the target area. Once the grubs are actively feeding, a curative application may be warranted. In this case, a product that moves quickly through the thatch and into the root zone is desirable. High populations of white grubs (Japanese beetles or European chafers) may cause significant turf damage in the spring of the year. It is difficult to control grubs in the spring because they are large and the window of treatment opportunity is short.

Help The leaves of my trees are turning yellow

Oak, maple and birch, and other trees may exhibit yellowish leaves by early summer. A closer examination of these leaves may show that while most of each leaf is yellowish-green, the veins are still  green. This condition is known as chlorosis. Chlorosis is a common problem with the above mentioned trees growing on the Great Plains. These tree species, growing on our typically alkaline soils, may exhibit chlorotic leaves by early summer. By late summer, the leaves also may have brownish patches of dead tissue. In extreme cases, the leaves may die, shoot growth becomes reduced, and eventually the tree dies. Alkaline soils are soils with a pH above 7. In urban areas the soils can be extremely alkaline due to the composition of construction material used to build roads and buildings and highly alkaline subsoils being brought to the surface.
It is not uncommon to find urban soils with a pH of 7.5 to 8.5. Alkaline soils reduce the availability of iron and manganese, two important nutrients found in tree leaves. These nutrients may be abundant in the soil, yet the alkalinity makes them insoluble and unavailable to trees. Merely adding iron to the soil will not improve the condition of the tree. The problem can be further compounded by low oxygen conditions that are common in poorly drained soils. Excessive amounts of phosphorus and potassium also can contribute to the development of chlorosis by interfering with the absorption of iron. The trees most affected by chlorosis are pin oak, silver maple, red maple, Amur maple and river birch. Walnuts, pines, yews and apples also may be affected, particularly on poorly drained soils. The primary deficiency for these trees is iron; however, maples also may be affected by pH-related manganese deficiencies. Maple trees growing on alkaline soils have shown symptoms of manganese deficiency in the Midwest and more eastern states. The best way to avoid chlorosis problems with pin oaks, silver maples, red maple, Amur maples, and river birch is to not plant them on alkaline soils, particularly poorly drained ones. If you already have one of these trees in the landscape, there are some possible treatments.

Lowering the soil pH with sulfur

Since high soil pH is the cause of the chlorosis, one possible treatment is to lower the soil pH. While this generally is considered the most direct method of correcting the chlorosis problems, the results may be disappointing as only the upper inch or so of soil is affected. This method usually is performed by broadcasting granular sulfur on the soil surface. It may provide a reduction in soil pH for several years, but the benefits of the treatment will probably not be seen until the year following application and probably will need to be repeated every couple of years. The general recommendation is to apply about 80 pounds per 1000 sq ft to lower the pH from 7.5 to 6 and 150 pounds per 100 sq ft to lower the pH from 8 to 6. The applications should cover an area that extends out from the trunk at least a distance equal to the tree's height. Heavy applications may injure grass. Inexpensive granular or feed-grade elemental sulfur is often available from your local feed store, elevator,

or farmer's cooperative. You also may find fertilizers that are advertised to help acidify the soil for acid-loving plants. However, these products generally would need to be applied at unrealistically high amounts to have any significant effect on soil pH. 
Chlorosis (Yellowing) of Shade Tree Leaves

Adding chelated iron to the soil

Chelated iron also can be applied to correct chlorosis. Iron chelates are organic complexes of iron that remain soluble even in alkaline soils. Iron chelates can be spread on the soil surface or a similar amount can be placed in a series of holes around the tree. The holes should be 1 1/2 to 2 inches in diameter and should be augered 2 feet apart beginning about 5 feet from the trunk and expending out at least a distance equal to two thirds the height of the tree. The holes should be about 6-8 inches deep. Place the iron chelate at the base of each hole and continue to backfill the hole with leaf compost. If compost is not available or uniform turf is desired, backfill the hole with topsoil and replace the plug of turf grass. Either treatment will provide benefits for a year or two. Follow the application rates on the fertilizer package. Chelated iron is available in both liquid and granular forms and is sometimes incorporated in complete fertilizers. The benefits of this treatment can be extended if elemental sulfur is also placed in the holes

Foliar applications of fertilizers

Trees and shrubs can absorb many nutrients, including iron and manganese, through their leaves. Begin the foliar applications just after the new leaves have fully expanded in the spring. If the first application of fertilizer is delayed until mid-season, it will be too late to affect the leaf color. Foliar treatment only affects the leaves present at the time of spraying. Leaves formed after the treatment may become chlorotic unless additional applications are made; therefore, some trees may require several applications, spaced about three weeks apart. The foliar application rate is 1 to 1 1/2 pounds of iron chelate per 100 gallons of water. If a sticker agent is not an ingredient included in the fertilizer you purchase, add about 1 pint of dish soap to the above rate to help the iron solution stick to the leaves. The treatments are good only for the current season and will need to be repeated again next year. Sprays of iron compounds may stain brick and concrete surfaces so be careful of any spray drift. The iron chelate spray also may injure the leaves. Always follow the label directions and test the spray on one branch a week before spraying the entire tree.

Injecting or implanting fertilizers into the trunk

Iron or manganese compounds also can be injected or implanted into the trunk of a chlorotic tree. Consider these treatments only after other measures have failed. Repeated drilling of holes in trees can result in long-term injury or decay. The injection uses liquid-filled capsules that force the iron or manganese sulfate into the tree under pressure. A hole is drilled near the base of the trunk and the capsule tube is placed into the hole that allows the fertilizer to be taken up into the sap stream of the tree. Since the iron is drawn directly up into the leaves, dramatic changes in leaf color can sometimes occur. Trees with chlorotic leaves, injected in the spring, often can have green leaves within a few weeks. The effect may last several years. If you are going to try this method use a commercial tree services like Trugreen or a registered arborist. rather than doing it yourself . The drilling must be done very carefully and the proper dose applied. A poorly constructed hole or improperly calculated dose may be ineffective or actually injurious to the tree.