Identifying turf problems requires expertise, experience and, sometimes,
good detective work. A homeowner may correctly identify a turf problem 30
to 50% of the time and an experienced turf manager might correctly identify
a turf problem 70 or 80% of the time, but neither will be correct 100% of
the time. The problems and their interactions are often too numerous and
complex to correctly identify.
Recognizing that a turf problem exists does not require much expertise,
but correctly identifying the problem does. Often a turf manager inherits
problems. At least, that is the rationale we use. Other problems result
from environmental stress such as shade, drought or extreme temperatures.
Some problems are the result of turf pests. The most common problems, however,
those we are least likely to identify, are the ones we create through our
management practices.
Early recognition and identification of a problem is essential to the maintenance
of fine turfs. Early symptoms of a turf problem rarely attract the attention
of a non-professional. A subtle change in color or growth rate, wilting
or footprinting earlier in the day than normal, cottony growth on the grass
in the early morning, birds or other animals actively feeding in the turf
or a combination of these symptoms may be the tipoff to a serious problem
ahead. After the turf thins out or brown patches appear in the turf, the
opportunities for effective control are greatly reduced.
The turf manager must make regular inspections of his turf to establish
a reference by which abnormalities can be readily recognized. For example,
difference in soil conditions may cause the grass in one area to wilt sooner
than in another area. Also, changes in the color or growth of a turf may
indicate a nutrient deficiency and requires frequent observation to detect.
The height of the grass before mowing, the number of baskets of clippings
removed from a golf green or lawn or the frequency of mowing required all
provide a reference to detect changes in growth rate. Color changes require
even closer observations, but they can be an early warning to a serious
turf problem. A subtle change in color may signal a nutrient deficiency,
a disease occurrence or an insect infestation. A turf manager familiar with
the normal color and growth rate of a particular turf is most likely to
recognize these early symptoms of a problem.
Maintaining a daily log in enough detail to show what, when, why and how
with respect to management practices performed is helpful. Fertilization
records can help explain changes in turf color or growth rate. Include cultural
practices such as mowing, watering, aeration, vertical mowing and topdressing
in the daily records. Record insect, disease and weed control treatments
along with the response obtained. The turf manager trying to identify a
problem without these records is at a serious disadvantage. Often, by reviewing
well-kept records, some potential causes of the problem can be eliminated.
For example, a recent application of nitrogen to a turf that appears chlorotic
and stunted along with a soil test report that shows adequate levels of
nutrients suggests that nutrition is not the problem.
In addition to the records of daily operations, keep soil tests, water and
plant analyses for several years for reference purposes. In critical situations
these analyses could provide helpful information.
Extension publications, conference proceedings, trade journal articles and
turfgrass news letters can provide valuable reference information. This
printed information can be added to this workbook for reference purposes.
Classifying Problems as to Origin. Turf problems should first be
identified as to their nature - cultural (man-made), environmental or pest-related.
Often two or more of these factors contribute to the problem. For example,
a grass that has limited shade tolerance (environmental) should not be mowed
too close (cultural). Likewise, a nitrogen deficiency (cultural) can be
a contributing factor to an outbreak of dollar spot (pest); or shade (environmental)
and over-fertilization (cultural) can contribute to an occurrence of leaf
spot (pest). When two or more factors contribute to the problem, all factors
must be identified before the problem can be effectively corrected.
Too often we identify only one factor contributing to a turfgrass problem,
when in fact, several factors are responsible. For example, many pest problems
are a result of environmental conditions and cultural practices. In fact,
pest-related problems such as dollar spot may be controlled most effectively
by changing the cultural practices that contributed to the problem. Pest
management programs must consist of more than the shotgun application of
pesticides to turf. Accurate identification of factors contributing to the
problem and timely application of pesticides is a better alternative.
Disease problems require accurate identification to obtain effective and
safe control. In addition to the symptoms expressed by the grass, environmental
conditions, grass species and previous cultural practices should be considered
when identifying pest-related problems. Turfgrass diseases are particularly
difficult to identify. Often, environmental conditions modify the disease.
Also, after the grass has been killed, it becomes increasingly difficult
to identify the cause. In many cases, microscopic examination by experts
is required to accurately diagnose a turfgrass disease problem.
Key to the identification of common turfgrass diseases.
Group I. Grass affected in distinct patches.
