1. Topdressing To Protect
Bentgrass Greens In Winter
An Iowa State study finds
that fall topdressing treatments
and nitrogen applications
visibly improve spring recovery
on two types of greens.
Nick Christians
Iowa State University
Kern Diesburg
Iowa State University
Jeff Nus
Kansas State University
This is a view of two study areas covered in the following article shortly after treat-
ment was applied. The modified soil is in the foreground, and the Nicollet soil is
in the back. Darker plots have been treated with the 1:1:1 topdressing; light plots
with the 7:1:2 topdressing; and the green plots are controls that received no
topdressing.
The green is the most expensive, periods of ice cover also can damage from desiccation where winter irrigation
highly maintained and delicate turfgrass greens. is not possible.
area on the golf course. In the central In the central plains of the United Many techniques and materials have
and northern United States and through States and Canada, desiccation is been used to protect golf course greens
much of Canada, winter is a particularly responsible for much of the winter from winter desiccation, including the
difficult time to maintain golf course damage on greens. These regions often use of protective blankets, polyethylene
greens. These areas are susceptible to have extended periods in the winter films, wood and synthetic fibers,
a variety of forms of winter damage, months with no snow cover and little branches and other debris, fences to
including cool temperature diseases, moisture from rain. They also are hold snow cover and a soil topdressing
direct low temperature kill, desiccation, known for winter and spring winds that layer. Each technique has been used
traffic and frost heaving. Extended dry the turf, causing extensive damage Continued on p. 68
66 Golf Course Management I September 1987

2. applications on the spring recovery of Fertilizer treatments were applied
TOPDRESSING from p. 66 these two types of greens. after top growth had ceased, between
Two adjacent experimental greens Nov. 10 and Nov. 18 in 1980, 1981,
that had been established with Penn- 1982 and 1983. Topdressing treat-
with success, but each has its problems, cross in September 1979 were used in ments were applied immediately after
including in some instances high the study. One area was formed of a the fertilizer was applied. The areas
Nicollet soil with a pH of 6.5. The received no supplementary irrigation
second green was composed of a during the winter and early spring. Each
A high degree of managerial "modified" soil that had been con- of the treatments was repeated three
skill and knowledge is structed of one part sand, one part times on each of the two greens.
required for use of any Nicollet soil and one part peat. The pH Data collection began each year in
was 7.9. Physical tests performed on the spring with the first sign of green
of these methods. this soil before the initiation of treat- color in any of the plot areas and con-
ments showed that this soil contained tinued until all plots showed complete
4.6 percent gravel, 62.3 percent sand, recovery from winter dormancy. The
material costs - and, with polyethylene
21.3 percent silt and 11.8 percent clay. data collected was designated spring
films and other synthetic materials, an
The bentgrass was maintained at a recovery, which was based on color,
increase in cool temperature diseases. 1/4-inch mowing height. The area was density and uniformity (the lack of
A high degree of managerial skill and
fertilized during the season with liquid winter damage), and rated on a scale
knowledge is required for the use of any
urea solutions at a rate of 0.2 lb. of 1 to 9, with 1 equaling no sign of
of these methods.
Nl1,000 square feet whenever the recovery and 9 equaling total recovery.
The use of other cultural practices
bentgrass showed signs of nitrogen defi-
with winter protection techniques has Varying Weather Conditions
ciency. Insecticides and fungicides were
not been fully investigated. For exam- Weather conditions during the four
used as needed during the season.
ple, the use of dormant fertilizer appli- winters of the study varied greatly. The
Three main treatments were included
cations may be useful with some of the 1980-81 winter was mild, with very little
in the study. The first was a control
techniques, although this practice
where no topdressing was applied; the
would not be recommended with poly-
second consisted of a 7: 1: 2 The 1981-82 season was
ethylene films and other methods that
(sand:soil:peat mixed on a volume
result in temperature increases and late
basis) topdressing applied at 0.77 cu.
the opposite extreme,
winter growth. with very cold temperatures
yd./1,000 square feet (0.23 inch
Iowa State Experiment depth) to the surface of the green; and and heavy snow cover.
In a four-year study at Iowa State the third included a 1: 1: 1
University, combinations of nitrogen (sand:soil:peat) applied at the same rate
fertilizer and two types of soil topdress- in the same way. snowfall or snow cover and monthly
ing were applied to Penncross creeping Each topdressing plot measured 10 mean maximum temperatures that
bentgrass greens that had been estab- feet by 10 feet. The topdressing plots ranged above freezing. The 1981-82
lished on both a native Iowa soil and a were further divided into three nitrogen season was the opposite extreme, with
soil modified with peat and sand. The treatments that included.a control, 0.5, very cold temperatures and heavy snow
objective was to observe the effects of and lib. Nl1,000 square feet applied cover. The 1982-83 winter began mild
fall topdressing and late-fall nitrogen in the form of gran ular urea. Continued on p. 70
The effects of topdressing treatments and fertilizer treat- Monthly mean temperatures, snowfall and snow cover on the
ments on spring recovery of Penncross creeping bentgrass. study area for 1980-84(0 degree centigrade; equals freezlrlg,
and 2.54 em equals 1 inch).;
68 Golf Course Management / September 1987

3. the greater moisture- and nutrient- The visible effects of topdressing were
TOPDRESSING from p. 68 holding capacity of the Nicollet soil. The apparent each year, but particularly in
earliest date of spring green-up and the years following mild winters. The visi-
C!nd ended with heavy snow, whereas duration of treatment differences did ble effects of fertilization were more
the 1983-84 season began with very not vary between the two soils, subtle .
cold temperatures and heavy snow but however. . The application of topdressing to
ended with rather mild temperatures bentgrass greens at a rate of 0.77 cu.
and a period in February with no snow The effects of topdressing were yd./l,OOO square feet after growth has
cover. greatest following the open, mild ceased in the fall may have a beneficial
Topdressing treatments improved winters of 1980-81 and 1982-83. The effect on spring recovery, particularly
spring recovery in each of the testing least benefit from these treatments was during mild winters with little snowfall,
years. However, the first date of visible observed after the extended snow cover regardless of whether the topdressing
green-up and the amount of time from and cold temperatures of 1981-82. has a high sand content. Spring recov-
first green-up to the time when no Neither topdressing material was con- ery can be further enhanced by the ap-
sistently better than the other on either plication of nitrogen fertilizer at rates up
soil type, although there was a slight ad- to 1 lb. N/l,OOO square feet to the
The effects of topdressing vantage to the 1: 1: 1 topdressing in the green's surface before topdressing ap-
springs of 1983 and 1984 on the modi- plication.
were greatest following
fied soil and the springs of 1981 and
the mild winters of
1984 on the Nicollet soil. The ratings Although topdressing and fertilization
1980-81 and 1982-83. for the 7: 1: 2 topdressing exceeded treatments did not increase cool-
those of the 1: 1: 1 only in the spring of temperature disease infestations on this
1982 on the Nicollet soil. It had been area and likely would not on most open
differences could be observed among expected that the darker-colored 1: 1: 1 areas in the Midwest, caution should be
treatments varied with the year. In topdressing would be consistently su- used with these treatments without the
spring 1981, treatment differences were perior to the 7: 1: 2, but this was not the use of fungicides in more protected
observed for 31 days, followed by 22 case. areas or in areas where there has been
days in spring 1982, 51 days in spring Effects Of Fertilization a history of cool-temperature diseases.
1983 and 15 days in spring 1984. The There was an increase in spring The extent to which topdressing
very short duration in 1982 can be recovery with increasing fertilizer rates treatments can improve spring recovery
attributed to the extended snow cover on both soils in each year, with the ex- will likely be surprising. If the method
into April. The extended period of 1983 ception of spring 1982. At no time did is being used for the first time, a small
was due to the lack of snow cover and the application of urea have a detrimen- untreated area should be retained so
warm temperatures in February fol- tal effect on the bentgrass. Even when that the real effects can be observed.
lowed by heavy snows in March and late-season snow covered plots that had
April. begun to recover in 1982, 1983 and Bibliography
The spring recovery ratings for the 1984, no signs of cool-temperature dis- 1. BEARD, J.B. (1964a) Effectsof ice, snow and water
creeping bentgrass on the Nicollet soil eases were observed on any of the covers on Kentucky bluegrass,annual bluegrassand
were generally higher than for equiva- treated areas, even though no winter creeping bentgrass. Crop Sci. 4:638.
lent treatments on the modified soil. fungicide applications were made after 2. BEARD, J.B. (1964b) Causal agents in winter inju-
ry of turfgrass and their relative importance. Agron.
These higher ratings are likely due to the 1981 season.
Abstr. p. 99.
3. BEARD, J.B. (1966) Direct low temperature injury
of nineteen turfgrasses.Mich. Agric. Exp. Stn. Bull.
48(3):377.
4. BEARD, J.B. (1969) Covers for the protection of
turfgrasses against winter desiccation and low tem-
perature injury. Agron. Abstr. p. 52.
5. BEARD, J.B. (1973) Turfgrass: science and culture.
Prentice-Hall, Englewood Cliffs, NJ.
6. BEARD, J.B. (1982) Turf Management for Golf
Courses. Burgess, Minneapolis, MN. pp. 452-458.
7. LEDEBOER, F.B. and SKOGLEY, C.R. (1967)
Plastic screens for winter protection. Golf Superin-
tendent. 35(8) :22-23.
8. WATSON, J.R., KROLL, H., and WICKLUND, L.
(1960) Protecting golf greens againstwinter kill. Golf
Course Rep. 28: 10-16.
9. WATSON, JR., and WICKLUND, L. (1962) Plas-
tic covers protect greens from winter damage. Golf
Course Rep. 30:30-38.
10. WATSON, J.R. (1964) Methods of minimizing
winter damage. Agron. Abstr. p. 103.
11. WATSON, J.R. (1968) Blankets to protect gol1
greens against winter injury. Agron Abstr. p. 61.
12. WATSON, J.R. (1968) Prevention and control of
Spring recovery of Penncross creeping bentgrass greens with and without desiccation on golf greens. In: Proc. of the First Int.
topdressing in Apri/1981. Plots showing no recovery are untreated controls. Turfgrass Res. Con/., Sports Turf Res. Inst., Bin-
gley, England, pp. 301-305.
70 Calf Course Management I September 1987