TURF CULTURE

Published by the United States Golf Association Green Section in the Interest 
of Better Turf for Golf Courses, Lawns, Parks, Recreation Fields and Cemeteries

CONTENTS

Pact

Arlington Turf Meeting.......................................................  65

Status of Milky Diseases of Japanese Beetle Larvae ... 84

R. T. WHITE

Growth Substances in Plants...............................................  88

F. F. DAVIS

Growth Substances on Turf Grasses................................  110

JOHN F. CORNMAN and JOHN W. BENGTSON

Hormones on Stolons ...............................................   Ill
Hormone-treated Seed...................................................................... 116
Vitamin Bt on Turf.......................................................................  119

What Others Write on Turf:

Germination of Carpet Grass Seed............................................. .... 121
Milky Disease of Japanese Beetle Grub............................................. 121
Harvesting Buffalo Grass Seed................................................................  123
Seed Formation in Kentucky Bluegrass..................................................  123
Chloropicrin May Control Some Plant Diseases................................. 124
The Leaf Cutting Ant...........................................................................  123

Our Letter Box........................................................................  126

Volume 2 

Number 2

NOVEMBER. 1940

TURF CULTURE

Published by

UNITED STATES GOLF ASSOCIATION GREEN SECTION

GREEN SECTION COMMITTEE

Fielding Wallace, Chairman, 

Augusta, Ga.

Robert F. Arnott, Upper Montclair, N. J.
Keith Conwat, Atlanta, Ga.
Melville G. Curtis, Philadelphia, Pa.
Robert J. Folet, Huntington, W. Va.
A. Oram Fulton, Cambridge, Mass.
J. Porter Henry, St. Louis, Mo.
H. Alfred Langben, New York, N. Y. 
Dr. M. A. McCall, Washington, D. G 
Curtis W. McGraw, New York, N. Y.

Chester Mendenhall, Kansas City, Mo.
Franklin L. Miller, Cleveland, Ohio 
Maxwell C. Milton, San Francisco, Calif. 
Dr. John Monteith, Jr., Washington, D. G 
James Morrison, Cincinnati, Ohio 
William Otter, Chicago, Ill.
J. Bernd Rose, Pittsburgh, Pa.
Joseph Rtan, Philadelphia, Pa.
A. G Statt, Minneapolis, Minn.
Wynant D. Vanderpool, Newark, N. J. 
Tom Walsh, Chicago, ILL

.xOXOXO

GREEN SECTION STAFF

John Monteith, Jr*, Director and Editor 
John W. Bengtson, Agronomist
F. F. Davis, Botanist
Gordon H. Jones, Agronomist 
George E. Harrington, Horticulturist 
F. H. Williams, Executive Secretary

<X>000<

Office of the United States Golf Association Green Section

For regular mail—P. O. Box 73, Benjamin Franklin Station, Washington, D. G
l"or telegraph, special deliver y mail and parcels—Room $632, South Building, Department 

of Agriculture, Washington, D. G

Subscription............................................................................................ $4.00 per Volume.

Copyrighted 1940 by
THE UNITED STATES GOLF ASSOCIATION GREEN SECTION

TURF CULTURE

Volume 2 

NOVEMBER, 1940 

Number 2

ARLINGTON TURF MEETING

The annual Arlington Turf Meeting, sponsored jointly by 
the Greenkeeping Superintendents Association and the United 
States Golf Association Green Section, was held this fall on 
Monday and Tuesday, September 16 and 17, with headquarters 
at the Hamilton Hotel in Washington, D. C. At 9 o’clock 
Monday morning the visitors assembled on the Turf Garden 
at the Arlington Experiment Farm for the annual review of 
the experimental work conducted there by the Green Section 
in collaboration with the Bureau of Plant Industry of the 
United States Department of Agriculture. The primary pur­
pose of this meeting has been to make it possible for green­
keepers, green committee chairmen, and others interested in 
establishing and maintaining better turf to see first hand the 
results of these experiments and to discuss their special prob­
lems with the staff of the Green Section in the light of these 
results. This year there were 200 or more in attendance, some 
coming from points as far distant as Miami and Kansas City.

The visitors were first conducted in a group over the plots 
on the Turf Garden as well as those which are located in various 
other sections of the Arlington Farm. The nature and purpose 
of the experiments were described, and the significance of the 
results which were apparent at the time were discussed by 

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TURF CULTURE

members of the Green Section staff. The plots were fully 
labeled so that it was possible for the visitors to go back at their 
leisure and look over the results of the experiments in which 
they were particularly interested.

Selected Strains of Grasses in Turf

On the Turf Garden the visitors were shown plots of many 
selected strains of the various turf grasses growing in turf. 
Each strain had been developed from a sample of turf selected 
because, for one reason or another, it had appeared to be par­
ticularly desirable. This single plant had been propagated 
vegetatively in the nursery until sufficient material was avail­
able for the vegetative planting of quadruplicate plots on the 
Turf Garden.

Bent Grasses

The plots of creeping and velvet bents have been maintained 
under putting green conditions. Two plots of each strain have 
been treated regularly for disease and two have not been treated 
in order to determine variations in disease resistance. Wash­
ington and Metropolitan strains were used for comparison pur­
poses among the creeping bents and Piper and Kernwood among 
the velvet bents.

Among the treated plots, the strains of creeping bents showed 
much less contrast than did those of velvet bents so far as 
color, density, and texture were concerned. Among creeping 
bent plots which have not been treated with fungicides since 
they were planted in 1937, C-l, C-16, C-ll, and C-9 showed 

November, 1940

67

the most disease resistant turf. C-52 and C-19 were also resist­
ant but to a lower degree. Later in the day when plots of some 
of these same strains were shown growing in a low pocketed 
area, it was seen that some of them which produced superior 
turf on the Turf Garden with its better air circulation did not 
do so well under such adverse conditions. In this area, the

The Greenkeeping Superintendents reviewing a portion of the series of plots estab­
lished on the Arlington Turf Garden to test the value of various combinations of 
fertilizers in the maintenance of bent turf. The plots were marked with cards showing 
graphically the relative amounts of nitrogen, phosphoric acid, and potash which they 
had received, as well as with the names of the materials used and the pH of the surface 
2 inches of soil at the time of the meeting.

plots of C-l, C-32, and C-27 were in best condition whereas 
Metropolitan, seaside, and the Colonial bents were particularly 
severely injured.

Among the velvet bents planted on the Turf Garden in 
1937, V-8, V-26, and V-19 appeared to be superior in most 
respects to Piper and Kernwood, the turf being generally denser 
and more resistant to disease.

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TURF CULTURE

A series of Colonial bent plots which had been planted with 
seed from various sources was also observed, but except for 
highland bent, which was lighter and more bluegreen in color, 
the turf on all of these plots was almost indistinguishable.

Kentucky Bluegrass

Similar plots of Kentucky bluegrass strains were shown. 
These plots, which had been planted vegetatively, were com­
pared with plots which had been seeded at the same time with 
good commercial seed and also with plots which had been 
planted vegetatively with random samples of old established 
bluegrass. These plots were maintained under lawn conditions 
and were not watered after the grass had become established. 
Variations were particularly striking in the 1937 series.

Considerable variation between the various plots was evi­
dent. Some strains have produced a turf which is much denser 
and more resistant to invasion by clover and weeds than is that 
of commercial bluegrass. Other strains have been decidedly 
resistant to disease, particularly leafspot, and still others have 
been particularly tolerant to being cut as low as /z inch. Also 
there were striking variations in the color and texture of the 
grass among the strains growing in turf. Plantings made in 
1940 showed that some strains fill in following vegetative plant­
ing much more quickly than random samples of bluegrass. In 
general, the outstanding strains are superior in most of these 
qualities.

Attention was drawn particularly to a plot of strain B-12, 
one-half of which has been cut at /z inch, and the other half 
at 1% inches. Another plot of B-12 which had been grown 
from selfed and open-pollin a ted seed was contrasted with a 

November, 1940

69

plot seeded with the best available commercial seed. This plot 
was not unlike plots of the same grass planted vegetatively and 
was superior in color, density, and texture to the turf resulting 
from commercial seed. The fact that seed from such strains 
as B-12 will produce turf which is decidedly better than that 
produced from commercial seed and not unlike that produced 
by vegetative planting of the parent plant indicates the pos­
sibility of propagating at least some of these superior selections 
on a large scale by means of seed.

Fescue

Vegetative plantings of numerous selected strains of fescue 
were also observed growing in plots comparable to the blue­
grass plots. Like the latter, the fescue plots were located on 
an open and exposed area and were not watered after the stand 
had become established. Plots of Chewings fescue served as 
the standard of comparison.

The turf on most of the plots showed scars as a result of 
severe summer injury, but there were decided differences in 
the various strains, particularly as to ability to resist invasion 
with clover and weeds, as well as to color and density. The 
1937 plot of Q-4 was marked and labeled as an example of a 
strain which is superior in most respects to Chewings fescue. 
Among the 1940 plots, the turf on one seeded with seed from 
Q-2 was much denser and generally superior to a plot seeded 
at the same time with Chewings fescue.

Other Crasses

Many other grasses were seen growing in turf, some of the 
most interesting of which were several species of Zoysia and 
various selections of Bermuda grass cut at different heights. The 

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TURF CULTURE

dense, durable turf produced by Zoysia matrella cut at % inch, 
% inch, and 1 /i inches attracted considerable attention. In 
other areas the visitors were shown plots of turf of Buffalo grass 
which is used in the West, crested wheatgrass which is used in 
the dry areas of the Northwest, and St. Augustine grass, centi­
pede grass, the two carpet grasses and others which are used in 
the South.

Soil Texture Plots

Plots were viewed which had been established 10 years ago, 
in the soil of which various materials such as manure, cotton­
seed hulls, buckwheat hulls, and peat moss were used to vary­
ing depths to improve the texture of the soil. Since their estab­
lishment, the levels of the plots have dropped varying amounts, 
depending on the material used and the depth to which it was 
incorporated in the soil. In most of the plots more than half 
of the original mixture has been lost. Plugs of these soil mix­
tures made to a depth of 8 inches had been placed on the most 
interesting plots to show the structure and texture of the soil 
to that depth.

Experiments With Disease Treatments

During the past season, more than 100 different chemicals 
have been tested extensively for their usefulness in connection 
with the control of turf diseases. In response to a recent 
renewed interest in the possibilities of copper compounds for 
the control of turf diseases, various copper preparations were 
again included this year among the materials tested. Large 
scale tests of all of these compounds have been made on bents 

November, 1940

71

growing in sod nurseries on nearby golf courses. The visitors 
were shown small plots on the Turf Garden which indicated the 
nature of the large scale tests and some of the results.

The best control of dollarspot was obtained with mercury 
fungicides, although one of the newer organic non-mercury 
compounds showed considerable promise. Lime had no perma­
nent effect. As did the tests many years ago, Bordeaux mixture 
with the normal amount of lime as well as with twice the nor­
mal amount of lime when applied daily gave little control of 
dollarspot and caused a decided yellowing of the turf. Copper 
sulfate alone burned the turf.

Turf Fertilizers

On the Turf Garden were seen 64 plots of bent turf to which 
various fertilizers and mixtures of fertilizers have been applied. 
These are the plots the results from which were discussed in 
the article on "Experiments with Fertilizers on Bent Turf” in 
the December, 1939, issue of Turf Culture. The unfertilized 
check plots were covered with a weedy, loose, open turf which 
had a starved appearance. Among the best plots at the time of 
the meeting were those which had been receiving combinations 
of ammonium phosphate and urea, and sulfate of ammonia 
and bonemeal, and the latter combination plus muriate of 
potash. The cottonseed meal and activated sludge plots were 
also in excellent condition.

The turf on excessively acid plots (pH 4.5 or less) was thin 
and had conspicuous large, bare areas, regardless of the type of 
fertilizer applied. At comparable levels of acidity, the plots 
which had received equal amounts of nitrogen and phosphoric 

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TURF CULTURE

acid did not show as much turf injury as did the plots which 
had received four times as much phosphoric acid as nitrogen.

On the farm lawn the visitors saw two series of fertilizer tests, 
identical except that one had been watered and the other had 
not. There were no apparent contrasts in the watered series, 
all of the plots having been about equally overrun with crab-

Differences in the quality of bent turf resulting from the use of different fertilizer 
combinations for a period of 16 years at the Arlington Turf Garden. The plot on the 
left has received urea and ammonium phosphate in such a proportion as to supply 
equal quantities of nitrogen and phosphoric acid. It was one of the best plots in the 
series at the time of the meeting. The plot on the right has received ammonium 
phosphate alone at such a rate as to supply the same quantity of nitrogen as that 
supplied to the left-hand plot. Note the large bare areas and thin turf on the right­
hand plot, which was one of the poorest in the entire series at the time of the meeting. 
This plot has received four times as much phosphoric acid and has developed a 
greater soil acidity than has the plot on the left, which received urea as well as 
ammonium phosphate.

grass and clover. The unwatered series presented decided con­
trasts between the plots which had received different combina­
tions of nitrogen, phosphoric acid, and potash. Aside from the 
fact that the plots which had recently received their fall appli­
cations of inorganic fertilizers showed some burn due to high 
temperature at the time of application, the turf appeared as 
described in the results from this series of experiments dis­
cussed in the December, 1939, issue of Turf Culture in the 
article on ’’Experiments with Fertilizers on Bluegrass Turf.”

November, 1940 

73

The visitors were reminded that these contrasting plots had 
resulted entirely from the different fertilizer programs used. 
The plots had been started on an old lawn established on acid 
soil. No seed has ever been sown on the plots since the experi­
ment was begun and no hand-weeding nor chemical control of 
weeds has been attempted on them. Those plots which had 
received nitrogen in combination with equal quantities of phos­
phoric acid showed a decided increase in turf grasses and a de­
crease in clover and weeds as compared with the unfertilized 
plots. Plots which had also received potash were not so good 
as corresponding plots without potash. On plots which had 
received lime in addition to these fertilizer elements there 
were still fewer turf weeds, but clover was decidedly encour­
aged.

Turf Nurseries

The visitors were shown the stock nurseries in which the 
strains of bents, bluegrasses, fescues, Bermuda and other grasses 
are propagated vegetatively for subsequent planting purposes. 
They were also shown the nursery in which the grass breeding 
program is conducted on bluegrasses and fescues. In this 
nursery, individual plants of these grasses, each produced from 
a single seed, are grown in rows for comparison with every fifth 
plant which is propagated vegetatively from the parent plant. 
All the plants in any one row originate from the same parent 
plant.

Attention was drawn particularly to the uniformity evident 
in both open- and self-pollinated lines among the bluegrasses. 
This uniformity among the progeny and the resemblance to 
the parent plant indicate the possibility of reproducing these 

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TURF CULTURE

strains by seed with little effort. Among the fescues, on the 
other hand, there were decided differences in vigor among the 
seedlings, particularly in the self-pollinated lines.

Chemical Weed Control

Numerous series of experiments in connection with the chem­
ical control of weeds in Kentucky bluegrass turf were seen on 
the farm lawn. In one series of plots treated last fall with three 
or more applications of arsenicals and other herbicides, plantain, 
chickweed, and in the case of arsenicals clover, had been elim­
inated and the turf was decidedly superior to that on the 
untreated plots.

Other plots on which summer treatments had been made were 
shown to the visitors. Severe injury to the turf grasses had 
resulted from the use of some of the herbicides, notably the 
arsenicals, and this was followed by the invasion of crabgrass, 
so that at the time of the meeting those plots were overrun with 
the crabgrass. Still other plots were seen which illustrated the 
burn from recent applications of herbicides; reduction of effec­
tiveness of the herbicides caused by rains immediately following 
the applications; effect of recent applications on plantains; and 
results from treatments with arsenicals in which the injury to 
the turf grasses was reduced by subsequent applications of 
ferrous sulfate.

Another area was seen in which all of the vegetation and 
seeds in the top few inches of soil had been killed with tear gas 
(chloropicrin) and then seeded with Kentucky bluegrass. Two 
flats were also seen, one of which contained compost which had 
been treated with chloropicrin and the other untreated compost. 
Both flats had been maintained under conditions favorable for 

November, 1940 

75

the germination o£ seeds. In the untreated compost there was 
a generous sprinkling of weed seedlings whereas in the treated 
compost there were none, indicating that the chloropicrin had 
killed the weed seeds.

Vitamins and Hormones

Several 4- by 8-foot plots of creeping bent were seen which 
had been watered during the difficult month of August with a 
solution of vitamin Bi three times a week. The turf on the 
plots which had received the same amount of water over the 
same period of time seemed to be equally as good in every way 
as that on the treated plots.

The visitors also saw a rather extensive series of plots which 
had been seeded in August with Kentucky bluegrass seed which 
had been treated with numerous different growth substances at 
different rates. As may be seen in the picture on page 112 
there was no significant difference evident between the turf 
from any of the treated seed and that resulting from untreated 
seed.

Luncheon Program

After the luncheon which was served on the lawn at the 
Arlington Farm, there were reports from 17 districts on turf 
conditions in their section of the country. Plans for this part 
of the program were worked out by Ed Cale, Chairman of the 
Education Committee of the Greenkeeping Superintendents 
Association. Large charts had been prepared previously and 
as the reports were given they were recorded graphically on the 
charts under the headings of weed infestation, insect injury, and 
diseases of turf grasses, as well as temperature and rainfall figures 

lb

TURF CULTURE

as compared with the normal for each district. These charts 
made it possible at a glance to get a comprehensive idea of turf 
conditions over those sections of the country represented.

These reports were followed by an interesting talk on the 
subject of ’’Forecasting Weather” by Kenneth S. Norquest of 
the United States Weather Bureau. He explained that the 
synoptic weather map is the basis of all weather forecasting 
systems today and then discussed the procedures which are 
followed in the construction of such maps. Data on present 
weather conditions are obtained from weather observations 
made simultaneously at about 750 stations in North America 
and on ships in the Pacific, Atlantic, Gulf of Mexico, and the 
Caribbean Sea. These observations which are made every 6 
hours describe and measure the meteorological conditions at 
each place. They are then coded and transmitted to central 
stations or forecast centers where they are uncoded and the 
results charted to form an instantaneous picture of the weather 
over an extensive area of the Northern Hemisphere. Thus, a 
comprehensive weather map is produced.

However, in order to study and interpret such a surface 
weather map it is necessary to know conditions in the atmos­
phere above the earth, say to 50 or 60 thousand feet. For this 
purpose observations of wind direction and velocity at various 
levels up to 18,000 feet are now made every 6 hours at about 75 
stations in the United States. In addition, observations of tem­
perature and humidity from the surface of the earth to about 
70,000 feet are made each day at about 30 stations. By charting 
and studying all of these observations and by observing and 
following the changes from day to day on the weather charts, 
it is possible for the forecaster to predict the weather for a day 
or two ahead. It is evident, therefore, that in spite of all the 

November, 1940

77

improvements in the technique of map analysis and the greater 
knowledge of the physical processes of the weather, a great 
deal depends on the ability of the forecaster to properly inter­
pret the facts which are revealed on the weather maps and 
charts.

Another interesting talk was that on the "Milky Diseases of 
Japanese Beetle Grubs” given by R. T. White of the Bureau of 
Entomology and Plant Quarantine, United States Department 
of Agriculture. The nature of the disease was described and 
examples of its natural occurrence discussed. Experiments with 
the inoculation of the bacteria into soils were described and 
examples cited of such tests on several golf courses including 
West Chester Golf Course at West Chester, Pennsylvania; the 
Maplewood Country Club at Maplewood, New Jersey, and 
Northampton Country Club at Cape Charles, Virginia.

Such inoculations have usually resulted in satisfactory reduc­
tions in numbers of grubs. On the Maplewood course, for in­
stance, the disease germs were introduced into the soil in Oc­
tober, 1938, when the average grub population was 36 to a 
square foot. The following June the population had been 
reduced to 13 to a square foot and 53 percent of these 13 were 
diseased. During the summer the number never exceeded 14 to 
a square foot and in October there were only 7 to a square foot 
and 30 percent of these were diseased. In the untreated areas at 
that time there was an average population of 5 1 to a square foot. 
In June, 1940, the treated areas were again examined. At that 
time four plugs, 1-foot square, were lifted and of these two 
contained no grubs, one contained one diseased grub and one 
contained two diseased grubs. Also, 50 percent of the grubs 
found 75 to 100 feet from the treated area were found to be 
infected.

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TURF CULTURE

A summary of the highlights of this discussion has been pre­
pared by Mr. White and appears on page 84 of this issue. A 
review of other articles on this same subject will be found on 
page 121.

Establishment of New Bluegrass Turf

Following the luncheon and the talks, the visitors were con­
ducted to another area where numerous series of demonstration 
plots have been set up by the National Capital Parks in collabo­
ration with the Green Section. These plots told an interesting 
story in dollars and cents of the relative importance of seed and 
fertilizer in the establishment of new turf; illustrated compara­
tive results from fall and spring seeding; and showed 1-year-old 
turf resulting from the use of various seed mixtures. The soil 
in the area on which these plots have been established was poor 
in all essential plant food elements, and was covered with a 
profusion of weeds which were merely plowed under immedi­
ately before seeding. The ground was never fallowed and the 
plots have not been watered nor weeded.

Relative Importance of Seed and Fertilizer

The fertilizer applied in all of the plots of this series was a 
10-6-4 mixture and pure Kentucky bluegrass seed was used. 
Seed was sown at rates varying from 1 to U pounds to 1,000 
square feet. The plots were seeded and fertilized in September, 
1939. The best plots of the series were the ones which had re­
ceived seed at the rate of 2 and 3 pounds to 1,000 square feet 
and fertilizer at the 40-pound rate. The total calculated cost 
of the fertilizer and seed used was $47 and $37 an acre respec­
tively. Even the plot which had received seed at only the 

November, 1940

79

1-pound rate but fertilizer at 40 pounds to 1,000 square feet 
showed a good stand of grass, although slightly more weedy 
than the $47 and $57 plots. This plot represented a cost of 
only $37 an acre.

Standing out in marked contrast with these plots which were 
heavily fertilized but seeded at low rates, were plots which

Relative importance of seed and fertilizer in establishing new bluegrass turf on poor 
soil. The dense, vigorously growing turf on the plot in the background was the result 
of combining an application of 10-6-4 fertilizer at the rate of 40 pounds to 1,000 square 
feet with seeding Kentucky bluegrass at the rate of 2 pounds to 1,000 square feet. 
The estimated cost of materials used in this practice was $47 an acre. Contrasted with 
this good plot is the thin, weedy turf on the plot in the foreground, which resulted from 
seeding at the rate of 15 pounds to 1,000 square feet with seed from the same source 
but not applying any fertilizer. This practice involves a cost of $145.

had been seeded at heavy rates. The plot, for instance, which 
had been seeded at the 15-pound rate but not fertilized had 
produced a very thin, weedy turf, although the cost for such 
a practice was $145 an acre. When this same seeding rate was 
accompanied by fertilizer at the 40-pound rate, the turf was 
not so good as it was on plots which had been seeded at the

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TURF CULTURE

2- or 3-pound rate. Earlier in the season the turf had looked 
good but disease had killed out much of the grass, and weeds had 
come in so that the final result was not so good as the result 
from seeding at lower rates, although the estimated cost was 
$173 an acre. Similar results were seen on the plot seeded at 
the 10-pound rate and heavily fertilized at a total cost of $125 
an acre.

Fall and Spring Seedings

The above plots demonstrated the results obtained from seed­
ing and fertilizing programs carried out in September and 
October. Similar programs were carried out the first of May on 
a corresponding series of plots. At the time of the meeting all 
of these latter plots were severely infested with crabgrass. In 
this series, however, the plots which had received the most fer­
tilizer were covered with 100 percent crabgrass, whereas those 
which had been fertilized at low rates still had some bluegrass 
present.

Seed Mixtures

Plots which had been seeded last fall with pure Kentucky 
bluegrass were compared with plots seeded at the same time with 
mixtures of Kentucky bluegrass and 10 to 60 percent Italian 
ryegrass in one series, 5 to 25 percent redtop in another, and 
1 to 10 percent of Astoria, highland, and seaside bents in still 
other series. Some of the best turf was that on plots seeded with 
Kentucky bluegrass alone or in combination with small amounts 
of Astoria or highland bents.

The mixture containing 10 percent ryegrass had produced a 
spotted, shabby turf but the plot did not contain as many weeds 
as did the plots seeded with higher percentages of ryegrass. As 

November, 1940

8i

the percentage of ryegrass increased, the amount of weeds on 
the plots increased and the turf became progressively thinner.
Plots which had been seeded with mixtures in which the pro­
portion of redtop was more than 10 percent had been badly 
diseased during the summer and weed invasion had followed in

Contrasting turf resulting from the use of two different seed mixtures. The plot on 
the left was seeded with a mixture of Kentucky bluegrass and ryegrass; the plot on the 
right, with a mixture of Kentucky bluegrass and highland bent. The picture was taken 
in September, I year after the plots were established. Note the abundance of weeds 
in the plot on the left, which was seeded with the ryegrass mixture, as compared with 
the dense stand of turf grasses and lack of weeds in the plot on the right. The right­
hand plot was typical of those seeded with mixtures of Kentucky bluegrass and small 
amounts of Astoria, seaside, or highland bents.

the path of the disease. At the time of the meeting, therefore, 
the plots presented a thin weedy turf. The plots which had 
been seeded with 5 to 10 percent redtop had better turf than 
any of the other combinations in the redtop series.

Experimental Greens

The following morning the visitors went directly to the Cap­
itol Golf and Country Club where they viewed and rated the 
experimental greens and were shown the weed-control and 
fertilizer plots on the tenth and thirteenth fairways respectively.

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TURF CULTURE

On the fifteenth green which has been under play for 2 years, 
C-l 5 was first choice with C-l a close second and C-52 and 
C-17 in third and fourth places respectively. Later in the 
morning the seventeenth green which had been under play for 
3 years was also rated. On it, C-36 which was not planted on 
the other green was first choice. C-l, C-17, and C-l5 took 
second, third, and fourth places respectively.

Fairway Weed-Control and Fertilizer Tests

Weed-control plots were seen on the tenth fairway. Arsenate 
of lead had been applied at rates varying from 5 to 40 pounds to 
1,000 square feet. Arsenic acid and arsenic trioxide were ap­
plied at the same time at rates which would furnish the same 
amount of arsenic. The crabgrass had been controlled in all of 
these plots. The arsenate of lead had been injurious to the blue­
grass at rates of 10 or more pounds to 1,000 square feet. The 
other two chemicals had also been injurious when applied at 
comparably high rates. When superphosphate had been applied 
at the rate of 2 pounds of P-O. to 1,000 square feet, however, 
less injury to the bluegrass resulted from the arsenate of lead 
treatment.

On the thirteenth fairway, numerous series of fertilizer plots 
were shown the visitors. Only a few of the results which were 
most interesting to them can be mentioned here. In a recent 
series of plots which had been fertilized with various combina­
tions of an inorganic fertilizer on the basis of a 9-9-4 mixture, 
applied at an annual rate of 2/2 pounds of nitrogen to 1,000 
square feet, it was apparent that crabgrass was more abundant 
on those plots which had received potash in amounts exceeding 
that supplied by the unmodified 9-9-4 mixture.

November, 1940

83

On a 6-year-old series, fall fertilized plots presented better 
turf than did those fertilized in the spring. There were fewer 
weeds and less clover on the plots which had received inorganic 
mixtures than on those to which organic fertilizers had been 
applied. Clover definitely had been stimulated by a single 
application of lime over this period of time.

Among other plots which had been planned to illustrate the 
results obtained on this course by fertilizing with each of the 
principal elements alone and in various combinations, the green­
keepers’ choice was a plot fertilized with nitrogen, phosphoric 
acid, and potash applied in a 12-6-4 mixture at rates sufficient 
to give 1 pound of nitrogen each spring and fall, without lime.
Recent plots established in 1938 indicated quicker results 
from complete mixtures in which the phosphoric acid was sup­
plied in the form of treble superphosphate rather than super­
phosphate. The explanation offered was that perhaps the 
treble superphosphate had released the phosphoric acid more 
quickly than had the superphosphate.

After luncheon which was served in the clubhouse the visitors 
returned to the Arlington Farm by way of a residential area 
in which they stopped to see a successful planting of Zoysia 
matrella in turf. Following informal group discussions at the 
Arlington Turf Garden, the third annual Arlington Turf 
meeting was adjourned.

If the ground remains soggy for several days in good weather, 
something is probably wrong with the drainage. Fall is a good 
time to look into this and perfect the drainage where necessary, 
thereby avoiding much injury to the grass this next season.

84

TURF CULTURE

STATUS OF THE MILKY DISEASES OF JAPANESE 
BEETLE LARVAE

R. T. White*

This article is a summary of a discussion given on September 
16, 1940, at Arlington Turf Meeting sponsored by the United 
States Golf Association Green Section and the Greenkeeping 
Superintendents Association at the Arlington Experiment Farm, 
Arlington, Virginia.

Early work at the Moorestown, New Jersey, laboratory indi­
cated that diseases of the Japanese beetle were playing a part in 
the reduction of this pest. It was not until 1933, however, that 
the organisms responsible for certain of these diseases were dis­
covered, and not until 1935 was the use of these newly described 
species of bacteria attempted for control under field conditions.
Diseases of the Japanese beetle can be grouped into four major 
classes, namely, bacterial, nematode, fungus, and protozoan. 
The bacterial group may again be divided into the "white 
group” and the "black group.” The white group seems at pres­
ent to be of most importance, and thus it is with this group that 
we are primarily interested.

At least two diseases of the white group, known as type A and 
type B milky diseases, have shown promise for utilization in 
larval control. Two heretofore undescribed species of spore­
forming bacteria, which develop in the blood of living larvae, 
are responsible for these diseases. The spores of these bacteria 
are microscopic in size and cause the blood to become turbid and 
of a milky-white color; hence the name "milky diseases.”

* Assistant Entomologist, Bureau of Entomology and Plant Quarantine, United States 

Department of Agriculture.

November, 1940

85

Repeated tests have shown the spores, not only to resist 
extended periods of drying, but also to be equally resistant to 
periods of exceedingly wet conditions. The spores have been 
held in soil with no grubs present for approximately 4 years. 
This ability of the organism to withstand such adverse condi­
tions of moisture and temperature indicates its usefulness under 
field conditions.

Experimental field plots were started in 1935 in areas in 
which preliminary surveys indicated little, if any, disease pres­
ent. At the present time over 256 experimental field plots have 
been established under a variety of conditions of dosage, interval 
of application, temperature, moisture, and soil type. They are 
located at different points in the states of Virginia, Maryland, 
Delaware, Pennsylvania, New Jersey, New York, and Con­
necticut, and in the District of Columbia. In certain of these 
plots larval reductions of over 90 percent have been obtained 
within a single season. In the earlier treated plots attempts to 
reestablish a grub population in the soil have failed owing to the 
high incidence of the disease organism which has developed; in 
other words, when the soil once becomes highly infectious it is 
impossible for larvae to survive therein long enough to mature.
In addition to the research work under way, a program of 
colonization of the type A disease has been undertaken by the 
United States Department of Agriculture and several cooper­
ating State agencies. Programs of disease distribution are under 
way in New Jersey, Maryland, New York, and Connecticut. It 
is planned to expand the colonization program as rapidly as 
possible.

Numerous examples of natural occurrence and build-up of 
the disease have been followed closely, and two such instances 
may well be mentioned at this time. Early in the fall of 1939 

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TURF CULTURE

at the Veterans’ Administration Hospital and Facility, Perry 
Point, Md., an average larval population exceeding 38 per 
square foot was found. Under ordinary circumstances in the 
absence of milky disease, severe injury to the turf would be 
expected under these conditions. An examination of the turf

Inoculation of a l-acre area of turf on the Mall in Washington with the causal organism 
of the Milky Disease of Japanese beetle larvae. The dust which was being applied here 
by the spot-colonization method consisted of talc containing a specified quantity of 
spores of the bacteria which produce the disease. The apparatus released 2 grams 
of the dust mixture at each spot and the spots in this test were placed every 10 feet. 
The estimation is that when grubs are present in the soil it will take I year for the 
disease to spread uniformly over the entire treated area from these spots placed at 
10-foot intervals.

area showed that approximately 4 percent of all larvae present 
were infected with milky disease, and that some reduction in 
the grub population had already been caused by the disease. A 
survey over the entire area in June, 1940, showed that only six 
larvae per square foot remained and 67 percent of these were 
diseased. Thus, a reduction of 94.7 percent in the larval popu­
lation occurred between September, 1939, and June, 1940, 
owing to the activity of the milky disease organism.

November, 1940

87

Surveys conducted at the Battle Hill Golf Course, Springfield, 
New Jersey, showed conditions paralleling those found at 
Perry Point, for during the same period a reduction of 94.5 
percent was recorded.

The situation in the District of Columbia is interesting and 
somewhat typical of other areas of comparable infestation. 
The beetle has been established there for a number of years and 
the infestation in several sections of Washington is now quite 
general. There is evidence, however, that the milky disease is 
also established to a limited extent through natural occurrence. 
In the spring of 1936, among several larvae collected in the 
Benning’s Road section, one was found to be definitely infected 
with milky disease. In larval collections made in June, 1940, 
from several parks in the southeast and southwest portions 
of the District, larvae infected with type A milky disease were 
found. Since the disease occurrence appears to be limited and 
of low degree of incidence, a number of plots have been recently 
treated in order to hasten the development of disease in Wash­
ington and adjacent areas in Virginia.

All but one percent of the world’s supply of Jute, the mate­
rial used in making burlap bags, comes from India. England 
has, therefore, been able to commandeer the supply for use as 
sandbags to be used in protecting the structures in London 
from air raids. With increased difficulty in obtaining burlap 
bags for fertilizers, cotton and paper bags can be substituted, 
although they are not as suitable under some conditions as are 
those made of burlap. It has been suggested that the use of 
cotton bags would help, in a modest way, to reduce our cotton 
surplus.

88

TURF CULTURE

GROWTH SUBSTANCES IN PLANTS

F. F. Davis *

During the past few years a tremendous quantity of pub­
licity has been given to the use of various substances to stimu­
late growth in plants. Most of the emphasis has been laid on 
the use of such substances for the rooting of cuttings of woody 
plants such as Camellia, rhododendrons, holly and others which 
ordinarily are extremely difficult to root, and for accelerating 
the rooting of other cuttings which are more easily rooted 
with the customary propagating practices.

More recently, the effect of these same substances on seed 
germination has been capitalized upon in the seed trade. As 
is frequently the case in commercial propaganda, promises arc 
made which far exceed, and in some cases have but little bear­
ing on, the actual facts which have been demonstrated in well- 
controlled scientific experiments. For this reason, as well as 
because of the confusion and disagreement which appears to 
exist among the various investigators themselves, it has seemed 
wise to make an effort at this time to give our readers some 
notion of the actual principles involved in the use of growth 
substances, and of what they can and cannot be expected to 
accomplish.

Materials having the ability to affect the growth and devel­
opment of plants when applied in almost infinitesimal amounts 
are spoken of variously as hormones, phytohormones, auxi­
mones, auxones, phytamines, vitamins, growth regulators, 
growth promoting substances, and simply growth substances. 
The latter is perhaps the most generally accepted and widely

Botanist, United States Golf Association Green Section.

November, 1940

89

used term, largely because it is all-inclusive and yet suggestive 
of the physiological activity of all of these substances.

Kinds of Growth Substances

The substances which have been found to stimulate growth 
of plant cells vary widely in characteristics from the gas, carbon 
monoxide, to the complex organic compounds such as vitamins. 
Various methods of classifying them have been proposed in 
the literature but the simplest, for our purposes, is to divide 
them into two groups.

Hormones

These are substances which are produced by the individual, 
the development of which they influence. The term was first 
applied to certain secretions present in man and other animals, 
and implies that they are "chemical messengers.” By definition 
they are substances which are manufactured in one part of the 
animal or plant and carried to some other part of the organism 
where, in extremely minute quantities, they influence such 
physiological activities of the cells as growth.

To the group of plant hormones belong various organic com­
pounds. The first to be recognized as such are two compounds, 
auxin a and auxin b, which have been isolated and purified 
from various plant tissues and from urine. They have not, 
however, been successfully synthesized in the chemical labora­
tory. Another compound intimately associated with auxins 
a and b is heteroauxin which has been shown to be indole-3- 
acetic acid or beta indole-acetic acid. Since this compound 
has been synthesized in the laboratory and was understood 
chemically long before it was recognized as a plant hormone, 

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TURF CULTURE

and since it is an active root-forming substance, it has naturally 
been among the first of the chemicals to be used extensively in 
investigations concerning the practical value of plant hormones 
to the propagator.

The vitamins, of which so much is written in connection 
with human and animal nutrition, are specific substances which 
are needed in minute quantities by, but not generally manu­
factured in, the animal body. They are manufactured by 
plants, but their function in the physiology of the plant has not 
been understood until recently. Now, it has been found that 
several of them, notably vitamin Bi (known to the chemist 
as thiamin or aneurin), are growth substances for plants. 
Therefore, such compounds as thiamin are vitamins for animals 
and at the same time hormones for plants, because they are 
produced in one part of the plant and transported to other 
parts where, in extremely minute quantities, they influence 
physiological processes such as growth.

Auximones

These are substances which alter the rate, kind, and direc­
tion of growth of plants when introduced from without in 
extremely high dilution. When present in sufficiently small 
amounts they stimulate the growth of plant cells, but when 
still less is present the stimulating effect is decreased. More­
over, the stimulation of growth diminishes rapidly with increas­
ing amounts of these compounds until a concentration is 
reached above which the compounds become increasingly toxic.
To this group of substances which are sometimes collectively 
termed synthetic hormones, belong compounds with widely 
diverse physical and chemical properties. Investigators in 
plant research laboratories around the world have been working 

November, 1940

91

with such substances, with the result that scores of different 
compounds are now recognized as having the ability to influence 
plant growth. Materials as well known and as varied as the 
gas, carbon monoxide on the one hand, and the much talked-of 
drug, sulfanilamide on the other hand, have been shown to 
belong to this group of compounds.

Kinds of Effects Produced

The general effects on cell growth in plants may be ex­
pressed in various ways, such as increase in leaf and shoot 
development, increase in number or length of roots, and 
general increase in dry weight of plants produced. As a rule, 
these substances alter the distribution rather than the total 
amount of growth, so that when a given substance is applied 
at a rate to stimulate root-formation it will probably inhibit 
top-growth, at least temporarily. This is the reason why the 
term growth regulators or simply growth substances is pre­
ferred to growth-promoting substances.

Growth of plants takes place by two distinct processes, cell­
enlargement and cell-division. The actual existence of plant 
hormones was first discovered through their stimulation of 
localized cell-elongation which resulted in the bending of the 
stem or other plant part to which the growth substances were 
applied. It has since been shown that the same substances 
applied at slightly greater rates or to other plant parts induced 
growth by the other process, cell-division. Growth by cell­
division, for instance, results in the formation of new roots 
on cuttings of stems and in some cases even on leaves. In still 
larger quantities, these same substances become growth inhibi­
tors rather than growth stimulants.

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TURF CULTURE

It is believed by some that the natural bending of shoots 
toward the light and away from gravity is due to a localized 
effect of plant hormones present in those organs. In the first 
case, the auxins, which are the hormones stimulating cell­
elongation, concentrate on the shaded side of the stem or leaf 
with the result that the shaded side grows faster than the 
lighted side and the stem or other plant part concerned bends 
toward the light. In the case of the response to gravity, it has 
been shown that in horizontally placed stems the auxins ac­
cumulate on the lower side causing a localized increase in 
growth in that region. The result is that the stem curves up 
or away from gravity.

Various more or less localized effects can be induced in plants 
by the external application of these growth substances. When 
leafy shoots are exposed to dilute vapors of these compounds 
or when the same compounds are applied to limited areas of 
plant organs in lanolin paste, in solution, or in talc, the leaves 
may grow down, stem tips may become enlarged, root forma­
tion may be induced, or stems may be caused to grow in the 
direction of gravitational pull rather than away from it. 
There is some evidence that seed germination can be accelerated. 
In one laboratory it has been shown that the damage caused by 
disinfecting seed with formaldehyde, copper sulfate, and mer­
curic chloride is reduced by the addition of small amounts of 
some of the synthetic hormones.

Certain compounds when applied to the pistil of some flowers 
have the power to stimulate cell growth in the ovary so that 
sterile fruits are produced. By such means, seedless fruits of 
such plants as watermelon, crooked neck squash, pepper, holly, 
and others have been produced experimentally. However, 
because of the difficulty of preventing on a large scale the 

November, 1940 

93

occurrence of natural pollination, this method has not yet come 
into commercial use.

The inhibiting effect of hormones not only occurs when the 
synthetic compounds are applied externally at excessive rates 
but also occurs commonly in nature. For instance, the well- 
known fact that many plants are pinched back to encourage 
the development of lateral shoots may now be explained by the 
fact that the auxins which are produced in the terminal bud 
stimulate the growth of the shoot but inhibit the development 
of the lateral buds. When the source of these growth sub­
stances is removed by taking off the terminal bud, the lateral 
buds are no longer inhibited. As they begin to develop, they 
in turn become sources of auxins for subsequent shoot growth.

Effects of Concentration

It appears that the concentration of growth substances used 
plays an important role in determining the effect which that 
substance will have on a given plant. Generally speaking, 
roots seem to be more sensitive than shoots to the synthetic 
hormones. A concentration which will stimulate root-elonga­
tion may not be sufficient to have any effect on shoot growth. 
When the same substance, however, is applied at a sufficiently 
high rate to stimulate shoot growth it may inhibit the elonga­
tion of roots. When applied at a still higher rate, the same 
substance may cause the development of new roots at the 
points where it is applied and at the same time inhibit shoot 
growth. Moreover, it may also inhibit the subsequent growth 
of the roots which it has initiated.

This effect of concentration is far-reaching in its applications. 
Natural growth hormones are present in varying amounts in 

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TURF CULTURE

most plant tissues. The quantity present varies with the species 
of the plant, the organ of the plant, the stage of growth, the 
environmental conditions under which the plant has been 
growing, etc. If all other factors necessary for growth are 
uniform, the plant which has the largest quantity of growth 
hormones in its tissues may be expected to give the least response 
to added growth substances.

When one considers that the concentrations with which the 
experimenter is dealing are rarely over 1 part in 1,000 and in 
many instances may be less than 1 part per million (p. p. m.), 
it becomes evident how careful the practical man must be in 
making up the solution or dust in which he intends to apply the 
growth substance.

Chemicals May Affect Specific Organs

The kind of response which may result from the application 
of growth substances to plants depends not only on the species 
of plant, its stage of development, and the rate at which the 
substance is applied, but also on the part of the plant to which 
it is applied and the kind of growth substance used. Certain 
compounds are decidedly specific in the effects they produce 
and the plant parts which they influence.

\ itamin Bi, for instance, has been shown to be indispensable 
for the elongation of roots but it does not actually initiate 
the development of new roots. So far, no direct effect on the 
giowth of stems, the time of flowering, or the number and size 
of flowers and fruits, has been satisfactorily demonstrated. 
The increase in vegetative vigor of some plants in response to 
tieatment with vitamin Bi is behoved by authorities to be 
caused by the increased vigor of the roots. Other vitamins

November, 1940

95

such as B? and B»;, nicotinic acid, and thiourea have been shown 
to be necessary for root growth in some species but vitamin Bt 
appears to be necessary universally.

On the other hand, the synthetic hormones such as beta 
indole-acetic, beta indole-butyric, and alpha naphthalene­
acetic acids appear to be less specific in their effects, the exact 
nature of the effects being determined by the rate of applica­
tion and the organ treated. When applied at the right con­
centration to cuttings they have the ability to induce the for­
mation of roots at the site of application but may inhibit their 
subsequent growth. A combination of one or more of the 
synthetic hormones to initiate new roots with vitamin Bi to 
stimulate their growth may, therefore, be expected to give the 
best results so far as rooting of cuttings is concerned.

In the following table the various kinds of effects are listed 
together with some of the compounds which have been shown 
to produce these effects, at least with certain species. This list 
is by no means complete and includes chiefly those compounds 
which are referred to most commonly in the literature on 
growth substances. A few compounds are included because 
they are well known for their physiological activity but arc 
not generally recognized as having any influence on the growth 
of higher plants. The latter are included only to indicate the 
diversity of the compounds which produce these effects.

A few generalizations have been ventured by certain author­
ities concerning the use of some of the more commonly em ­
ployed synthetic compounds. For instance, according to some 
investigators, indole-acetic acid and the naphthalene com­
pounds tend to spread throughout the plant and produce gen­
eral or systemic effects, whereas indole-butyric acid tends to 
induce a more localized response. According to some, there 

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TURF CULTURE

appears to be less danger of shock to the cuttings when the 
naturally occurring hormone, indole-acetic acid, is used to 
induce root-formation, although in many cases superior rooting 
results from the use of indole-butyric acid, alpha naphthalene­
acetic acid and other synthetic compounds.

Generally speaking, the naphthalene-acetic acid is more 
potent than the indole compounds and should be used at lower

Plant Organs and Compounds Affecting Tfieir Growth and 
Development

Roots:

Formation of New Roots
Auxins a and b
Beta indole-acetic acid (hetero­

auxin)

Potassium indole-acetate
Beta indole-butyric acid
Beta indole-propicnic acid
Alpha naphthalene-acetic acid 
Phenyl-acetic acid
Coumarin
Vanillic acid 
Sulfanilamide 
Methylene blue

Shoots:

General Top Growth

Auxins a and b
Biotin
Vitamin B2 (riboflavin)
Vitamin C (ascorbic acid) 
Thiourea
Beta indole-acetic acid
Beta indole-butyric acid
Beta indole-propionic acid
Alpha naphthalene-acetic acid 
Naphthalene-acetamid 
Indolc-acetamid

Elongation (Not Formation 
of New Roots)
Vitamin Bi (thiamin or aneurin)
Vitamin B2 (riboflavin)
Vitamin B«
Nicotinic acid
Thiourea

Leaf’ Growth

Adenine
Alanine
Arginine
Uric acid
Other amino acids and purines

November, 1940

Otaries:

Sterile Fruit Production

Beta indole-acetic acid
Beta indole-butyric acid
Beta indole-propionic acid
Alpha naphthalene-acetic acid
Ethyl alpha naphthalene-acetate
Methyl alpha naphthalene-acetate

Seeds:

Increase or Acceleration 
in Germination

Auxins a and b
Beta indole-acetic acid
Beta indole-butyric acid
Alpha naphthalene-acetic acid
Phenyl-acetic acid

97

Effect on Subsequent Seedling 
Growth
Beta indole-acetic acid
Beta indole-butyric acid
Alpha naphthalene-acetic acid
Vitamin C (ascorbic acid)

rates. Phenyl-acetic acid, on the other hand, is only about one- 
tenth as active as indole-acetic acid and must be applied at 
heavier rates. The metallic or ammonium salts of the acids 
are apparently less toxic to the plant and more effective in in­
ducing formative effects than are the acids themselves. The 
same is true for the methyl and ethyl esters.

Also, there is apparently a difference in the quality of the 
roots formed as a result of treatment of cuttings with the 
various synthetic compounds. Those resulting from a treat­
ment with indole-butyric acid are more nearly normal than 
those which develop after the use of alpha naphthalene-acetic 
acid.

Natural Occurrence

The discussion thus far has been concerned with the response 
of plant organs to applications of various growth substances.

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TURF CULTURE

It should be remembered, however, that auxins and vitamins 
are manufactured almost universally by green plants for their 
own use and are, therefore, hormones in the true sense of the 
word. The actual amount of these compounds which may be 
synthesized by any particular plant depends on the species of 
plant and the conditions under which it is grown.

Auxins, for instance, are present throughout all parts of 
higher plants, but tend to be most abundant near the regions 
where they are manufactured or stored. They are synthesized 
in the tips of actively growing organs and are transported 
down toward the base of the plant. Long before the existence 
of auxins as such was understood, the fact was recognized 
that cuttings without leaves rooted better when at least one 
bud was present. It is interesting to note that as early as 1880 
this fact was explained by the assumption that a specific 
substance was formed in the shoot and was normally trans­
ported toward the base. In cuttings, this substance was believed 
to accumulate at the base because it could go no farther, and 
there to result in the formation of roots. In recent years it 
has been shown that this assumption was correct and that the 
specific substance was an auxin which was synthesized in the 
growing bud.

Vitamins, on the other hand, are believed to be manufactured 
in the leaves of green plants, the slow-growing plants such as 
Camellia, Rhododendron, and Azalea producing materially less 
than the rapidly growing annuals. From the leaves, the vita­
mins are translocated to all parts of the plant, the seed fre­
quently containing the highest percentage of them.

Moreover, it has been shown that manure, compost, plant 
debris, soil microflora, seed meal products, and other organic 
materials used to enrich soil contain appreciable amounts of 

November, 1940

99

vitamin Bi. Therefore, plants growing in soil which contains 
generous quantities of organic matter have an abundant supply 
of Vitamin Bi even if they do not make it in sufficient quantity 
for themselves. In fact, the addition of Vitamin Bi to plants 
growing in such soils may result in a reduced growth due to 
the toxic effect of an over-abundance of growth substance. It 
has been suggested that "sickness” of highly manured green­
house soils which is sometimes described may be simply a 
matter of toxic concentrations of growth substances.

In view of this universal distribution of growth substances 
it is not reasonable to expect phenomenal results from their 
addition to plants growing under normally good cultural con­
ditions. When normal conditions are disturbed, such as occurs 
when cuttings are made, when well-established plants must be 
transplanted, or when an attempt is being made to germinate 
old or poor seed, there is a good possibility that some of the 
growth substances may become limiting factors in the growth 
of the plants concerned and that a favorable response might 
be expected if the right growth substance were added in the 
right concentration. When plants are grown in water or sand 
culture, or in poor soil lacking in organic matter, it may be that 
they do not have available a sufficient supply of hormones for 
best growth and will therefore respond to their addition from 
without.

Factors Complicating Results with Growth 
Substances

It should be remembered that growth substances represent 
only one group of factors necessary for plant growth. Among 
other factors involved, are the external ones such as light, tem­
perature, soil moisture, and nutrients; and the internal ones 

100

TURF CULTURE

such as proper activity of the various enzymes, normal syn­
thesis of carbohydrates, and the stage of development of the 
plant or part of the plant concerned. For optimum growth, 
the status of all of these factors should be favorable. Moreover, 
increasing any one of these factors will not result in increased 
growth unless all of the other factors are already present in 
quantities sufficient to support such increased growth. There­
fore, it is only when the growth substances are the factors 
limiting growth that their addition may be expected to stimu­
late growth. Even then, the proper compounds must be added 
at the right concentrations if growth is to be stimulated in any 
desired direction.

There is some evidence that these compounds give better 
results in acid than in neutral or alkaline media. Vitamin Bi, 
for instance, has been shown to decompose when in contact 
with alkaline materials and therefore may not be expected to 
give satisfactory results in alkaline or "sweet” soils or where 
lime-impregnated water is used. Some investigators also have 
found that beta indole-acetic acid and other synthetic com­
pounds are more effective when applied in solutions with an 
acidity between pH 4 and 6 than in neutral or alkaline solu­
tions. It would seem wise, therefore, in making up the final 
dilute solution to use water which had been acidified with a 
weak acid such as acetic acid. Vinegar is a readily available 
source of acid for this purpose. In field work, it would seem 
that better results might be expected generally on acid than on 
alkaline soils.

Frequently, the addition of two or more different growth 
substances may give better results than is obtained by the addi­
tion of either alone. For instance, Vitamin Bi, yeast extract, 
biotin (a component of the vitamin complex in yeast extract), 

November, 1940

101

and theelin (one of the female sex hormones in animals) have 
all been found on occasions to increase the results obtained with 
the synthetic hormones such as beta indole-acetic and beta 
indole-butyric acids. Also, a mixture of the synthetic hor­
mones is sometimes better than any one of them alone. Such 
results are to be expected since it is entirely reasonable that 
more than one factor may be limiting the type of growth 
desired. Sometimes, also, the carbohydrate supply in the twig 
to be rooted is insufficient to support the growth of roots 
initiated by the hormones. If such is the case, merely supple­
menting the hormone treatment with honey or sugar solution 
will increase the results so far as rooting is concerned.

Recognizing the importance of the many interacting factors 
which influence the growth of plants, it is not surprising to 
find the literature filled with conflicting results following 
treatment of various plant organs with growth substances. 
Moreover, there are probably other internal and soil factors 
the importance of which is not recognized today. Particularly 
with plants grown under field conditions, it is difficult, if not 
impossible, to evaluate all of the factors influencing their 
growth and to determine which are limiting ones. Locally 
planned and executed field tests on a small scale may frequently 
indicate, however, whether or not favorable results can be 
expected from a given type of treatment.

Methods of Application

Growth substances have been applied to plants in various 
ways, the method depending on the compound used, the plant 
parts to be treated, and the kind of results desired. The most 

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TURF CULTURE

common method used practically is to immerse the bases of 
cuttings in dilute solutions for 12 to 48 hours, depending on the 
concentration of the solution and the kind of cutting. Immer­
sion in talc mixtures of the same compounds just before plant­
ing the cuttings has also proved effective in many cases.

When decidedly localized areas are to be treated such as is 
necessary for the production of sterile fruit, the compounds are 
applied in a paste of lanolin or sheep’s wool fat. On the other 
extreme, whole plants or parts of plants have been exposed to 
vapors such as carbon monoxide, ethylene and others.

The effect on germination of seed and on subsequent growth 
of seedlings has been investigated by soaking seed in solutions of 
these compounds or by dusting them with the talc mixtures 
and then following the rate and final percentage of germina­
tion as well as the vigor of resulting seedlings and mature plants.
Also, there are some experiments described in which solutions 
of these compounds have been sprayed on foliage of growing 
plants or applied to the soil in which they are growing.

As is to be expected from the foregoing discussion, the rates 
recommended in many cases vary over a wide range for the 
same compound. With vitamin Bi, however, investigators are 
comparatively well agreed that in solution a concentration of 
0.01 to 0.1 p.p.m. is a safe starting point. The rates at which 
the synthetic hormones have given favorable results have varied 
from 0.01 to 1,000 p.p.m.

Practical Results with Growth Substances

Unquestionably the hormones play fundamental roles in the 
physiology of plant growth, some of which are now recognized 
and understood at least in part. However, because of the al­

November, 1940

103

most universal distribution of hormones throughout plant 
tissues and in fertile soils, and because of the minute concen­
trations required, beyond which the compounds become toxic, 
the problem of using them practically to stimulate various types 
of growth of plants or plant organs is not a simple one to solve. 
The results which have been published to date vary over a wide 
range from actual inhibition of growth, through failure to get 
either stimulating or inhibiting results to outstandingly suc­
cessful stimulation. Therefore, it is impossible in the limited 
space of a few pages to summarize the results which appear in 
the literature. An attempt has been made in that direction, 
however, to give the reader an idea of where to start if he is 
anxious to try some of these materials on his plants.

Results with Cuttings

The immersion of the bases of cuttings in dilute solutions 
or dust mixtures of synthetic hormones has in many cases stim­
ulated the formation of roots. The successful rates used have 
varied over a wide range from 0.01 p.p.m. to 1,000 p.p.m. 
Generally speaking, dust treatments can be made at the higher 
rates with less danger of injury. Also, the dust treatment is 
perhaps simpler because the base of the cutting can be immersed 
in it and planted immediately, whereas when solutions are used 
the cuttings must remain in them for 12 to 48 hours, the length 
of time depending on the concentration of the solution and the 
species of plant.

With solutions of indole-acetic and indole-butyric acids, rates 
as low as 0.1 p.p.m. have been effective in some instances but S 
to 20 p.p.m. may be considered a safe starting point. Less alpha 
naphthalene-acetic acid is required, effective stimulation having 
been achieved at rates as low as 0.01 p.p.m. In general, when 

104

TURF CULTURE

applied at the base of cuttings, the highest non-toxic concentra­
tion of these synthetic compounds will give the best results. 
This concentration varies with the species of plant used, but 
generally is less for green cuttings than for dormant ones. With 
mixtures in talc, effective stimulation has resulted from use of 
mixtures varying in concentration from 50 p.p.m. to 1,000 
p.p.m.

Subsequent treatment with vitamin Bi, biotin, or yeast ex­
tract has in many cases resulted in much improved final results, 
probably because of their stimulating effect on root elongation. 
Biotin has also stimulated shoot growth.

Hormone treatment, however, is not the "shot-gun prescrip­
tion” which will solve all of the problems of the propagator. 
It should be regarded merely as an additional tool to be used in 
conjunction with the most careful practices which the propa­
gator has at his disposal. Their use neither guarantees successful 
rooting of cuttings which are otherwise difficult to root nor the 
acceleration of rooting of cuttings which are normally easily 
rooted. In fact, numerous individuals have published the re­
sults of experiments in which they have been partially or en­
tirely unsuccessful in stimulating root production in cuttings 
with growth substances.

Results with Entire Plant

Experiments have been performed in which whole plants 
grown in water or sand culture have responded favorably to 
hormone treatment. It should be remembered that plants 
grown under these conditions do not have access to the organic 
matter and microflora present in fertile soils which are natural 
sources of abundant supplies of growth substances. Stimulating 

November, 1940

105

effects might be expected, therefore, under these conditions 
which would not appear if the same plants were grown in good 
fertile soil.

Vitamin Bi, in extremely low concentrations, has stimulated 
root growth of seedlings which in turn has resulted in generally 
increased vegetative vigor of the entire plant. When various 
species were grown in sand, watered with nutrient solutions and 
treated with vitamin Bt it was found that common crop plants 
such as tomato, peas, and corn, which contain relatively large 
quantities of vitamin Bi in their leaves, showed no response. On 
the other hand, plants like Camellia which contain no detectable 
vitamin Bi in the leaves, and other species which contain less 
than 10 milligrams to 1 kilogram (2.2 pounds) of dried leaf 
tissue, showed increased growth as a result of the addition of 
0.01 p.p.m. of vitamin Bi. Moreover, the less vitamin Bi there 
was present in the leaves, the greater was the increase in weight. 
For instance, trivialis bluegrass (Poa trivialis) which had a vit­
amin Bi content of 4.2 milligrams gave more response than did 
Colonial bent (Agrostis tenuis) which contained 6.0 milligrams. 
It should be remembered that these experiments were performed 
on plants growing in sand rather than soil.

In other experiments, adenine, uric acid, riboflavin (vitamin 
B->), and ascorbic acid (vitamin C) have been shown definitely 
to influence top growth under some conditions. The first two, 
used at the rate of 0.01 p.p.m. have also been shown to stimulate 
the plant to synthesize vitamin Bi. Solutions containing 2.5 
p.p.m. of riboflavin or 10 p.p.m. of ascorbic acid when added 
to plants growing in sand have decidedly stimulated leaf growth, 
the leaves of the treated plants being consistently coarser in 
texture, thicker, and darker in color than those of the un­
treated plants. This increased growth was associated with a 

106

TURF CULTURE

general increase in vigor of both top and root growth.

In field grown plants, root growth and resultant vegetative 
vigor has been increased by dipping the roots of the plants into 
solutions containing 1 or 10 p.pm. of vitamin Bi at the time of 
transplanting. The transplants were dipped into the solutions 
momentarily and immediately reset into the soil. Such treat­
ment not only resulted in helping the plants to become reestab­
lished more quickly but also in increasing the ultimate size and 
vigor of the plants. In some cases, time of flowering came 
earlier and size of fruit was increased. In other experiments, 
stimulation of growth has resulted from watering the soil in 
which plants were growing with a solution containing 0.1 
p.p.m. of vitamin Bi, and in a few cases stimulation has re­
sulted from actually spraying the foliage of field grown plants 
with such a solution.

Field grown plants have also been stimulated to increased 
growth by some of the synthetic hormones. Plants growing in 
rich soil did not show as much response as those growing in 
poor soil or sand which was watered with nutrient solutions. 
Some plants have been stimulated when watered with solutions 
of the synthetic compounds at concentrations as low as 0.01 to 
0.05 p.p.m. whereas others showed no effect at these concen­
trations and definite repression of growth with a concentration 
of 1.0 p.p.m. Another investigator reports that spraying seed­
lings with a solution of 1,800 p.p.m. of indole-acetic acid ac­
celerated both vegetative growth and flowering.

When it comes to stimulating the growth of plants by incor­
porating the synthetic hormones in the soil, the optimum 
dosage apparently varies with the substance used, the method of 
application, the composition of the soil, the climatic conditions 
and the age and kind of plant. More field work is necessary 

November, 1940

107

before any conclusions can be drawn or recommendations 
made concerning the practical use of growth substances on 
plants growing in soil.

Results with Seeds

The results from seed treatment are as contradictory as arc 
those from the treatments already described. Of 22 articles 
written in half a dozen countries, 12 give evidence showing 
cither increase in or acceleration of germination, increase in 
vegetative vigor, shortening of time required to come into 
flower, or increase in size and number of fruits produced. On 
the other hand, the remaining 10 articles give equally as con­
vincing evidence that germination and subsequent growth of 
seedlings were either not affected or were inhibited by similar 
seed treatments.

One laboratory in this country claims as a result of extensive 
work with oats, tomato, and wheat, that soaking seed in solu­
tions containing beta indole-acetic acid at concentrations not 
exceeding 10 p.p.m. increased the percentage of germination, 
whereas treatments of seeds with solutions containing 100 to 
200 p.p.m. of the same compound, retarded germination but 
eventually resulted in improving the seedling root system, 
hastening shoot growth, and possibly increasing the size of fruit.
As opposed to this, there are the results from another lab­
oratory in which seeds of 29 species including Kentucky blue­
grass and perennial ryegrass were used. The seeds were soaked 
for 24 hours in solutions of beta indole-acetic, beta indole- 
butyric, and alpha naphthalene-acetic acids at concentrations 
varying from 0.316 to 316 p.p.m. Seeds were germinated in 
the laboratory, in sand, and in the field, and the general con- 

108

TURF CULTURE

elusion had to be drawn that there was no effect on germina­
tion, vegetative growth of the seedlings, nor on time of maturity 
and flowering.

Others claim that dust treatment is more effective, safer, and 
easier to apply than solutions. In one series of investigations, 
the injury resulting to crop seeds from treatment with formal­
dehyde, copper sulfate, or hot water to kill fungus infections, 
was materially reduced by the addition of beta indole-acetic, 
alpha naphthalene-acetic, or phenyl-acetic acids in concentra­
tions varying from 0.01 to 5.0 p.p.m. Such treatments did not 
accelerate the time of germination, although applications of the 
indole-acetic acid in dust to cereal seed at the rate of 2 p.p.m. 
did result in increased yield of roots and tops.

In another laboratory the application of this dust containing 
1,000 p.p.m. of alpha naphthalene-acetic acid stimulated ger­
mination of tomato seeds, when applied at the rate of 1 ounce of 
dust to 9 or 10 pounds of seed. When combined with an im- 
merson of the roots of the seedlings for 2 minutes in solutions 
containing 10 p.p.m. of beta indole-butyric acid at the time of 
transplanting, the treatments resulted in hastening the time of 
flowering and increasing the yield of fruit. Similar but pre­
liminary treatments of Kentucky bluegrass and Chewing’s 
fescue seed gave indications of an acceleration of germination, 
increase in root growth, and greater drought resistance of the 
turf the following summer, but these results have not been 
confirmed.

So far, as stated in the article on page 110 of this issue, pre­
liminary tests which have been made by members of the Green 
Section staff on Kentucky bluegrass and perennial ryegrass seed, 
although made at the same rate and following the same method, 
have shown no such effects.

November, 1940

109

Absence o£ beneficial effect either on germination or subse­
quent growth and development of the seedlings has also been 
reported recently from an extensive series of dust treatments 
in which beta indole-acetic, beta indole-butyric and alpha 
naphthalene-acetic acids and a commercial preparation were 
applied to wheat and soybeans, although the plants were fol­
lowed until maturity. In fact, the final results indicated 
slightly lower values for the treated lots of seed. This the in­
vestigator feels may have been due to the talc, since talc alone 
produced corresponding results. He applied the dusts, which 
contained the growth substances in concentrations ranging from 
250 to 32,000 p.p.m., at rates varying from 1 ounce for 3 
pounds to 1 ounce for 30 pounds of seed.

Other workers, applying vitamin Bi and synthetic com­
pounds to agricultural seed actually obtained inhibition and in 
addition found double the number of mold- and bacteria- 
infected seedlings. Since many fungi and bacteria do not man­
ufacture their own growth substances and must therefore ob­
tain them from the medium on which they grow, it is not sur­
prising that, if present at all, they would be most abundant on 
the seeds coated with growth substances.

According to an article in Science, the vitamin content of 
grass leaves is much greater than that of any of the four standard 
classes into which all fruits and vegetables are divided. On an 
equal weight basis, grass leaves in general contain 10 times as 
much vitamin Bi and 25 to 250 times as much vitamin A as 
can be obtained from any of the vegetables or fruits.

110

TURF CULTURE

GROWTH SUBSTANCES ON TURF GRASSES

John F. Cornman and John W. Bengtson*

In the preceding article the fact has been emphasized that, 
although growth substances are unquestionably significant in 
the life of plants, they are almost universally distributed in 
plants and in organic matter in the soil and are therefore nor­
mally accessible to plants growing under favorable conditions. 
It is, therefore, only in cases where they are the factors which 
limit growth that stimulation can be expected from their 
application. Even then, the right substance must be applied 
at the proper concentration if germination or growth is to be 
stimulated.

In spite of these well recognized facts, however, voluminous 
publicity has been given to the claims of commercial firms as 
well as of enthusiastic investigators concerning the amazing 
results achieved by their application. Little cans or bottles of 
these amazing chemicals to be used as dust or in solution, and 
even seed which has previously been dusted with one hormone 
or another, are now available on the market under various trade 
names, and results little short of miraculous are promised to 
those who use them.

Exploratory investigations have been necessary to determine 
whether or not hormones are as effective on turf grasses as 
scientists have found them to be on some other plants, or even 
a fraction as beneficial as some enthusiasts claim they are. So 
far, the most uniform and best results appear to have been 
obtained with cuttings. It was only logical to suppose, there-

Horticulturist and Agronomist, respectively, of the United States Golf Association 

Green Section.

November, 1940

III

fore, that hormones might have some effect in accelerating the 
rooting of grass stolons, particularly those of the slow growing 
species such as Zoysia and velvet bent.

In addition, it appeared that some of these growth substances 
might prove to be valuable in midsummer when the failure of 
roots in turf is most pronounced. If, by adding them to turf 
at this time, root growth could be stimulated, injury from 
drought and other causes might be avoided. Also, it appeared 
that some of them might be useful in speeding up the germina­
tion of the seed of such slowly germinating grasses as Kentucky 
bluegrass when a quick establishment of turf is desired.

Therefore, during the past 2 years, the Green Section has 
been testing in a preliminary way the effects of a few of the 
growth substances on the rooting of stolons, root development 
of grass in turf, and the germination of grass seed. So far, no 
encouraging results have been obtained. The results have 
either been entirely negative or so inconsistent that no conclu­
sions could be justified either in favor of or opposed to their use 
in the establishment or maintenance of turf.

Hormones on Stolons

In three series of greenhouse experiments in the fall of 1938 
and the spring of 1939, stolons of “Zoysia iiiatrella, velvet bent, 
and the Washington and Metropolitan strains of creeping bent 
were used. The bent grass stolons, about 2 inches long, were 
taken from mature growth in the center of nursery rows and 
the Zoysia stolons from the old growth of plants growing in a 
warm greenhouse. Although an attempt was made to select 
uniform stolons, there was some difference in the number of 
nodes per stolon planted. The nodes on the Washington stolons 

112

TURF CULTURE

were much closer together than were those on the other stolons.
Solutions of the commercial product, Auxilin (a beta indole- 
butyric acid preparation) as well as of beta indole-acetic, alpha 
naphthalene-acetic and ascorbic acids were used. In the first 
two series the stolons were immersed in the solutions to a depth 
of % to 1V2 inches and in the third they were completely 
immersed. Treatments were made at greenhouse temperatures

Turf resulting from the use of Kentucky bluegrass seed which had been treated with 
various synthetic hormones, compared with that produced by untreated seed. Front 
row, left to right—talc dust containing 1,000 p.p.m. of indole-butyric acid, the same 
at 100 p.p.m., Rootone, Hormone powder, Auxan; center row—untreated seed, Trans­
plantone, Hormodin, untreated seed, Hormonized dust; back row—talc dust containing 
1,000 p.p.m. of naphthalene-acetic acid, the same at 100 p.p.m., thiourea, talc and 
untreated seed. The seeds were dusted thoroughly with the chemicals at the rate of 
I ounce of dust to 10 pounds of seed and were immediately planted in 4 by 4-foot plots 
on August 10, 1940. This picture, taken on September 3, shows no significant difference 
between the turf resulting from the planting of untreated seed and that resulting from 
the use of seed given any of these various treatments.

of 80 to 85 F. The time of treatment varied from 24 to 96 
hours in the first experiment, 12 to 48 hours in the second and 
4 to 24 hours in the third. For comparison purposes, similar 
stolons were soaked for equal lengths of time in tap water. 
Immediately following treatment, the stolons were planted in 
flats of sand. The bent stolons were kept in a relatively cool 
house and the Zoysia in a warm greenhouse at 80 to 85° F.

In the first two series of experiments the Auxilin was used 
according to directions at the rate of one-half measure to a 

November, 1940

113

pint of water and the other substances at the rate of 10 parts 
per million (p.p.m.) of water. In the final series the rates 
were doubled.

In the first experiment, 3 days after the last of the stolons 
were planted, counts were made of the number of nodes which 
had no roots and the average number of roots to a node. On 
the Washington bent, roots were found on three to five of the 
nodes of each stolon, Metropolitan bent developed roots on one 
to two of the nodes of each stolon and velvet bent usually 
formed roots at only one node on each stolon. In the second 
and third experiments, only velvet bent and Zoysia stolons were 
used and counts were made 12 and 4 days respectively after the 
last stolons were planted.

Stolons of Washington and Metropolitan creeping bent, 
velvet bent, and 'Zoysia matrella were used in the first experi­
ment. Those stolons which were planted with no treatment 
produced fewer roots per node and had a greater percentage of 
nodes with no roots than either the stolons which were soaked 
in water or in Auxilin solution, except in a few cases where 
the stolons had been soaked in the Auxilin for 96 hours. In 
general the stolons treated with Auxilin solution gave results 
similar to those soaked in water, but in some cases the number 
of roots per node was greater and the percentage of nodes with 
no roots was smaller than in the water-treated stolons. How­
ever, in an equal number of cases, the reverse of this was true, 
particularly following the Auxilin treatments for the longer 
periods of time.

After the results of the first scries had been obtained, the 
creeping bent stolons were dropped from all subsequent series 
of experiments, since such stolons normally start growth rapidly 
within a few days after planting. The Zoysia and velvet bent 

114

TURF CULTURE

stolons are much slower to establish themselves under field con­
ditions and therefore they alone were used in the second and 
third series of experiments. In these experiments beta indole- 
butyric, alpha naphthalene-acetic and ascorbic acids were used 
in addition to the Auxilin and water treatments of the first 
experiment. Much the same results were secured in the second 
series as in the first except that the stolons planted without 
treatment produced a lower percentage of nodes without roots. 
In fact in this series the untreated stolons were as good in this 
respect as were the treated ones. Also, the untreated stolons 
produced as many roots per node as the treated ones, and in 
some cases more. As in the first series, there was a great deal 
of variation in the number of roots per node, so that the differ­
ences in average numbers could not be considered significant.
In the third series of experiments, however, all of the treated 
Zoysia and velvet bent stolons gave results far superior to those 
with untreated stolons in that they had many more nodes pro­
ducing roots. All the treatments, including the water, doubled 
the number of roots per node in the Zoysia stolons. Most of 
the hormone-treated stolons of Zoysia produced more roots per 
node than did the water-treated stolons, but the number per 
node in all cases was so variable that differences in averages 
could not be considered significant. All of the velvet bent 
stolons which were treated in this series produced an equal or 
greater number of roots per node than did the freshly planted 
stolons. In most cases the chemical treatments produced a 
slight increase in the average number of roots per node, over 
water-soaked stolons, but again the individual numbers were 
so variable that this increase was not considered significant.

In May, 1938, stolons of Zoysia mafrella and Zoysia japonica 
and the roots of three selected strains of Kentucky bluegrass 

November, 1940

115

were soaked in Auxilin solution for a 24-hour period before 
planting in field plots. The solution used contained beta indole- 
butyric acid at the rate of 10 p.p.m. Comparable lots of stolons 
and roots were soaked in water for the same period of time. As 
a check against these soaking treatments fresh stolons of Zoysia 
and fresh bluegrass roots were planted at the same time.

Before being soaked, the Zoysia mafrella and Zoysia japonica 
stolons were stopped to two degrees of fineness, some being 
coarsely chopped and others merely shredded. In addition, 
some of the Zoysia japonica stolons were also finely chopped. 
Fresh stolons were chopped in the same way and planted with­
out soaking.

The stolons and roots were then planted in soil which was 
low in fertility and contained but little organic matter, and 
all plots received the same treatment following planting. The 
following fall estimates were made of the percentage of cover 
on each of the plots. The stolons which had been soaked in 
water had produced the densest turf in all plots except those 
planted with coarsely chopped Zoysia matrella stolons. In no 
case did the Auxilin-treated stolons or roots produce a denser 
turf than did corresponding material soaked in water, although 
in most cases the turf was denser than on those plots planted 
with fresh stolons. In some cases, however, the turf produced 
by fresh stolons was significantly superior to that produced by 
Auxilin-treated stolons or roots. In these cases the Auxilin 
apparently inhibited the growth of the grasses.

There were no significant changes in the density of the turf 
on any of the plots the following spring. During the summer 
there was no significant difference in vigor or drought resistance 
on any of the plots.

116

TURF CULTURE

Hormone-Treated Seed

In several series of experiments, Italian ryegrass seed and 
Kentucky bluegrass seed from two different sources were 
treated with talc dust containing various concentrations of 
several different hormones as given in the table on this page. 
The seeds were treated with the dust at the rate of 1 ounce of 
dust to 10 pounds of seed. Treatment simply consisted of

Table of Treatments Used on Seed of Italian Ryegrass and 
Kentucky Bluegrass

Key letter of
treatment

Compound
used

Proportions
in talc

Parts per
million (p.p.m.)

A
B
C
D
E
F
G
H
I
M
N

O

T

None
Talc alone
Alpha naphthalene-acetic acid
Ditto
Ditto
Beta indole-butyric acid
Ditto
Ditto
Rootone
Thiourea
Vitamin Bi (thiamin)
j Thiourea, 1 part 
}
/Napthalenc-acetic acid, 3 parts)
Hormodin A

Pure talc
1:2,000
1:1,000
1:250
1:2,000
1:1,000
1:250
As directed
1:1,000
1:1,000

500 p.p.m.
1,000 p.p.m.
4,000 p.p.m.
500 p.p.m.
1,000 p.p.m.
500 p.p.m.

1,000 p.p.m.
1,000 p.p.m.

1 :l,000

1,000 p.p.m.

As directed

coating the seeds with the dust by shaking them in a jar with 
the calculated amount of dust.

The seeds were then placed in sand, in flats or in petri dishes 
on filter paper for germination. In most of the experiments 
the petri dishes were kept in the dark in the laboratory, whereas 
in some of the Kentucky bluegrass experiments they were 
placed in thermostatically controlled germinators and sub­

November, 1940

117

jected to the optimum conditions of alternation of temperature 
and light. In still other experiments, Kentucky bluegrass seed 
was treated with hormones and sown in well-prepared seed beds 
in order to follow the effects of the hormones on the establish­
ment of turf.

Italian Ryegrass Seed

Duplicate lots of 50 Italian ryegrass seeds were dusted with 
hormone treatments A to O, inclusive, and the seed germinated 
in petri dishes in the dark in the laboratory. Germination 
counts were made after 48, 66, 72, and 96 hours. After 96 
hours, the length of tops and roots of the best 25 seedlings in 
each lot were recorded and the average compared with that for 
the best 25 seedlings coming from untreated seed. The experi­
ment was originally set up on January 31 and repeated on Feb­
ruary 5 and February 17. In general, results which might have 
appeared significant in one experiment were not duplicated in 
other experiments.

Although at the end of 48 hours there were indications of 
increased germination in some of the lots of treated seed, notably 
those treated with 1,000 p.p.m. of beta indole-acetic acid, such 
increases were scarcely evident after 66 hours. At the end of 
96 hours the untreated seed had germinated as well as any of 
the lots of treated seed. It was concluded that under these 
conditions and at the rates used, the final percentage of ger­
mination of Italian ryegrass seed was not significantly altered 
by any of the growth substances used. The stimulation in speed 
of germination which, in a few instances, appeared at the end 
of 48 hours was of such short duration that it could not be 
considered as worthwhile in practical large scale plantings of 
the seed.

118

TURF CULTURE

Measurements of the 25 best seedlings showed considerable 
variation in length of roots and tops in both the treated and 
untreated seed. A comparison of the averages of root length 
shows that in both experiments in which measurements were 
taken there was a significant increase in length following 
7 of the 14 treatments tried. However, the increase with talc 
dust alone was as great as or greater than that with any of the 
other treatments except for beta indole-butyric acid at 1,000 
p.p.m. and Vitamin Bi at 1,000 p.p.m. The only treatment 
which was accompanied by a significant increase in length of 
tops in both experiments was 1,000 p.p.m. of indole-butyric 
acid. It should be remembered that these seedlings were grow­
ing in petri dishes and were discarded after the ninety-sixth 
hour.

Kentucky Bluegrass Seed

In February, Kentucky bluegrass seed was dusted with hor­
mones, using treatments A to T, inclusive, as given on page 116. 
Immediately after treatment the seeds were planted in flats 
of sand and germinated in the warm greenhouse at 80° F. 
Germination counts were made from the eighth to the twen­
tieth day. Probably because of slight inequalities in watering, 
the results in duplicate flats varied over such a wide range that 
the significance of any differences which appeared was ques­
tionable. There was an apparent retardation in germination 
in evidence from the eighth to the twelfth or thirteenth day 
following treatments with talc alone, 1,000 p.p.m. and 4,000 
p.p.m. of alpha naphthalene-acetic acid, 1,000 and 4,000 p.p.m. 
of beta indole-butyric acid, Rootone and Vitamin Bi. How­
ever, by the twentieth day germination was approximately 
equal in treated and untreated seed.

November, 1940

119

In April, Kentucky bluegrass seed was again dusted with 
hormone treatments A, B, D, G, H, I and T. Duplicate lots 
of 200 seed were placed on blotters in petri dishes and germi­
nated under conditions of alternating temperature and light 
which are generally accepted as the most favorable for the 
germination of Kentucky bluegrass seed. Germination counts 
were made on the ninth, thirteenth, eighteenth, and twenty­
seventh days but no significant differences appeared between 
the percentage of germination of the untreated and any of the 
treated seed.

At the same time, bluegrass seed from the same sources was 
treated with the same hormones and planted in field plots. 
There was no apparent difference in the rates at which the 
bluegrass seedlings appeared following any of the treatments 
as compared with the plots planted with untreated seed. As 
the season progressed, crabgrass invasion was equally severe in 
all of the plots.

In mid-August of this year the experiment was repeated 
and at the time of writing (3 months after planting) all of the 
plots are practically equally covered with bluegrass seedlings. 
To date, therefore, the field experiments as well as the germina­
tion tests indicate that under our conditions and at the rates 
applied, alpha naphthalene-acetic acid, beta indole-butyric acid, 
Vitamin Bi, Rootone and Hormodin A have had no significant 
effects in increasing the speed of germination or the total ger­
mination when applied to Kentucky bluegrass seed.

Vitamin Bi on Turf

Turf of redtop (Agrostis alba) was grown on soil from 
which the topsoil had been removed to a depth of 1 % inches. 
Duplicate 4- by 4-foot plots of this turf were watered three 

120

TURF CULTURE

times a week with 2^2 gallons of a solution containing 0.1 
p.p.m. of Vitamin Bi. Comparable plots received the same 
amounts of water; this was enough to soak the ground thor­
oughly. The treatments, begun in June, were continued until 
early in September. No effect of the treatment could be 
observed, either during the period in which the solutions were 
applied or until the plots were abandoned the following May.
In another experiment, duplicate 4- by 8-foot plots of two 
different stolon-propagated strains of creeping bent have been 
watered with a solution of Vitamin Bi. On these plots 1 
gallons of a solution containing 0.2 p.p.m of Vitamin Bi were 
used three times a week during the critical month of August 
when root growth on bent normally is at the lowest point of 
the season. No effect, of the treatment on the grass was 
discernible.

From the results of the preceding tests in which stolons, seed, 
and turf of various grasses were treated with numerous prep­
arations of different types of growth substances, there appears 
to be little or no likelihood of helping grass in a practical way 
with any of the growth substances now available.

Mowrah meal used on turf as an earthworm expellant is made 
from the beans of the Bassia latifolia tree, which grows to a 
height of 40 to 50 feet in tropical India. The tree is strictly 
tropical and probably cannot be grown anywhere in the United 
States. The wood is tough and the beans yield an edible oil. 
Mowrah meal is made from the cake left after the oil is ex­
pressed. The meal is not suitable for feed but is used as a fer­
tilizer, and when finely ground as an earthworm expellant. It 
is used also to stupefy fish.

November, 1940

121

WHAT OTHERS WRITE ON TURF

In this department will be given the substance of research in the various 
fields of scientific investigation which seems to have a definite bearing on 
turf improvement. The articles will summarize results of recent investiga­
tions made in various parts of the world. They are not published here as 
recommendations but simply as information for our readers and as sugges­
tions which may have practical applications in many situations. Where the 
Green Section’s tests or the information it has obtained from other reliable 
sources in this country substantiates or contradicts the results obtained by 
other investigators, comments to that effect may be included as a guide for 
our readers. In all other cases the reader will receive in brief the results and 
conclusions as given in the original papers.

GERMINATION OF CARPET GRASS 
SEED

E. H. Toole and V. K. Toole of 
the United States Department of 
Agriculture reported in the Journal 
of the American Society of Agro­
nomy the results of their studies on 
the germination of carpet grass seed 
under laboratory conditions. Fresh 
seed was found to germinate about 
90 percent. The same seed after be­
ing stored in the laboratory for 3 
years germinated 81 percent. On 
the contrary, seed which had been 
stored for 1 year in a warehouse 
in the region of production in Mis­
sissippi showed only 67 percent 
germination at the end of the first 
year, S3 percent after the second 
year, and only 5 percent at the end 
of the fourth year. These figures 
would seem to indicate that the con­
ditions under which carpet grass seed 

is stored profoundly influence the 
ability of that seed to germinate.

Several temperatures were tried in 
order to find the best temperature at 
which carpet grass seed will germi­
nate. The best results were obtained 
with an alternating temperature of 
68° F. for 17 hours and 95° for the 
remaining 7 hours.

MILKY DISEASE OF JAPANESE BEETLE 
GRUB

Milky diseases A and B of grubs 
of the Japanese beetle are caused by 
bacteria which grow and produce 
spores in large numbers in the blood 
of living grubs. It is the spores 
which give the blood of living grubs 
its characteristic milky appearance. 
As many as 20 billion spores have 
been found in the blood of a single 
grub. In recent issues of the Journal 
of Economic Entomology, Ralph T.

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TURF CULTURE

White and S. R. Dutky of the Bureau 
of Entomology and Plant Quaran­
tine of the United States Department 
of Agriculture have described experi­
ments demonstrating the possibility 
of using these bacteria to control 
the grubs in turf.

Grubs are inoculated with the bac­
teria and then incubated in soil kept 
at a temperature of 86° F. for 10 
to 12 days, at the end of which time 
the grubs each contain between 1 
and 3 billion spores, depending on 
the number of bacteria with which 
they were inoculated. These dis­
eased grubs are then used to inoculate 
the turfed areas in which the grubs 
are to be controlled. When they 
are to be used immediately, the dis­
eased grubs usually are ground and 
the resulting material suspended in 
water. If it is to be stored for future 
use, the ground material is mixed 
with talc and dried. The prepared 
infectious material is introduced into 
the soil in localized spots or dis­
tributed over the entire area by 
spraying the dilute suspension of 
spores in water or by mixing the talc 
preparation with enough sand or 
sieved soil to give sufficient bulk to 
spread like fertilizer. In some cases 
living inoculated grubs have been 
introduced on the plots, and even 
infected soil has been successfully 
used for inoculation purposes.

Dosages of 25 to 1,500 million spores 
per square foot of turf have resulted 
in a reduction of healthy grubs to 
the point where no serious injury to 
turf has occurred.

The writers cite an experiment at 
Cape Charles, Virginia, in which the 
grub population was reduced from an 
average of 121 to 6 healthy grubs 
to a square foot during the period 
from July to September, 1939, 
whereas in the untreated areas 74 
healthy grubs to a square foot were 
present at the end of that period.

The spores have been shown to be 
resistant to extreme cold as well as 
to excessive moisture or drought and 
consequently remain living in the 
soil in spite of most adverse condi­
tions. To quote from Mr. White’s 
article, "Data indicate that when 
once the soil becomes highly infec­
tious with the causal agent, no sub­
stantial population of Japanese beetle 
larvae can exist. Serious turf injury 
can thus be reduced, if not entirely 
prevented, by the introduction of the 
causal agent of type A milky dis­
ease. A rapid build-up and spread 
of the organism may be expected 
when a reasonably heavy larval popu­
lation occurs.”

Experimental results apparently 
indicate that it should be possible to 
prevent severe turf injury from the 
Japanese beetle grubs by introducing 

November, 1940

123

the bacteria into the soil before the 
Japanese beetle arrives, or shortly 
after it has reached a given area and 
before numbers of grubs sufficient 
to cause severe turf injury have be­
come established.

The Bureau of Entomology and 
Plant Quarantine, however, empha­
sizes the fact that this method of 
controlling the Japanese beetle is still 
in its early experimental stages. The 
material is being used only by the 
Department of Agriculture coop­
erating with official State agencies 
in this work. No material is avail­
able for general use at this time.

HARVESTING BUFFALO GRASS SEED
Buffalo grass is an important grass 
in the dry regions of the United 
States, but seed has been difficult to 
obtain. The seeds are borne on very 
short stalks, so that they cannot be 
reached by mowers, and hand gath­
ering is too costly.

H. O. Hill of Texas has recently 
described in the Journal of the 
American Society of Agronomy a 
machine by which a man can collect 
about 1 pound of seed an hour. The 
cutter bar and the roller are removed 
from an ordinary lawn mower and a 
grass catcher is attached. A canvas 
shield is fixed over the lawn mower 
and the shield extends well up the 
handle bar. The rotating cutter 

blades then clip the seeds and beat 
them back into the catcher or against 
the shield, which in turn deflects 
them into the catcher.

The removal of the cutter bar re­
duces the amount of grass hay caught 
along with the seed, so that all but 
the finer particles of trash can be 
quickly removed by hand. The dirt 
can be removed by floating the seed 
out in a tub of water. This cleaning 
is not necessary when the collector 
himself is to use the seed.

SEED FORMATION IN KENTUCKY 
BLUESGRASS

In the April, 1939, issue of Turf 
Culture, page 144, investigations 
were reported which indicated that 
in Sweden the formation of seed 
without fertilization was found to be 
common in Kentucky bluegrass. E. 
Akerberg, whose work was mentioned 
in connection with that report, has 
since published in Hereditas a more 
detailed account of his work with 
Kentucky bluegrass.

According to him, it is possible to 
determine whether seed was set apo- 
mictically (without fertilization) or 
sexually (as a result of fertilization) 
by examining the progeny resulting 
from seed set in a single panicle. 
When the resulting seedlings exhibit 
a constancy in characteristics and 

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TURF CULTURE

resemble the mother plant, the con­
clusion is drawn that the seed was 
formed apomictically. On the other 
hand, when they are aberrant—that 
is, deviate from the typical plant— 
and exhibit striking variations among 
themselves and from the mother 
plant, it is safe to say that the seed 
was produced sexually. Microscopic 
studies of the number and nature of 
the chromosomes have verified the 
conclusion that lack of variability is 
associated with apomictic seed forma­
tion and that variability is associated 
with sexual seed formation.

Akerberg examined 703 plants of 
Kentucky bluegrass grown at the 
Plant Breeding Institution at Wei- 
bullsholm. These had been obtained 
either by isolation, free-flowering, or 
cross-pollinating of strains which 
were considered to be apomictic. Of 
these 703 plants only 9.2 percent 
were aberrants. In other words, 90.8 
percent of the plants had come from 
seed which was produced apomic­
tically.

Akerberg then studied Kentucky 
bluegrass elsewhere in Sweden and 
also in Norway and Germany. In 
these studies he considered the plants 
resulting from the seed of a single 
panicle as families. He grew 44 such 
families. Among the 185 plants ex­
amined belonging to these 44 fami­
lies only 5.9 percent were aberrants 

and these were limited to seven of 
the families. Therefore, in nature he 
found 94.1 percent of the seed he 
examined was produced apomic­
tically. These figures indicate that 
apomictic seed formation is common 
in other strains as well as in those 
cultivated at Weibullsholm.

CHLOROPICRIN MAY CONTROL 
SOME PLANT DISEASES

Treatment with chloropicrin is 
known to aid in the control of weeds 
by killing a large proportion of the 
weed seed in soil. This aspect of the 
problem has been discussed in Turf 
Culture for January, 1939. F. L. 
Howard and F. L. Stark, of the 
Rhode Island Experiment Station, 
writing in Seed World also call at­
tention to this weed killing prop­
erty of tear gas and point out that 
the susceptibility of weed seed to 
treatment varies, some being more 
susceptible than others.

They also give data showing that 
many soil diseases may be controlled 
and plants consequently make a 
better growth and yield larger crops 
after the soil has been treated with 
chloropicrin. Treatments were made 
in the field at rates of 201, 217 and 
369 pounds to the acre and the ma­
terial put into crowbar holes made 
1 5 inches apart. Onions yielded 43 
percent more in treated than in un­

November, 1940

125

treated soil, egg plants 206 percent 
more and millet 46 percent more. 
Other crops also yielded much better 
after the soil was treated.

The same men with J. B. Smith 
published in Phytopathology the re­
sults of a study on the use of chloro­
picrin for the control of nematodes 
in tomato greenhouses. They found 
that chloropicrin and carbon disul­
fide injected into the soil gave re­
sults that compared favorably with 
those secured by steam sterilization. 
Dosages of chloropicrin which de­
layed initial nematode infection until 
an extensive root system had de­
veloped were sufficient to give nor­
mal yields.

P. A. Young, of Texas, writing in 
Phytopathology, reported that chlo­
ropicrin injected into sandy soil at 
rates of 2 50 to 450 pounds to the 
acre usually controlled all or most 
of the Fusarium wilt troubles with 
tomatoes, and the root nematode of 
watermelons, besides killing weed 
seeds such as those of Johnson grass, 
crabgrass and pigweed.

A Russian investigator, Mr. Sche- 

petilnikova, found that flax sick soils 
treated in the laboratory with chlo­

ropicrin and tested periodically 

showed no fusarium or Asterocystis 

spores. The beneficial effect extended 

into the following year.

, THE LEAF CUTTING ANT
While there have been no reports 
of the leaf cutting ant damaging 
turf, E. V. Walter, L. A. Seaton and 
A. Mathewson in the United States 
Department of Agriculture, Cir­
cular 494, state that few plants are 
immune to attack. Reports have 
been received of damage to cereal 
and forage crops in Texas by the 
species, Atta texana. It is not im­
possible, therefore, that this ant 
may attack turf.

The ant cuts green vegetation, car­
ries it into its nest and on this de­
caying vegetation grows a crop of a 
special fungus on which it feeds. 
The ants are good gardeners and 
carefully keep down all fungi 
not wanted. The ants in a nest 
range in size from the queens through 
fighters to the smallest workers. The 
latter are the gardeners. Larger 
workers gather pieces of leaves and 
once they start on a particular tree or 
crop they seldom let up until all the 
foliage is stripped.

The best control so far worked out 
is with carbon disulfide. Under 
Texas conditions the authors advise 
that this be injected into the nests 
between late February' and early 
April as during this time the queens 
are likely to be in the center of the 
nest. Later they leave the nest and 
establish homes of their own, increas­
ing the centers of infection.

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TURF CULTURE

OUR LETTER BOX

The Green Section receives numerous inquiries concerning local turf 
problems and is always glad to reply to them. With the hope that some of 
these questions and answers may be helpful to others besides the original 
correspondent, a few of them will be published. While most of the answers 
will have a general application, it should be remembered that each recom­
mendation is intended for the locality designated at the end of the question.

Control of snowmold.—The end 
of our playing season comes rather 
early in the year, usually at the end 
of September. The ground gradually 
becomes frozen and sometimes we 
have snow covering our greens from 
the second week in October to the 
second or third week in April. When 
the snow is melting in the spring, 
some of our turf is covered in spots 
with a cobwebby fungus growth. 
The spots are from 6 to 9 inches in 
diameter and the grass usually dies. 
These spots may expand and merge 
and eventually the turf takes on a 
mottled or patchwork effect. Is this 
snowmold and what is the best 
remedy? (Ontario.)

ANSWER. — Undoubtedly the 
damage you describe is due to snow­
mold. The most effective control of 
snowmold involves the following 
principles:

1. Use no winter cover, such as 

straw or leaves.

2. Provide for a rapid run-off of 

water as the snow melts.

3. Use resistant grasses. Seaside 
bent and fescue are very susceptible.
4. Protect the turf by fall appli­

cations of corrosive sublimate.

5. Avoid late summer or early fall 
applications of fertilizers, which tend 
to stimulate a late growth of grass.

Resodding a green of established 
Bermuda grass.—The area on which 
we intend to build a green is already 
well sodded with Bermuda grass. 
This grass is used exclusively in this 
section for sodding greens. Must we 
dig up this old grass and replant or 
can we keep mowing it down close 
until the tender shoots start to grow? 
(Texas.)

ANSWER.—If the area you in­
tend to use for turf is now well cov­
ered with Bermuda grass, keep it 
mowed closely and new shoots should 
soon thicken the turf so that it will 
be satisfactory for putting green 
purposes. The process can be has­

November, 1940

127

tened by applying sulfate of am­
monia at the rate of 5 to 10 pounds 
to 1,000 square feet. Apply when 
the grass is dry and water it in. 
After mowing it would be well to 
rake the ground severely with a 
garden rake or topdress liberally with 
fresh soil. If necessary to thicken 
the sod, the surface can be leveled 
and Bermuda grass seed sown. The 
turf should then be kept well watered 
for a time.

Bumpy turf.—Our greens were 
planted vegetatively with Washing­
ton bent 7 years ago. This season 
the players are complaining that the 
greens are bumpy and that the sur­
faces are very uneven. Will you 
please advise us how often the greens 
should be topdressed and give us 
other information on the accepted 
practices of maintaining this grass? 
(New York.)

ANSWER.—From the standpoint 
of growth of grass, topdressing is de­
sirable but by no means necessary. 
From the putting standpoint, how­
ever, topdressing is distinctly desir­
able since it provides a true putting 
surface.

It is well to topdress greens when­
ever the surfaces become uneven. 
This occurs more frequently on some 
types of soil than on others. Golf 
courses are definitely affected by the 

amount of play. No set rule can 
therefore be laid down as to the fre­
quency of topdressing that is best 
for any set of greens. Sometimes 
topdressing is applied to surfaces that 
are badly matted and the topdressing, 
therefore, has no chance to work 
down into the lower layers. In such 
cases the more often greens are top- 
dressed the more irregular they may 
become.

In handling Washington bent 
greens it is a common practice to 
rake or brush the greens severely 
to remove as much of the excess 
growth as possible and thereby enable 
the topdressing material to work 
down into the low areas where it is 
matted in. If there is a tendency 
to produce an excessive amount of 
mat the raking or brushing process 
may be repeated throughout the sum­
mer every week or two. In the sum­
mer, rakings or brushings should be 
very mild, however. Topdressing is 
applied as needed and thoroughly 
matted in.

Coarseness of redtop.—Can you 
tell us if redtop will start out coarse 
in the spring and gradually get finer 
because of cutting as the summer 
progresses? (Colorado.)

ANSWER. — Redtop ordinarily 
does not get finer during the sum­
mer. At seeding time redtop and 

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TURF CULTURE

many of the bents try to send up 
flower heads even in closely cut 
turf. The leaves attached to these 
flowering stalks are especially coarse. 
These will usually disappear by mid­
summer although the regular leaves 
of the redtop will remain coarser 
than those of some of the other turf 
grasses.

Slime mold on grass.—On our 
lawn there have suddenly appeared 
irregular shaped growths which are 
taffy-colored at first and later be­
come black. When the lawn mower 
goes over the grass a fine black soot­
like material blows over the lawn. 
Will you please tell me what this 
growth is and how to get rid of it? 
(Ohio.)

ANSWER.—The soot-like devel­
opment which you describe is one of 
the fungi known as slime mold. It 
is a superficial growth which grows 
on grass when the conditions of tem­
perature and moisture are favorable 
for its development. The black 
dust-like material consists of very 
fine grains which are the spores and 

act as seed to propagate the fungus. 
Ordinarily the fungus grows in the 

soil and is not detected until it sud­

large irregular, light brown or grey 
masses or tiny steel grey bodies, 
sometimes hundreds of them on a 
single grass blade or clover leaf. 
Both types of fruiting bodies mature 
rapidly and break open, exposing the 
masses of black spores inside. When 
mowers run over these areas they 
spread the spores over a large area 
of turf. Ordinarily if you take a 
hose at that stage you can rinse this 
black dust off the grass and you will 
find that it causes no permanent 
damage to the grass.

Commercial ferfilizer vs. manure 

for fopdressing furf.—We have had 

quite a bit of discussion about 

whether it is better to use sewage 

sludge or cow or horse manure when 

top-dressing the fairways on our 

course. We have no means of steri­

lizing the manure and must spread 

it by hand. We should be grateful 
for any advice you can give us. 
(Florida.)

ANSWER.—All our experimental 
work has shown that for fairway 
fertilizing it is better to use sewage 

denly sends up the fruiting bodies 

sludge or some commercial fertilizers 

which you have observed. At first 

these fruiting bodies may be the 

than cow or horse manure as top­
dressing.