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Cleansing of Eating and Drinking Utensils. (Ralph L. France.) Field studies
have been made of the methods employed in the cleansing and sanitization of
eating and drinking utensils in public establishments throughout this area. Bac-
teriological examinations indicate that these methods are not satisfactory. Work
is being continued on this project.

Laboratory Service. (Ralph L. France.) Following is a list of the types and
numbers of examinations made during the past year.

Milk (bacteria counts) 895

Ice cream (bacteria counts) 153

Water 124

Eating and drinking utensils 120

Miscellaneous 106

Butter fat: 71

Solids: 22

Mastitis: 12

Burlap: 1

Total 1,398



ANNUAL REPORT, 1941 21

DEPARTMENT OF BOTANY

A. Vincent Osmun in Charge

Diseases of Trees in Massachusetts. (M. A. McKenzie and A. Vincent
Osmun.)

The Dutch Elm Disease Problem. For several years in the cooperative program
for the study of the Dutch elm disease in Massachusetts, intensive effort has
been concentrated in Berkshire County as new stations for the causal fungus,
Ceratostomella ulmi (Schwarz) Buisman, were reported in nearby New York and
Connecticut. During recent years, the circulation of numerous false reports
that the disease was present in Massachusetts, and even the publication of
photographs of trees removed because they were affected by the disease have
sometimes confused and alarmed the public. At least a part of the confusion
has resuhed from the failure to distinguish between the fungus which causes
the Dutch elm disease and the principal carrier insect, Scolylus miiUistriatus
Marsh., which is a bark beetle infesting certain areas of Massachusetts, notably
southern Berkshire County and the region east of Worcester County.

The spread of the disease into Massachusetts was delayed for several years
by the eradication of diseased trees in the adjoining states, although early in
1941 it was pointed out^ that elms in southwestern Massachusetts were in im-
mediate danger from the encroachment of the disease on Berkshire County
from New York on the west and Connecticut on the south. However, in Septem-
ber 1941 the first Massachusetts elm in which the presence of the disease could
be officially established, was eradicated вАФ a young tree about 20 feet in height
growing on private property in the town of Alford. Typical symptoms of foliage
wilting and streaking of the woody parts were present. The Scolytus beetle
was not found in the tree but has been observed in the town. In the vicinity
of the diseased tree and elsewhere throughout Massachusetts, hundreds of other
trees showing symptoms macroscopically indistinguishable from those of the
Dutch elm disease were checked in field and laboratory studies during the past
year, but no additional trees with the disease have been discovered. The work of
the organized project of this Station in collecting and studying specimens from
suspected trees has been supplemented by other public and private groups and
by individuals, including the Massachusetts Department of Agriculture, the
United States Department of Agriculture, the Massachusetts Forest and Park
Association, town and city tree wardens, employees of other municipal and state
departments,- arboriculturists, public utilities, and private citizens.

The most constructive procedure in attempting to check the spread of the
disease is the removal of all elm material in such a condition as to be attractive to
carrier beetles. The quantity of such material present in any location may be
related to a number of factors, as in southern Berkshire County where drouth
injury and repeated attacks of leaf-chewing insects have seriously weakened
many elms in such a manner as to make them suitable for infestation by beetles;
and the destruction of this material will doubtless prove of inestimable value in
limiting the population of carrier beetles of the Dutch elm disease fungus.

Other Tree Problems. Sixty-nine diseases of thirty-four species of trees, in-
cluding eleven diseases of elm were identified from more than 500 specimens and
inquiries received during the year. The Cephalosporium wilt of elm was reported
from 21 municipal'ties in which no previous cases of the disease were reported,



'McKenzie, Malcolm A. The Dutch elm disease problem in Massachusetts. Published in
"Progress Report including Transcriptions of Certain Papers presented at the Eighth Annual
Five-Day Short Course for Tree Wardens and Other Workers with Trees," M. S. C, March 28,
1941.



22 MASS. EXPERIMENT STATION BULLETIN 388

making a total of 173 cities and towns in which the disease has been found in
Massachusetts. Also, a fungus, Verticilliuni sp., was isolated from elms in 8
communities in which it was not previously known, and reports show a total of
96 municipalities in which this fungus has been found in woody plants in Massa-
chusetts.

The extended period of dry weather during the summer of 1941 was a serious
cause of tree injury, and therefore, additional trouble associated with winter
injury may be expected from this source next year, especially in the case of ever-
greens, which commonly experience winter injury even in years of normal rainfall.

Because of outbreaks cf elm pests during the summer of 1940, a circular^ was
prepared this year and distributed to meet the demands for information on the
subject.

A disease known as bleeding canker of hardwoods has been reported to be
increasing in New England and, at least under certain conditions, the writers
have seen cases in which attempted remedies have caused more damage than
the fungus. A fungus, Phytophthora cactorum, has been described* as the cause
of the disease, and an organism believed to be the same fungus has been isolated
by the writers from elm, maple, beech and oak in Massachusetts, although
evidence of serious disease in the host was not always conspicuous. A possible
injection treatment emplojnng "Helione Orange" and requiring skilled tech-
nicians has been described^ following preliminary experimental work. Critical
evaluation of the results may be possible at seme later date; for the present,
however, specific recommendations cannot be made.

Current miscellaneous activities of the project included the preparation of
parts of the program of the annual Five-day Short Course for Tree Wardens,
the compiling of a progress report, ^ the discussion of wood-destroying fungi^ at
the Eastern Pest Control Operators' Conference, and the preparation of news-
paper press releases.

The Importance of the Investigatio7i of Tree Diseases in National Defense.
In this brief outline of phases of the project which have expanded in relation to
national defense, it should be pointed out that it is not possible to distinguish
sharply between basic and emergency activities. In fact, none cf the following
activities are completely new to the project, but increased demands on the part
of the public have been classified under three arbitrarily selected groupings
among which there is considerable overlapping.

1. Housing projects, new real estate developments, and increased prosperity
in general have resulted in increased interest in trees and tree diseases around
homes and along streets and highways.

2. As lumbering operations near the point of demand for wood have in-
creased, owing to the necessity for curtailment of transportation costs, supply
of labor, shortage of materials, etc., certain types of forest-tree diseases have
increased both in the forest and in nearby ornamental trees. The practice of
cutting only mature forest trees as a crop maintains a highly desirable, relatively
stable biological balance, but only about 5 percent of the nation's forests are
operated on this basis in normal times and no hope for an increase in yield-basis
operations can be held in the present emergency.



''McKenzie, M. A., and Becker, W. B. Timely spraying protects elms against midsummer
defoliation. Amherst, 1941.

'Howard, F. L., and Caroselli, N., Phytopathology 30:11. 1940.

^Howard, F. L. Science 94:2441 :345. October 10, 1941.

^Transcriptions of certain papers presented at the eighth annual five-day short course for tree
wardens and other workers with trees. Amherst, March 24-29, 1941.

'McKenzie, M. A. Wood decay fungi, published in the "Proceedings of the First .\nnual Eastern
Pest Control Operators' Conference," Amherst, January 13, 14, and 15, 1941.



ANNUAL REPORT, 1941 23

3. Fungus attack on trees does not end when the tree becomes lifeless wood,
although proper seasoning and protective treatment will greatly prolong the
life of wood in service. Because of the neglect to consider damage from wood
decay fungi and related factors, extensive damage to wooden structures has
already been observed and additional trouble may be expected.

For the most part, it is common knowledge that tree disease investigations are
essential for defense, but the importance of constant vigilance against tree dis-
eas s has been stressed^ in connection with work on tree problems during 1941.
Insidious inroads on public wealth by disease fungi would be rampant if the
prosecution of essential disease investigations were relaxed in favor of what,
for a thoughtless moment, might appear a greater defense priority need. Disease
investigation is primary, vital defense, and in retrospect it is basic to the strong
position which this nation holds today.

Damping-off and Growth of Seedlings and Cuttings of Woody Plants as Affected
by Soil Treatments and Modification of Environment. (W. L. Doran.) An Ex-
I)eriment Station bulletin on some of the more imniediatel)-' useful results of work
done under this project has been published^ and is now in considerable demand.

Work on the vej;etative propagation of white pine is being continued. Cut-
tings rooted in larger percentages and responded more to treatments with root-
inducing substances, if they were made with the basal cut at the base of the
current year's wood rather than at the base of wood two years old. They rooted
better in sand-peat or sand than in sandy soil, and, in one experiment, treated
cuttings rooted better in sand than in sand-peat. Best results with January
cuttings, 67 percent rooting, were obtained from treatment with indolebutyric \
acid (200 mg./l., 5 hr.), but there was 58 percent rooting of cuttings treated with
naphthaleneacetic acid (100 mg./l., 4hr.), and only 13 percent rooting of the
untreated cuttirgs. Results were less good if cuttings w^ere taken in summer,
fall, or earlier in the winter.

Much attention was given to the rooting of cuttings of hemlock and a paper
was published^ on that subject. Cuttings of hemlock, taken in November, rooted
best, 100 percent in fourteen weeks, after treatment with indolebutyric acid
(100 mg./l., 24 hr.), but naphthaleneacetic acid was also very effective and there
were indications that it is sometimes even more effective than indolebutyric
acid. Results obtained justify the suggestion that propagators working with
late-fall cuttings made of wood of the current year make some use of naphtha-
leneacetic acid although, with cuttings made with the basal cut at the base of
wood two years old, indolebutyric acid in relatively high concentrations was
very effective.

A note was published^ on the rooting of cuttings of umbrella-pine, another
species which is usually considered difficult to propagate in this way. They failed
to root or to root at all well, treated or not, if taken in September or October;
but if taken in January, they rooted 92 percent after treatment with naphtha-
leneacetic acid (100 mg./l., 2 hr.), decidedly less well if treated with indolebutyric
acid. Rooting of December cuttings of Poncirus trijoliata was also much more
improved by naphthaleneacetic acid than by indolebutyric acid, and lilac cut-
tings responded better to naphthaleneacetic than to indolebutyric acid. But



'McKenzie, Malcolm A. Municipal shade tree problems in national defense. Published in
"Proceedings of the Annual Meeting of the Mass. Tree Wardens' Assn.," February 13, 1941.

'Doran, William L., The propagation of some trees and shrubs by cuttings. Mass. .^gr. Expt.
Sta. Bui. 382, 56 pp. 1941.

-Doran, William L. Propagation of hemlock by cuttings. Amer. Nurseryman 74: 6: 18-19.
1941 (Contribution No. 413.)

^Doran, William L. Propagation of umbrella-pine by hormone-treated cuttings. Florists Ex-
change 97:9:9. 1941. (Contribution No. 414.)



24 MASS. EXPERIMENT STATION BULLETIN 388

indolebutyric acid gave much better results with cuttings cf Hinoki cypress than
did naphthaleneacetic acid.

Untreated cuttings of Clematis lanuginosa var. Candida and the Clematis variety
Ramona rooted at least 80 percent if taken in mid-July, less well if taken a month
earlier or later, and their rooting was not markedly improved by treatment with
indolebutyric acid.

Cuttings of Daphne Cneoriim, taken in July, rooted 75 percent without treat-
ment, more than 90 percent after treatment with Hormodin No. 1, and less well
than the checks if treated for several hours with solutions of root-inducing sub-
stances cr with water only.

Up to 24 hours' treatment with water, only, did not affect rooting cf hardwood
cuttings of Juniperus com munis var. stricta, Ilex crenata var. Helleri, hemlock,
or mock-orange.

Best results with these cuttings of mcck-orange (100 percent rooting in five
weeks) followed treatment with Hormodin No. 3. Cuttings which were given a
short (six hours') treatment with naphthaleneacetic acid rooted more slowly
although also to the extent of 100 percent, a decided improvement over results
with untreated cuttings for they rooted only 58 percent.

Cuttings of the Rhododendron variety Cunningham's White developed better
roots if treatment with a sugar solution (3.0 percent) followed treatment with
indolebutyric acid. But treatments with sugar solutions, whether applied before,
after, or with root-inducing substances, failed to increase the percentages of root-
ing of fall cuttings of that plant or of Gordonia and Daphne Cneorum.

Study of Diseases of Ornamental Herbaceous Plants, Caused by Soil-Infesting
Organisms, with Particular Attention to Control Measures. (W. L. Doran.)
Formaldehyde properly diluted may, it was found, be applied safely and effec-
tively to soil immediately after seeding without determining the e.xact rate of
application of the solution to each square foot of soil surface. That, however,
is most commonly 1 to 13^ pints per square foot. Formaldehyde, so applied to
soil immediately after seeding that each square foot received 2 cc. of it, controlled
damping-ofT of Delphinium, Viola, and sweet pea well and equally well whether
each square foot received 0.75, 1.25 or 2.0 quarts of the solution.

Formaldehyde, 4.9 cc. (1 teaspconful) in 1 gallon water or, what is the same
thing, 1 tablespoonful in 3 gallons, gave perfect and safe control of damping-oflf
cf Nemesia, columbine. Zinnia, China aster, hollyhock, Phlox, Nicotiana, Ver-
bena, Lobelia, and two species of Dianthus when it was applied to soil immediately
after seeding without determining exactly what volume of the solution was
applied per square foot. This method^ is noteworthy for its simplicity, .since
there is no working of chemicals, such as dusts, into soil, no waiting, and, because
soil must usually be watered immediately after seeding, not a single additional
operation is involved.

When formaldehyde 0.5 teaspoonful in 1 gallon of water was thus applied im-
mediately after seeding, it gave fair but less complete control. If this very
dilute solution of formaldehyde was applied more than once, that is immediately
after seeding and again once or twice or three times more at intervals of two
days, there was injury to Scabiosa by three applications, not by two, and to
China aster by four applications, not b\' three. But results with these repeated
applications were not promising, for damping-off was just as well controlled by
one application immediately after seeding.

Formaldehyde applied to soil not previously disinfected improved the growth
of Calendula, Zinnia, and China aster. But when formaldehyde (2 cc. per square



'Doran, William L. A simple control of damping-off. Florists Exchange 96:21:10. 1941. (Con-
tribution No. 408.)



ANNUAL REPORT, 1941 25

foot) was applied to soil which had been steamed five days previously, there was
some injury, as compared with growth in steamed soil, and there was certainly
no improvement in growth as compared with growth in untreated soil. It is
concluded that the stimulatory effect of formaldehyde on growth is due prin-
cipally or wholh- to its freeing the plants of the retarding effects of parasitic soil
fungi, and it is concluded further that formaldehyde may be dangerous, as re-
gards its effect on some plants, if applied to soil recently steamed.

Spergon (2.7 gm. per square foot) gave fair control of a root-rot of sweet pea
seedlings when applied to soil one day before seeding, and there was no injury.
But it gave no protection if seeds were sowed thirty days after soil treatment.

Copper oxylate applied to the surface of soil after seeding failed to prevent
damping-off of any species.

Semesan (1.1 gm. in 1.2 quarts water per square foot), applied to the soil sur-
face before seeding but not worked into the soil, was not injurious, controlled
damping-off fairly well although not completely, and increased by 27 to 100
percent the numbers of seedlings of marigold, Scabiosa, pansy, and sweet pea
which lived. Results were less good when the dry Semesan was worked into the
soil, fcr it was then apparently not sufficiently concentrated near or at the soil
surface.

Chemical Soil Surface Treatments in Hotbeds for Controlling Damping-off of
Early Forcing Vegetables. (\V. L. Doran, E. F. Guba, and C. J. Gilgut.) Es-
pecial attention was given to the possible use of ammonium hydroxide and
ammonium sulfate as soil disinfectants.

Ammonium hydroxide, 12 cc. per square f'oot of soil surface, controlled damping-
off fairlj' well and without significant injury to seedlings of beet, although seeds
were sowed within five days after soil treatment. However, 16 cc. ammonium
hydroxide gave better control although, for safety', it was necessary to wait about
seven days before seeding.

Ammonium sulfate had little oi no fungicidal effect in acid soils, with pH values
of 5.0 to 6.0, but it had a decidedly fungicidal action in soil which, as a result of
the earlier use of hydrated lime, had a pH value of about 7.0.

When ammonium sulfate and hydrated lime, one part of the former and two
parts of the latter by weight, were intimately mixed and this mixture (at the
rate cf 10 gm. ammonium sulfate per square foot) was worked into moist soil,
there was a strong odor cf ammonia and damping-off was well controlled. It
was, however, necessary on grounds of safety to wait more than five days after
soil treatment before seeding.

Hydrated lime alone, applied to soil, usually increased the number of plants
which lived and reduced the severity of damping-off, but the disease was not
controlled to any such degree as it was by ammonium sulfate and hydrated
lime applied together.

Control of Greenhouse Vegetable Diseases. (E. F. Guba, Waltham.) Ap-
proximately 30 percent of the greenhouse tomato growing area in the fall crop-
ping season of 1941 was planted to the Bay State tomato, developed for resistance
to Cladosporium leaf mold from hybrids of Lycopersicum pimpinellifoliiimX L.
esculentum. The new tomato was released for trial in 1939. In the fall cropping
season of 1940 a new physiologic form of the fungus, to which Bay State is com-
pletely susceptible, was noted at Swansea, Bristol County. In 1941, other in-
stances of the complete susceptibility of Bay State to the new form of Clado-
sporium were observed. Globelle (Ohio) and Vetomold (Ontario) likewise de-
veloped for resistance to Cladosporium, and derived from red currant, have
shared the same experience. The new physiologic form of the fungus is infectious
to L. pimpinellijolium (Jusl.) Mill, and L. hirsutum Humb. & Bonpl., causing



26 MASS. EXPERIMENT STATION BULLETIN 388

yellowish infection flecks and ultimately necrosis. On the lower surface of the
spots, under moist conditions, the fungus sporulates rather freely, although it
is much less virulent on Bay State than the original prevalent form of the fungus.
Both L. pirn pin ellifolium and L. hirsutum show a high immunity reaction to the
original physiologic. form of Cladosporium. L. peruvianum (L.) Mill, is immune
to both physiologic forms but peruvianum will not hybridize with esculentiim.

Causes and Control of Decay of Squash in Storage. (E. F. Guba and C. J.
Gilgut, Waltham.) Gourds instead of squash were treated with various disin-
fectants and chemical coatings after harvest to determine to what extent these
treatments influence keeping. The organisms causing decay of squash similarly
attack gourds and the results from such treatments are generally applicable.

The merit of spraying gourds with Bordeaux mixture 4-4-50 and 1 pound
calcium arsenate during the growing season was investigated, although it is
recognized that the spraying of squash is difficult. The results indicate that
fungicidal field treatments result in less decay after harvest and that the progress
of decay is further inhibited by coatings of shellac. The value of disinfection
between harvest and storage is not clearly shown. A dry ventilated storage
following protection in the field with Bordeaux mixture and calcium arsenate
was definitely advantageous in the control of decay.

It is apparent, particularly as the result of this season's work with gourds,
that considerable infection responsible for decay in storage may take place in
the field, without being evident at harvest.

Gardenia Stem Canker. (C. J. Gilgut, Waltham.) It was determined from
a histological study of gardenia cankers that the hyphae of the infecting fungus,
Phomopsis gardeniae Hans. & Scott, are confined to the discolored bark and wood
of the cankered section of the stem. Cuttings taken from diseased plants and
from healthy plants did not become infected when propagated side by side in
clean sand, nor did plants from these cuttings become cankered when grown in
greenhouse benches.

Disease Resistance and Heredity of Carnations. (E. F. Guba cooperating
with H. E. White, Waltham.) Approximately 75 varieties of carnations have
been studied for their reaction to fungus wilt diseases. Also, growers have in-
dicated the performance of a long list of varieties in relation to these diseases
under their respective growing conditions. In a compilation of these reports
and tests, it is apparent that certain carnation varieties have rather consistently
maintained healthy growth. The wilt diseases under consideration in this study
are caused by Alternaria diantJii (blight), Rhizoctonia solani (stem rot), Fusarium
dianthi (branch rot) and F. avenaceum and F. culmorum (stem and root rot),
,and are not equally prevalent. Frequently, only one of these diseases may be
troublesome year after year in the same establishment. Twenty-six varieties
showing the greatest promise as sources of disease resistance under natural con-
ditions have been selected for further study. The reactions of these varieties
to each wilt disease in so far as available will be more carefully scrutinized under
more favorable conditions for disease and artificial methods of inoculation before
hybridization studies are undertaken. The results of this program should deter-
mine the nature, justification, and direction of further efifort in the development
of desirable disease-resistant types of carnations.

Miscellaneous Tests and Experiments. (E. F. Guba and C. J. Gilgut, Waltham.)

L Apple Scab Control. Ground and chemically prepared sulfurs of a max-
imum particle size of 50 and 3 microns respectively were compared on an equiva-
lent sulfur basis, and in combination with lead arsenate, and lead arsenate and



ANNUAL REPORT, 1941 27

lime, for loss of sulfur by weathering, for scab control, and for chemical injury.
There were no apples to harvest from the untreated row because cf a complete
June drop caused by the plum curculio. In this row 20.3 percent of the leaves
were scabby and only a small amount of this was primary infection. In the
sprayed rows, irrespective of whether the sulfur was coarse or fine, there was
no scab.

The results confirm the work of previous years to the effect that sulfur particle
size and concentration of sulfur are not as important in scab control as good
spraying. Chemical determinations of the residues after spraying revealed that



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