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DESICCATIDN 0F DORMANT RED
' RASPBERRY CANES IN
RELATION TO HARDINESS

THESIS TUB THE DEGREE OF M. S,

E. A. H. Banks
1934

 

a, smart

 

DESICCATION OF DORMAUT RED RASPBERRY

CAKES IN RELATION TO HARDINESS

A THESIS
SUREITTED TO THE FACULTY
OF THE
MICHIGAN STATE COLLEGE
OF
AGRICULTURE AND APPLIED SCIENCE
IN PARTIAL FULFILLMENT
OF THE REQUIREEENTS
FOR THE
DEGREE OF EASTER OF SCIENCE

Department of Horticulture
East Lansing, Michigan
1 9 3 4

‘ (Mm/4 MS 5’.
07‘7””! /./fl W

THESIS

ACKNOELEDGEiEKT

The writer wishes to express his appreciation to
Professor V. R. Gardner for his invaluable guidance and in—
terest in this investigation, to Professor F. C. Bradford
for his careful and helpful criticisms of the manuscript,
and to Dr. J. W. Grist for his helpful suggestions in the
analytical work. Thanks are also due to Dr. E. J. killer
for his assistance in supplying the wax emulsion used, and
to Mr. E. F. Palmer, Director of the Horticultural EXperiment
Station, Vineland Station, Ontario, for his COOperation in

the work carried out there.

93841'

TABLE OF COITEIT3

Introduction
Review of Literature

Comparison of Winter Injury in Different
Seasons at Vineland Station, Ontario

Summary of Four Seasons Studied
General Plan of EXperimental Work

EXperiment on Rate of Water Loss from
Detached Canes

Length of Cane in Relation to Amount of
Injury —— 1931

Length of Cane in Relation to Amount of
Injury —- 193

Number of Canes per Hill in Relation to
Vinter Injury ~— 1931—32

Experiment on Removal of Old (First Formed)
Canes in Summer

Experiment on Rest Period of Viking RaSpberry --
1932—33

EXperiment on Artificial Freezing of Canes taken
from the Field during Winter —- 1932—33

A Comparison of Artificially Frozen Canes with
Those Frozen under Field Conditions

Spraying ENperiment on RaSpberries in East Lansing

1931—32

Spraying EXperiment on Viking Raspberries in
Vineland Station, Ontario —- 1932—33

Laboratory Test on Spray Materials
Water Content of RaSpberry Samples
Chemical Analysis

Discussion

Summary

Literature Cited

Page

16
19

27

28

29

31

33

37

38
39
41
45
51
53

55

-1—
INTRODUCTION

Winter injury to red raSpberry canes is a problem through—
out most of the raspberry growing sections of North America.
The injury is most commonly manifested in spring by a partial
or complete failure of growth in the tip section of the cane.
Often this is not extensive enough to be of practical importance
but in many cases the entire upper half or more of the cane is
either completely dead or else the buds in this region make
very feeble growth. Less often, death of the entire cane occurs.
This may be due either to injury to the base of the cane, to
the crown, or to the roots.

In order to present a logical consideration of the causes
and possible prevention of winter injury it is necessary to
recognize the fact that there are several distinct types of
injury.

Occasionally early fall freezing may completely kill the
young laterals, or any tender, late—growing shoots. Such in—
jury obviously belongs to the "immaturity" class. It is not of
much importance except in the occasional unusual season of
severe early freezes.

Later injury may be represented by outright killing of
various tissues by very low temperatures. If the plants are
partly protected by a blanket of snow or other mulch material
the injury usually extends back to the protected part and,
upon thawing, the exposed parts will show the characteristic

browning of tissues killed by freezing. Where the soil is bare

and unprotected direct freezing injury may occur at the crown

or roots.

A third type of injury is that which is described as
being due to "winter drying". This appears to be the most
common and widespread type. It may occur in combination with
more or less direct freezing injury of certain tissues, or it
may be relatively serious in seasons when winter injury would
be quite unexpected, if drastic drops in temperature were the
chief cause, and when periodic examinations throughout the
winter and early spring have shown no definite symptoms of
injury.

Since freezing itself is a desiccating process, it is
obvious that moisture conditions play an important part in the
over-winter survival of raSpberry plants.

Cultural methods, the application of fertilizers, fall
cover crops, degree and time of pruning, protective mulches,
and protective Sprays all affect the water economy of the plant.
Therefore, before further considering the possible means of
prevention of winter injury it is necessary to make an analysis
of the information already available on these methods of treat~

ment and their relationship to winter injury.
REVIEW OF LITERATURE

A review of the literature on the nature of winter killing
in general, and the theories regarding frost resistance in plants,
would be too voluminous to include here. Adequate discussions of

the literature have been written by Gardner, Bradford, and Hooker

-3...

(12), Chandler (6) (7), Maximov (20), Martin (19), Crane (9),
and others.

It is now generally agreed that the formation of ice
crystals in the intercellular spaces results in the withdrawal
of water from the cells as freezing progresses, thus producing
a dehydrated condition of the plant cell. There are two main
views on the causes of death from dehydration. One lays the

cause to the chemical influence of increased concentration of

 

salts and acids on the colloids of the protoplasm; the other

 

to the mechanical injury of protOplasm caused by compression
or grinding of the cells by ice crystals which accumulate in
the intercellular Spaces. But, whatever is the ultimate cause,
the loss of water from the cells is admitted.

Susceptibility of Varieties Red raSpberries are less

 

subject to winter injury than blackberries and are usually
hardier than black raSpberries also, although contradictory
reports have appeared from different parts of the country. In
Nebraska (27) the black raSpberry has been reported as hardier
than the reds. Card (5) reports that the reds are less hardy
than blackcaps in the eastern states, although Stene (22),
reporting from Rhode Island, says that red raSpberries suffered
much less injury than blackberries and blackcaps, especially
in 1927-28. Slate and Rankin (21) state that winter injury on
red raspberries is more troublesome in the Hudson Valley than
elsewhere in New York state, and that "black and purple raSp-
berries are rarely injured except where poor site conditions

prevail".

-4...

Latham, King, Sunbeam, Ohta, and Chief are classed as
hardy in Nebraska. In Michigan, Latham is reported to stand
lower temperatures than many other red varieties, while Cuthbert
is more subject to freezing injuries than some of the other
varieties.

Locklin (17) reports that in western Washington Cuthbert
is the variety most severely injured by low winter temperatures
and that Antwerp and Marlboro are injured only in the most
severe winters. He notes the fact that Cuthbert is very slow
to drop its leaves, to stop cane growth, and to harden up the
cane tips.

Stene (22) lists Latham, June, Cuthbert, and Herbert as
being hardy in that order in Rhode Island.

Slate and Rankin (21) describe Latham, Chief, and Herbert
as being generally considered very hardy to severe winter
temperatures; June and Ontario as sufficiently hardy for New
York conditions; Newburgh not yet sufficiently teated but so
far entirely hardy in central and western New York; Lloyd George
as generally rather tender in New York but showing no signs of
injury at Geneva where cover crOps have been used; and Cuthbert
as being moderately hardy.

Slate and Rankin emphasize a fact that has been noted by
others; namely, that certain varieties of the red raSpberry
which are more inherently hardy than others may show contra—
dictory behaviour in certain localities. For example, Viking,

which is resistant to the very low temperatures common at Ottawa

_ 5 _

and Montreal, often suffers rather severely from winter injury
in the Hudson Valley. This is eXplained as being due to the
fact that dormancy is broken by unseasonably warm weather in
late winter and it is stated that this injury has been more
prevalent during mild winters.

Effect pf,§21l Conditions Egg Cultural Treatments Since
the importance of maturity in preparing plants for winter has
been emphasized, a resume of the literature bearing on the
maturity of raSpberry canes and the effect of soil conditions
and cultural treatments in preparing the plants for winter will
serve to crystallize some of the information already available.

Craig (8) found that summer—pruned Cuthbert raspberries
suffered more injury at Ottawa, Ontario, than unpruned plants.

Gardner, Bradford and Hooker (12) advise against summer
pruning, stating that "immature canes, laterals on canes pinched
back, and suckers that develop late are sometimes injured by
comparatively mild freezing".

Card (5) expresses doubt of the "current belief" that a
comparatively dry fall favoring a slow well ripened growth of
wood promotes resistance to winter injury, and cites the fact
that slender canes produced during the latter part of the season
often winter—kill less than older large canes. He also notes
that ”during one winter in Nebraska the mercury feEl below zero
but once, and then only five degrees below, yet unprotected
canes were entirely killed......The following winter was mucn
colder, but the preceding summer and autumn were favorable,

with plenty of rain. The plants, therefore, went into winter

_ g _

quarters with a good supply of moisture in the ground. Both
raSpberry and blackberry plants came through that winter in
good condition without protection".

Card also says that excessive, as well as deficient,
moisture may contribute to winter injury.

Lott (18) corroborated Card's findings in reporting that
the removal of the first two crops of young shoots from the
Cuthbert raSpberry caused a significant increase in hardiness.

Hilton (15), in reviewing Card‘s observations offers the
suggestion of Bradford that second growth induced by cool and
rainy autumns folloWing a hot dry summer is an important factor
in producing injury in raSpberries. "This view would assign
immaturity as the immediate antecedent of the injury, and, at
the same time, recognize that the older canes of the current
season would be most liable to second growth and hence actually

less mature in the fall.“

Locklin (17) states that "most injury can be laid to fall
freezes coming before the cane tips have ceased growth and to
low winter temperatures occurring in weakened fields. When the
canes are properly mature it is seldom that temperatures low
enough to cause serious damage have occurred in western Washing-
ton". The fact that Cuthbert, which is the variety most subject
to injury in western Washington, is slow to drop its leaves in
autumn and is most likely to react to growing conditions, sup-
ports these conclusions.

Thornber (25) and Taylor (23) state that raspberries are

freer from injury if grown on a moderately dry soil.

_ 7 _

Teske and Gardner (24), reporting the results of a field
survey of a number of Michigan plantations, say that "invariably
winter injury was found in the low-lying fields or localized
in depression 'pockets‘ or ‘draws‘ in plantations otherwise
free from trouble of this kind".

Harris, East Malling (13), reported more killing on low
ground where there was more water.

Brierley (4) states that rapid resumption of growth after
heavy rains led to the conclusion that the red raspberry is
very sensitive to variations in the moisture supply of the
soil.

Bregger (2) reported that deep cultivation, when continued
throughout the life of the plantation, was apparently highly
favorable. _

Slate and Rankin (21), on the other hand, say that "raSp—
berries are shallow rooted and easily injured. Four inches
is sufficiently deep (for cultivation) and it is advisable to
shorten the cultivator teeth next to the plants". They also
advise not continuing cultivation much beyond the picking
season as “the growth stimulated by late cultivation will not
mature sufficiently to withstand the winter". In addition,
-Slate and Rankin point out that "cover crops are rarely used
in raspberry plantings in this State (N. Y.) but they are use—
ful and deserve the attention of every grower. Not only do
they add considerable humus to the soil, but what is more
important, they aid very materially in ripening the canes by

competing with them for food and moisture during the fall, thus

_ 8 _

preventing rank growth and consequent winter injury".

Hilton (15) concludes that cultural methods similar to
those used with tree fruits, which reduce moisture in the soil
in the fall would likewise have the same effect upon hardening
raspberries. Although similar advice has frequently been given
by other workers but little direct eXperimental evidence has
been brought forward to prove definitely the value of such a
general recommendation. Lott (18) found that a cover crop of
oats materially increased the hardiness of raspberry canes
but this seems to be the result for one season only and he
does not state what the moisture conditions in the fall were.
The winter in question was characterized by severe freezing
near the end of December, at which time most of the injury in
the field took place. Freezing injury at this date when the
canes had possibly not yet had their rest period broken could
quite justifiably be laid to immaturity of the canes, but often
raspberries are found injured when no such definite killing
freeze has been eXperienced early in winter and when autumn
conditions have been such as to lead one to believe that
immaturity was not a factor.

Hilton found that the canes, or parts of the cane, most
resistant to artificial freezing in the laboratory had slightly
lower moisture content and a slight increase in pentosan content
over less resistant samples. Also, Lott found a close degree
of correlation between observed hardiness, the percentage of
bound water in the tissues, and the percentage of pectin present.

In other words, canes attain a "hardened" condition, as evidenced

_ 9 _

by their chemical or physico—chemical constitution, which is
related to their ability to withstand freezing; but whether or
not ordinary cultural factors are important in inducing this
hardened condition appears to be somewhat cpen to question.
Moreover, in many cases it appears doubtful whether the degree
of hardiness is of prime importance in assisting the plants to
escape winter injury.

It seems likely that natural weather conditions often play
a far more important part than artificial cultural treatments
and indeed would, in such cases as extremely dry summers fol—
lowed by wet autumns, or vice versa, outweigh any effects of
applied cultural treatments, except possibly in irrigation
districts. Therefore it would appear that broad general recom—
mendations regarding the alleviation of winter injury by cul—
tural practices are of doubtful value and should be preceded

by more careful inquiry into Specific conditions.
A COMPARISON OF WINTER INJURY IN DIFFERENT SEASONS
AT VINELAND STATION, ONTARIO

In order to gain further knowledge of the conditions under
which winter injury actually occurs in the Niagara district of
Ontario, graphs of the maximum and minimum daily temperatures
were compiled, together with a record of the daily precipitation,
for several winters for which notes on winter injury were avail-

able.

‘10...

Season 9; 1924~25 Notes on winter injury for this
season were obtained from work done by W. H. Upshall (28)
on Cuthbert raSpberries at Vineland Station, Ontario. He
states that "winter injury was rather severe, though no more
so than commonly occurs other years". Rating the canes from
1 to 10, with 1 indicating very slight injury and 10 indicating
a completely dead cane, the check canes received a mark of 5.
It is presumed therefore that the canes were about 50 per cent
injured in this season.

The fall of 1924 was exceptionally dry in the Niagara
district. Upshall says,"It is possible that there was an
actual deficiency of water or at least that the soil water was
not easily absorbed. Then again the canes may have absorbed
plenty of water but may have lost it too rapidly in reapiration
or by evaporation; in other words the water—holding power of
these canes may have been low."

The winter was generally characterized by steady low
temperatures. The temperature dropped to zero on several oc—
casions in the latter part of December and to ~20 and ~70 on
January 27 and 28. The lowest autumn temperature was 150F on
November 18. In spring the lowest temperatures were 3° and 2°
on March 2 and 3 and 190 on March 16. There were no severe
cold days in the latter part of March or in April.

Season'gf 1930—31 This winter followed an exceedingly
dry summer and fall. The total rainfall for November was only
.71 inches, as compared with a 1916-1932 average of 2.48 for

the same month. Every month from April to November, inclusive,

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-12..

was below normal in rainfall.

Examination of the temperature graph shows extreme tempera-
ture fluctuations at the end of November and beginning of
December. The temperature dropped steadily for four days to a
minimum of 13° on November 28 and 29. This was followed by a
rapid rise to well above freezing, accompanied by rain. On
December 2 the temperature had again reached a minimum of 9°.
After a steady climb the temperature again descended to 6°
on December 16.

January and February were characterized by fairly steady
low temperatures, reaching a minimum of 3° on February 1. From
the middle of February the minimum temperatures gradually as—
cended to above freezing by the end of March and drOpped no
lower than two or three degrees below freeging from then on.

The winter injury to raSpberries was comparatively slight
in the Niagara district. Measurements made at Vineland Station
showed an average length of cane for 21? canes of Viking of 5.4
feet with an average of 1.0 ft. killed back or injured, or 18.5
per cent injury.

Season 2£_1931—32 Although the winter of 1931—32 was
exceptionally mild, many raspberry plantations in the Niagara
peninsula suffered rather severe killing back of the canes.

An examination of the weather conditions shows that on
March 9 the temperature drOpped to 8°. This was a steady drOp
accompanied by high winds over a period of three days. Immedi—
ately before this the minimum temperature had remained at or

above freezing for a week, the maximum temperatures for the

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VINILANO JTNION. ONVMIO.

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_ 14 _

same week ranging from 47° to 36°.

Two other brief drops in temperature had occurred on
December 31 and February 16, with readings of 11° and 13°,
respectively, both occasions being immediately preceded by
high temperatures between 50° and 65°.

Except for several other temporary drops to slightly
below 20° during December and February, the winter was charac-
terized by warm weather, the temperature in many cases remaining
above freezing for several days at a time. There were no sud—
den drops in temperature after the middle of March.

The injury in the Viking block at Vineland Station was
more severe than in the same block in the preceding year, but
not as severe as in many commercial plantations in the district.

In November, 1931, there were several reports of second
crOps of raSpberries due to the warm moist autumn.

Season 9: 1932—33 The winter of 1932—33 was comparatively
mild, with many days of warm weather occurring in January and
no very sudden and severe drOps in temperature except in February
when the temperature dr0pped from a maximum of 46° on the 7th
to -2.0° and —Z.7° on the 9th and 10th. A period of daily pre—
cipitation for all of the first week of February was concluded
by nearly half an inch of rainfall on the 7th; this preceded by
two days a drop to ~2°F.

At Jordan Station, Ontario, several raSpberry plantations
showed a scattering of more or less completely dead canes through—
out the rows. In one or two instances where careful examination

was made the injury was situated chiefly at, or just above, the

Figure 3

 

 

 

 

 

 

 

 

 

 

MXIHUH AND HINIHUH TEHHMTURES.

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_ 15 _

crown and seemed to be due to an excessive amount of surface
water lying on the ground just previous to the severe freeze
of February 9 and 10. In other instances the origin or location
of such injury was not so apparent. Reports were received of
numbers of plantations in eastern Ontario and Quebec suffering
from extensive injury of a type apparently similar to that of
the Jordan area. Where this scattering of completely killed
canes did not occur there was only a very slight dying back of
the tips. In general, it can be said that the typical tip
injury was not predominant this season, i.e., the canes were
not killed 2&23 but were rather killed up from a point near
the base.

The block of Vikings at Vineland Station seemed to have
good surface drainage and only very slight tip injury occurred.
In this year,weather records and location of the injury suggest

severe freezing of wet tissues as the primary factor.
SUMMARY OF THE FOUR SEASONS STUDIED

1924—25 A very dry summer followed by long continued
moderately severe cold in late December and parts of February
with severe cold at the end of February.

Rather heavy injury.

1930—31 A very dry summer and exceptionally dry November
followed by a moderately cold winter with fluctuating low temper-
atures in December, January, and early February.

Comparatively light injury at Vineland Station.

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-17..

1931-32 A very warm November followed by a very mild
winter. The most severe drops in temperature were to 110
and 13° at the beginning and middle of February, following
maximum temperatures of 50° or 60° for two days previously in
each case.

Distinctly heavier injury than in 1930—31, which
was a much colder winter.

1932—33 Another very mild winter. A dr0p to 12° on
January 1, following warm weather. A drOp to ~2.7° on February
9 and 10 following a wet day.

Ordinary tip injury less than in any of the
other three years at Vineland, but injury occurred to the crowns
and bases of canes in other localities.

The conclusion to be reached from this study of injury in
different seasons is that the general severity of the winter is
often not a clue to the amount of injury to be eXpected. Long
continued cold appears to be conducive to fairly heavy injury.
Sudden drops in temperature following warm conditions may or
may not cause considerable injury; or injury of varying types
may be encountered according to the moisture conditions of the
soil. In none of the winters studied could it be said that late
fall or very early winter freezes were a definite cause of injury.
In 1930-31 when such injury might possibly have been eXpected at
the end of November the injury recorded was rather light. The
injury of the winter of 1931—32 may on circumstantial evidence

be attributed to immaturity.

Average Insight In feet

1‘6

Figure 5

 

Winter Injury 8/ Seasons

at Vine/and Station, Ontar/o.’

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ABOél EUWGZ £3263

B/ack = flea/thy cane.
Cross-hatched = Injured Cane
Figures at top = percent/afar]

 

 

_ 19 _

Although many facts seem to point to the conclusion that
the combination, or sequence, of weather conditions during the
winter season has more to do vith winter injury to raSpberries
than either the actual severity of the winter or the cultural
treatments of the plants, yet, in the four seasons studied,
the heaviest killing back of canes did occur in the 1924—25
season, which was a season of long continued cold.

The evidence indicates that this season was probably very
conducive to the "winter—drying" of canes so often mentioned in
the literature. The canes went into winter with a low SUpply
of water in the soil. The long period of cold without excessive
precipitation produced drying atmospheric conditions. The frozen
condition of the soil may have prevented the canes from taking
up the water necessary to replace that lost.

In view of this fact an eXperiment was planned to study

the effect of the prevention of moisture loss from the canes by

means of wax Sprays.
GENERAL PLAN OF EXPERIMENTAL WORK

R. A. Emerson (11) had coated raSpberry canes with paraffin
wax and found little or no injury on the protected canes. In
this eXperiment a paraffin wax emulsion, developed at Michigan
State College, which could be Sprayed on, was used.

The first work was done at East Lansing in the autumn of
1931. Canes of three varieties, Viking, Cuthbert, and Latham
.were Sprayed with wax emulsion, applied with a small wheelbarrow

type of Sprayer.

-20...

Samples of the Sprayed and unSprayed material were taken
throughout the winter season. Determinations of the total
moisture content were made and the samples were preserved for
chemical analysis. Determinations of various carbohydrate
fractions, lignocellulose, lignin, and pectins were later made
at Vineland Station.

In addition to the Spraying eXperiments started at East
Lansing and carried on at Vineland, several other experimental
treatments were carried on. These involved thinning out the
canes, which were grown in the hill system, to l, 2, 3, and 6
canes per hill; also summer and fall pruning of the canes, late
cultivation of.a number of hills with application of nitrate
in order to retain the foliage as long as possible. These were
used as supplementary experiments chiefly to gain pointers for
future work. No conclusive evidence of effect on winter injury
was obtained from any of these "side" experiments but a careful
analysis of various observations and measurements of winter

killing did bring to light some interesting facts.
EXPERIMENT ON RATE OF WATER LOSS FROM DETACHED CANES

Material supplied through the kindness of Mr. W. J. Strong,
of the Experiment Station at Vineland, was so analyzed.as to Show
the loss of water. Canes were cut November 19, 1931, and sealed
at the ends and hung in a natural position outside all winter.
Ten canes each of eight varieties were used. and each cane was

weighed at frequent intervals through the winter.

-21...

Figure 6 shows distinct varietal differences in rate of
water loss. The varieties used also differed considerably in
average size of cane, but apparently size of cane and variety
each has an independent effect on rate of water loss. Viking,
which was the largest—growing variety, had the Slowest rate of
water loss while Herbert, which was the smallest, had a rate
greater than that of Lloyd George, which was intermediate in
size.

To study more closely the effect of size of cane on water
loss the individual canes of all varieties were grouped according
to their original weights into: (1) large branched canes, (2)
small branched canes, (3) large unbranched canes, and (4) small
unbranched canes. The data showed that after four days, during
which considerable moisture loss took place, the greatest dif-
ference between any of these groups was between large branched
canes and small unbranched canes, with mean water losses, res—
pectively of 8.84 and 15.78 per cent, a difference of 5.94 per
cent. The probable error of the difference was only 1.213;
therefore this difference seemed to be significant. The least
difference was between small unbranched canes and small branched
canes with mean water losses of 15.78 and 14.02 per cent. Since
the difference, 0.76, is less than the probable error of the
difference, 1.234, this difference is not significant.

After 122 days the greatest difference between any of the
groups was between large branched canes and small unbranched
canes, with mean water losses of 48.84 and 47.64 per cent, res~

pectively. Since the difference, 1.20, is less than three times

-58..

the probable error of the difference, .733, this difference is
probably not significant.
The various groups arranged in order are as follows:

Per cent water loss
after 4 days

Large branched canes 9.84 f .482
Large unbranched canes 13.20 i .835
Small branched canes 14.02 i .533
Small unbranched canes 15.78 1 1.113

The fact that large branched canes showed less rapid
water loss than small branched canes or unbranched canes upsets
somewhat the hypothesis that large canes are more subject to the
drying out type of winter injury because of their greater height
and more exposed surface causing them to become depleted of
water more readily. This led to the question, do the larger
canes actually suffer a greater percentage of injury? An af—
firmative answer was given by the study of winter—killing measure—
ments made on a large number of individual canes in two different
seasons, as will be shown later.

Hildreth (14) had concluded, from a similar drying experiment
on apple twigs done in 1924~25, that cold winter weather may have
relatively little evaporating effect on twigs. The measurements
made at Vineland on the loss of water from out and sealed canes
of raSpberry showed that the rate of water loss was considerably
faster, particularly in the initial stages, than with the apple
twigs studied by Hildreth. Moreover, the loss with raSpberries

continued until the canes were completely dry and dead.

Pen tun Lou I. lunar

 

 

 

.—2'Z.a“

Figure 6

__..—.N».. 'mt'- - v-r\ v

 

RATE OF MOISTURE LOSS FROM CUTCANES '
OF DIFFERENT RASPBERRY VARIL'T’ES. '

(a. u u can.) or and nrnly. on! and "dad a“ flog-p ~an

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- ‘L—+~OUNAN

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(nu mm) X, N
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(I r Mun) -‘

 

 

 

 

u4~gremgaytmnut

 

 

 

 

 

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(What u:
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-23...

Hilton (15) found that by directing a current of air upon
raspberry canes in the laboratory he was able to obtain injurious
effects similar to those often encountered in the field after
more or less severe winters.

The conclusion, therefore, to be reached from a comparison
of raSpberry with apple is that winter desiccation has far greater
possibilities of being a serious factor with the raSpberry than

with apple.
LENGTH uF CARE IN RELATION TO AMOUNT OF INJURY —~ 1931-

In the Spring of 1831 individual measurements were made on
217 canes of Viking. The total length of each cane was recorded
together with the length of the dead portion. The measurements
were made in Spring after the buds had had ample time to exhibit

signs of growth. Table 1 presents a summary of the measurements.

Table 1. Length of Cane in Relation to Amount of Injury «~1830—3l

(Canes grouped according to length)

 

2 ft. 3 ft. 4 ft. 5 ft. 6 ft. 7 ft. 8 ft.

 

Total number

 

of canes 12 18 35 54 58 33 7
Wofwcanes
uninjured 12 17 23 3O 28 10 1

 

Number of canes

injured 1 12 24 30 23 6

 

Per cent of O

canes injured 5'6 34.3 44-4 51.8 59-5 85.7

 

Average length

of dead por- 1.5 1.4 1.7 2.3 3.1 4.3
tion, in feet

 

 

 

‘—

Injury eXpressed
as per cent of 35.0 34.0 38.3 44.3 53.?
total cane lengtw

 

 

 

 

 

 

 

 

 

 

-24...

Not only was the absolute amount of injury in the tall
canes greater than in the medium and small canes but also the
actual percentage of injury was greater. This is in agreement
with eXperiments that Show that the removal of the first two
cr0ps of young canes reduces the amount of winter injury, since
most of the canes over 6 feet in height had originated early
in the season.

It must be borne in mind that the injury measured in this
particular experiment was of the typical tipakilling kind which
is variously attributed to immaturity and to drying out. The
peculiar significance of this occurrence lies in the fact that
it followed a summer and fall of extraordinarily light rainfall,
when maturity as usually understood, should have been excellent.
As pointed out elsewhere there are frequently seasons when
killing originates near the ground level and results in injury

more serious than this type.
LENGTH OF CANE IN RELATION TO AMOUNT OF INJURY —— 1932

‘In the Spring of 1832, individual cane measurements again
were made, this time on 272 canes of Viking. The measurements
were taken after the canes had started into growth so that badly
weakened buds showing feeble growth could be clearly distinguished
from those of full vigor or those completely dead. For each cane
was recorded, in feet, the length of uninjured cane, the length
of weakened, or partially injured section, and the length of

completely dead cane. Table 2 summarizes the results.

_ 25 -

 

 

 

 

Table 2. Length of Cane in Relation to Amount of Injury ——l93l-32
(Canes grouped according to length)
2—3 ft. 3—4 ft. 4—5 ft. 5—6 ft. 6—7 ft. 7-8 ft. 8—9 ft.
Total No. ‘
of Canes 12 ll 46 80 67 44 12
Av. length
of injury 0.0 .25 1.01 1.52 2.14 2.85 3.31
per cane
in feet
Azéngeiot 1 0.0 5.30 20.18 25.35 30.50 35.68 35.77
injury a (r 0) (12.73>(:1.23) ($1.15) (11.51) (£1.27) ($2.38)

 

 

 

 

 

 

 

 

 

Table 3 summarizes the injury in like manner except that only

the completely dead part of the cane is considered instead of

weakened plus dead part. Figure 7 combines tables 1 and 2 in

graphic form.

Table 5.

Dead Cane —- 1931—32

(Canes grOUped according to length)

Length of Cane in Relation to Amount of Completely

 

Total No.
of canes

2—3 ft.

3-4 ft.

5‘6 ft 0

6"? ft.

7-8 ft.

ft.

 

18

14

141

117

73

23

 

Av. length
of dead
part per
cane in
feet

0.19

0.36'

0.69

0.78

0.87

 

 

'Av. length
of dead
cane ex—
pressed
as per—
centage
of the

cane length

 

 

 

 

7.2

 

8.0

 

9.9

 

9.8

 

 

 

 

I +

i +

 

Length or cane m net (upper/”nit 0F class)

~u+uo~Noob

Q\

-10»-

Figure 7

 

Length 0F Cane In Re/at/on to/lmount 0F ln/ar/
/95/—/952 56.3

 

 

 

.....

 

         

  

an.
§

..
.c
o

o:

o
.

s
..
,s .

 
 

.

 
     

- ‘
’q‘.
. o
.

5
o

 

 

Figures at top or Columns = percentage total Injury
S/ngle crass-hatched - dead part

Double Cross-hatched. = wwened or partlulg' Injured.
Solid. black = health] cane

 

-27...

NUMBER OF CAKES PER HILL N RELATION TO WINTER INJURY —— 1931—32

The average percentage of injury per cane for plants with

4, 5, 6, and 7 canes per plant is shown in table 4.

Table 4. No. of Canes per Hill in Relation to Winter Injury

 

 

 

1931-32
Percentage of cane length
Plants with
Injured Completely dead
4 canes per plant 19.2 i 1.60 6.0 I .436
5 canes per plant 21.9 i 1.68 7.3 t .653
6 canes per plant 28.2 i 1.83 10.0 1 .897
7 canes per plant 31.6 2 2.37 10.7 t 1.39
8 canes per plant 26.9 t 2.87 10.1 t 2.44

 

 

 

 

 

Plants with fewer than four canes and over seven canes
(up to 11 canes) were not numerous enough to warrant conclusions.
Their means did not follow any particular trend.

The plants with the greater number of canes were probably
the more vigorous. The fact that these suffered the greater
injury indicates that weak plants may not neCessarily be the
most susceptible to injury.

The autumn of 1931 has been mentioned as characterized by
a considerable amount of late growth. It is therefore of high
interest that the distribution of injury is essentially the same

as that following the dry autumn of 1930.

1+ 1+ H

I +

1+ 1+ H M-

1 +

~28-

EXPERIMENT 0N REMOVAL OF OLD (FIRST FORMED) CANES IN SUthR

All new canes tall enough to protrude above the fruiting
canes were cut out of a row of Vikings July 3, 1932. At this
date the first berries were just beginning to ripen.

The following Spring, none of the canes on the treated
row were dead for more than a few inches at the tOp, while
several canes on each of the adjoining rows were killed back
from one to two feet and a number were killed back more than
six inches. I

When examined on June 6, 1933, just when the first flowers
were beginning to Open the average height of the treated row
was practically the same as that of the adjoining rows except
that there were no nine— and ten—foot canes scattered through
the row. Most of the vigorous canes were about five or six
feet tall and appeared to have better growth of fruiting laterals
than the large canes of the adjoining rows, although it is pos—

sible that the check plants bore more lower laterals which were
not so conSpicuous.

Table 5 shows that the average length of injury per cane
was less in the treated row and also that the percentage of un—

injured canes was lower.

 

 

 

 

 

Table 5. Winter Injury After Removal of the First Formed Canes
in Summer, 1932 — 33.
Treated Row Adjoining Rows
North side South side

Total No. of canes in row 170 131 150
Total No. of canes injured 19 17 16
Av. length of injury, in inches 2.68 7.18 5.06

I

 

 

 

 

-29...
EXPERIMENT ON REST PERIOD OF VIKING RASPBERRY —— 1932 — 33

Observations were made to determine the approximate duration
of the rest period.

Samples of canes were cut at intervals from November 23 to
January 3 and placed in vessels of rater in the greenhouse at a
temperature of about 70°F. Each lot was left in the greenhouse
until shoot growth had ceased and the canes vere dead. Notes
were made as follows:

Sample Brought in November gg, Canes were evidently in a
complete resting condition at this date since no bud activity
Occurred in eight weeks or more, except in one cane which was
exposed to outside temperatures by poking the tip through a hole
in the greenhouse. A 12—bud section of the tip was exposed for
9 days (December 3 to December 12) and breaking of some of the
buds (down as far as the 15th bud) occurred by January 6 on this
cane.

Sample Brought in December 1 No activity after 30 days
(January 6). One bud had burst on one small cane after 33 days.
Some canes were still completely inactive after 35 days. Only
weak bud develOpment had occurred by end of January (55 days).

Sample Brought.ig December 15_ One cane showed signs of
buds swelling after 22 days. Remainder of the canes were still
inactive after 27 days. Scattered bud activity occurred after
30-35 days. NO buds had made any appreciable grovth after

bursting, even after 47 days.

_ so _

Sample Brought‘ig Decemberugg. No activity after 14 days.
Buds bursting after 19 days. Had made only weak growth after
35 days.

Sample Brought lg January 3 Had made moderately vigorous
shoot growth by the end of three weeks. This was about the
same rate of growth as use exhibited by later samples taken
February 25. Canes brought in April 4 required only two veeks
to reach a similar stage of shoot development.

It was noticed in some of the samples brought in in December
that egg—laying punctures of the snowy tree cricket caused a
marked stimulative effect on the Opening of the buds above the
injury.

The conclusions from these observations are that the Viking
raspberry, under 1932—33 conditions, is in a deep resting con—
dition by late November, that the resting period is partly broken
by late December and probably completely broken early in January.

Locklin and Hardyl, in noting that Cuthbert reacts readily
to growing conditions, suggest a causal relationship between
profoundness of rest period and susceptibility to freezing injury.

The above eXperiment shows that it is very unlikely that
Viking would suffer from premature starting in late fall or very

early winter.

1- Locklin. H- b: and Hardy, Max B. Artificial freezing

of red raSpberry canes. Wash. Bul. 260, p. 45. 1932.

1 _

I
on

A further observation on maturity conditions of the cane
was obtained in 1932—33 by comparing a number of Viking canes
which had retained their foliage at the tips until comparatively
late in fall with a number of canes, of similar size and general
appearance, that dropped all their foliage comparatively early.

No difference in tip injury was observed.

EXPERIEEIT ON ARTIFICIAL FREEZING OF CASES TAKEN FROm

TIE FIELD DURING KINTER —— 1938—33

On February 25, 1933, Viking canes were taken from the
plot at Vineland Station. They were cut at 10:45 A. N., placed
in water for two hours on arrival at Guelph at 1:30 P. m. and
half of them were then placed in cold storage at 30F for approxi—
mately 40 hours.

Then taken out of the cold storage room they were distinctly
shrivelled on the surface, particularly at the basal end, though
the tip section for 12—20 inches showed scarcely any shrivelling.
After the bases had been wrapped in moist burlap for 2% hours
the shrivelling had disappeared and the canes resembled the check
canes which had been kept standing in water without freezing.

Examination 2£_Oanes gg'March.§;.19§§. There was apparently
much more bud injury on treated canes than on the check canes.
The tips of the buds appeared dried out and dead, although they
showed little discoloration. he bases of the buds showed con-
siderable discoloration. The buds on the checks showed some

slight discoloration; particularly those from the base Of the

|
(\1
DJ
|

canes, this being due, no doubt, to the freeze of February 10.

The check canes also show slight signs of brown'r* of the cambiUm

in the tOp section. It is notetorthy that many of he canes as
brought in from the field showed a poor appearance of the cambium
in the tOp half or tOp third of the cave with healthy appearing
buds, while the relative condition of buds and cambium appeared
to be reversed in the lower half of the cane. The canes kept

in the cold storage showed brovning of the cambium throughout

and in more severe degree.

On March 13, 1933, only two out of 12 frozen canes showed
any signs of life after being kept in water in the greenhouse.

A few buds were feebly bursting on these two canes. All unfrozen
check canes were bursting fairly uniformly along the cane.

,Thg Effect pf ~2,7°F'ig,3hg FieldI 1932—33 Examination was
made February 15, 1933, five days after the severe freezing
weather of the 9th and 10th when the temperature dIOpped to —2.7F.

The canes in general showed no signs of injury to the buds
on the tip section (about 25 bud section). The bottom 1% foot
sections showed a certain amount of browning or discoloration
about the "neck" of the buds-”apparently mostly in the vascular
system. Some rusty brown discoloration of the pith in this region
also occurred. The gr und at this time was fairly well frogen.
Some canes to Which wax had been applied in the fall were in—
cluded in this study.

In the waxed canes (basal section) there mas more injury
than in unwaxed canes. Five representative waxed canes had an

average of four buds out of five examined showing brownhugas

I
()3
c .1
I

compared with an average of two or three discolored buds on un—
waxed canes, rith the remaining two or three buds shoving no
injury or only extrehely slight indications of injury. Super—
ficial examination of an additional number of canes bore out
these observations.

This behaviour of the canes is possibly attributable to
the fact that the base of the cane is more liberally supplied
with water than the tip and in the vexed cane this condition
is accentuated by partial prevention of evaporation. Hence a
larger amount of free water in the vascular system of the region
injured might account for freezing injury in these places. Late
Spring observations showed the the canes apparently made good
recovery from most of this injury.

A COMPARISON OF ARTIFICIALLY FROZEN CANES WITH
THOSE FROZEN UNDER FIELD CONDITIONS

A comparison of those canes vnicn had undergone a temperature
of _2.70 in the field tith those artificially frozen at 3°, or
over five degrees higher, substantiate the theory that the presence
of free water may be an important factor with certain types of
freezing injury. The artificially frozen canes had libera op-
portunity to take up free water immediately before freezing and
showed severe injury as compared with slight injury previously
suffered in the field at a lower temperature. However, it is
probable that the rapidity of the artificial freezing may have

been important in causing injury.

-34..

Whether it was rapidity of freezing or increased amount
of water that increased he injury, this particular experiment
does not indicate desiccation as a factor concerned.

The eXperience in a raSpberry plantation at Jordan Station,
Ontario, also points to the effect an excessive supply of free
water may have on susceptibility to freezing. In the particular
field observed, there was an unusual amount of surface water
lying in the field (due to a blocked ditch) immediately before
the severe February freeze. In the Spring there has a heavy
scattering of completely dead canes throughout the plantation.

Examination showed marked discoloration and browning, parti-
cularly noticeable in the pith, at, or for a few inches above,
the crown. The tissue above this area vas mostly only dried
and dead but not discolored. It is highly probable that the
injured part of these canes has in a very water—soaked condition
shortly before the freeze. In a great many cases the injury
appeared not to extend down into the crown or roots.

This observation though primarily indicating the greater
susceptibility of hater—soaked tissue, indicates just as clearly
that the upper portion of the cane may die from desiccation
under extreme conditions. Since the upper portions vere dead
before the close of tre dormant season, lack of vater, rather

than of nutrients, seems indicated.

 

 

 

 

 

 

 

 

 

 

 

Viking canes cut Febuvary 25, 1933.
Photographed March 25. Untreated.

 

~3b'

Figure 9

 

 

 

 

 

 

Viking canes cut February 25, 1933.
Photographed March 25. Frozen in cold
storage room at about 30F for 40 hours.

-37...
SPRAYING EXPERIMENT ON RASPBERRITS AT EAST LANSING —— 1931—32

As a study of the possible effects of decreased desiccation,
certain canes at East Lansing were Sprayed with a max emulsion.
The material used was a compound developed by Dr. E. J. Miller
at the Michigan State College and containing:

Water, 100 parts by weight
Paraffin wax, 10 parts
Ammonium linoleate, 3 parts
Bentonite, 3 parts

This has applied from a small wheelbarrow type of Sprayer.

The Spray was applied on December 3 to two sections of a
row of Vikings and to part of three rows of Cuthbert and two
rows of Latham. About 40 feet of each row were treated and the
remaining parts of the rows acted as checks.

Previous to the date of application only mild freezing
weather had been encountered, chiefly at night. The temperature
was between 45° and 50° F at the time of application but fell to
as low as 5° or 10°F a few days later

Method 2; Sampling At least 10 canes of uniform size and
representative of the row were taken at random from each lot.
The bottom 18 inches of each cane were discarded and a one foot
section immediately above that was used as a sample. With Latham,
only 18 inches of the base of the canes vere discarded, because
of their shortness. The buds vere removed, the wax removed by
gentle scraping and the sample cut into one—fourth or three—
eighth inch pieces, and veighed. This was done with as little

delay as possible. The material was heated at 90°C for 45 minutes,

then dried at 70°C to constant weight.

The wax was removed from later samples by holding each
portion of cane under a stream of hot water for two or three
seconds and then quickly wiping Wltfl a dry cloth. It has
found by eXperiment that the quantity of water absorbed was
not sufficient to affect the fresh weight when the sample
was weighed about ten minutes later.

Samples were taken January 6, February 12, February 29,
April 3, and May 3, 1932.

On April 23, it was found that the raSpberries in this
eXperiment had been pruned; hence the amount of injury could
not be measured. Previous casual observation indicated, how—
ever, that it had been rather light in the whole block.

At the time the last samples were taken the Viking buds
were just beginning to burst. Cuthbert and Latham were
slightly more advanced.

The moisture content at this time was in the same order
as the Opening of the buds, as follows:

In order of Opening —- Cuthbert, Latham, Viking

Moisture content -— 51.1% 48.1% 43.3%

SPRAYING EXPERIMENT ON VIKING RASPBERRIES AT THE HORTICULTURAL
EXPERIMENT STATION, VINELAND STATION, ONTARIO +— 1932-33

Spraying with wax emulsion was done on November 14, 1932,
in a manner similar to that folloved at East Lansing in the

previous season.

l
m
(0

I

The temperature was 55°F at the commencement of Spraying
but had dropped to 45°F at 4:45 P. M. when spraying was com—
pleted. Practically no freezing temperatures had been recorded
before the date of Spraying, but several days of cold weather
followed soon after the first Spray was applied. On November
25 the weather had turned warmer and an application of raw lin—
seed oil emulsion (about 10% strength) suggested by Swartwout
of Missouri (correspondence) was given to a second lot of canes.
On November 30, which was warm and sunny, the first lot of canes
was reaprayed with wax emulsion as some of the wax had disap-
peared from the north side of the canes.

On April 4 examination of the canes in the experimental
block showed little sign of injury. Most canes showed little
or no Sign of drying out at the tips, but on the bottom half
of the canes the basal part of the buds showed internal dis—
coloration in many cases.

There was no significant difference between waxed and un—
waxed canes in the amount of injury in this season, partly
because of flaking off of the wax, which may have been due to
cold weather immediately after application, and partly because
only slight injury was present in the whole block.

More than half of the treated canes had practically no
tip injury and the remainder had two or three inches of dead

tip with one cane exhibiting 15 inches of dead tip.
LABORATORY TEST ON SPRAY MATERIALS

Carefully selected single cane samples of (l) unSprayed,

(3) wax.emulsion—, (3) 10% oil emulsion—, (4) 50% oil emulsion—

...40...

treated Viking canes were taken from the field on December 14,

1

1952. Each cane was cut into thirds and each part was sealed

at the cut ends with melted paraffin. The rate of moisture
loss under room conditions was observed for a period of days,

until the canes began to crack from excessive drying.

 

 

 

 

Table 6. Loss in Weight of Sprayed RaSpberry Canes
Original
weight Per cent loss in weight
in grams
Deo.14 ?Deo.15 Dec.16 Dec.l7 Dec.19 Dec.20
Tips Unsprayed 8.2 . 12.9 18.8 29.5 38.7 40.7
Wax 10.1 i 9.3 13.7 20.3 32.8 36.1
50% 511 7.9 , 17.7 25.3 35.7 43.8 44.9
10% 511 10.9 ’ 13.5 19.0 27.0 38.7 41.1
Middle Uneprayed 22.1 7.4 10.7 15.9 25.5 30.5
Wax 24.7 5.5 8.2 12.3 20.5 23.5
50% 011 27.8 7.7 11.4 17.5 30.8 35.3
10% oii 25.0 7.5 10.8 15.8 25.7 30.7
Base Unsprayed 34.5 6.6 9.8 14.5 26.1 28.3
Wax 39.5 5.1 7.5 11.3 18.4 22.6
50% 511 35.9 5.4 8.0 12.1 21.8 25.7
10% 011 44.2 5.5 9.4 14.0 24.7 29.4

 

 

 

 

 

 

 

Table 6 and the graphs in Figure 10 show that the wax

emulsion up to this time served as a protection against drying.

The 10% oil emulsion lot was practically no better than the

check, except in the bottom third of the cane.

The 50% oil

emulsion had caused injury to the canes, particularly in the

upper part.

ferent sections of these canes.

This may account for the irregular loss from dif-

 

 

 

1

1067:”! "m cm 32139194

 

WATER CONTEKT OF RASPBERRY SAMPLES

_ 41 _

Tables 7, 8, and 9 show the percentages of total water

in the samples taken throughout the season, both at East

Lansing and Vineland.

Table 7. Water Content of Samples of Waxed and Unwaxed

Canes at East Lansing, 1931—32

 

 

 

 

 

 

 

 

 

 

Jan.6 Feb.12. Feb.29 Mar.12 Apr.3 May 3..
Cuthbert 44.6 41.8 39.9 38.7 40.2 51.1
Cuthbert, waxed 40.9 41.8 40.3 35.3 40.8
Viking 44.4 41.9 39.1 36.6 40.8 43.2
Viking, waxed 44.0 42.1 37.3 37.7 36.7
Latham 44.4 43.3 41.9 41.9 43.6 48.1
Latham, waxed 44.6 45.2 42.7 40.5 43.6
Average of all 43.8 42.7 40.2 38.5 40.9 47.5
Average waxed 43.2 43.0 40.1 37.8 40.4
{Average not waxed 44.5 42.3 40.3 39.1 41.5

 

 

 

* Heavy showers the previous day. Surface water in low places.
** Last samples taken just as buds were bursting.
Table 8. Water Content of Samples of Waxed and Unwaxed
Canes at Vineland Station, 1932-33
Nov.23 Jan.3 Feb.15 Mar.14 Apr. 18
Viking 45.7 40.6 40.0 39.9 54.1
Viking, waxed 42.2 42.4 42.7 50.2

 

 

 

 

 

 

 

 

-42...

Table 9. Water Content of Various Parts of Viking Canes,

Vineland Station, March 2, 1932

 

T0p Section Middle Section Basal Section

 

 

Av. of 45 small canes 38.2 45.5 43.7
Av. of 14 large canes 34.7 35.4 35.4

 

 

 

 

 

About half of the large canes showed some signs of shrivel-
ling at tne tips.

An examination of Table 7 shows that there was great vari—
ation in the water content of both sprayed and untreated varieties.
Two other points to be noted are that the average water content
of the waxed samples did not deviate significantly from the
average of untreated samples and that Latham, even unwaxed, a
hardy variety, maintained a somewhat higher and more uniform
water content throughout the season than the other varieties.

The curves presented in Figure 11 illustrate these points.

The failure of the wax to maintain a higher water content
in the canes this season can be attributed partly to the fact
that the winter has generally warm, with fluctuating periods of
wet weather and wet soil conditions, and also to the fact that
during the latter part of the season the wax coating had suffered
from partial peeling and flaking.

Figure 12 shows that at Vineland, in 1932—33 the wax was to

some degree successful in preventing loss of moisture.

 

f5
9"
9:
9x

2

a.

37

—iz~

F ll.

Water content or samples or waxed 2 unwed canes
East Lansmg /93/-32

 

    

 

 

V
I mm,

yuan, . and

Ammat med
Average 01!
Average. and

 

 

— Lit..-

 

F 12.

Water content or samples ac med 8. awed canes
Vineland Station. 1932 -33

     

King , waxed ?M_

«0";-

Vlmnq . not

Nov. . . . Apnl

 

_ 45 _
CHEMICAL ANALYSIS

In order to obtain some indication as to what chemical
changes occur tha may affect the desiccation-resisting abilities
of raSpberries, or their susceptibility to injury, certain chemical
analyses were made.

Methods After the canes had been Chopped and dried, as
described previously, they were ground to pass a BO-mesh screen
and stored in tightly corked bottles.

Two—gram samples were subjected to a summative
analysis leading to the ultimate determination of lignocellulose
and lignin, as described by Grist and Batjeg/(lO).

Three grams of the dry material were used for
the determination of total pectic substances and soluble pectin,
according to the method used by Appleman and Conrad (1).

Reducing sugars, total sugars, and dextrin and
soluble starch were determined by the Shaffer—Hartmann method.

Results‘gi Chemical Analyses The results of the chemical
analyses are presented in Table 10 and in Figures 13 and 14.

There was a very slight upward trend in the percentage of
pectin during the winter with a slight decline in sprins. This
agrees fairly well with the results of Lott (18), who found a
lack of seasonal deveIOpment of pectin in some of his samples,
although he found a distinct increase in percentages of bound
water and pectin in samples from raSpberry plots in which the
first two orOps of young shoots had been removed. The analysis

was not sufficiently accurate to indicate whether there was a

_ 4e _

distinct difference between varieties in their pectin content.

Sugars show a gradual increase and then a rapid falling
off with the commencement of reSpiratory activity in Spring.
This is in keeping vith the observations of many investigators
that in woody plants, or in starch—storing plants in general,
the starch is transformed to sugar on exposure to cold.

Dextrin and soluble starches show a decrease during winter
and then a rise at the time of the sharp decline of sugars in
Spring, thus indicating a changing back of the sugars to starch.

Lignocellulose and lignin show a marked decline, parti—
cularly towards late winter, and then a sharp rise at the
time sugars show a sharp falling off. It is probable that the
absolute amount of lignocellulose remains somewhat more constant

than it appears from the curve constructed on the percentage

 

dry weight basis, but, since the lignocellulose makes up the
greater pr0portion of the dry weight, the relative changes in
lignocellulose percentages cannot be accounted for entirely by
the fluctuations of the other constituents of the dry matter.
It seems that there is a breaking down of lignocellulose;
possibly to hemicelluloses and lignin, and from there to pectic
substances and eventually to simple sugars following the scheme
of biosynthesis mentioned by Crist and Batjer (10).

The similarity of the curve of the rater content with the

lignoCellulose and lignin curves was very marked.

-47..

 

 

 

 

 

Table 10. Chemical Analyses of Viking Samples from
Vineland Station —~ 1932—33.
(In percentages of dry height)
Dextrin
Total Reducing and Total Pectic"I
Sugars Substances Soluble Substances Soluble Pectin*
Starch
not not not not not
waxed waxed waxed waxed waxed waxed waxed waxed
Nov. 33
1932 13.73 6.13 4.55 1.35 .15
Jan. 3 n
1933 14.72 6.78 6.95 4.10 1.58 1.42 .16 .25
Feb. 15 -
1933 14.94 6.24 6.47 3.92 1.65 2.15 .20 .32
Mar. 14
1933 12.96 5.38 5.78 2.13 1.80 1.70 .23 .35
A r. 18
£933 3.5 2.43 3.06 2.58 1.70 1.42 .26 .15

 

 

 

 

 

 

 

 

 

 

 

 

* Average of three varieties.

 

_ 48 _

Table 11. Results of Chemical Analysis of Viking

 

 

 

Samples, East Lansing —+ 1931—32
Total Water Lignocellulose"I Lignin‘
Content
Per Cent Dry Weight Per Cent Dry Weight

Jan. 6 43.8 61.4 22.5
Feb. 12 42.7 61.0 20.3
Feb. 29 ' 40.2 60.6 19.1
Mar..12 38.5 59.3 17.6
Apr. 3 40.9 58.2 18.2
May 3 47.5 60.7 21.7

 

 

 

 

 

‘ Average of four determinations.

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_ 51 _
DISCUSSION

It has been shown that the red raspberry, particularly
the Viking, is more susceptible to desiccating conditions than
certain other rwoody plant tissue such as apple twigs.

Under eXperimental conditions desiccation takes place
less rapidly in large canes although, in the field, large canes
suffered more injury than small canes, thus seeming to indicate
that desiccation has not a factor in the increase of injury
with increase in length of canes. However, it should be borne
in mind that the cut canes vere unable to renew their supply
of moisture. Since raspberry canes dry easily, it is highly
probable (and field observations seem to bear it out) that
they also take up moisture readily. Hence, under field con—
ditions, the smaller canes may be better able than large canes
to maintain their moisture content, particularly if a limited
supply of tater and unfavorable absorption conditions (because
of frozen soil or frozen conducting tissue) make it difficult
for the longer canes to supply their upper parts with vater.
In other words, desiccation E21 be a factor, but is has not
been proved whether increased injury in larger canes is due to
desiccation or to other factors such as immaturity. Further
knowledge of the desiccation of large and small canes should
be obtained from a detailed study of moisture fluctuations in
undetached canes.

No conclusions could be reaChed on the effect of prevention
of desiccation on hardiness because (1) adequate protection from

n

desiccation has not attained, and (2) there was absence of suf—

_ 52 _

ficient injury in the material studied to permit cohpsrison.

Besides desiccation as a possible cause of injury three
other plausible causes of injury may be considered: (1) im—
maturity from prolonged growth, (8) immaturity from renewed
growth in the fall, (3) premature development in Spring. Of
these, the last may be eliminated since bud injury, Which is
characteristic of premature develOpment, is rare in the rasp—
berry. Tne second type, immaturity from renewed growth in tne
fall, is improbable, provided the canes have satisfactorily
reached the beginning of their rest period at the time con-
ditions favorin; renewed grovth occur, but otherwise may be a
factor. The fact that the canes which held their leaves longest
were no more susceptible than those which dropped them early,
in a season when drought defoliation was unlikely, is evidence
against immaturity from prolonged growth in the fall. On the
other hand, the greater injury to the taller canes and to canes
which formed early in the season may be evidence that immaturity
is a factor. The greater susceptibility of canes in hills with
the greater numbers of canes is also an indication of prolonged
fall growth since such canes are ordinarily tore vigorous.

In brief, it has not yet been proven whether desiccation
or immaturity from prolonied or renewed fall growth is the pri—
mary antecedent of winter injury in the raSpberry. Much of the
evidence can be construed as supportin; either hypothesis since
many conditions characteristic of maturity are also character-
istic of an ability to resist desiccation.

Possibilities for further investigation lie (1) in a more

detailed study of moisture conditions in the growing, or unde—

tached cane and (2) in a close study or the growth cycle of

individual anes folloved by Observations of vinter injury

in the same canes.
SUXIARY

1. An eXperiment on the desiccation of cut and sealed
raspberry canes shoved that reapberry canes dry more rapidly
than other voody plant tissue such as apple twigs.

8. Large breHChed canes dried less rapidly than small
unbranched canes which raised a doubt that large canes may
be more subject to injury from desiccation, but field results
showed that large canes d3 suffer a greater percentage of
injury of the so—called "dryin;" type than small canes.

3. Under ordinary field conditions plants with six and
seven canes per hill suffered progressively more injury than
plants with only four or five anes per hill. Since the plants
With the smaller number of canes were probably weaker plants,
‘this indicated that the E,reater susceptibility to injury at—
‘Lributed to sucn plants may be in reality loner recuperative
‘power.

4. The results of an eXperiment on the effects of removing
'the first formed canes in summer appeared, in a slight measure,
to corroborate Lott's findings that the removal of the first
tvo crOps of young canes increased the hardiness of the later
Canes.

5. Viking vas found, in 1932—53, to be in a complete

resting condition by late November. The rest period seemed to

be partly broken by late December and probably completely
broken early in January.

6. No difference in tip injury res observed in 1332-3
betveen Viking canes that dropped their foliage early and canes
that retained their tip foliage much later.

7. Artificial freezing at 30F of canes vhich had been
allowed to take up vater produced more severe injury than had
been suffered by canes under ordinary moisture conditions in
the field at nearly —3°F. This, however, may have been due to
rapidity of freezing. Genes in fields where there was excess
surface water suffered injury at or, mostly, just above the
crown. This may be of a similar nature to Johnston's (16)
report of greater susceptibility in buds frozen while wet.

8. Because of failure to maintain a good coating of wax
throughout the season, wax sprays mere rather unsuccessful in
preventing desiccation during winter. Some protective effect
was obtained in 1932—33 but the amount of injury was very small
both on treated and untreated canes.

9. Results of chemical analysis showed a marked decline
towards late winter of lignocellulose and lignin, followed by
a sharp rise at the time total sugars and reducing substances
showed a sharp falling off. The total water content follored
Closely the lignocellulose and lignin curves. Pectins showed
a slight upward trend during winter mith a decline at the

beginning of Spring.

10.

11.

I
U]
UI

I

LITERATURE CITED

Appleman, C. O. and Conrad, C. M. Pectic constituents
of peaches and their relation to softening of the
fruit. Ind. Agr. Exp. Sta. Bul. 285, 1926.

Bregger, J. T. Use of the survey method in showing cul-
tural factors in red raspberry production. Proc.
Amer. Soc. Hort. Sci. 28: 200, 1931.

Brierley, W. G. Notes on the fall flowering habit of
the red raspberry. Proc. Amer. Soc. Hort. Sci.
28: 180, 1931.

Growth studies in the Latham raSpberry.

 

Proc. Amer. Soc. Hort. 801. 28: 182, 1931.
Card, F. W. Bush Fruits. N. Y. 1917.

Chandler, W. H. The killing of plant tissue by low
temperatures. Mo. Res. Bul. 8, 1913.

Fruit Growing. N. Y. 1925.

 

Craig, J. Cent. EXp. Farms. Ann. Rept. 10: 119, 1896.

Crane, H. L Physiological investigations on the resistance
of peach buds to freezing temperatures. W. Va. Agr.
Exp. Sta. Bul. 236, 1930.

Crist, J. W. and Batjer, L. P. The stone cells of pear
fruits, eSpecially the Kieffer pear. Mien. Agr. Exp.
Sta. Tech. Bul. 113: 5, 1931.

Emerson, K. E. Unpublished data, cited in Fundamentals of
Frugt Production; Gardner, Bradford and Hooker. N.Y.
192 .

Gardner, Bradford and Hooker. Fundamentals of Fruit Pro—
duction. N. Y. 1922.

Harris, R. V. E. Malling Res. Sta. Ann. Rept. 1930. p. 137.

Hildreth, A. C. Determination of hardiness in apple vari—
eties and the relation of some factors to cold
resistance. Minn. Agr. Exp. Sta. Tech. Bul. 42.
1926.

Hilton, Geo. C. Master's thesis. Mich. State 0011. 1926.

Johnston, E. S. Undercoolina of peach buds. Amer. Jour.
Bot. 9: 97. 1922.

17.

18.

19.

27.

-55..
LITERATURE CITED (Continued)

Locklin, H. D. Relation of season of pruning out old
Cuthbert raSpberry canes to amount of winter
injury. Eastern Wash. Agr. Exp. Sta. Bul. 9w
(New Ser.) 1928.

Lott, R. V. Correlation of chemical composition vitt
hardiness in brambles. mo. Res. Bul. 95. 1926.

Martin, John H. Comparative studies of winter hardiness
in sheet. Jour. Agr. Res. 55: 495. 1927.

Maximov, N. A. Internal factors of frost a; o drou
resistance in plants. Protoplasma 7: 1

Slate, G L. and Rankin, T. H. Reapberry growing in
N. Y. state N. Y. Agr. Exp. Sta. Bul. 625. 1933.

Stene, A. E. The fertilization of red raSpberries. R.
I. Agr. EXp. Sta. Bul. 22 . 1951

Taylor, 0. M. Varieties of raSpberries and blackberries
with cultural directions. N. Y. Agr. EXp. Sta.
Bul. 278. 1906.

Teske, A. H. and Gardner, V. H. Management methods in
the raSpberry plantation. Mich. Agr. Exp. Sta.
Spec. Bul. 165. 1927.

Thornber, I. S. RaSpberries, blackberries, and loganberries
in "aohizrtoi. lash- gar. Exp. Sta. Bul. 87. 1909.
Upshall, W. H. A study of the influence of summer de—
foliation of red raSpberry canes on their subsequent
behaviour. master's thesis. Mich. State. Coll.
192

higgans, C. C. and Hcppert, E. H. Cane and bush fruits
for Nebraska. Neb. Exten. Circ. 125 . 1925.

Fab :3 SI

ROOM use ONLY.

 

 

 

   

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