GROWTH

AND

OF

D E V E L O P M E N T

THE

B L U E B E R R Y
( V A C C I N I U M

FRUIT

C O R Y M B O S U M

L .

AND
V.

A N G U S T I F O L I U M

AIT.)

by
ROGER STACY YOUNG

A THESIS
Submitted to the School of Graduate Studies of Michigan
State College of Agriculture and Applied Science
in partial fulfillment of the requirements
for the degree of
DOCTOR OF PHILOSOPHY

Department of Horticulture
1949

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TABLE OF CONTENTS
Acknowledgments................................................3
Introduction . . .

4

Review of Literature.......................................... 6
Materials and Methods . . . . .

9

Results
'typical Development
................
14
typical Cluster Development........................... 17
Terminal, Medial, BasalCluster Portion Development. •
.19
Development of First, Second and Third Harvested Berries .22
Comparison of Late Blossoming with TypicalClusters.
• .24
Development of Varieties and Species................... 26
Seasonal Development.............
29
Cluster Location. . . . . . . .
.30
Discussion.

•

•

•

Summary.

•

•

........................

........................

Explanation of Tables
Literature Cited.

.32
.33

........................... 36
.....................

43

Figure 1— Fruit development for the first harvested fruits,
volumes for transverse and axial diameters and ratio
.........................15
of the two diameters
Figure 2— typical cluster development........................... 13
Figure 3— Fruit development for terminal, medial and basal
cluster portions.............

21

Figure 4— Fruit development for first and second harvests
and fruits remaining................................. 23
Figure 5— Fruit development for typical and late blossoming
clusters............. • ................ . . . . . 2 5
Figure 6— Average fruit developmentfor Lowbush No. 1, Rubel
and Jersey for 1946, 1947 and 1943
Figure 7— Fruit development as to position on plant— north and
south exposure and direct and indirect sunlight . .

389904

27
.

.31

-2 -

Table I— Total Monthly Rainfall and Monthly Mean Temperature
for the Months of May, June, July and August at South
Haven Experiment Station............................... 10
Table II— Cluster Size Distribution for Jersey and Rubel,
1947 and 1 9 4 3 ....................................... 16
Table III— Per Cent of Fruits Harvested in the Separate Harvest­
ing Operations and Per CentofTerminal, Medial, and
Basal Fruits Harvested From
199JerseyBerries(1943) • 19
Table IV— Average Duration in Days for the Stages of Fruit
Development.
............ 26
Table V— Average Computed Volumes for Transverse and Axial
Diameters Based on a Sphere and Ratio Volume Based
. . . . 3 7
on an Oblate Spheroid. ...................
Table VI— Volume for the Grand Average, Terminal, Medial and
Basal Cluster Portions of Rubel ...................... 33
Table VII— Volume for Grand Average, Terminal, Medial and
Basal Cluster Portions of Jersey
............ 39
Table VIII— Volume for Late Blossoming Clusters for Rubel,
Jersey and Lowbush No.l. •

40

Table IX— Average Computed Volumes for the Transverse and
Axial Diameters Based on a Sphere and Ratio Volume
Based on an Oblate Spheroid ......................... 41
Table X— Volume for the Grand Average, Terminal, Medial and
Basal Cluster Portions • • • • • • • • • • • • 4 2
Table XI— Grand Average Volume for First and Second Harvests
and Berries Remaining on Plant on September 10 . •

•

.43

Table XII— Grand Average Volume for Late Blossoming Clusters.

•

*44

Table XIII— Volume for Grand Average, Terminal, Medial and
Basal Cluster Portions .............
. . . . . 4 5
Table XIV— Grand Average Volume for Lowbush No. 1 for 1947 and 1943 46
Table XV— Calculated Volume for a Typical Cluster, Fruits Numbered
1 to 8 from Terminal to Basal......................... 47
Table XVI— Average Volume of Fruits for North and South Exposure
and for Fruits Exposed and Shaded to Direct Sunlight.

• 47

-

3-

A C K N O W L E D G M E N T S
Acknowledgments are due to Dr, H. B, Tukey and
other members of the Horticultural Department and to
Dr. E. F. Woodcock of the Botany Department of Michigan
State College and to Professor Stanley Johnston and the
staff of the Michigan Agricultural Branch Experiment
Station, South Haven, Michigan for their valuable
assistance and criticism given during the planning and
execution of the study and preparation of this manuscript.

-

4-

INTRODUCTION
Various native lowbush and highbush species of blueberry have been
used as a source of commercial production*

Only since about 1900 has

the blueberry been cultivated in North America*

The cultivated blueberry

industry has reached importance for many specialized growers and has
increased the need for a basic study on the growth of the fruit.
Botanical Relationship
The taxonomic classification of the blueberry has not yet been defi­
nitely settled*

Camp (4) has attempted a classification but still has

difficulty in placing many of the natural hybrids*
The blueberry belongs in the suborder Vaccinieae of the Ericaceae
or Heath family (&).
with scaly buds*
last.

The plants are shrubs or somewhat woody plants,

The flower is a raceme with terminal buds opening

The Vaccinieae have a calyx-tube adherent to the ovary, which

forms an edible berry or berry-like fruit, crowned with short teeth like
calyx lobes*

The Vaccinieae (Whortleberry group) contains the genus

Vaccinium* a 4- or 5-celled (or imperfectly £- or 10-celled by false
partitions), many seeded berry; Gaylussacia. a 10-celled ovary with a
single ovule in each cell; and Chiogenes* a 4-celled, many seeded berry.
There are four species of blueberries (Vaccinium) which are marketed
in quantity in the United States; namely, the highbush blueberry
(Vaccinium corymbosum L.), the lowbush blueberry (Vaccinium angustifoli urn
Ait*), the dry-land blueberry (Vaccinium pallidum Ait.), and the rabbiteye blueberry (Vaccinium ashei Reade)•
The highbush blueberry (V^ corymbosum L*) is a native from Maine to

-

5-

southern Michigan, and south to the Gulf of Mexico#
important commercial species grown in Michigan#
moist woods, or upland areas#

It is the most

It is found in swamps,

The plants growing to a height of 1 to 4

meters have blue or black fruits, 5 to 10 mm# in diameter and of good to
excellent quality#

The berries ripen in no definite order within the

cluster, but when blossoming, the terminal blossom is last to open and the
basal first#

Vihere several clusters are located on the same fruiting

shoot, the terminal cluster blossoms open first followed by the next more
basal cluster and so on to the most basal cluster#

Some clusters may have

all their fruits matured before September while others have only one or
two berries matured at this time.

From this species have been selected

wild forms of large fruit size and good flavor that have been used in
producing new varieties.
The lowbush blueberry (V. angustifolium Ait.) is native to the north­
eastern United States and parts of Canada.

It is an upland species with

fruits of 5 to 7 mm. in diameter and of a bright blue color ripening
earlier than the highbush blueberry (V. corymbosum). The plant grows to
a height of 5 to 20 cm.
The dry-land blueberry (V# pallidum Ait*) is found in northern
Alabama and northward to Maryland.

The plants growing from 30 to 80 cm.

high, have dark blue to black fruits, 5 to 7 mm. in diameter, and usually
of fair quality.
The rabbiteye blueberry (V. ashei Heade) is native of Louisiana to
North Carolina.

The plant grows 1.5 to 6 meters high and has dull black

fruits 8 to 18 mm. in diameter which are usually of poor quality and often
seedy.

-

6-

REVIEW OF LITERATURE
Relatively few studies have been made of the growth of fruits.
all cases the resulting grand growth curves fall into two classes;

In
(1)

the curve is essentially a straight line as shown by the works of Anderson,
Gustafson, and Sinnot on cucurbits and (2) a sigmoid-shaped curve as shown
to occur in the peach (Prunus persica [L.] Batsch.) (5), fig (Ficus carica
L.) (6), and both sweet and sour cherry (Prunus avium L. and

cerasus L.)

(21— 22).
The sigmoid curve has a period of accelerated growth from blossoming
to 49 days after blossoming in the case of the peach (P. persica) (5) or
22 days after blossoming for the sour cherry (P. cerasus) (22)•
period has become known as Stage I (Figure 1).

This

The duration of the period

immediately following this accelerated rate of growth determines the time
of maturity of the fruit as shown by Conners (5) and Tukey (21— 22) for
the peach and sweet and sour cherries.

The duration of this stage for the

sour cherry (P. cerasus) is 5 days for Early Richmond, an early variety,
and 28 days for English Mbrelo, a late ripening variety.

In this period,

known as Stage II (Figure 1), there is little increase in fruit size but
embryo and seed development is known to occur for the fig (6), peach (5),
and cherries (21— 22).

A second period of accelerated rate of growth

occurring at the end of Stage II and continuing to fruit maturity is known
as Stage III (Figure 1).
reaches its greatest size*

During this last stage of development the fruit
Stage III is inconsistant in duration for

either early or late maturing varieties.
Bailey (3) has reported that the blossoming period of the blueberry
lasts 3 or more weeks and that the harvesting period is from 4 to 6 weeks

-

in length*

7-

Harvests are usually made at intervals of 10 to 14 days#

He

also has reported that the average total number of days from full bloom
to first harvest is 51 to 60 days for 15 varieties#

His study, extending

over a period of 8 years, has shown that the total number of days vary
from 7 to 25 days depending on the variety.

More specifically both Rubel

and Jersey varieties had an average of 54 days from full bloom to first
harvest with a variation of 17 days for Jersey and 11 days for Rubel
during the 8-year 3tudy#
Botanical information concerned with a morphological description
about the genus Vaccinium is limited to a few publications#

Schnarf (16)

states that the inner epidermis becomes a protective layer for the embryo
sac in the Ericaceae family.
megaspore mother cell.
normal type.

One primary archesporial cell becomes the

The embryo sac development follows that of the

According to Schnarf (17) the normal type of embryo sac

development is as follows:

A megaspore mother cell undergoes five divi­

sions before formation of the egg-cell and the embryosac originates from
only one macrospore (megaspore).
phases:

Further development consists of two

(1) leads to formation of a macrospore and consists of two

successive divisions for the conversion of the diploid mother cell into
monoploid macrospores and (2) usually carried out by one macrospore, the
foundation for the fully developed embryo sac is laid down by 3 nuclear
divisions.

This stage is characterized by great growth and formation of

the micropylar and chalaza poles.

After first division of the macrospore

nucleus, the embryo sac elongates and a large vacuole forms.

At the chalaza

end are 3 antipodal cells and one polar nuclei and at the micropyle are 2
synergids, one egg cell and one polar nuclei.

The normal type shows great

—

3*

variation in the second phase (embryo sac formation).
The endosperm is generally cellular throughout, one exception being
V. corymbosum (16).

§tevens (20) reported that endosperm development in

V* corymbosum may begin by formation of cross walls following first primary
endosperm division or by a period of free nuclear division . From the
terminal endosperm cells are found endospermic haustoria, which are multinucleate at first and later having cross walls formed.

Peltrisot (13— 14)#

Artopoeus (1), Stevens (19— 20), and Samuelsson (15) have found the two
haustoria in 32 Ericaceae species.
Samuelsson (15) found hetertrope (amphitropous) ovules in
V. uliginosum. and

myrtillus,

vitis idea while Hofmeister (10) finds a flattened,

symetrical anatropous ovule in V. myrtillus and
ing of the embryo sac development in

uliginosum. In speak­

microcarpum, V. myrtillus, V.

uliginosum, and V. vitis idea Samuelsson (15) states that "the oecurance
of four tetrad cells muct be assumed to be typical.

The embryo sac

becomes developed within a single strong integument; the micropyle is
very small as is the embryo sac.
ment above the tapeta zone."

The egg apparatus lies in an enlarge­

Hofmeister (10) describes

uliginosum as

"the endosperm arises out of repeated binary fission (dichotomy) of one
individual the inferior two-thirds of the embryo sac occupies the cell."
In V, myrtillus he found that "the embryo sac is first cut in half by a
cross wall near the middle and later cross walls formed in each half and
the micropylar end is cut off by a wall; thus the embryo sac is five
superimposed cells without free nuclear division."
The cellular structure of the fruit is best described by Muller (12).
Epidermal cells are square to rectangular with the outer wall thickened,

side walls are pitted.

The mesocarp is made up of an outer 2 to 3 layers

of collenehyma cells with parenchyma cells increasing in size towards the
center of the berry.

Intercellular spaces become larger towards the center.

Gleisberg (7) described the types of berry growth occurring in the
cranberry (Vaccinium oxycoccus). The shape depends upon which direction
growth is greatest from the center of the ovary when in the blossoming
stage.

Should the growth be equal in all diameters a spherical fruit

would result but if the growth is greatest in the transverse diameter
then a flattened fruit would result; likewise, should the growth be great­
est opposite the calyx end a pear-shaped fruit would be formed.

In this

cranberry study all shapes of berries were found depending on which diarn^
eter or diameters growth was greatest.

The fruits do not grow in the

same diameter relationships throughout the season.

Growth may prevail

in one direction for a time then in another and so on until the fruit has
reached maturity.
MATERIALS AND METHODS
The plants used in this study were growing on a Saugatuck sandy loam
soil at the South Haven Experiment Station and the Triangle Blueberry
Plantation, South Haven, Michigan where commercial pruning and fertiliz­
ing practices were carried on.

With the exception of the Jersey variety

used in 1943 all plants used were located at the Experiment Station.

The

soil in the Triangle Blueberry Plantation field adjoining the Experiment
Station land was of a slightly higher organic matter and the Jersey plants
were of higher vigor.

-

10-

During the three years of the study, the driest growing season on
record was recorded in 1946 and the growing seasons of 1947 and. 1943 were
below normal in rainfall*

The following table gives in part the climatic

conditions for the three years compared with the mean*
TABLE I— Total Monthly Rainfall and Monthly Mean Temperature for the
Months of Miay, June, July, and August at South Haven Experi­
ment Station
Rainfall (Inches)

Mean
1946
1947
1943

May

June

July

August

3*60
2.66
4.03
4.99

3.77
1.60
2.73
2.92

2*51
0.02
1.46
1.43

2.94
0.95
0.30
1.26

Departure from Mean
for the Four Months
-6.49
-4.30
-2.17

Temperature (Degrees Fahrenheit)

Mean
1946
1947
1943

May

June

July

August

55.1
55.4
50.3
51.2

65.0
65.9
63.9
63.4

70.4
71.6
63.8
72.8

68.7
66.4
76.5
70.9

Materials
The two varieties and species used were the varieties Rubel and
Jersey both of which are Vaccinium corymbosum L* and a lowbush species,
Vaccinium angustifolium Ait*, selected from the northern part of Michigan
and designated by Mr. Stanley Johnston as Lowbush No. 1.

The Rubel plants

were in their nineteenth growing season and the Jersey plants of the Tri­
angle Blueberry Plantation were in their eighth growing season in 1943.
During 1946 only Rubel was used while in 1947 and 1943 Rubel, Jersey, and
Lowbush No. 1 were used for the study.

-

11-

Typical blossoming clusters of berries as well as late blossoming
clusters were studied.

Those blossoms blooming in mass throughout the

field are here known as typical blossoming clusters or berries.

Late

blossoming clusters are those which were found in full bloom 20 days
after the blossoming period of the typical blossoming clusters.

These

late blossoming clusters or berries make up lass than one per cent of
the entire crop.
For the three-year study 14,000 measurements were made on 457 indi­
vidual berries from clusters selected at random throughout an area of
uniform plants.

In 1946, 30 Rubel berries had transverse and axial

diameter measurements made from blossoming to fruit maturity.

The berries

were allowed to remain on the plant until fruit abscission occurred
naturally or during the measurement operation.

No regular harvesting

schedule was used.
In 1947, five clusters (28 berries) of Rubel, ten clusters (61
berries) of Jersey and one cluster (5 berried of Lowbush No. 1 were
measured.

Besides these typical blossoming berries, one late blossoming

cluster each of Rubel (6 berries), Jersey (6 berries), and Lowbush No. 1
(4 berries) was measured.

Only the transverse diameter measurements were

used since the two diameter measurements made on Rubel the year before
resulted in the same type of sigmoid curve even though the axial diameter
is less than the transverse diameter.
until natural abscission occurred.

The fruits remained on the plant

No regular harvesting operations were

used on the measured fruits.
In 1948, six clusters (34 typical blossoming berries) of Rubel,
twenty-eight Jersey clusters (199 typical blossoming berries), six late

-

12-

blossoming clusters (24 berries) of Jersey, and four clusters (16 typical
blossoming berries) of Lowbush No. 1 were measured by the transverse
diameter.

Of the 199 typical blossoming Jersey berries, 45 berries

(five clusters) were measured by both the transverse and axial diameters.
The berries used for the measurements in the 1948 season were harvested
with the normal commercial harvesting operations.

This is especially true

for the Jersey variety as it was located in a commercial field.

There

were two harvests for the season, August 16 and 31 for Jersey and August
10 and 25 for Rubel.
Harvesting Operations
There are no set times for the harvesting of blueberries,

Tiie fruits

mature over a period of about ten weeks and require several harvests since
some berries of a cluster or even whole clusters are later in reaching
maturity than others.

The fruit in turning from a green to a blue or blue-

black color passes through a very short period of red coloration.

When

the fruit has reached the blue or blue-black color, it is mature as far
as the commercial producer is concerned and is ready to be harvested yet
the fruit may not have reached its highest quality at the time of first
appearance of the blue or blue-black color.
reached maturity

After enough fruits have

a harvesting operation is made.

A second and third or

more harvests are made when enough fruits have matured to warrent another
harvest.

The number of harvests required is variable with the season and

the grower.

-

13-

Measurements
Measurements of the individual berries were made in the morning on
Monday, Wednesday and Friday of each week from full bloom to maturity of
the fruit by means of a vernier caliper and recorded in millimeters.

All

fruits received a transverse measurement and some fruits received in
addition an axial measurement.
Calculations
Each of the diameter measurements were converted to volume (cubic
millimeters) computed on the bases of a sphere or an oblate spheroid
depending on whether transverse or both axial and transverse diameter
measurements were made.

In computing the oblate spheroid volume, the

ratio between the two diameters is important.

The formula used for find­

ing the volume of an oblate spheroid is 4/3 T T a^b where a equals the
%Znrii-

major^axis diameter and b equals the minor^axis diameter.

Turrel (23)

using this formula has tabulated the volumes for oblate spheroids having
diameters of 1.0 to 15.0 in 0.1 units which were used where both trans­
verse and axial diameter measurements were made.

When only the transverse

diameter measurements were made the volume of a sphere (4/377"5^) was used.
These computed volumes for each berry on a given day were averaged to find
the average berry size in cubic millimeters.

Since the position of each

berry in a cluster was known, the clusters were divided into three nearly
equal portions so as to compare the terminal, medial, and basal portions.
The berry volumes for each of the three portions were averaged in order
that the mean berry size could be found on any one day that measurements
were made.

The data on Jersey collected in 1948 will be used in the fig­

ures of the text since the data is based on a larger number of measurements

-

14-

and is similar to the Jersey data of the previous year.
RESULTS
Typical Development
The grand growth curve is of the normal sigmoid shape with three
distinct periods of growth as found in many plants (Figure 1).

Stage I,

an accelerated rate of growth, has a duration of 28 days from full bloom
for both early and late maturing varieties.

The duration of Stage II,

when little fruit size increase is evident, determines the time for fruit
maturity; thus for a single plant the duration of this stage may vary as
much as 42 days.

Stage III, the second accelerated rate of growth, con­

tinues until maturity (blue or blue-black color) of the fruit.

The rate

of accelerated growth is shown by the steepness of the growth curve
(Figure 1).

The second period of accelerated growth is of a slightly

lower rate than the first.
Thereremains much to be determined
the period

of retarded fruit growth.

as to what occurs during Stage II,

It is very possible that seed devel­

opment occurs at this time as it does in other fruits.

From free hand

sections one observes that the increase in flesh size is due to an in­
crease in cell size and not to increase in cell number.
A relationship exists between the computed volumes of the transverse
and axial diameters (Figure 1).
greater berry size and
and III).

The transverse diameter volume gives the

has a higher rate of accelerated growth (Stages I

Stage II is of a slightly longerduration when axial diameter

measurements are made.

Since these two diameter volumes (transverse and

axial) show varying growth curve characteristics, a ratio

of the major

-

15-

IN CUBIC
M ILLIM ETER S

vo lum e

700

STAGE

STAGE 1

STAGE H I

U

600

500

TRANSVERSE
400!

RATIO

\

300

AXIAL

200

100

25
JUNE

20
JULY

25

30
AUGUST

FIGURE 1— Fruit development for the first harvested fruits, volumes for
transverse and axial diameters and ratio of the two diameters,
taken from Table IX (Jersey 194&)

-

16-

and minor axis, using the formula Volume - 4/3 Tf a^b, where a is the
majorAaxis and b is the minorAaxis, can be used to reduce the differences
of the two measurements and produce a more average growth curve.
From the data of the 1946 and 1947 seasons (Tables V, VI, VII, VIII,
and XIV) when no formal harvesting operations were carried out on the
berries being measured, the berries remained on the plant up to 17 days
after first turning a blue color before dropping off the plant*

The

average time for fruits to remain on the plant after turning from the
green to blue or mature color was 10 days for Rubel and 12 days for Jersey*
The cluster size ranges from 3 to 13 fruits per cluster in the case
of the Jersey clusters studied*

The Rubel variety had an average cluster

size of 6.8 fruits based on the 10 clusters used in the measurement
studies for 1947 and 1943*

From these few clusters studied both varieties

are essentially of the same size; namely, 7 fruits per cluster.

The

distribution data for Table II is based on 47 Jersey clusters and 10
Rubel clusters used in 1947 and 1943.
TABLE II— Cluster size distribution for Jersey and Rubel, 1947 and 1943
Number of Fruits
Per Cluster
2
3
4
5
6
7
8
9
10
11
12
13
14
Total

Frequency (Per Cent)
Jersey
Rubel
0.0
4.3
3.5
17.0
3.5
23.4
12.8
17.0
2.1
2.1
2.1
2.1
0.0
99.9

0.0
0.0
10.0
20.0
10.0
20.0
20.0
20.0
0.0
0.0
0.0
0.0
0.0
100.0

-17Typical Cluster Development
The average cluster size for Jersey in 1947 and 1943 was seven fruits#
A representative cluster of eight fruits was chosen to show the individual
fruit growth curves (Figure 2) • The fruits were numbered 1 to 8 from
terminal to basal position within the cluster.
One fruit was removed from the cluster atthe time of the first
harvest,

five fruits were removed in the second harvest and two fruits

remained in the cluster for the third harvest.

The one fruit that reached

maturity for the first harvest was located fourth from the terminal and
had the smallest diameter (10.4 mm.) of all fruits at the time of maturity.
This one fruit had turned to its mature color (blue or blue-black) three
days before being harvested.

The five fruits harvested at the time of

the second harvesting operation were numbers 1, 2, 3, 5> and 7 in the clus­
ter.

They turned a blue color in the following order— 1, 5, 3, 2, and 7*

The sizes of these fruits at the time of their maturity (second harvesting
date) varied considerably, 10.8, 11.1, 11.8, 11.f, and 10.6 mm. respectively
for the five fruits.

Fruits 6 and 8 were harvested in the third harvesting

operation which took place after the measurement data had ceased.

Their

respective sizes at the time of the last measurement date (September 10)
were 9.5 and 8.4 mm.

Fruit 6 had turned blue on September 6 and fruit 8

was just starting to turn (red color) on September 10.
The largest fruit of the cluster is the first fruit to mature.
after a harvesting operation this is true of the remaining fruits.

Even
The

growth curves of all fruits in this one cluster during the first half of
Stage I are the same.

The growth started to vary at the end of Stage I

and continued with increasing variability until maturity of the fruit.

V

-

19-

All fruits except number & had increasing growth curves of various rates
throughout the season.

The growth curve of fruit & had a gradual declin­

ing curve during the latter part of Stage II and up to the time of the
second harvest when five fruits of the cluster were removed*

At this

time fruit 8 had a rapidly increasing growth curve*
The one fruit maturing first (number 4) had the shortest duration of
Stage II and the two fruits (numbers 6 and £) maturing for the third har^
vest the longest duration of Stage II; the five fruits harvested at the
time of the second harvest had essentially the same duration for Stage II*
Of the eight fruits in the cluster four had nearly the same accelerated
growth rate during Stage III*
Terminal * Medial* Basal Cluster Portion Development
The blossoming of the cluster in relation to the portion of the cluster
is:
open.

basal first followed by medial, with the terminal the last blossoms to
Contrary to what might be expected, the first fruits to mature are

not basal.

From the 199 Jersey berries measured in 1948, of the 30*7$ that

were harvested in the first harvesting operation, 9*7$ were basal, 13*98$ were
medial, and only 6*98$ were terminally borne berries (Table III)*
TABLE III— Per Cent of Fruits Harvested in the Separate Harvesting
Operations and Per Cent of Terminal, Medial, and Basal
Fruits Harvested From 199 Jersey Berries (1948)
Harvest

First
Second
Third
Total

Cluster Portion

Total

Terminal

Medial

Basal

6*98
13.98
10.75
31.71

13.98
13.45
9.70
37.13

9.70
10.20
11*30
31.20

30.66
37.63
31.75
100.04

-2 0 -

The different portions of the cluster (terminal, medial, and basal)
develop differently (Figure 3).

The rate of growth for all portions of

the cluster remains equal for the first 10 days after full bloom, the
berries having reached a diameter size of 4.3 mm.

The medial portion of

the cluster has the highest rate of growth with the terminal and basal
portions of the cluster nearly equal at the end of Stage I, the average
berry sizes being 7*7, 8.2, and 7*8 mm. for the terminal, medial and
basal portions respectively.

This relationship remains the same during

the growth in Stage II and the early part of Stage III, the average
increase being 1.1 mm. or approximately 14$.

At the end of Stage III

the medial growth rate is much greater than the basal and terminal por­
tions, the average sizes being 9*5, 10.7, and 9*9 for the terminal,
medial, and basal cluster portions.

The growth of the berries after

the first harvest is nearly the same as during Stage III of the first
harvested berries with the rate of growth of the medial portion being
much less yet the magnitude of the curve remains greater for the medial
than for the terminal or basal portions at the time of the second harvest.
The average diameter sizes at the end of Stage III of the second harvested
fruits are 10.3, 10.5, and 9*6 mm. for the terminal, medial and basal por­
tions of the cluster.

The basal portion of the cluster has the greatest

rate of growth near the end of the season (September or just before the
third harvest) due mainly to fewer terminal and medial berries remaining
in the cluster.

The size cannot be given as their final stage of growth

was incomplete when recording of data stopped on September 10.

-

volume

IN

21-

CUBIC

M ILLIMETERS

700

600

500

MEDIAL

B ASAL

300
TERM INAL

200

100

20
JUNE

JULY

30
AUGUST

FIGURE 3— Fruit development for terminal, medial and basal cluster
portions, taken from Table X (Jersey 194&)

-

22-

Development of First, Second, and Third Harvested Berries
The duration of Stage II is directly correlated with the time of har­
vesting,

The Jersey berries measured in 194# had two commercial harvesting

operations, August 16 and 31.

Approximately 1/3 of the berries remained

after the second harvest (Table III) and were not mature until after
September 10 when the measuring data ceased.

These berries are here re­

garded as the third harvest even though their growth was not yet completed.
The duration of Stage I is 28 to 30 days (Table IV) for all berries
harvested.

The rate of growth of the berries in this stage is the same for

the first and second harvested fruits while those fruits of the third har­
vest have a much slower rate of growth (Figure 4).

The average fruit

diameter at the end of Stage I is 7*3, 3*1, and 6.7 nan. respectively for
those berries of the first, second, and third harvesting operations.
The average berry size at the end of Stage II for the first, second,
and third harvests is S.3, 9*6, ai*d 3.6 mm. respectively, while the dura­
tion of this stage for the first harvest is 14 days, for the second harvest
is 36 days and the third harvest is 56 days.
The second period of accelerated growth continues to fruit maturity
at a less accelerated rate than in Stage I.

The berries of the three

harvesting operations have the same rate of growth for Stage III.

The

average berry size at the time of harvesting is 10.1 and 11.6 mm. for the
first and second harvests.
their growth was incomplete.

The third harvest berry size cannot be given since
The average volume of the fruit is greatest

for the second harvested berries.
The greatest number of fruits were picked in the second harvest (Table
III).

Forty-five per cent of the berries of the first harvest were growing

-

23-

IN CUBIC
M IL L IM E T E R S

volum e

700

600

—

500

—

400

SECOND HARVEST >
F IR S T

300

200

THIRD

HAR VEST

HARVEST

100

25
JUNE

JULY

20

25

30
AUGUST

SEPTEM BER

FIGURE 4— Fruit development for first and second harvests and remaining
fruits3 taken from Table XI (Jersey 1943)

-24on the medial portion of the cluster, twenty-three per cent were terminal
and thirty-two per cent were basal fruits.

The second harvest was made

up of fairly equal portions of berries with thirty-seven per cent ter­
minal, thirty-six per cent medial, and twenty-seven per cent basal.

The

third harvest would have had thirty-six percent of its fruits harvested
from the basal portion followed closely by thirty-four per cent terminal
and thirty per cent from the medial portion of the cluster.
Comparison of Late Blossoming With Typical Clusters
The first measurements for typical blossoming berries were made on
June 5 with the blossoms in full bloom while the first measurements made
for late blossoming berries were on June 25 when they were in full bloom.
The same type of sigmoid growth curve (Figure 5) results for late blossomring fruits as for typical blossoming fruits of Jersey.

The late blossoming

clusters required only one harvesting operation made at the time of the
second harvest for the typical blossoming fruits.
Stage I is essentially the same for both types of clusters.

The end

of Stage I is difficult to determine in the late blossoming berries since
the curve is less abrupt than the typical berry curve.

The average size

of the fruit at the end of Stage I is S. 2 mm. for the typical berries and
S.6 mm. for the late blossoming fruits; thus the rate of growth is slightly
higher for late blossoming fruit.
Stage II is more prolonged for late blossoming berries, being 24 days
as compared to 14 days for typical fruits.
Stage III for both types of clusters has the same accelerated rate of
growth.

The late blossoming fruits have a longer duration of this stage;

therefore, the average berry size is larger, 10.7 mm. as compared to 10.1

-25-

IN C U B IC
M IL L IM E T E R S

volum e

7 0 0 __

600

LATE

BLOSSOMING

500
TY P IC A L

BLOSSOMING.

400

300

200

100

JUNE

JU LY

20

30

AUGUST

25
SEPTEM BER

FIGURE 5— Fruit development for typical and late blossoming clusters,
taken from Tables X and XII (Jersey 1948)

-26for typical fruits at maturity.
Development of Varieties and Species
So far the discussion has been limited to one variety, Jersey, in
giving the various forms of growth curves.

A comparison of Jersey (V.

corymbosum) with Lowbush No. 1 (V^_ angustifolium), which matures its
fruits three weeks ahead of Jersey shows that Stage II for Lowbush No. 1
is of a very short duration (Figure 6).

In comparing the first harvest of

each species, Lowbush No. 1 had a 5 day duration for Stage II while Jersey
had 14 days (Table IV).

The total number of days from full bloom to

maturity (first harvest) is approximately 50 days for Lowbush No. 1 and 70
days for Jersey.

The rate of growth for Lowbush No. 1 approaches that of

a straight line*

The fruit size is on the average considerably smaller

than that of Jersey*
TABLE IV— Average Duration in Days for the Stages of Fruit Development
Variety
I

Stages
II
III

Total
Days

Jersey

Fruits of First Harvest
Fruits of Second Harvest
Fruits Remaining (Sept. 10)

30
28
28

14
36
56

26
20
18*

70
84
94+

Rubel

Fruits of First Harvest

30

15

20

65

Lowbush
No. 1

Fruits of First Harvest

29

5

16

50

The grand growth curve for Rubel (Tables V, VI, and XIII) is compara­
ble to that for Jersey except that it is of a higher magnitude as the
calculated volume was computed as a sphere for transverse diameters in­
stead of an oblate spheroid as in the case of Jersey (1948).
average Rubel had a smaller berry than did Jersey (Figure 6).

On the
The Rubel

-27-

tN CUBIC
MILLIMETERS

volume

700

600

500

400

300
JERSEY,
RUBEL

200

LOWBUSH

NO. I

100

JUNE

JULY

20

30

25
AUGUST

FIGURE 6— Average fruit development for Lowbush No* 1, Rubel and Jersey
for 1946, 1947 and 1948

-28fruit s in the 1948 season grew like those of Jersey in relation to posi­
tion of the fruit within the cluster, the medial portion producing the
largest fruit*

The duration of Stage I remains the same as for Jersey

and Lowbush No. 1, 30 days, but the duration of Stage II for the first
harvested fruits is 15 days for Rubel in comparison to 14 days for Jersey
and 5 days for Lowbush No. 1.

Stage III tends to be somewhat longer for

Jersey than for Rubel as Jersey ripens about a week later.
There is a definite correlation between time of blossoming and matur­
ity of the fruits.

Early varieties such as Cabot, June, and Rancoccus,

and Lowbush No. 1, blossom several days ahead of Rubel and Jersey.

The

maturity for these early varieties is as much as two to three weeks ahead
of Rubel and Jersey.

The number of days difference for blossoming between

Jersey and the early varieties is much less than the difference existing
at maturity of the fruits.
The late blossoming Rubel berries (Table VIII) grew similarly to those
of the late blossoming Jersey.

The Rubel berries have a more distinct

period for Stage II lasting 20 days than do the typical Rubel fruits.

The

magnitude of the curve is greater for late blossoming fruits than for the
typical blossoming Rubel fruits at the time of fruit maturity.

The two

accelerated rates of growth (Stage I and Stage III) were higher for the
late blossoming than the typical blossoming fruits.
The late blossoming fruits of Lowbush No. 1 (Table VIII) had a shorter
duration of Stage II than the typical blossoming Lowbush No. 1.

The growth

rate was somewhat higher in the case of the late blossoming fruits.

4

comparison of the Lowbush No. 1 with Jersey revealed that the rate of growth
was more rapid for Stages I and III while the duration of Stage II was less

-29than 5 days as compared with 14 days for the typical Jersey fruit.
Seasonal Development
The typical growth curve for the Jersey variety of 1948 (Figure 1)
was of a slightly

lower magnitude than for the 1947 season(Table VII)

due to the mannerof computing the volume.

The duration of each of the

three stages of growth was the same for both years but the rate of growth
for Stages I and III was of a more accelerated rate for the 1947 seasonal
curve.

Full bloom for 1948 was five days ahead of that for the 1947 sea­

son and the time of maturity was of the same variation.
A variation in growth for the different portions of the Jersey cluster
occurred for the two seasons.

The medial portion curve in 1948 (Figure 3)

was of the highest magnitude throughout the season while in 1947 (Table VII)
the basal portion curve had the highest magnitude of growth from blossoming
to the end of Stage II at which time the medial portion surpassed the basal
portion and continued to be of the highest magnitude for the remainder of
the growing season.
The late blossoming fruits of Jersey in 1947 (Table VIII) had a higher
accelerated rate of growth for Stages I and III than the typical blossoming
fruits.

For this reason the berry size at the start of Stage II and at

maturity was greater for the late blossoming fruits.
Little if any variation occurred for the two seasons growth in the
case of Lowbush I\fo. 1 (Table XIV) for the typical blossoming fruits other
than for the size of the fruit at the time of fruit maturity.

The 1947

curve had the highest magnitude due to having a more steadily increasing
curve.

One variation cannot be said to be more typical than another since

only 25 berries were measured for the two seasons.

-30The typical fruit growth for the Rubel variety was similar for the
three seasons of study (Tables V, VI, and XIII) . The rate of growth in
Stage I for 1947 remained low for the first 20 days following blossoming
after which a very accelerated rate of growth occurred and continued to
the end of Stage I.

The accelerated rate of growth (Stage I) started

immediately after blossoming for the 1948 season.

The second accelerated

rate of growth (Stage III) was less accelerated in 1947 than in the 1948
season, but neither was as accelerated as the growth of Stage I.

The mag­

nitude of the Rubel fruit growth curves for the three seasons showed the
influence of the weather conditions very markedly.

The berry size being

smallest in 1946 and largest in 1948 when the rainfall was least and
greatest respectively.
The three cluster portions (terminal, medial and basal) for Rubel in
1947 and 1948 (Tables VI and XIII) had variable growth curves.

The curves

were essentially the same with the exception that the terminal portion
for 1948 produced the smallest fruits and in the 1947 season produced the
largest fruits of the cluster.
Cluster Location
The rows of plants from which all berries were measured run in an
east-west direction.

Clusters of fruit studied were located on the

north and south sides of the plants.

The clusters could be exposed to

the sunlight or shaded by the plant foliage.
The growth of the fruits showed a slight variation depending on
which side of the plant the berry was located.

The fruit on the south

side tended to be larger throughout most of the growing season than
did those located on the north side (Figure 7)•

The fruit size difference

-31-

700

m il l im e t e r s

SUN

SOUTH
500
SHADE

N O R TH

300

100

JUNE

25

25
J U LY

AUGUST

FIGURE 7— -Fruit development as to position on plant— north and south
exposure and direct and indirect sunlight, taken from Table
XVI (Jersey 194S)

-32at the time of the first harvest was 0*7 mm. with the fruits on the south
side having attained the largest size.
Sunlight had a greater influence on the fruit size than did direction
exposure (Figure 7)*

Little difference in growth occurred during the

early part of Stage I but by the end of Stage I the fruits exposed to the
sunlight had reached a diameter size of 7*3 mm. as compared to 7*2 for
shaded fruits.
the berries.

During Stage II the variation remained the same between
The size of the fruits exposed to the sunlight averaged

10.9 mm* as compared to 9*9 mm* for shaded fruits at the time of their
maturity.
DISCUSSION
Data were collected during three seasons having below normal rainfall.
During some of the extremely dry weather, particularly noticeable during
the final stage of growth (Stage III), shriveling of the berries occurred.
In the 1946 season the berries did not regain their turgidity as was the
case of most shrivelled fruits in the 1947 season.

This was due to the

more prolonged drought conditions of the 1946 season.

Some blueberry

growers practice irrigation to some extent but usually too late to be of
full benefit for the final swell (Stage III) of all fruits.

From the

data, for irrigation to be effective for all fruits, it must be used
during any dry period occurring in Stage III*

For most locations in

Michigan some, irrigation would be to the advantage of the grower in that
fruit size and quality should be better when optimum water relationships
are maintained in the plant throughout the growing season.
The fruits of the late blossoming clusters were larger and matured
more evenly throughout the cluster than the typical blossoming clusters*

-33These late blossoming clusters always required at least one less harvest
for the removal of all fruits.

With the harvesting operations being the

most expensive to the grower it might well be profitable to delay blossom­
ing two to three weeks by possible application of some growth regulating
materials, thus reducing the number of harvests required for the removal
of all fruits from the plant and also increasing the fruit size.
Fertilizer applied so as to be of benefit for Stages X and III would
be of value in attaining better growth of plant and increasing fruit size
and quality with a good nutritional balance of the elements essential for
good plant growth.
The position of the cluster on the plant is important.

Those clus­

ters exposed to the sun matured their fruit before those clusters found
in the inside of the plant and shaded from direct sunlight.

Pruning of

the plant with the thought in mind of having all the bearing surface
towards the outside of the plant in contact with direct sunlight would
help in maturing the crop more evenly and thus possibly reduce the number
of harvesting operations.
SUMMARY
Development of the fruit of the blueberry is similar to that for
such fruits as the peach, cherry, and fig.
stages of growth namely:

There are three distinct

an accelerated rate of growth following ferti­

lization and lasting about 29 days in the case of the blueberry, a period
of retarded growth for the pericarp, and a second accelerated rate of
growth of the pericarp or the final swell of the fruit.

Fruit maturity

depends upon the duration of the retarded period of growth which varies
from 14 to 56 days.

Fruits will tend to remain on the plant after

-34reaching maturity (blue color) for 12 days in the case of Jersey and 10
days for the Rubel variety.

The average cluster size for Jersey is 7

berries and for Rubel 6.8 berries.
The growth of the individual fruits of an average sized Jersey cluster
are variable after Stage I*

There is no definite order of development of

the fruits in the cluster nor can a definite relationship of size be made
since all portions have some large and small fruits reaching maturity for
the first or the last harvesting operations.
cluster matures first.

The largest berry in the

When it is harvested the largest of the remaining

fruits is then first to reach maturity and so on until all fruits are
mature.
A variation exists between the terminal, medial, and basal portions
of the cluster.

While each portion contributes a third of the entire

crop, the medial portion produces the bulk of the first harvest.

For

the second harvesting operation the three cluster portions (terminal,
medial and basal) contribute 14$, 13$, and 10$ of the total crop.

The

third harvest consists mostly of basally positioned fruits followed closely
by terminal with the medial portion contributing the least.
The berries harvested in the first harvesting operation have the
shortest duration of Stage II while those of the third harvest have the
longest duration of the period of Retarded growth.

The two accelerated

stages of growth (I and III) for the fruits of the three harvesting
operations are of the same acceleration and duration.
A comparison of the growth curves for Lowbush No. 1, Rubel, and
Jersey shows that Jersey produces the largest fruit followed by Rubel
and then Lowbush No. 1.

The growth curves are the same general shape.

-35The rate of growth for the two varieties (Jersey and Rubel) and the two
species (V^ corymbosum and

angustifolium) for the first and third

stages of growth are essentially the same but their times of maturity are
different.

Lowbush No. 1 is the first to reach maturity due to the short

duration of Stage II while Jersey matures last with Rubel intermediate.
Late blossoming clusters which are in blossom 2^ days after the typi­
cal blossoming clusters mature their first fruits about 2$ days after the
first fruits of the typical blossoming clusters are matured regardless of
whether they are of an early or a late maturing variety.
The amount of rainfall determins to a large extent the magnitude of
the growth curves from season to season.

The rainfall does not seem to

have any influence to any degree upon the length of Stage II for the growth
of the blueberry fruit.
Sunlight has a greater influence on beriy size than does the exposure
direction.

Fruits exposed to direct sunlight have a larger transverse

diameter than do shaded fruits.

Fruits with southern exposure are some-

■what larger than those on the north side of the plant due to the amount
of sunlight.

-36explanation

OF TABLES

All volume averages and volumes are recorded in cubic millimeters.
The data presented in Tables IX to XI have the volumes calculated on
the basis of an oblate spheroid while Tables VI, VII, VIII, XII, XIII,
and XIV have the calculated volumes based on a perfect sphere.

Tables

V and IX have the volumes calculated by both methods.
The variation existing between the number of berries used for deter­
mining the average volumes for terminal, medial, and basal portions of
the cluster and the total number used in finding the grand average volume
is due to not using one cluster for the terminal, medial, and basal por­
tions that was included in the grand average as the cluster was broken off
early in the season.

This occurs in Tables VI and VII.

The number of berries used in calculating the average volume decreases
as the berries reach maturity and abscission takes place or they are harvested.
Regular harvesting operations for berries measured in 1946 and 1947
were not carried out.

The Jersey and Rubel varieties used in 1943 were

harvested as in a commercial field.

These harvests occurred on August 16

and 31 for Jersey and August 10 and 25 for Hubei.
In Tables XIII and XIV (1943) the number of berries being measured
was increased on July 12 to replace a cluster which had been previously
broken off in the cultivation operations.
The relationship between volume in cubic millimeters and its diameter
in inches and millimeters is shown by the following:

-37Volume

Diameter

Cubic Millimeters

Millimeters

Inches

100

5.3

0.225

200

7.3

0.300

400

9.1

0.375

600

10.5

0.420

800

11.5

0.450

TABLE V— Average Computed Volumes for Transverse and Axial Diameters
Based on a Sphere and Ratio Volume Based on an Oblate
Spheroid (Typical Blossoming Rubel 1946)

0)
U
UD
0) <
j> 4^
m Q>
to

<D
-p
c6
Q
July

13
15
17
22
24
26
29
31
August 2
5
7
9
14
16
18
19
21
23
26
28
31

EH Q

7.9
7.9
7.9
8.3
8.3
8.4
8.2
8.1
8.3
8.3
8.5
8.8
9.1
9.5
9.8
9-9
9.9
9-7
10.0
10.1
9.0

<D
m
U
CD

>

a>
w g
c
3
c j rH
U O
E-< >

258
258
258
299
299
310
289
278
299
299

322

357
395
449
493
508
508
478
524
539
382

(D
4}
rH ©
CtJ §
•H ©
« -H
<3 Q

i— 1
ttf

5.8
5.6
5.7
6.0
5.9
6.3
6.4
5.9
6.2
6.2
6.5
6.6
7.2
7.5
7.9
7.8
7.9
7.4
7.5
7.4
7.6

102
92
97
113
108
131
137
108
125
125
144
151
195
221
258
248
258
212
221
212
230

*2

<D
rH

O

>

<D
g
•OH 3
-p I—I
nJ o
Ctf>
190
183
186
216
213
233
225
203
224
224
246
268
312
354
397
400
405
365
393
395
322

29

27
24
23
21
18
9
7
5

4
3
2

-38-

June

10
16
18

20
22
24
26
28
30
July-

2
4
7
9

252.4

251.0

14
16
18

16.1
14.5
16.5
16.5
25.6
30.3

25

366.8

452.8
475.0

6
8
11

390.3

512.6

420.2
461.6
481.0

667.0

20
22
25
27
29

1

672.0
526.0

3
5

486.4

8
10
12

604*5
621.4
641.7
551.3
590.6

15
17

316.6
321.0
22
21

338.4
391.0

6

406.6
426.2
20

5

598.6
19

12

693.4
756.2
784.6

1066.0
1066.0

3

2

1118.0

8
6

521.0

5

1140.0
1148.0
860.0

9

20.8
20.0
25.6
28.7
40.8

51.0

8

105.1
114.9
174.3
200.5
207.9
227.3

250.6

284.0

241.3
279.1
281.4
274.0

287.3
298.5

291.8
291.8

311.8

305.3
298.7
298.7
314.2
326.4
333.1
362.7
382.5
394.5
389.6
436.3
438.3
455.0
478.6
527.4
465.5
513.5
532.5
669.I
669.I
669.1
492.5
528.4

- 324.3
344.3
345.3
369.9
385.1
419.7
434.4
444*1
447.6
560.7
555.2
577.2

5

608.2
1
0

626.3
468.5
459.4
509.5
539.9
573.8
614.3
590.4

632.1

3

Number of
Berries

Basal
Average

Number of
Berries

Medial
Average

Number of
Berries

203.3
230.4
254.9
258.5
267.4
299.8

1

486.9
497.2
593.1
591.6
615.5
642.8

32.9
46.3
81.5
134.3
169.3
219.1
227.6
249.4
251.7
245.0
276.5
278.9

163.8
27

13.2
15.9
22.7

24.2

106.7

4

13
15
18

7

60.6

282.2
290.5
291.3
304.0
322.7
336.7
344*9
351.5

25
28
30

September

28

224.8

11

21

August

16.2
16.5
20.7
23.5
30.7
39.6
75.5
118.5
141.7
189.3
204.9

Terminal
Average

<D
-p
CO
Q

Number of
Berries

Grand
Average

TABLE vx •Volume for the Grand Average, Terminal, Medial and Basal
Cluster portions of Rubel (1947)

-39TABLE VII--Volume for Grand Average, Terminal, Medial and Basal Cluster
Portions for Jersey (1947)

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June

10
16

17.6

18

30.4
32.5

20
22
24
26
28
30
July

2
4
7
9

11
14

16
18

21
25
28
30
l
August
4
6
8
11
13
15
18
20
22
25
27
29
September 1
3
5
y
&
10
12
15
17

O 03
f t (I)
© *H
&
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Quu
^t
€
3 f
©

r©H ©
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m
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ff
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ft ©
© •t-i
&o u
ft
Ilf*
s
3i f©t

60

16.4
22.9
26.7
27.9
29.5
50.5
95.3

18

S
a

PQ
pq

24.8
40.0
71.5
125.1
192.9
250.7
304.5
339.3
370.8
379.8
383.4
392.6
393.3
404*4
406.7
419.9
441.2
442.9
448.9
495.7
494.0
562.5
630.8
651.7
701.6
760.9
779.5
753.5
772.4
778.1
664.5
584.4
653.9
542.8
505.3
514-4
540.0
452.0
453.8

E-t
E-* ■<
-a!

iS2=5
5 0CQ
Q

57
52

51

50

194.5
248.5
395.0
339.1
349.8
347.5
362.4
370.7
377.8
392.4
398.6
415.9
417.4
417.4
473.2

17

48
47
46
44
42
39
29
20
19
16
13
12
11
9

529.3
580.7
598.7
638.8
694.2
713.7
724.5
772.6
811.4
761.9
493.2
328.6
397.7
341.0
368.8
412.4
406.8
441.5

ctj crj
-h f t
tJ

©

© ^>

S

18.6

ft to
©
©

© **H
h
ft
ao
u
g
ft
§
3 ©

u
P ®©
18

16

15
14
11
7
6
5

bQ

®

18.1

27.2

27.9
32.4
41.9
78.4

29.9
35.2
49*8
95.3
162.3
237.6
297.2
344.9
373.0
393.2
396.4
403.8
418.5
419.7
423.9
428.5
431.1
450.1
452.2
453.3
489.6
458.4
521.3
558.8
563.9
619.6
699.1
688.5
684.0
696.5
663.5
587.7
598.2
623.5
651.8
695.7
740.6
776.9
427.2
527.2

315.8
339.7
366*4
393.6
395.9
408*4
414.6
429.3
455.3
456.6
478.3
526.5
540.5
639.8
752.1
786.9
841.2
885.5
891.8
856.6

17
16

15
14

860.6
873.7
626.5
674.6
678.0
596.9
461.7
455.5
385.0
422.5
438.1

12
8
6
4
3
2

o
ft ©

©
01
bO
©
ii—1
H as
© *h
© ft
£
£
£
to ©©
ro
S
ft
© >
PQ
f Q < J j! S P Q

23.6

382.1
386.1

464.6
49

,, bO

'H
o

141.8
318.0
268.1

146.2
59

0)

^ ®
18

17

16

15

14
13
10
7
6
5
4
2

-40-

©

-P

05

Q
June

23
30
July
2
4
7
9
11
14
16
18
21
23
25
28
30
1
August
4
6
8
11
13
15
18
20
22
25
27
29
September 1
3
5
8
10
12

P Q

&
F 2?
® £ >
22.4
28.7
37.0
54.1
127.1
200.6
285.3
391.2
499.3

CfH
o
©
Lt ©
© •H
ft ^
Sn
Un
§
3 ©I
©
3
SJ CP

6

14.1

=H
O

©
©
© ■H
ft
g Jh
3 ©©
9
s
a pPQ
q

6

19.6

511.8
517.0
565.8
565.8
575.7
584 >4
591.0
620.3
559.5
612.8
636.8
587.6
691.9
664.5
677.3
683.6
655*5
837.5
723.1
622.3
729.6
755.0
874.7
874.7
850.1

©
bO
aj
© c U
r
Q e3 ©
3 E >
P 3d 5«<
a;

4
2

22.0
32.2
71*7
106.0
140.5
228.8
279.2
293.6
302.7
325.1
325.1
331.5
337.0
343.7
356.0
339.7
370.9
390.9
398.7
446.3
512.0
549.7
575.4
648.9
657*0
713.4
7H.9
758.2
798.3
605.8

696.6
676.6

sCO: ©
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3

cs

«=<

Number of
Berries

TABLE VIII --Volume for Late Blossoming Clusters for Rubel, Jersey and
Lowbush No. 1 (1947)

12.9
25.2
40.1
54.9
84.5
91.3
105.2
109.6
175.6
184.7
184.7
184.7
207.3
285.7
330.7
393.8
479.3
571.6
601.9
647.6
668.1
707.6
675.2
690.3
671.0
656.7
0

5
1

-41TABLE IX— Average Computed Volumes for the Transverse and Axial Diam­
eters Based on a Sphere and Ratio Volumes Based on an Oblate
Spheroid (Jersey 1948)

co
u
© u
©
>
P
CO ©

©
co
u
©

9
Vi -H

§ rH
Vi O
t-t >

■3 §

4.56
5.06
5.51
7.36
7.79
8.03
8.47
8.62
8.89
8.86
8.93
8.91

51.0
69.5
87.1
212.0
268.0
268.0
322.0
333.0
382.0
382.0
382.0
382.0
395.0
421.0
449 •0
478.0
493.0
524.0
572.0
606.0
641.0
716.0
697.0
463.0
493.0
516.0
508.0
564.0
556.0
493.0

3.29
3.94
4.28
5.75
6.14
6.35
6.99
6.97
6.96
6.88
6.99
6.94
7.05
7.22
7.36
7.46
7.55
7.63
7.84
8.06
8.22
8.56
8.48
7.41
7.59
7.55
7.09
7.69
7.25
7.68
7.04
7.23
7.54

©

©

■cp
d
Q
June

July

August

Q

14
16
15
23
25
28
30
2
7
9
12
14
16
23
26
28
30
2
4

6
9
13
16
18
20
23
25
27
30
September 1
3
6
10

9.06
9.32
9.53
9.67
9.82
9.98
10.28
10.46
10.68
11.10
10.95
9.61
9.81
9-95
9.86
10.15
10.19
9.76
9.29
9.30
9.47

©
CO S

V
i
©

>

421.0
421.0
449 •0

3

‘rH

o
©
3
rH

O

>

18.8
33.5
41.6
102.0

119.0
134.0
180.0
180.0
180.0
172.0
180.0

172.0
183.0
195.0
212.0
221.0
226.0
230.0
248.0
278.0
289.0
326.0
322.0
212.0
230.0
230.0
187.0
239.0
204.0
239.0
182.0
195.0
221.0

©

o s
•H 3
P rH
CCJ O
«

>

36.6
51.1
68.1
164.0
198.0
211.0
269.0
267.0

Vi
©
P
D
3

a

CO
©
*H
Vi
Vl

©

cq

45

290.0
286.0
290.0
286.0
297.0
326.0
340.0
374.0
377.0
390.0
439.0
453.0
477.0
555.0
523.0
357.0
382.0
390.0
380.0
406.0
419.0
377.0
317.0
326.0
359.0

44
43
41
40
39
33
20
18
17
14
8

-42TABLE X— Volume for the Grand Average, Terminal, Medial, and Basal
Cluster Portions (Jersey 1948)

a>
1o
June

5
14
16
18
23
25
28
30
2
July
7
9
12
14
16
20
23
26
28
30
2
August
4
6
9
13
16
18
20
23
25
27
30
September 1
3
6
10

Q>
ttO
•rt cd
G U
ed

©
>

11.4
27.3
40.7
53.8
135.1
168.1
226.7
251.4
260.9
287.4
281.8
297.0
297.0
307.5
330.9
337.7
351.5
364.8
383.8
388.9
415.1
450.7
497.0
538.8
533.8

484.4
482.7
523.6
516.0
544.5
550.5
546.3
341.0
370.0
433.0

o

OD
^ CD
a) -h

JO u
g u
•3 o)
3

PQ

199

194
193

192
190
188
187
185
184
174
163
129
125
123
119
118
116
105
58
51

i—1

cti
G
•h
P

C

(D
bO
«d
^

©

© >
E-4 <|J

14.7
21.4
30.9
39.7
107.5
146.2
208.1
227.7
236.6
267.8
265.4
274.5
277.7
285.6
307.1
304.5
323.3
338.1
366.7
356.1
380.9
410.5
440.3
441*8
399.5
443*4
460.0
495.8
509.7
538.4
552.5
566.9
315.5
351.3
400.4

o

oo
©
© *H

Hp u
©
a

©
r—\

bQ

<0 aJ
•
H©
h
t©j
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pq

63

60

59
58
57
53
50
48
47
45

12.0
28.6
43.6
55.8
140.3
194.7
253.7
276.3
288.6
318.9
309.9
326.4
325.0
337.3
353.2
376.2
387.6
4H.4
425.6
438.7

16

©
hO
1
—cd1 cd
© ©
cd >
PQ <

73

11.5
28.4
43.9
56.8
139.8
171.7
212.3
240.9

a

PQ

71
69
68

499.9
547.8
638.0
655.9
580.0
557.8
611.4
582.3

65
60
42
39

591.0
604.9
368.7
402.8
453.6

O »
© •©H
n

U

U
U

P ©

a

PQ

63

251.0
72

568*6

605.0
44
40
20

o ©
©
© •H
n
U
U
"hP ©

37
36
35
32
17
14

272.2
270.4
283.0
282.1
296.6
312.8
327.6
325.9
341.5
349.8
353.5
393.2
416.0
451.5
499.2
509.5
403.7
433.5

466.8
484.6
493.2
510.8
460.0
336.6
361.9
451.6

62
61

60

59
56
53
39
37
33
21

-43TABLE XI •Grand Average Volume for First and Second Harvests and Berries
Remaining on Plant on September 10 (Jersey 1948)

bO

0

-P
10
-p 0
0) >

U U

•H 06
tc

June

5
14
18
25
30
July
7
12
16
20
26
30
August
4
9
13
18
23
27
September 1
6
10

11.4
27.3
53.8
168.1
251.4
287.4
297.0
307.5
330.9
351.5
383.8
415.1
497.0
538.8

O

m

U 0
0 •H
o U
'3 U
3
a

0
cq

72

68
66
63
61
52
47
32
0

-P

xf m
G

©

o >

o u
0 cd
CO X

12.1
21.8
44.9
175.1
278.6
315.6
322.7
332.5
354.4
368.8
391.0

o
u

0
0

3

©

0

S cq

69

416.4
454.6
508.0
655.3
744.6
777.9
810.6

64

60
47
0

•5

<0
©
•H *H
cd U
a ^
© ©
X CQ

a

7.6
17.1
30.3
104.2
159.6
186.1
193.5
201.2
213.2
217.1
226.3
232.2
239.2
246.7
272.2
284.8
298.0
326.5
370.0
433.0

O

0

U 0

0 »H
a
3

0

525 CQ

-44TABLE XII— Grand Average Volume for Late blossoming Clusters (Jersey
1948)

©

-P

cd
Q
June

25
28
30
July
7
9
12
14
16
20
23
26
28
30
2
August
4
6
9
13
16
18
20
23
25
27
30
September 1
3
6
10

0
tuO 0
cd g
0 rH

> O

<aj fc>

20.5
23.3
23.3
104.6
138.1
199-4
231.9
275.0
319.4
349.1
361.4
373.5
378.4
381.9
400.9
404.9
411.2
433.7
442.3
457.8
479.1
497.9
516.3
542.0
596.0
628.5
648.5
664*6
630.0

<
V
h
O

m

U 0
0 •H
Q U
s U
3 0
s PQ

24
12
24

23
21
19

-45-

31
29
28
26
25
23
20
6
5
4
0

12

8
10
9

459.9
486.0
489.9

511.0
8
3
2

0

320.4
361.8
408.8
310.5
428.3
A62.4
460.1
471.3
463.0
482.1
521.6
570.3
619.4
680.1
756.9
887.9
976.5
1032.8
1080.3
524.O
697.0
998.0
1050.0
1150.0

10
12
11

10
9

1

0

36.3
120.4
155.1
201.2
271.3
306.6
360.1
372.3
385.3
419.6
439.7
455.7
471.0
505.6
503.2
568.3
612.6
697.7
775.5
762.3
700.8
772.8
824.0
651.5
882.5
977.5
1150.0
1230.0

h

u

©
PQ

192.2
227.2

469.6

584.6
651.1
717.0
638.0
606.O
786.0
872.0
928.0

44-4
157.3

ho

a

oo

11

3
S

rH

H
o

26
25
32

21.3
60.4
76.6
99.5
198.8
232.1
304.7
318.0
338.7
384.8
-381.9
405.9
395.7
413.7
437.7

«* ©

vo

34

S;

•H
Jh
S*
©
pq

O
©
t-i ©
©
© -h
■rH
©
o

0soo

34.3
114.1
140.1
177.6
265.2
302.0
359.3
368.2
385.4
425.3
429.4
446*0
440*4
467.6
489*9
538.6
566*2
617.0
665.2
724.0
779.2
847.2
901.9
623.5
734.8
905.0
1018.8
1059.0

o
§
3

rH So

U) vji

5
14
16
18
23
25
28
30
2
July7
9
12
14
16
20
23
26
28
30
August 2
4
6
9
13
16
18
20
23
25

S

(0

J
j ©©
©

j
o

June

s

o

5

o i—1

©

TSoP

Cm
O (0
J
©
©H r;©
J5
•9 f-.
3 ©
S cq

Number of
Berri es

TABLE XIII-— Volume for Grand Average, Terminal, Medial and Basal Cluster
Portions (Rubel 194#)

-46table

XIV— Grand Average Volume Tor Lowbush No. 1 for 1947 a.nd 194$

C"- ©
-4- -P
cd
rH Q
June

11
13
16
18
20
22
24
26
28
30
July
2
4
7
9
11
14
16
18
21
23
25
28
30
August 1
4
6
8
11
13

Q>
bO
TS cd
U
c
*
a
■4 It) 3)
Os U >

pH C5

46.7
46.7
66.6
69.4
69.4
75.7
106.1
107.3
104.3
112.0
129.1
152.9
200.3
163.6
191.9
105.9
127.2
146.3
146.3
202.9
212.7
324.6
324.6
363.4
363.4
363.4
224.9
409.3

O

u
©

(0
©
•H
Ih

U
§
3
Q>
5 3 CQ

5

2

0

to ©
-4- -P
cd
rH Q

June

5
14
16
18
23
25
28
30
July
2
7
9
12
14
16
20
23
26
28
30
August
2
4
6
9
13
16
18
20
23
25
27
30
September 1
3
6
10

©
bO
cd
Ci
to g
- 4 cd 2?
O
J* >
rH C5 < ti

48.9
87.1
104.1
111.1
117.4
140.9
173.3
174.3
203.5
161.1
200.7
236.5
269-4
290.7
391.6
441.0
453.2
470.7
492.5
484.9
479.3
493.9
517.4
434.7
505.9
531.3

466.4

«H
O

©
»h ©
© •H

rQ
s
3
3

Ci
©
PQ

9
16
15
14
13
9
15
14

8
6
5
4

473.9
430.1

441.0
469.1
428*4
417.9
451.3
331.3

3
2

-47table

XV

Calculated Volume for a Typical Cluster, Fruits Numbered 1 to
8 from Terminal to Basal (Jersey 1948)

Date

Fruit Number

1
5

June

14
18
23
25
30

7
12
16
20
26

July

30
4
9
13
18
23
27

August

September

6
10

2

8
8

8
8

24
83
108

24
83
108
218

201
222
222
246
246
264
264
230
331
297
450

630
606
—

222
231
246
246

284
306
312
355
367
450
578

716

3

4

5

14
14
24
83

14
14
43

14
14
28
108
152

120

108
201
222
222
227
246
254
264
280
308
331
450
667
861

152

201
222

201

204

250

201
256

286
297
340
340
398
393
433
644

284

306
312
393
539

—

—

269

870
861
-

6

7

8

8

8

8

23
35
93

14
35
108
138

23
35
51
108
141
151
151
185
185
191
191
213
208
227

126
155
165
188
185

201
208
216
231

246
246
268
280
276
374
447

201
204
204
246
246
264
284
312
331
355
382

468
539
—

238
231
209

198
297

TABLE XVI— Average Volume of fruits for North and South Exposure and for
Fruits Exposed and Shaded to Direct Sunlight (Jersey 1948)
Datei
June

July

5
14
18
25
30
7

12
16
20
26
30
August

9
13

Exposed

Shaded

South

North

10.5
37-3
79.6

13.8

12.1

10.5

247.6

240.6

38.7
75.4
204.3
286.9

29.6

200.6

17.1
29.7
148.7

272.2
270.6

267.9
286.9
296.9
316.9
331.7
359.7
386.0
443.8
452.2

280.7
310.4
331.8
395.7
417.5
503.0
551.4

323.6
332.6
344-8

364.4
394.8
439.6
498.3
593.5
683.0

59.0

192.2
254.8
280.6
284.2
300.7
320.4
348.9
367.9
412.5
476.6
491.0

X

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1 t
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. Tukey,

21

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. ___________
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22

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