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UNITED STATES DEPARTMENT OF AGRICULTURE

e228

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owe 20 tly s om e's o®,

Washington, D.C. July 17, 1924

INHERITANCE OF COMPOSITION IN FRUIT THROUGH VEGETATIVE
PROPAGATION.

BUD VARIANTS OF EUREKA AND LISBON LEMONS.

By E. M. Cuace, Chemist in Charge, C. G. Courcu, Assistant Chemist, and F. E.
Denny, Associate Chemist, Laboratory of Fruit and Vegetable Chemistry.1

WITH AN INTRODUCTION
By A. D. SHamet, Bureau of Plant Industry.

CONTENTS.
Page. Page,
MUR MC UOME tana ee See ee ete eee EUSA: 1 | Discussion of results:

INI G0). (2) (1 (51: Oy SS eRe eee eee ae ee ae ae 2 Variability in citrus fruits_._.-__._--____ 14

Experimental procedure: Differences in composition of fruit from

parm iqamet Lid Tad REL ee Eel) SS 3 the same tree and from trees of the
Significance of determinations made-____- 3 SaIMes train do Pi ae ek epee ee 14

IWIGEHGUSULANalYSIS== Ure ee 4 Differences in composition of fruit from
HVOSTITSPES ae ON Oe ies eae ET pede Tey ee ty 5 trees of different strains__________-____ 15
SUTIMAG Yen pk metas. 2 ENR NS a 18
qsiterature cited 1325) £32 4 Lushek S82) Eee 18

INTRODUCTION.

A study of the physical characteristics of striking bud variations
of the important commercial citrus varieties was begun in 1909 in
southern California, to determine the extent and frequency of the
occurrence of these bud variations and their relation to commercial
orcharding. While some variations in trees and fruits have been
found to be due to varying environmental conditions, others have
proved to be inherent. These inherent variations were studied in
progeny rows in experimental orchards in several places in southern
California. From the data on the behavior of these progenies, a
distinction between the fluctuating and the inherent variations has
been established beyond any question of doubt (5, 6).

In the course of the study of the physical characteristics of the
bud variations, and of the trees and fruits arising from them, as
found in established citrus groves in southern California, it was sug-
gested that a knowledge of the chemical composition of the fruits

1C. P. Wilson, C. O. Young, and R. H. Kellner, of the Laboratory of Fruit and Vegetable Chemistry,
collaborated in the analytical work. The authors also wish to express their gratitude to Dr. G. F. Mc-
Ewen, ofthe Scripps Institution for Biological Research, for his advice and cooperation.

2 Italic figures in parentheses throughout this bulletin refer to Literature cited, page 18.

89252°—24t 1

2 BULLETIN 1255, U. S. DEPARTMENT OF AGRICULTURE.

from typical trees of the strains arising from bud sports might be of
value. In developing a method for conducting such a study, it was
decided to analyze samples of fruit from some of the strains haying
distinctly different physical characteristics.

The object of the work was to determine whether or not there are
characteristic differences in the composition of citrus fruits which can
be correlated with the physical characteristics of the fruit produced
by trees or branches of trees belonging to different strains. Tf such
differences of composition exist, the results obtained in these studies
will be of value in measuring the progress of the work for the improve-
ment of citrus varieties through bud selection based upon systematic
individual tree performance records. This bulletin gives the data
from the analyses of samples of lemons borne on trees belonging to
distinct strains of the Eureka and Lisbon varieties.

The results of this work have also suggested the possibility of
securing through bud selection, based upon performance records
which include a comparison of the fruits and their physical character-
istics, strains adapted particularly for oil production, acid produc-
tion, or other specific purposes of lemon by-products manufacture.
In any event, it gives a more definite measure of the comparative
quality of the fruits than is possible from any other method of study
thus far tested. 2

With these preliminary studies and the records of production,
including the quantity and commercial quality of the fruits produced
by typical parent trees of the different strains of the lemon varieties,
and with adequate progenies from these trees now coming into full
bearing, it is hoped that these investigations may be continued to a |
point where they can be made of practical value in the selection of
strains for commercial propagation for specific purposes, and for the
selection of individual trees in those strains as sources of budwood
which will be used in propagating important strains for commercial
orcharding.

‘ THE PROBLEM.

The work here reported was done with the hope of showing the
extent to which fruit from different Eureka and Lisbon lemon trees
varies in composition, whether or not this variation is greater between
different strains of trees than between individual trees, and whether
or not the peculiarities of composition found in the fruit of parent
trees are transmitted to the fruit of progeny trees by vegetative
propagation.

Some characteristics, of course, are inherited by certain species.
For example, the acid and sugar contents of lemons differ from those
of oranges and pomelos. Moreover, certain strains of navel oranges
are so different from other strains as to be readily recognized without
chemical analysis. Thus Washington Navel oranges differ from
Thomson oranges, such differences apparently being transmitted to
offspring by budding.

The extent to which inheritance of composition prevails is of
interest to plant breeders and to citrus growers. Certain strains of
Kureka ane} Lisbon lemons have physical differences which they
transmit to their progeny. An effort will be made to determine
how far this property extends to the elements of composition. If

INHERITANCE THROUGH VEGETATIVE PROPAGATION. a

productiveness and shape of fruit are inherited from tree to tree, or
transmitted -by strains of trees to their progeny, perhaps specific
gravity, percentage of rind, and acidity of Juice are also transmitted
properties. 3

Elements of composition are more readily influenced by environ-
ment than are many physical characteristics of fruit, so that it is
difficult to prove that composition is inheritable. Decided variation
in the composition of fruit from a single tree occurs, two fruits from
the same spur often differmg markedly in composition. The position
of the fruit on the tree, the quantity of water used in irrigation,
fertilization, cultivation, and the stage of maturity of the fruit when
gathered, all influence its composition. By careful methods of sam-
pling, and the selection of healthy trees which have received identical
treatment, the influence of these factors may be reduced to a minimum.

EXPERIMENTAL PROCEDURE.
SAMPLING.

The original plan was to select a few trees of each of the well-
defined strains isolated by Shamel and his coworkers (5, 6), together ~
with some single trees of sporting strains, and to ascertain by the data
obtained from monthly sampling and analyses the differences which
might be expected in the progeny. This plan, however, had to be
modified, for it soon became apparent that trees of nonproductive
strains would not mature enough fruit at certain seasons of the year
to permit satisfactory sampling. Sampling was continued in all
eases, however. Although some of the data obtained may not be
strictly comparable where strains of trees are being considered, they
may be useful in studying inheritance in individual trees.

Study of the data derived from analyses of samples over an ex-
tended period showed that not enough trees had been selected to
make certain that the errors due to variation between trees of the
same strain had been obviated. As it was impossible to increase
the number of trees and maintain the analyses on the original scale,
the number of determinations on each sample was reduced, samples
ere ween less frequently, and as many trees as possible were in-
cluded.

The monthly samples consisted of from 18 to 24 fruits. These
were as nearly as possible representative of the commercial fruit upon
the tree and were selected for size without regard to color. They
were packed in cartons and mailed to the laboratory at Los Angeles,
where analysis was begun, usually within 48 hours after picking.
When any delay was necessary, the fruit was left in the cartons,
whieh were placed in storage at from 35° to 45° F.

In the second period of the work, samples from several trees of
each strain, consisting usually of 25 or more fruits, were taken. These
samples were subdivided into lots of 5 to 7 fruits each, and each lot
was analyzed separately. This method afforded a good opportunity
to observe the variability of fruit from individual trees.

SIGNIFICANCE OF DETERMINATIONS MADE.

Several points were involved in selecting the elements of com-
position to be determined. The feasibility of making the determina-
tion on a large number of samples was considered, as well as whether

4 BULLETIN 1255, U. S. DEPARTMENT OF AGRICULTURE,

or not the element would vary, and whether or not the variation was
sufficient to be commercially important. The object being to dis-
cover chemical or physical differences existing between strains of
fruit of the same variety, the outstanding characteristics were chosen
for observation. Whenever possible, characteristics had been studied
in the field by A. D. Shamel and his associates (5, 6), so that the data
here reported are the results of laboratory work alone. Thus, the
tree characteristics and the yield, color, shape, and size of fruit, and
its seed content, were determined in the field; while specific gravity
of the fruit, percentage of rind, oil, pulp, and juice, and percentage
of acid and sugar in the juice, were determined in the laboratory.
In the second phase of the work, the determinations were confined
to specific gravity of the fruit, percentage of peel, and percentage of
acid in the juice.

Specific gravity is of value in judging the quality of citrus fruit.
First, and probably of greatest importance, is the compactness of the
fruit. Puffy, coarse-textured, hollow-centered fruit has a low specific
gravity. As the juice constitutes nearly two-thirds of citrus fruit
by weight, the specific gravity of the juice, to that extent, determines
the specific gravity of the fruit. For this reason, considering oranges
of equal size, the heaviest ones are usually the sweetest. The texture
of the rind perhaps plays but a small part in determining the specific
gravity. Coarse rind, however, is usually accompanied by coarse
rag and flesh and hollow centers.

The oil content of citrus fruit is of Importance only in so far as
oil is a by-product of the citrus industry. Other factors being equal,
however, the fruit producing oil in greatest quantity and of highest
quality is of most value. Ou occurs in comparatively small quan-
tities and a decided variation in the content is necessary to appre-
ciably affect the value of the fruit.

Rind, pulp, and juice, of course, are primary factors in judging the
quality of citrus fruits. A fruit with a thin rind may not ship as
well as one with a thicker and tougher covering, but the consumer will
choose the former where opportunity offers.

Insoluble solids in the pulp indicate its texture, coarse, tough pul
having a high content of insoluble solids. Cell and partition alts
are included in the material measured by this determination.

Sugar, of prime importance in oranges and grapefruit, is of little
value in lemons. ‘There seems to be some difference, however, in the
quantity contained in lemons of different strains.

Acid is of great importance in all classes of citrus fruit. In oranges
and grapefruit it is an indication of immaturity; in lemons it is the
valuable constituent of the juice, both when the fruit is sold fresh
and when it is used for the manufacture of citric acid.

METHODS OF ANALYSIS.

The methods of the Association of Official Agricultural Chemists
were used in making the determinations, wherever such methods
existed. Otherwise, others of recognized accuracy were employed.

Specific gravity of the fruit was determined by weighing it first
in air and then under water. No difficulty was experienced with
air bubbles clinging to the fruit.

The volatile oil in the peel was determined by the method of Wilson
and Young (8), using the whole fruit finely ground. No method has

a

INHERITANCE THROUGH VEGETATIVE PROPAGATION, 5

been discovered by which the peel can be removed from the fruit
without loss of part of the oil which it contains. Where oil was
determined, half of the sample was taken for the oil determination,
division as to color and size being made as evenly as possible. The
fruit for the other determinations was then pared, as little as possible
of the white rag being left adhering to the pulp. Both the rind and
ulp were weighed, and the percentage of each was calculated, any
oss falling where it had occurred. The pulp was passed through a
food grinder several times and thoroughly mixed, and samples were
taken for the determination of insoluble solids. Each sample was
washed with cold water, placed in a Gooch crucible, and dried at the
temperature of boiling water.

In determining the juice content, a purely arbitrary method was
adopted. The pulp was considered to be the sum of the juice plus
the insoluble solids. The percentage of insoluble solids was obtained
by actual determination, and the percentage of juice was calculated.
This method gives a result somewhat higher than could be obtained
by using mechanical methods, but these methods are arbitrary and
have the disadvantage of being almost impossible of standardiza-
tion, so that duplication of one analyst’s results is rarely possible,
while those obtained by several analysts vary greatly. The figures ~

iven, therefore, represent the theoretical quantity of juice present.

he best mechanical devices, unless extraction with water was used,
peuld recover scarcely 80 per cent of the quantity indicated in the
tables.

Total sugar was obtained by inversion with hydrochloric acid, and
reducing sugars were determined by the methods of the Association
of Official Agricultural Chemists. The optional method, treating
the cuprous oxide with ferric sulphate and titrating the resulting
ferrous salt with potassium permanganate, was used.

Acidity was determined by titrating the cold juice, diluted with
distilled water, with standard alkali solution, using phenolphthalein
as indicator. Repeated determinations, titrating nae boiling and
while hot, did not materially change the results. Apparently any
error due to the presence of carbon dioxide is less than that caused by
the difficulty of determining the end point.

RESULTS.

The results obtained are given in Tables 1 to 6, inclusive. The
description of the physical characteristics of these trees, and of the
yields obtained from them, may be found in the bulletins of Shamel
and his coworkers (3, 6).

Table 1 gives data derived from monthly analyses of the fruit of
trees representing two strains of the Eureka variety—the Eureka and
the Shade Tree.

6 BULLETIN 1255, U. S. DEPARTMENT OF AGRICULTURE,

TABLE 1.—Composition of Eureka lemons of different strains (monthly samples).

| Spe- | Aver-

Insol-

t Total :
cific age 5 Acid
Sample No. Month | grav- | weight| Oil. | Rind.| Pulp. | Juice. | solids | SU84" | “j
picked. : F in mee
ity of of in sui juice.
fruit. | fruit. | pulp. 5
EUREKA STRAIN
(TREE 34-575). Grams.| Per ct.| Perct. | Per ct. | Per ct. Per ct.| Perct.| Per ct.
LTS = Se er June s #222 ue 0.9416 | 115.1 |] 0.35} 38.8) 60.7) 59.7.) 54 tit 4.91
ce) a ied ahs Oe 28 E15 ee wily ee 9355 | 133.3 46-47) 6°52, 941) BL. 2 4 3245p 2 2s 4. 32
gL) OR EAS Ee oa Ce August_____] .9394 141. 2 38. 5 61.1 59. 6 2. 46 223 4, 68
1GGsse =o oe ee ee September -- 9437. 2a. Oil cowl, [esas] eet eee eee 2 eet 5. 60
B607. 340 Saigo e. pid October____- 9624 | 117.8 30.5] 69.6] 68.0] 2.24] 2.99 4.58
18 (THY oe a ts aes November_-_| .9080| 123.7 A101 358: Dub Pbia2 Ie yukon med 4.96
Bb Oe eae es es December--- 9098 125. 0 43.4 56. 3 55. 2 1. 81 1. 93- 4.98
EA Mee Sl OE Pe ae See January____- 9133 | 118.5 40.6] 58.9] 580) 1.65) 1.95 5.01
184/67 ( 2) Selepatae neh betel aie February - -- 9087 123. 0 44.4 55. 4 54. 7 1. 33 1. 98 5. 04
BSBOe tech) 134 22 Miarchis= - 9086 } 126.6 44.7} 54.0} 53.0} 1.98] 1.69 4.90
OOS eke ee BE October__-_-_- 9527 101.0 35. 6 64. 4 62.9 2. 39 2 73 4.70
EVOVERES SOAS foee FOL November __ 9588 104. 8 36. 6 64. 1 62. 7 De Ah 2. 34 5. 09
ATS SRE GO Boas UTa ts ore. December___ 9457 | 119.2 37.8 | 62.1.) 61-0) 1.69} 2.65 5.12
Ce DN at cept aos afi January____- 9322 113.3 38.6] 61.4 60. 4 1, 65 pasy 5.15
PAT DORS ea cy vise, 654 e106 a Wiarche yer 4) see ieee: 120, 2 40.8 || (58. 6.) 57.8]. 1.39') 2.47 5. 22
TRG Rat 8 Si a eddee5 April: #2 xs 9238 111.9 42.6 57. 2 56. 4 tah! 1. 87 6. 21
PZOUER ON Ae ES Ee Se Miay 2282583 9308 107. 4 42.8 a1. 2 56. 4 1. 46 1. 59 4.86
(Average fe -=- i sae ines 30 9822 | 119.1 40.2; 59.5] 58.4] 1.92] 2.12 5. 02
| = OG3 Siar ard a Pee eee Oe +.09 | +.07 | +.05
EUREKA STRAIN |
(TREE 34-75-12). |
0591: ee ee ae aes See Mays 3 sees . 9234 PARI 36. 5 61.9 60. 8 1.78 2. 24 5.61
TUG oye ret ac iei ee 9 ijubo Gee cee . 9342 | 112.3 37.3 | 61.6] 60.5] 1.65] 2.16 5. 21
115305 Ree Sr oe July ie eee 9382 89. 2 32.5 | 67.6] 66.5] 1.54] 1.83 5. 02
GOP Sse gine 2 Tae August_-____- . 9825 107.5 31.0} 68.3 66. 6 2. 44 3. 20 4. 67
ABOGN: BAR AE ES Cth September__| .9639] 116.1 33.5 | 65.8] 64.5 |" 2.07 | 3:25 4.75
1 BY 010) Sey Ore en ee eae October___-- 9707 116. 2 29. 5 70. 4 68. 8 2. 28 2. 92 4.26
1857/4 Deke te ae ee Cae AMWAY ees 9352 | 108.0 24.0] 75.4] 74.6] 1.15] 3.25 4,85
ByS48 2 PVA es wap eee February___| .9148} 122.3 37.4] 62.5] 61.3] 1.90]° 2.98 5. 25
164.5); ree er) eee Miarchizs 52 . 9305 119. 0 34. 4 65.0} 63.5 Deval 2. 49 5.15
B87 sew Ps Cas 2 oc SE ATi eno 9264 129. 7 3oyZ 64. 1 63. 2 IS 2. 28 5. 41
IBOSF ae Poe Mia fe eee 9454 112.5 32.8} 66.6 65. 2 1.89 2) 2 5.79
AS Ae eee LN a Se January__-_- 9631} 109.1 30..9 || ,69..2.} 68.0 [> 1.87 | 2:77 5.12
5 LING): 2 Se ee Ln be os February - _- 9517 105. 6 34. 2 65. 2 64. 1 1. 69 2. 76 5, 22
A/S BOARS S Sieh poe ca a Marche e se . 9500 122. 9 34. 7 65.9 64. 8 1601 }4 2: 65 5. 22
TTICG | (piel Pea ofa be BP ce Apr see . 9277 114.3 41.1 58. 9 58. 0 1. 58 2. 43 5. 06
DOD ws en a ARS Miayiiss- ta 9360 | 120.0 ALLO) STH) P5601. fe 115,93) fr 2520 4.99
Average. ._-.-_- ER Soe ae .94384 | 114.1 34.2} 65.4) 64.1] 1.81] 2.60 5. 10
as LS adh fiestas a os ed a Se jp +.06 | +.08 |-+.05
EUREKA STRAIN bp LL be
(TREE 344-8).
15S 7 aed Spe apie ieee Oy ' Widen ee 9268 110. 9 35. 8 63. 2 62. 0 yes 2. 33 5. 46
LHS Mee he ma Fe JuMeLE tae 9262 121.4 40. 6 58. 6 57. 6 1. 69 1.91 5.14
SG) en el Ve ad Ansiby tote 9444 115. 0 39.3 60.2} 59.0 2. 05 1.95 5.10
GOD ESe Se hse oe eee See AU EUStH en . 9667 123.9 34.3 65. 0 63. 4 2. 56 2. 55 4, 65
GOUT er oe Ee September= | S63Ei ON 2LN4 ee Nes | Se eee 4) eee 5, 44
ia Xfce Se We SEEN OD October __-_-_- 9624 | 117.8 30.5 | 69.6} 68.0] 2.24] 2.99 4.58
IBG2 ar eee os Fe November -- 9500 ; 126.3 BAS ON G45 85 “OL G) |e eee eee 4. 98
1B atte, We epee me vn emer December__-} .9480] 114.3 35.0] 64.8] 63.6} 1.86] 2.74 5.76
Byles ta SS as ie January_-_-- 9054 | 121.7 41.1; 585] 57.6]. 1.47] 2.48 5. 07
Bite St See) February__-| .9178]} 126.1 BO: Oi 09: by |e Gic Ont ea. MO) ees 5. 44
5231) ge eg Caer meee Mareba2 2 - 9149 | 128.5 41.1} 57.7] 56.4] 2.26]: 1.98 5, 22
IBGSieee eee ee Nee 14 he ee 9494 121. 0 34. 6 65. 4 64. 2 LoVe, 1. 86 5. 68
BOSS) so. Te Siti Juries: “24g. 9690 118.8 34.8] 65.6 64. 0 2.50} 2.30 4.83
Bil OGG iio. 5 eee September __ 9774 114.8 30. 6 68.8] 67.3 2. 15 2. 94 5. 09
LOODLE Tk SAAR See tae October-_-_-_- 9705 106. 1 30. 3 68. 7 67. 2 PA fe 1 5. 02
WQS 4 pests po oh hk ee November_-| .9564] 107.4 31,5 | 67.:8 |) 66..2)) 2:35 | 2:45 6.31
143 712 Se penta gt rm toh he 8 January--.-- 9563 | 112.7 31.9 1. 68. 2:1) 66. 741, 2°98 51" 2068 5.15
12 aan pa 2 Me Oe als February_-_-| .9475 | 103.0 33.31 66.6] 65.3} 1.98] 2.59 5.12
11 7 A ae aC a Se March. __--- . 9074 122. 0 35. 1 64. 6 63.8 1. 34 1.97 5. 09
11270, Sh ee ea IS hee pe Miay se 9522 110. 5 38. 4 61.3 60. 4 1. 47 1. 88 5. 22
AV CYAR Otis t bear 2 ee .9456 | 117.2 35.0| 64.6; 63.3] 2.00| 2381 5.17
Se 00S) He. cee fa est eee Biel ee +.06 | +.06} +.04
SHADE TREE STRAIN a ns ai ane aa
(TREE 34-54-11).
(a GUN eS Soa oR November _-| 0.9178 | 143.0 39.7 1) 69, 95]. 58. 6:|. 227 |.22u85 4, 67
TRO oe Red unre BAS March. .._.- . 9140 153. 4 43. 8 55. 8 55. 0 1. 46 2. 46 4. 67
115 fe Je ae ry aed = ee November -.-} .9592] 117.5 36:0] 63.7]. 62.0) 2.57] 2.63 4. 96
‘Py CR 0D a See RD si December-_.-| .9502] 115.3 34.4] 65.7 | 644) 2.129) 272 4. 64
tlh ag NS Seta ea ST January-__--- - 9396 | 115.2 38.4] 61.3] 60.1] 1.89] 2.87 4.85
TIGR oars 2 aby See eel. 2 ake . 9235 133. 1 39.8 59.8} 59.0 1. 44 2. 60 4. 80
VAL cE ara) A se) SS Siege AOR soe . 9405 116. 9 38. 1 60.8 59. 9 1. 56 2620 4. 96
Tht a ee Oe bE Miaiy age b Ss 2 . 9447 113. 6 35.6] 64.5] 63.6 1. 34 2, 24 4.42
JAIVOTARG SE ei UE eee . 9362 126.0 38.2) 61.4] 60.3 1. 88 2. 52 4.75
+.004 |______.- = el Pee ee) ee +.12] +.06) +.05

ee | | | O————————_ |
a a a a Sa

INHERITANCE THROUGH VEGETATIVE PROPAGATION.

TasLe 1.—Composition of Eureka lemons of different strains (monthly sam-
ples) —Continued.

PDe:
Month CEG
Sample No. a re erav-
picked, ity of
fruit.
SHADE TREE STRAIN
(TREE 34-74-4).
TSB ae fee na Viey Scere 0. 9583
LEIS) a ea | une == se ee 9862
HG BG he BS i Cees peo apliviay eee . 967
TAD sek tes pea ATI STSG 9688
TDs ee Doe pain es 2 September -_- 9533
[oC eee Sa ae pee Si } October_=2_- 9620
TEES PAS 2 ch eles ok a ae | November -- 9476
TEE ZUG iad Ne a BS RTS ta December-_-_- 9599
1 B30 (i) PE See IR a ap January...__| . 9356
TB ii Wee See aR NAN Is Ea March= 228 - 9323
USXS8 1/0 Ss 8 i ES ial IMpriler ess 9516
LAO YEAS i pes CON RS ae Sa | October__-_-_- 9672
UTI eethie, * 2p aaleape beddle eaie November _- 9688
TITIES Jens ed Spa oy apa January___-- 9543
TINGS oe WE See eae as February ___} .9694
TSS aye! ie gi pe Se March: 252... $531
USNC UAE) TEENS Sa ee 2 Se . 9585
=. 002
SHADE TREE STRAIN
(TREE 34-74-18). |
Lia ee RT January._--- 0. 9276
TO Dee eee BO March 222-5 . 8930
POG MES ee ses sis eae November -- 9546
11S }7f oe he co MOS ee January_____ - 9616
i orperense ate ho March __-._- 9440
AtKeragessas 1. oe | DP ee aN . 9362
| +. 009
SHADE TREE STRAIN |
(TREE 34-75-14).
TSU oie oe ae ae leMiay _ = so. 0. 9467
EGO sean te et Juiner Yee SS 9548
HG wes eet ene Fk arly 9663
TG HU Se oe 2 es ia Sa ree August______ 9588
BG Oceana oe or ee September_-_| .9500
BG0GHS ee oe eee October__-___ 9717
1B ype She ios Se eR aes March. 22._- . 9036
RSS a ee April. | yA . 9397
iC Rakes Cees I ae May! 328 22 . 9554
TUSTIN GBC AN eteh? | sense o January.s._- . 9491
DMF 4 nee A een Mareh. =. . 93885
RIG ie ee te oe Aprile Be Be 3 . 9475
Oy see Ae sha PS ee Wives 2 eed . $556
ISAS ee ee, | . 9491
+. 003

Grams.
136. 5
112.
135.
131.
136.
115.

ODM ONOMIMOMUIWAD IW

4.41

al lal ol ol cl al ol col ad ol
LERSSRSASKSES

Er ys
Ro

>

eee Total
Oil. | Rind.| Pulp. | Juice. | solids ar sas
in .
pulp. juice
Per ct.| Per ct.| Per ct.| Per ct.| Per ct.| Per ct.
0.26| 45.7| 54.1] 52.8] 2.45] 2:24
.30] 46.7] 53.2] 51.7| 2.82]. 2.38
.31| 43.6) 56.2| 544] 3.91] 3.97
.36 | 37.9] 62.0| 60.4] 254| 3.46
.44| 41.6] 584] 568] 2.64] 3.12
.59 | 31.9] 68.0] 66.1] 2.73| 2.83
.59| 35.1] 64.3] 626] 2.75| 3.04
.64| 33.6| 66.2] 645] 2.57] 2.06
51 | 37.0| 62.7] 61.3] 2.28]. 3.24
-57 | 41.0] 58.6:|. 57-3| 2241 268
.46| 40.5| 59.1] 57.7| 2.41] 221
.74| 41.8] 5821 568] 2.40] 2.49
591 30.2[ 69.7| 67.9] 253] 2.53
.59 | 33.6] 66.1] 64.7| 218] 3.02
.58 | 37.9] 61.9| 60.6| 2.07] 3.09
.46| 40.0] 59.8] 586] 1.87] 2.43
.50| $8.6] 61.2] 59.6] 2.48] 2.75
SFROOt PAPAL daw ide dn G8 +.05 | +.08
0.50} 36.8] 62.6; 61.3] 2.09] 268
.49| 39.8] 59.4] 582] 2.00] 2.89
-63 |. 33.1] 66.7| 64.9| 2.72) 2.51
.65| 33.5] 66.0| 64.7] 2.02] 2.59
Bets | es bs Any See 1.96] 2.23
.56 | $5.8 | 63.7 | 62.3| 2.16] 2.58
2 09 [Sl 2 te [oxsteee | +.10| +08
0.37] 39.1] 60.3] 59.0] 210] 2.20
.39 | 39.6| 60.1] 589] 1.99].2.12
.30| 35.1| 64.6] 63.0] 247] 2.43
-38] 37.6| 622] 60:6] 2.57| 3.64
.38| 35.4| 6441 628] 245] 3.90
-41} 30.3| 69.7| 682] 2.15| 4.08
.51| 37.9| 61.4] 60.3] 1.80] 2.89
441 36.9| 62.8] 61-6] 1.86| 2.47
.53 | 34.8| 63.9] 628] 1.80] 2.25
67 |-33.0| 67.1 .65-7| 2.07| 3.09
51]. 38.2] 61.5| 60.6] 1.59] 2.88
48} 35.8| 63.8| 62.8] 1.54]. 2,01
541 40.5| 59.5] 586] 1.61] 2.59
.45| ‘86.5 | 63.2) 61.9| 2.00| 2.81
week Opal ets Taal ee teks a +.07 | 4.14

BULLETIN 1255, U.

<

w

. DEPARTMENT OF AGRICULTURE.

Table 2 contains data derived from monthly analyses of the fruit
of trees representing three strains of the Lisbon variety—the Bull,
the Open, and the Dense Unproductive.

TaBLE 2.—Composition of Lisbon

Sample No.

BULL STRAIN (TREE |

1-56-12).

TA) = ewe eo =

ae = Fe eae ew eS

iL Yay 2 ees Beer

1-26-9).

DENSE | UNPRODUC-
TIVE STRAIN
(TREE 1-29-12).

lemons of different strains (monthly samples).

oil, | Rina Pulp.
Per ct.\| Per ct.| Per ct.
0.31] 45.4] 53.9
40] 41.5] 58.1
.69 | 43.6} 55.6
.56 | 42.7| 57.0
-72) 39.9] 59.3
-63 | 39.5] 59.7
.50| 38.2] 61.6
.49 | 42.6| 57.1
.50| 37.3] 62.5
.56| 39.5| 60.1
.69| 34.1] 65.7
-65 |] 345] 65.6
.56| 35.8] 641
.56} 39.5] 60.2
.51]° 39.5] 60.4
44] 41.3] 58.4
37 44.1 | 53.7
54] 40.0| 59.6
S602 (ASE to oy
0.36 | 32.8! 66.4
28} 31.8] 67.6
5424 27-0"| 72:5 |
-47 | 38.2] 60.9}
Sas 4+ 32°74 67-0
.46 | 33.2| 66.5
30 37. 2 | 62.7
.39 | 33.7] 66.0
.36 | 36.3] 63.4
.39| 37.5] 62.4
.63 | 31.0} 68.9
.54 | 32.2]. 67.8
.521 36.5] 63.2
CATA T: 7 hn 6251
.41| 39.3! 60.6
44 38. 8 | 60. 6
.438| $4.8] 64.9
+. 01 | =e. 6 Juu.__--
0.34 | 349] 648
.44| 31.9] 67.7
.69 | 36.2] 62.8
.72 | 38.3 | 59.7
.75 | 38.6] 60.8
Ta S474 B51
.66| 37.9] 61.6
755" Sac 7 a 6150
.66| 31.5] 68.0
.85| 343] 65.5
.85| 341] 65.9
.52| 36.9] 63.1
.65| 40.0] 59.7
.58 | 40.1] 59.4
.60| 394] 59.7
56a)? 8%. Bil. BL 2
.64| 86.6] 62.9
+.02 | +.5 |--..---

|
oes
Nant cific
| Aobea vaeads
eee es ity of
| fruit
{
petted ee
| t
|
mie coy! 0. 8914
otly 2 - 9286
November__| .8903
December___| . 8863
| January_____ . 9065
| February ___| .9032
March: ___ . 9032
| J3% ¢) el Ce . 8825
Miy tb eo -. 9142
June 2-¥ lo . 9116
October_____ 9348
November _- 9002
December_-- 9140
January-.-.--- 8728
February ___] .8928
March_____- 8953
JME Se . 8361
. 8979
= 003
May-..--_- | 0.9176
lye oak | 9204
IATISUIS Teo .9113
December_- | . 8989
January--___- | . 8756
= BON Pes 9177
Marche) . 8995
Atprile, #3 . 9046
Vey te ee . 9189
JInie be ae . 9087
November_-_} . 9493
December__-_| . 9426
| January---_-- . 9142
| February-_._-| .9119
VaXy 0) it (Oe . 9663
Misty Shictin <3 . 8550
|
. 9095
+. 003
|
Juries fee 0. 9303
PUY ee 9486
November- - 9138
December-_-_-| .9006
January ____- 8554
February.__.| .9239
March. -____- . 8996
Apri sre . 9015
WEA Yee eee . 9143
JUNO {co ee . 9124
October_-_.-_- | . 9227
December___| .9414
January -__._- . 9280
February ---- 9253
Aprile? 8255
May seu | 8934
. 9148
+. 003

| ; Insol-

Total
uble
Juice. | solids ecu
in Pe a
| =
Per ct.| Per ct.| Per ct.
| 534 1.158] 1.53
| 57.3| 1.35] 1.22
| 543) 239] 219
| 55.8) 216) 2.45
| 581] 192) 298
| 58.31 232] 215
| 60.5) 191} 299
\wiG/4 | 127 | dene
61.81 1L07| 1.06
| 59.4 | 1.33] 1.04
64.4; 1.98] 2.38
| 63.9] 259] 264
| 626! 237] 2.68
(sont i ae Boole wee
| 50.41) 1671 1.26
| 57.4| 173 | 205
52.7| 1.89) 1.58
58.5; 1.85| 1.88
eraty. | £6 =
eae
|
| 65.3] 1.61] 1.62
| 66.6] 1.55] 1.48
| 71.4] 150] 152
| 59.3) 265! 231
| 65.6 | 214 | 2. 29
65.2| 2.04! 2.38
61.6| 1.81} 174
64.8| 1.77} 183)
| 62.5] 1.44] 1.79
| 61.2) 1.91) 1.65
67.0} 2.69| 3.84
66.3| 230! 3.11
61.8| 227| 3.17
| 60.9} 1.84} 291
| 89.6| 1.68| 2.43
| 59.8} 135] 18l
Rie hy Hea Si deceas S=)
63.7| 1.91| 2.24
vane yl +.07 | +.12
64.0] 1.32] 1.11
66.7] 1.45] 1.09
| 61.4) 222) 1.74
58.7 | 1.65 | 1.98
59.8| 1.66] 2.00
64.1! 1.48] 1.94
| 60.8) 1.30| 1.53
60.3! 1.21} 1.29
67.5; .81| 1.24
64.7) 125) 82
64.4/ 2.99] 1.87
61.9! 1.87] 1.84
58.7 | 1.56| 2.69
58.4/ 1.66] 2.02
58.9] 1.44] 1.89
61.2] 1.39] 1.44
62.0| 1.54] 1.68
rhe +. 06 | +.08

ac)

QU OU pe Grr Or Go on ym He oS
iw)
is

PELGBRBBSSE!

1° 2)
for)

—
ed

SReESRs ser RerBVes

QP GO 7 O71 Gon pp a Be a on Oo on
ON KRONOS

—————

&S

Sas

PU OH GH He He Oo OH Co
BRRSRBZSYRSSESERYE

Ht gx
aR

INHERITANCE THROUGH VEGETATIVE PROPAGATION. 9

Table 3 gives the results of analyses when the work was extended
to a greater number of Eureka trees, and Table 4 the results when
the work was extended to a greater number of Lisbon trees.

TABLE 3.—Composition of strains of Eureka lemons.

; Tree No. No.of eee Rind. _| Acid in juice.

ne

EUREKA STRAIN.

Per cent. Per cent.

48.9+1.5 5. 240. 03
46. 31.0 5.5 . 04
37.04 .8 4.8+ .12
38. 8 .4 4.64 .05
35.14 .3 4.7+ .03
35.9+ .6 44+ .04
38. 0+ .9 4.64 .10
37.64 .3 4.74 .07
42. 14+ .2 4.89+ .02
41.8+ .3 4.904 .04
45.2+ .8 4.94+- . 04
42.34 .7 4.80+ .03
41.9+ .3 4.79+ .05
40.74 .5 §. 15 . 03
43.34 .8 5. 01+ .02
44.64 .6 4.58+ .06
43.34 .9 4.62+ .04
44.14 .3 - 4.974 .07
42.14 .4 5. 20+ . 01
31.6+ .3 4.44+ .03
34. 7+ .6 4. 27+ . 04
33. 8 .5 4.53 . 06
31.74 .5 4.29+ .06
35.4 .3 4.694 .05
38. 9+1. 0 4. 80+ .07
41.0+ .4 4.75+ .06
41,.9+ .6 4.934 .03
43.54 .9 4.96+ .08
44.44 .4 4. 67+ .02
38. 5 .7 5. 04+ .07
33.8+ .6 4. 78+ .05
34.9-+ .4 4.394 .06
50. 4-1. 4 4.5+ .08
52.0+ .9 4.64 .02
48.54 .6 4.4+ .09
46.9+1.3 4.6+ .07
53.14 .4 4.9+ .04
41.2+ .4 4.7+ .03
39. 6+ .4 4.8+ .03
34.34 .6 4.4+ .05
36. 6+ .9 4.44 .04
34.04 .4 4.1+ .05
43.64 .5 4. 70+ .06
43.84 .5 5. 08+ . 05
39. 8+ .5 4.52+ .02
38.9+ .5 4. 76+ .03
46.64 .7 4.90+ . 06
45.2+ .5 4.764 .05
42.64 .8 4.67+ .05
34.94 .5 4. 76+ . 04
34.34 .4 4.18+ . 04
35.9+ .3 4.62+ .04
36.9 .5 4.744 .04
37.64 .4 5. 08+ . 01
33. 8 .6 3. 76+ . 06

89252°—247,——_2

10 BULLETIN 1255, U. S. DEPARTMENT OF AGRICULTURE.

TABLE 3.—Composition of strains of Eureka lemons—Continued.

No.of} Specific

Tree No. fruits.) gravity. Rind. Acid in juice.
DENSE UNPRODUCTIVE STRAIN.

June, 1920 Per cent. Per cent.

LE Sa Ne Mi ea NE AES te AEE AS, ah DD et A 11 | 0. 958-40. 002 65. 0O-1.3 4. 7+0. 08
ae G4 A b>. Geet ep 2 E.R i Se 10} .957+ . 003 49.4+ .8 5.0-+ .04
yy A fa at Re ROO Sovak LAS a! SWE eked Ue eee 15 | .959+ .003 47. 6+1.1 4.7+ .05
31. Al J (57.8 fo re aie es CNSR NY 18 PJ eS eet 26 | .962+ .008 51.2+ .1 4.8+ .04

February, 1921:

4 Cy (Yea? ea Oe aN eth SOP) Warp meena Eg th 1 SL eA le 35 | .924+ .003 37.34 .5 | 4.34 .05
a Te A eS ti RS Bae A ee Beka 40 | .925+ .002 35.1-+ .6 4.3+ .01
34-76-32. 1 TER eet RAY ee 0 ee cde 40 | .926-+ .003 39.94 .5 4,9+ .04
Bd— (6-403 toe OR! | UA ei. ea 35 | .915+ .003 39.7+ ..5 4.7+ .04
SUEY BO SRR EN Sates Una yl Oe es 9 2c a Pai 30] .932+ .004 36.8 .7 4.6-+ .08
Sd-fA—-40 2 fo 8s cou yO | BO, shes fp een 40} .923+ .003 40.0+ .6 4.6+ .03

June, 1921
S4— 7A 40 bee tek ee OS CAR oe 13 . 940+ . 008 37.44 .9 4,944 .05
7 TV a Ne FC Ps on LN | ge eae 20 | .920+ .004 39.54 .7 4.47+ .04
A F0—3 48 RE ON OU EER Pe eek 28} .934-+ .002 40. 8+1.0 4.89+ .02
ESO I is a NR 25 . 925+ . 002 40.8 .2 4. 62+ .03
232 EA Fp see | amen Lan) SPS ORT eee MR A) DA cag Ah tres 20 | .925+ .004 43.54 .8 4. 70+ .04
4 Gao a Seek ee Ps A ate Se ee 24 | .920+ .002 39.94 .3 4.49+ .03
SAV StS 46 oe EBs it SAD i OR se 20 | .938+ .002 39.54 .4 4.73 .05

November, 1921
S4-75-37 4k SO BD. Bs 8 29 . 943+ . 002 35.44 .4 4.15+ .05
SAO 3 en SUA 8 ACA 2 Se a 30 - 947+ .001 34.7+ .3 4.30+ .02
84-74-40) 16. cel Dies oP S00 eee GG hee Sen 27 | .945+ .002 36.74 .4 4.18-+ .07
cet iS BERRI hs Seman PL a A de ou Be WY Se 35 . 947+ . 001 33.0-+ .4 5. 07+ .03
SAR A142 ee PB oth GO. ee ee See 35} -..946+ .001 30.8-+ .4 4.40-+ .04

TABLE 4.—Composition of strains of Lisbon lemons.
Tree No. Nove esas Rind Acid in juice.
LISBON STRAIN.

November, 1920: Per cent. Per cent.
Oy lO Fe eh pee oe me carey ot naes "Bie ee 45 | 0.90440. 001 41. 5-40. 4 6. 3-40. 05
Toi on a ek ee le len ten. Ses ee 35 | .898- .001 41.64 .3 6. 2+ .07
Dees De ae ae at ey CR ey 35 911+ .001 40.8+ .5 6. 1+ .08
D2 lG6. te es Mgr ane Se EP aeerageet fring cr Wt ewe, eee et 50 | .915+ .002 37.54 .5 6. 2+ .02

February, 1921:

1 SSS RO URS me RA RACE NM SS TERR ricci He ay YU SE Medel Be ge 40 | .884+ .001 41.84 .3 5.8 . 04
D068 0 Fog eee ot kee OE py eye oe 2 40} .890+ .003 42.0+ .7 5. 8 .03
Dee Oo Fe ry i ee Dat ce eee aa Ee 40 8938+ . 003 39.9+ .4 5.44 .05
7 fas ede ey al rmbiene ai Twine Danie ieea ete pote os 7 To Berk = Salo ye 40 893+ . 002 40.54 .3 6.0 . 06
I 281 es Say OA Li grs onl aa A eee CAR 40 897+ . 003 42.2+ .1 5. 7+ . 04
May, 1921: -
SOS one ae aie Gee eine th oye ION bee IO 25 | .869+ . 003 41.44 .7 5. 2 .03
POSH Sap sy ee pan os ees eee ee ES 30 871+ .001 41.34 .5 5. 5 . 05
a8. te a re RS aN le eee RE 34 867+ . 002 42.0+ .3 5.3 . 04
Da he 9 os Bee ry kk gee ey ete ek 4 30 874+ . 002 42.9+ .4 5. 6 . 02
g E71 Fae Mineo Wiieas See ytiapeas heat) rps kee Geatimytat 9 34 867+ . 002 43. 6+ .2 §.4+ .05
Ji U1 ba OS eee rene Svbiit sox mamniclnlen te) Woes BR Ininhs tee 25 875+ . 004 42.64 .7 5. 6+ .03
1 ET7-{ Goal Wf pe Wie ee SO dS Seal Sie Ce eee ey ce Meee 25 869+ .002 44.14 .3 5. 3+ .03
P8168 digit Scan. Pam ce we cl we 29 | .864+ .001 43.44 .5 5. 5+ . 03
2h 10 ERAS pee bn nae od ae oe 32] .870+ .004 43.2+ .9 5. 6+ .03
Jie 16 Fae eee a a oe ass Bee 29) .875+ .002 43.34 .8 5.44 . 04
January, 1922:
ESS ye eee Ue eancae Raed DERN Palais tieananm 7 0" Uae ges Swe BU 25 | .891+ .003 39. 6+ .3 5.4+ .02
y Ee aera Ye Sd eee Seed 30] .897-+ .003 38. 5 .5 5. 7+ . 03
DG ok ee OA Oe ee ae eS CE 35} .897+ .002 38. 5+ .4 5.84 .02
S127 iy ine Sr Sar egret EO eng A eh heee e 2 30 | .897+ .002 40.34 .6 5.6 .03
P2816. os oe aR oe ee ee ee ee 35} .900+ .002 37.3+ .6 5. 7+ .05
I= 10 st AR a on me Seay ee ee 30} .894+ .002 39. 2+ .5 5. 7+ . 03
AA ee ee ane ae Jeena poole 40] .887+ .002 40.6+ .4 5. 7+ .03
dao pa1G he on pees me tem, Seemed oe ae 35 893+ . 003 40.34 .4 5. 7 .05
OPEN STRAIN.

November, 1920

eee tt pe aay ee tL eee ae re lea ee 50 910+ . 002 38. 0+ .4 5. 6— . 04
Oke so oe oo One ce aa 6 ee em tees 50 920+ . 001 36.44 .4 5. 44 . 03
Daal Pts eee 8 ee op ee eee eee ee 50 924+ .001 36.8+ .3 5.4 .04

February, 1921
te A A iia ie pln hc 5 et A panel Cae alan pS NV Naa A ps sce 35 887+ . 002 42.0+ .4 5. 2 . 10
{ooh eens OS ECS PU OP Cr ES 40 | .884+ . 001 411+ .5 6.4 . 06
1 Dt i beste ea acres © ana eee aber CP TP" IOS, Seal SL 40 | .894+ .002 388.14 .8 5.44 .07
Peay eet SAS Ci Sea re od ha th Re Se ce SM ea 32 887+ . 002 39. 8+ .4 5. 2+ .04
1204146 oe ees eee eer ees 40 885 . 002 40. 6+ .6 6.3 .07

+

INHERITANCE THROUGH VEGETATIVE PROPAGATION,

11

TABLE 4.—Composition of strains of Lisbon lemons—Continued.

Tree No.

Specific
_ gravity.

———_— | | —

OPEN STRAIN—continued.

May, 1921
TiS Be Se GE rn SS ee Ae A MRE A (5 RR 28 | 0. 900-40. 003
Re me ee te he UN eg pes TA ig 19} .898+ .004
TIPO re 2: Ee Se SE See is Le are) ey el 24 890+ . 003
Boa ee tee cee aN 9 } feetney | 4 25 871+ . 003
Ike Sse Se aes oo eS eee Ss ae eee cer anaes wee 18} .903- .005
InnS od Ke aces daa anaes Se pm eget TAG eh ay 24 - 909+ .005
SE ESTES 1S 0) SE A ST iA a ed FN Mpeines, S 22 . 889+ .003

January, 1922
UGS 5 511 SUS SS eee aaa ees Ieee ae See eee ee et 30 . 897+ . 004
Neha = eae eee ee EET ae ee Me he Ae 40 | .890+ .003
SS 2 IR (eae, 4-9 aS A, eee ee Smee Qe 35 . 888+ . 003
Tis EES Sees cn oral agin gE Rept dea ae Sueegs Beene: Oa 35 | .891+ .004
ie ein ee ee SN ee on eee oe ee eee 25 900+ . 003
SO Aiea nae nee RE eee aoe. A eS OS 29 881+ . 002
HESS Sts ee are a, Ee eee ree) ee eee £t 34 903+ . 002

DENSE UNPRODUCTIVE STRAIN.

November, 1920:
Tisspad 5 poe Merten ae Natit yagi td Shee gene e 1 Or 50 896+ . 002
Ty eat at Fs Sn Moat Caran iada ee! Mh ae gee anes 35 911+ .001
Tosa PR SESE PRAY SAE ATR ae ae Se 30 893+ . 002
TS Sey oS Bacal ait tae Liles sais REE cod aeiniair ieee 3p 35 892+ .001

February, 1921
2 Seater cet hs Sot ae Ae eR ey eye gS 40 898+ . 003
TRESS TY y/o fe ae re Oe See ean Oe Wee one Be 40 895+ . 002
Lay4l Si Lere Pew than pallets Biwi stale te omeeh ieat eae Te Waeee Se 40 895+ . 002
ea! Sy Ae Gea eens Peet eee er eee ee eG ae Oe 40 889+ . 004
Se 8 a ga pre Ya ane oe ewe te rE 40 901+ . 002

May, 1921:
4 yb oy LJ Lt De ei oat, ea Saati Sen eitienes Cpe ape de 30 | . 895+ .003
TOA sai ee EN, SCE: GEES as Caen Ae 20 . 889+ .002
lad Riyal es BAe eile eats tnd Pema enS Sie 18 | .904+ .002
14) Sd AE OS SR Beer te meee Meenas Ren YS 21 . 893+ . 002
TST ST/L he SSUES ae Ace ES ba ee eee) Rn pare a, 31 . 894+ . 002
TDA RE eS rs A Eas eee ee Le ee Oe 20 906+ . 003
pe A ee Sie ot BEN See ed 17 899+ .005

January, 1922
OSB ee eh Ae S00 eo as 28 913+ . 004
AP eo SRE. OOUO. eEREB of OGL 24 | .909+ .002
78 OE ee PE A) ORR Tel 25 | .908+ .004
DISS) er cameaee epee aan nance, gare a area marae iene eoaereane Sie 25) .894+ .004
RD Se eee ce ee. ot PRR) EON 30 . 906+ . 004
LS a ne ON i ak See ee Deeneeeae On 30 | .908+ .004

BULL STRAIN

February, 1921:
risa ip aine = Reet ese eee RAN SN ee Se 44 | . 888+ .002
TRG oS ee a SS Oe ae, oe ne ee ee one 40} .892+ .003
Ara eens byw rake mn Wet! fee 35 . 896+ . 003
Ht pia eemeR MTR Cor Sri star A unite ter ey Ab 40 | .894+ .002
TSS TE (ne I Do ng egg pr ee 40 889+ . 003
idl hee re ae PURGE Sule We Ci LY oe hg a 40 896+ . 003
Te a ed eg 2 40 903+ . 002
iN epee rman ene. A SS Ba ee es 40 882+ .002

May, 1921
era Ieee ey ae Ty MEY op AE 25 873+ .002
JIRTCRE TIS aS pe Sa Rae Se SR ea oS ee a ae 29 | .868+ .004
Thee Se es Le fag FUE er I GR Dr ae ns 30 877+ .002
Lie Pal Se et er a ee ee tae eee oe 25 . 868+ . 002
TS Wiel(R eit te ee Eee eee nes ae 26 . 860+ . 004
era er ee wees rn ee ei ee 28 875+ . 003
Sea Ward pe ere A ail en ape RON SNE Be ue Se AN 8 ok 25 860+ . 001
rey Ere ets mere Mice UA A ee Sa 30 878+ .001
Ea maeyea sive eee en eae SL)! pe eg de oe ee 35 871+ .003
See A A ea Lat 27 . 860+ . 002

January, 1922:
Nein nema Pee sje eB ie Aa 2s oe ay ee he 35 880+ . 004
Te FTP Lea od A ee eee Ae eee pe ae 35 881+ .002
Dag ee ek ee ee ee ee 40 874+ . 003
eisai apie te Ye A a 35 876+ . 002
Her Alh. 2 a e See e e e e e 40 885+ . 002
Refs a i on he og eee ee eS oe Se 40 892+ . 002

Orbs COM WOH “TI 00 OO He > 01 00

DORON STE OUNTWWOMHFE PP RROD WOR

pares. Wi ls Awe (ave P) wet ete Omer CM Ye ©
ANNDAaI IT HMOIPWMAINWKLPNTO POBDWAIDPHLr

5. 0352

ore

GINO oTST RT
NOL Nw OW
iF AP iE IEA

Or or or Or Or Or O11 Or Orn > Or Cn Or Or Or Or Or Org
RENAE MOORS NS Imeneimen om po
KARE PRR APY OREO

He» He Or Or > OD

ororor
COND
FF

CAN EN EN CANAAN NNN HON SON NN OTN OTS
bo

12 BULLETIN 1255, U. S. DEPARTMENT OF AGRICULTURE,

Table 5 contains a summary of the data in Table 3, and Table 6 a
summary of the datain Table 4. The probable error of the average,
the combined average, and the combined probable error, were calcu-
lated by using Mellor’s formulas (3).

TaBLE 5.—Average composition of strains of Eureka lemons (Table 3).

Number | Number Specific

Date. of trees | of fruits A Rind. Acid in juice.
sampled. | analyzed. gravity.
EUREKA STRAIN.

1920 Per cent Per cent.

a Caen 0 ee Ge Me I pee Me hn 2 30 | 0. 948-40. 0014 47. 140. 84 5. 31-40. 024
1921

MGHTEHARY? OCs toe BAe 9 Bors 6 189 927+ .0011 36.9+ .17 4.60 . 020
Pec eS OME 2 kr Qa aglla teraPee N Matec Be sep 11 303 901+ . 0006 42.44 .11 5. 05 . 007
ING embers: 22 Ae) tes eee es 5 145 956+ . 0005 33. 4+ .17 4.43+ .019
GombpIRER' Sveraves= 2 FL SSeS Hl. WEES Leds eeaen ees 932+ . 0003 39. 1+ . 08 4.96+ .006

1921:

SMALL OPEN STRAIN.

INHERITANCE THROUGH VEGETATIVE PROPAGATION. 13

TABLE 6.—Average composition of strains of Lisbon lemons (Table 4).

Number | Number Gnecine
Date. of trees | of fruits neer: ¥ Rind Acid in juice.
sampled. | analyzed. 8 y-
EL YOUN TD BOTT of
LISBON STRAIN. |
1920: Per cent. Per cent.
4 INOW ORD GI ay FL em 4 165 | 0. 905-0. 0006 40, 9-0. 20 6. 20-9. 018
1921:
HWebruany eee oe ee seek co ede ol IS 200 | . 888+ . 0008 41.9+ .09 5. 75+ . 018
11 inci pela pain en eg ler | 10 293 | .869 . 0005 Boe il | 5 Ave O10
1922: |
LEV TT ONT 0 ES SNE ee eens Rs | 8 260 895+ . 0008 39.4+ .15 5.64 .010
Combined averages____-___._--_- fue aE te olf Aik oye 886 . 0003 | 41. 8-+ . 06 5. 64-L . 006
OPEN STRAIN. |
1920: |
November......-- Ging ony nr | 3) 150 | 921 0007 |’ 37.04: 21] 5.50 . 021
921: |
TENE) 2) af B15 1s epee ah pe eee a al | Out 187 886+ . 0007 40. 7+ . 22 5. 24+ . 027
IVE EVO LTE LORE! Are room cl ey 7 160 891+ .0013 40.9+ .20 5. 08 . O11
1922:
Saran y 27 8 ARK SINE 2 ee i. 228 | . 893+ . 0010 88.34 .13 | 5.32+ .013
Gombmnedraverices oe eae |. me Ne . 900-£ . 0004 | 39, 5 2 12 | "5. 234". 007
DENSE UNPRODUCTIVE STRAIN. |
1920: | L
Naver berate. ete Leet a se Pay 4 150 - 900+ . 0008 40.44 .17 5. 94+ . 009
1921:
HDR Aye oe eee See eye | 5 | 200 . 897+ .0010 40.6 5. 50-— . O1€
Mig aeres Sey fee yee oe OR h eer 7 157 896+ . 0011 39. 6a) ..15,| 5 (5. 09==). 012
1922:
amtiany eps Sees El ee Se 6 162 907+ .0013 40.1+ .15 5. 51 . 016
Combined averages sen. ae Be el | CA and . 899+ .0005 40. 23-08 | 5.57: . 006
BULL STRAIN.
1921:
TENET 0) 1) Fo eee ene Re I at MN SIT 8 3h . 892+ . 0008 42,2+ .17 5. 38 .015
Sa WTS ps a a 19 280 . 869 . 0006 45. 5 . 08 §. 22+ .0i1
1922:
5 ENE ELE Be cB Se a TO | 6 225 882 . 0009 40.14 .13 5.72: .013
@ombimedraverages=-s) =. sce eet) oe eee. laze oeeee . 877+ . 0004 43. 8+ .06 5. 42+ . 007

14 BULLETIN 1255, U. S. DEPARTMENT OF AGRICULTURE.

DISCUSSION OF RESULTS.
VARIABILITY IN CITRUS FRUITS.

Certain differences in the data reported exist. It is necessary to
ascertain whether these differences in composition are inherent in
the fruits of individual trees or whether they extend beyond the indi-
vidual tree and constitute a difference between strains.

Citrus fruits are variable in composition, and the time of year in
which lemons mature has a bearing upon their composition (1). In
comparing the composition of fruit from different trees, therefore, it
is impossible accurately to compare samples from two trees unless the
fruit was gathered at approximately the same time. This does not
mean that the samples must be picked the same day, or even perhaps
the same week, but they should be picked in the same month. Cer-
tainly samples gathered during different seasons of the year are not
comparable. Such precautions become unnecessary only when the
number of samples is so great as to preclude the probability of error
from seasonal variations in composition. Therefore the comparisons
obtained in the later experiments are between lots of fruit gathered at
approximately the same time.

In order to determine the significance of any difference, not only
the variation in composition between samples of fruit from the same
tree, but also the variation in composition existing between samples
of fruit from different trees of the same strain must be carefully
observed. Only in cases where the difference as a whole between
strains is greater than that between trees of the same strain can it
be safely assumed that a significant difference exists.

DIFFERENCES IN COMPOSITION OF FRUIT FROM THE SAME TREE AND FROM TREES
OF THE SAME STRAIN.

The variability in fruit from the same tree is shown best by the
probable errors given with each determination in Tables 3 and 4.

As the number of subsamples making up each sample to some
extent affects the probable error, unusually large errors were some-
times due to the small number of subsamples taken. The difference
in composition of samples from the same tree gathered at different
times also varies. Notwithstanding these facts, it seems that, as a
whole, where 25 or more fruits constitute a sample, different trees
show approximately equal probable errors.

The variation in specific gravity of Kureka lemons, as shown by the
probable error, is from 0.001 to 0.008, being in most cases from
0.002 to 0.003. Only 3 of the 77 samples reported in Table 3 show
probable errors in specific gravity greater than 0.004. Naturally
the variation in rind is greater than that in either specific gravity or
acidity of the juice. This is due in part to the nature of the fruit
and in part to the accuracy with which the analytical determinations
can be made. The probable errors in this determination vary from
0.1 to 1.5, with an average error of approximately 0.6. Eight samples
have errors of 1 or more, but 6 of the 8 samples consisted of 15 fruits
or fewer. The samples are rather uniform in acidity, the probable
errors ranging from 0.01 to 0.12, the average being close to 0.05.

The variation in the specific gravity of Lisbon lemons is from 0.001
to 0.005, with an average midway between these limits. The prob-
able errors for the rind vary from 0.1 to 1.5, with an average of

-

INHERITANCE THROUGH VEGETATIVE PROPAGATION. 15

approximately 0.5. The probable error of the acidity results vary
from 0.01 to 0.11, the average being approximately 0.04.

Any differences in uniformity can be accounted for by the fact that
the Lisbon variety afforded a better opportunity to get uniform
samples. The average number of fruits to a sample was 33 for the
Lisbon, against 26 for the Eureka; but the number of samples con-
taining less than 25 fruits was 29 in the case of the Eureka, with only
10 in the case of the Lisbon.

Taken as a whole, the variability in fruit from the same trees is
not great in either variety; neither is the variability of the fruit from
different trees-of the same strain. The probable errors of the three
determinations are about equal when comparisons between strains
are made. Isolated cases of high average probable errors are usually
due to the fact that a single instance of a high probable error has
affected the average.

When the differences in composition of fruit from trees belonging
to the same strain are considered, only a few trees have fruit which
varies greatly from the general average. Both the monthly samples
and those taken later have instances of variation, however.

In the case of the Eureka trees, the results on the monthly samples
(Table 1) show that the fruit from tree 34-57-5 has a lower specific -
eravity and a higher percentage of rind than the other two trees of
the Eureka strain; also the percentage of sugar in the juice is some-
what lower than that shown by the others. The later results
(Table 3) show that the lemons from tree 34-73-7 had a higher
specific gravity and a lower percentage of rind than any ot the other
samples of the group taken at the same time. ‘The fruit of the Shade
Tree strain (tree 34-74-13) (Table 1) is high in acid, but only five
monthly samples were available for consideration. Among the trees
sampled later, tree 34-76-56 (Table 3) of this strain shows one
peculiarity; each of the three times it was sampled the fruit from
this tree had a higher acidity than that from any of the other trees
of the group sampled at the same time.

There are similar instances in the Lisbon variety. ‘Tree 1-27-10
of the Lisbon strain has a higher acidity than most of the other trees
of the strain. The two samples taken from tree 1-27-11 have low
specific gravity and high percentage of rmd. In the Dense Unpro-
ductive strain the four samples from tree 1-30-9 have a high per-
centage of rind and low specific gravity. Tree 1-29-8 apparently
produces fruit with a tendency in the opposite direction. The fruit
of tree 1-29-12 has a high percentage of acidity. In the Bull strain,
tree 1-56-17 has fruit with the highest acidity of the group, but there
seem to be no other instances of consistent tendencies.

Considering the matter as a whole, differences in composition of
fruit from different strains of trees are not greatly affected by the
unusual composition of fruit from the few trees consistently above
or below the average.

DIFFERENCES IN COMPOSITION OF FRUIT FROM TREES OF DIFFERENT STRAINS.

Some differences in the composition of lemons from different
strains of trees exist. Are these differences significant? What con-
stitutes a significant difference for this purpose?

When the methods of comparison of Wood (9) and Pearl and
Miner (4) were used, practically all of the strains showed great

16 BULLETIN 1255, U. S. DEPARTMENT OF AGRICULTURE.

differences. When the numbers of items in the series to be com-
pared were about the same, use was made of ‘‘Student’s” method (7),
casting out the items most favorable to the desired resulé to make
the items even in number. None of these methods, however, were
satisfactory in most cases. The method of Dr. George F. McEwen,
of the Scripps Institution for Biological Research, at La Jolla, Calit.,
therefore, was used (2) and Doctor McEwen’s advice was followed in
the treatment of all comparisons. Even when all the methods
showed significant differences, these differences were not considered
strongly positive unless a majority of the group samples (Tables 3
and 4) showed the difference. No case was considered strongly
positive when any one group of the three or four showed a reversal of
the tendency.

EUREKA VARIETY.

The samples of the Eureka lemons show few marked differences.
The greatest difference is in the acidity of the fruit of the Eureka
and Shade Tree strains (Tables 1 and 3). All the monthly samples
of the Eureka strain trees had a higher acidity than any of the Shade
Tree strain, excepting tree 34-74-13. Of the five samples obtained
from this tree, four were unusually high in acidity as compared with
other samples from trees of the same strain.

The next greatest difference is that in acidity between the Eureka
strain and the Dense Unproductive strain (Table 3). As no monthly
samples of the latter were obtained, the comparison is based on the
samples obtained in 1920-21. The difference in acidity between
samples of these strains taken in June 1920 and June 1921 is highly
sionificant. Although the February and November samples do not
maintain the differences, they do not show a reversal. The best
that can be said of this difference is that it is possible.

At first glance a difference may seem to exist in the specific
eravity of the Eureka and Shade Tree strains, but further study
shows that this is only barely possible. The results from the monthly
samples are not convincing, for while the difference is slightly ip
favor of a higher specific gravity for the Shade Tree fruit, 1t is not
sufficiently great to be conclusive. The June 1920 and June 1921
samples show a difference in favor of the Shade Tree strain. The
February 1921 group shows no differences and the November group
shows a decided reversal.

No consistent differences in specific gravity of the fruit, per-
centage of rind, or acidity of the juice between the strains of the
Eureka variety are shown. Some differences may exist in the con-
stituents determined on the monthly samples, but these data were
not derived from a sufficient number of trees to make conclusions
from them possible.

LISBON VARIETY.

The greatest difference shown by the Lisbon variety is that of
acidity of juice between the Lisbon and Open strains. As no monthly
samples of the Lisbon strain were collected, conclusions are based
on the later samples (Table 4). In each of the four groups the
chances are very high that the difference occurring is significant.
In November 1920 the lowest acidity of the Lisbon strain fruit is
higher than the highest of the Open strain. In February the lowest

INHERITANCE THROUGH VEGETATIVE PROPAGATION. 17

acidity of the Lisbon fruit is equal to the highest acidity of the Open
strain fruit. In May 1921 and January 1922, while the results for
the fruit from the two strains overlap, the chances are exceedingly
high that the difference is significant. The highly significant dif-
ference shown favors the conclusion that the acidity of the Lisbon
strain is greater than that of the Open strain.

Another marked difference in acidity exists between the fruit of
the Lisbon and Dense Unproductive strains. In each group of
samples the highest acidity shown by the fruit of the Dense Un-
productive strain is only slightly higher than the lowest acidity
shown by the fruit of the Lisbon strain. In each case the chances
are high that the differences shown are significant, and it seems
probable that this difference is characteristic of the strains.

A difference may also exist between the acidity of the fruit of the
Bull strain and that of the Lisbon. Although there are but three
comparable groups, the May 1921 samples show great odds that the
Lisbon fruit is more acid than that from the Bull strain trees. The
odds are not so great in February 1921 but are still in favor of the
Lisbon strain, while the January 1922 samples show no appreciable
difference. With two high chances out of three, a difference may
exist.

One other difference in acidity in this variety may be classed as
probable. With a single exception, the fruit of the Dense Unproduc-
tive strain has a higher acid content than that of the Open strain.
The two trees compared when the monthly samples were taken,
showed this difference to some degree, but the chances that the
difference was significant were not high. In the November 1920
roup the lowest acidity of any of the Dense Unproductive strain
ruit is distinctly higher than the highest acidity of any of the Open
strain fruit. The chances that this difference is significant are very
high. This difference is strongly evident in the January 1922 group,
and to a smaller extent in the February 1921 group. The May 1921
group shows practically no difference in acidity. tn four out of five
cases the Dense Unproductive strain is higher in acidity than the
Open strain.

Several differences in the percentages of rind, between the strains
of the Lisbon variety, are worthy of consideration.

The tree of the Bull strain sampled monthly bore fruit with a
higher percentage of rind than that borne by any of the other trees
sampled at that time. The greatest difference shown was between
the Bull and Open strains, and the chances are high that the differ-
ence shown is significant. This difference is maintained in the
groups of samples taken later (Table 4). In the May 1921 group
the lowest figure for the Bull strain is higher than all but two of
those for the Open strain, and in the other two groups the over-
lapping is shght. There seems to be little doubt that a probable
difference in this respect exists.

The fruit of the Bull strain tree sampled monthly is also higher
in rind than that of the Dense Unproductive tree. This difference
is again noticeable in the February and May groups of the later
samples. In the May group there 1s no overlapping of samples, the
lowest proportion of rind in any of the Bull strain fruit being nearly

. 2 per cent higher than that in the highest Dense Unproductive fruit.

The January 1922 group shows no difference, however.

‘

18 BULLETIN 1255, U. S. DEPARTMENT OF AGRICULTURE.

The fruit in all three groups of the later Bull strain samples shows
a higher percentage of rind than the Lisbon fruit. This difference
is greatest in the May 1921 group but is also decidedly marked in
the January 1922 group. The samples taken in February 1921
show the difference but to a smaller degree than the others. AlI-
together, it seems that a probable difference exists.

The only difference in specific gravity between the strains of the
Lisbon variety occurs between the fruit of the Dense Unproductive
and the Bull strams. In May 1921 and January 1922 the specific
gravity of the lowest Dense Unproductive samples was higher than
that of the highest Bull samples. In the February samples the
difference was not maintained, but the monthly samples show a
significant difference in this respect. Therefore a probable difference
exists. ;

SUMMARY.

From the data presented it may be concluded that the following

robable differences exist:

In the Lisbon variety—The Dense Unproductive strain has a
higher specific gravity than the Bull stram. The Bull strain has
the highest proportion of rid found in any of the strains of this
variety. The Lisbon strain is more highly acid than either the Open
or the Dense Unproductive strain. The Dense Unproductive strain
is also more acid than the Open strain.

In the Eureka variety.—The Eureka strain is more acid than the
Shade Tree strain. Other differences may exist, but the data at
hand are inconclusive in these cases.

LITERATURE CITED.

(1) Cuacez, E. M., Witson, C. P.,and Cuurcn, C.G. The composition of Cali-
fornia lemons. U.S. Dept. Agr. Bull. 993 (1921), 18 pp.

(2) McEwen, G. F. Unpublished manuscript.

(3) Meruuior,J.W. Higher mathematics for students of chemistry and physics.
New ed. Longmans, Green & Co., London, 1919.

(4) PEARL, RAyMonn, and MINER, J. R. A table for estimating the probable
significance of statistical constants. Jn Maine Agr. Exp. Sta. Bull. 226
(1914), pp. 85-88.

(5) SHame., A. D., Scott, L. B., Pomeroy, C. S., and Dysr, C. L. Citrus-fruit
improvement: A study of bud variation in the Eureka lemon. U. S&S.
Dept. Agr. Bull. 813 (1920), 88 pp.

{6) Citrus-fruit improvement: A study of bud variation in the |
Lisbon lemon. U.S. Dept. Agr. Bull. 815 (1920), 70 pp.
(7) “Srupmnt.’”? The probable error of a mean. Jn Biometrika, 6 (1908):

1-25.

(8) Witson, C. P., and Youne, C. O. A method for the determination of the
volatile oil content of citrus fruits. Jn J. Ind. Eng. Chem. (1917), 9:
959-964.

(9) Woop, T. B. The interpretation of experimental results. Jn J. Bd. Agr.
(London) Sup. 7 (1911): 15-37.

ae —

J

ORGANIZATION OF THE
" UNITED STATES DEPARTMENT OF AGRICULTURE.

June 10, 1924.

meerciary of Agriculture. Henry C. WALLACE.
PASSISMETE 1D CCTELET YR oe ee NY Howarp M. Gore.

Be Merecton oy Screnttjic, Work. = ee KE. D. Bau.
Direcior of Regulatory Work________--__-- WALTER G. CAMPBELL. .
Director'of Extension Work.) >. 2222222 2) C. W. WARBURTON.
Gen ROME AT ede) Meg F erty ws alee OS TU eae GN R. W. WILLIAMS.
ERC INTEC re Ps LT COAL So eo re fe he Pe SS SS oe CuHaruses F. Marvin, Chief.
Bureau of Agricultural Economics_-_____--- Henry C. Taytor, Chief.
Bureau of Animal Industry. 02 22 oe JoHN R. MouuEr, Chief.
UE CANL OF LONE ST RAUSEN Ys 2 OO Oe NE WiuuiAM A. Taytor, Chief.
Hiprest Serie. Le oe Se Wes hy ee W. B. GREELEY, Chief.
SICA OF GREMIUSEKIR ok ee ae NE AS C. A. Browne, Chief.
ESS TOPS QTIIIE/ OPA OES NI is OR ge aE ca Mitton Wuitney, Chief.
Peo} LE RLOMOLOGYS= 282 L. O. Howarp, Chief.
Bureau of Biological Survey__..---~------- E, W. Netson, Chief.
PEE OND OF WE ALOE LOCUS) ee 62) ie ewe) re THomas H. MacDona tp, Chief.
Bureau of Home Economics__________---_- Louise STANLEY, Chief.
Office of Experiment Stations____________-- EK. W. AuuEN, Chief.
Fized Nitrogen Research Laboratory_____-__- F. G. Corrrety, Director.
NeDIICRLTO NS wegen wore el he ee NE ee L. J. Haynss, In Charge.
LUE SETI L See SS aN ea CLARIBEL R. BARNETT, Librarian.
Rederabdaoriiculiural: Board 22 C. L. Maruart, Chairman.
Insecticide and Fungicide Board_________-_- J. K. Haywoop, Chairman.
Packers and Stockyards Administration_____ | CHESTER MorRILL, Assistant to the
Grain Futures Administration _._..-_---__-_- Secretary.

This bulletin is 2 contribution from

eer cawpOf CO REMISUTYy 2 C. A. Browne, Chief.
Laboratory of Fruit and Vegetable Chem-
TSE gp NO IN Ne ERE SED ll MEET E. M. Cuacs, In Charge.

19

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