Identification of citrus varieties through observations of leaf characteristics
Item Type text; Thesis-Reproduction (electronic)
Authors Braman, Charles Durwood, 1934-
Publisher The University of Arizona.
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Download date 06/10/2021 16:16:48
Link to Item http://hdl.handle.net/10150/347601 IDEM) IFICJ.T 1 ON OF GITETIS: ¥11IETIES THROUGH OBSEHmTIOHS OF LEAF CHARAGTEH1STIGS
"by Gharlee Burwood Biaman
A Thesis Submitted to the Faculty of the BEPABTMEBT OF HORTICULTURE
In Partial Fulfillment of the Requirements For the Degree of MASTER OF SGl'EFCE
In the Graduate College THE UNIVERSITY OF ARIZONA
1 9 6 7 STATEMEHf BY AUTHOR
T M s thesis has "been siihmltteS im partial . fulfillment of requirements at The University ef Arizena ani. is deposited. in the Ihiversity Eibrary t@ he made available to herrowers under rules of the Library0 Brief quotations from.this thesis are allowable without speeial permission, provided that ae®urate aetenowledgmemt of source is made* Bequests for permission for - extended- quotation from or repreduetion of this manuseript in whole or in part may be granted by the major department or the lean, of the. Graduate 001 lege when in his judgment the proposed use of the material is in the interests’;-of scholarships In all other instances, however 5 permission must he., obtained from the author 0
SIGHED [Al4U.A*p.c
APP10YAL. BY THESIS DIRECTOR:
This thesis has been approved on the date shown below:
f2 r r ^ .. Bro loss l o d n e y / f . iBate Hortieultmrist AGENGWXEBGMEMT S’
Th© aath©sr wialaes- t® espr©ss M s sineer®
appireelation for the extensive time ani. expert assistan@©'
rendered T&j Br 0. Bess Bedney in the preparatlem ©f tMe$
thesis6 The writer wishes t® thank B r Bettert 0O Emehl. and Thomas Males in the assist a®.©© of the analysis @f
data,- Ehrthermere, the anther wishes; t© extend his-
appreciation, t® lr.0 Steve laziOj head of the department of Hortienltnre, for providing the facilities; which helped to make this investigation possible<> TABLE OF CONTENTS _ Page
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iv LIST' OF TZB1ES Table' Page
10 '©empar.lsen of Eour Orange Varieties * • • » « 3© ' Ilo G'omparison of Four Orange Varieties » @ 31 11 1.0 O'omparisen of One Orange and Three ICandar xn.s o ® o o a o o o © o * o ® o o o © @ 3^ ir. Goraparisen of Four Mandarin Varieties 0 © © © 33
¥e Comparison of Two Grapefruits and Two Lemons o o © © © © © © © © © © ©, © © © © © © 3^
VI o Comparison of Two Lemon and Two Hybrid Varieties ©©©©©©©©©©©©o© 33
Vile Comparison of One Tangelo and One Tangor © © 36
Till* Duncan’s Multiple Range Groupings for Ratios of Made, Petiole and Mean Groupings for Oil Glands © © © © © ©. © © © © © © © © © © © 3^
H e Average Blade and Petiole Ratios (Length/ Width) and Oil Gland Counts (Per©3315 S'q© Cm©) For 26 Citrus Varieties ©©©©©©©©©©©39
v LIST OF FIGUBES
Figure I’age le Field Oiomparison of Species and Hybrids » 0 . 1 2 2 s Gibmpar i son of Gba^r act eristics in Determining Variety of linltnora. Trees . 22 3 e G'omparison of Ebmr' Grange Varieties . .... 3© 4 e Comparison of Fonr Grange Varieties ...... »■ 31 5® Comparison of One Orange and Three Mandarins. 32 6 . Comparison of Four Mandarin Varieties „ „ » » 33 7 ® . Comparison of Two Grapefruits and Two Lexsion.s o ® ® ® o ® ® o ® o o o © © © © © ® © 3^' 8 . Comparison of Two Lemon and Two Hybrid Varieties ©©.co©.©.®..©®..©. 33
9 © Comparison of One Tangelo and One Tangor © © 36 ABSTMCT
In the eitrue industry, variety identification has always heen derived from inspection of the flower and fruite There do sen ""t seem to he any method of identification to date, which involves the use of leaves of the varieties in question*
The orchard tree, when in production, can he identified hy flowers and fruits, however, the nursery tree is another problems
.Keseareh in this thesis was conducted on the assumption that a method of. identification of the varieties hy the sole use of leaves of the plant, might he practical* Four methods of attack were used in isolating leaf characteristics; that would aid in identification of the varieties* These methods are: leaf photographs, hlade ratios, petiole ratios, and oil gland counts per unit area* All ratios were calculated as the length of the hlade and petiole divided hy the width of same*. Analysis of Variance and the Duncan1s Multiple Bange Test were used to find statistical differences between varieties* By using a combination of these four methods mentioned ahove, most of the twenty-six varieties studied
in this thesis are easily identified*
vii INTEOBUCTI OS'
Within the eitrus industry ©f today nmrserymen and growers alike are mostly dependent on flowers and fruit for eitrus variety identifieation0 The present manner whieh is heing employed requires either flowers or fruit t© establish the variety of the tree in qtiestion0 In the desert area, sueh as the Yuma Mesa, the trees have flowers and fruit for a few months during the year, and the eitrus nursery has no flowers or fruit at all0 From years of experience and consistent work with citrus5, most growers believe that the only way to insure proper grove management is "by definitely knowing the variety of each tree that is planted in the particular grovea However5, it is not unusual to find a tangerine or mandarin in an orange grove0 This creates years of delay and expense of removing the unwanted tree and planting the desired varietyo
In this thesis four methods of approach will he applied in the search for a valid and usable method of leaf identification^ By these methods one should be able to indicate the species, and in some eases, the variety of the tree in question,,
1 The ©hJeetives ©f this paper are t© f ind, an easy . and reliable means of establishing the identification, for the major ©itras varieties6 Through photographs and measurements of some of the ©itrns leaf ©hara©teristies s, the differences and similarities of the varieties:- will be ezposeda Z'onr major areas? of investigation will be foiloweds they aret
Cl)? visnal ©haraeteristies of the leaf, (2 ) blade measurement ratios, (-3 ) petiole measurement ratios,
(h): oil. gland .©©nnts: per unit areaQ EITEEATITEE E W I E W
What are the eharaeteristies ©f a eitrus leaf?
Bhtehelor and Wehher (f) explore this question in seme
detailo They state that the leaves are rieh in green and yellow pigment and tests indicate that the leaves are relatively stable against disintegrative ageneies© These preliminary tests indieat© the reason for the extreme hardiness of the eitrus leaves© The leaves are also rieh in oil and hesperidiho The oils derived from the fruit9
is as, reeognised item in e©mmeree0
A further look into the leaves and faetors affeating them is examined b y 'E<>. 0/V Humphries and
We. Wheeler (k}a They say, “always the growth of the leaf is strongly influeneed by the environment, the basic form of this growth is genetically @:©ntrolled6,l: All these factors affect the shape of the leaf and meed to be taken into aoeounto , The petiole, aeeordimg’ to Bobins, Wilfred, and Wier (?) , “has; its own specialized structure enabling it to support the leaf blade, to conduct water, food, and inorganic salts, and to disconnect itself from the stem at the close of the growing season with out exposing living
stem tissue to drying out or to imfeetiomo”
3 ■ ■ k ©ensieleraMe werk lias "b@em deae ®a the @11 of ©itrus leaves in relation t© Identification ©f varieties?*
Zesterson et al<, (5) have found that by using gas-liquid chromatography they ©an differentiate among different varieties of citrus* These men further believe that their methods are accurate enough to be used as a. basis of taxonomic data* Ih:.discussion of their data they state, "in many eases; it has been possible to distinguish between oils for the same species grown;and distilled in different areas*.11 The obvious chemical differences between species of the same genera# should assist researchersi and taxonomic personnel in the identification of these species and some day the individual varieties* They further believe that additional refinements of tM@- system will enable researchers to identify nucellar from zygotic seedlings* Similar results were obtained by Berlnger, Edwards# and Wolford (6 ) using infra-red and ultra-violet spectrophotometry* These gentlemen obtained refractive indexes and stated that # “the high degree of accuracy of the refraetometer makes the variations evident *“ The article# “Eootstock Identifieatiom.Zor ©ranges11' by Ir*. W 0. Zo. Sitters (2 ): points out the shert-oeatings ©f our methods; used today and reviews some of the chemical and visual methods; which have been tried in identification of rootstock varieties* 5 Bro Bitters mses various methods to sort out rootstook varietieso In some eases he uses leaf eharaeteristies and drawings of various varieties to indieate major foliage ©haraeteristies0 Type of unions on the citrus tree, rough, smooth, overgrowth of stock, and scion also help to denote the various varieties* Ghemieal tests have also "been an aid in this work;
Hass and Halma have developed those tests and Br* Bitters believes these may be a step in the right direction*
Harold H* Hume (k) has used the citrus leaf in the description of varieties in M s book, “Gltrus Fruits"'* In describing the varieties, th©'leaves are used as a further index of visual classification under the section, Bbtamy of ditrus Fruits and Their Relatives* Satchel or and "Webber (l) have found, that the best method of rootstock identification is by inspection of
suckers from the roots* These men state, "Anyone familiar with citrus species can usually Identify the different ones by the foliage or the odor of the crushed leaves*" There is still a definite lack of a field type identification which is quick, simple, and accurate* EXPEMMEIT AL: ElOGEDFEE'
lm the establisMag @£ metheds f®r eltras leaf
IdLentifieat.ieii,. feua? metheSe'have been tried?
(a) visual ©haraetexisties ©f leaves threugh.
phetegxaphSg (1$). hlade zatioSj, (©) petiole ratios* (d) neQ #11 glands / 0.3315 square ©entittet@rs»
.Bitty leaf samples were, taken fox eaoh ©f the twenty-six Varieties ©©vexed im this thesis-* $h@ varieties whleh are ©ommon to this area* ax© presented here0 CQltrms sinensi s-0.she©k) Grange G-ronp. IXOvita
Hamlin . . - ©amphell Waleneia
Indian liver
Weeds Valensia Enterprise Havel
■Warren Havel
(Gitras sinemsls-Qsheek) Grange Bed Group
Tar©©©© (Q/ltr,ag y et i ® ul at a-B lane &) Mandar in and. Tangerine Sing Mandarin
Satsuraa Mandarin Wi11 ow Leaf Tangerine Baney Tangerine Algerian Tangerine Wise Tangerine
Kinnew: Mandar in. 'i#itrns •paradisi'Mae Wadyeni Granefrmit Group
Marsh Seedless Sed Blush
(Sitras 1 imon Ehrmann) Lemon Group
Eureka Mueellar
Lisbon Bue.ellar Millsweet Gmeussar© Hybrid Group Mmequat (©itrus aurantif ©lia X Fortimella) Minneola (BBwen Grapefruit X Baney Tangerine) . Grlande (Bowen Grapefruit X. Baney Tangerine) T'empl'e (Mandarim X Sweet Orange)
The leaves were ©elleeted with the following requirements in minde (l) All the leaves were taken from the northeast quarter of the tree, to eliminate sunburn ©haraeteristies6 (2) All leaves taken were well proportioned5, so as to eliminate odd shaped leaves from inseet and. other damage0 (3 ) heaves ehosen were not all large or small M t a random assortment of eaeh0 This produees a ratio w M e h represents the entire variety^ (%)' The leaves were palled from the tree5, not ©atc Balling the leaf cansed separation of the leaf at the assetssion son© between the petiole and the stem of the treeQ . .
• Eaeh sample of fifty leaves was placed in a plastl© qmart hag and had a tag inside indicating variety and lee at ion of the tree sampl©cL0
(€} To prodmee as mneh uniformity as possible5, all leaves were collected from one tree for eaeh variety* This tree was visually inspected to be as eharaeteristie of that variety as possible«, The measnrements of the fifty leaves of eaeh of the tw@mty=elx varieties were taken with a Vernier G'aliper<, The measurements were read to 1/100 of a centimeter*
In preparation of this thesis a. new idea in leaf description, is explored^ which involves photography of the leaf by ns© of a back lighting technique* This method mtilizes the skeleton characteristics of each variety as shown by the representative leaf* 9 flie phstegraphs were made fey msing a % m l y a S3 prefeeeienal earner a a This is a "bellows type eamera made la
«lapanQ fM s partiettlar eamera was used leeamse ef the extremely fine lens and very ©lose feeal length wM e h ean "be employ@d0
fhe method of obtaining these photographs is best presented in am itemised step fey step pr©©edmr@o
(l). ©Main the representative leaf for .the variety in quest ion; fifty leaves were pieked. and one leaf was seleeted for the ph©t@graph0
(2')-'B a k e eertain the leaf is well proportioned* the odd shaped or seared leaf is ef little value. (3 > Pla©e the leaf on a pieee ef eardboard about l/l6 of an ineh in tM©kn©ss.o ■
{h); ©imt eut a per feet' silhouette of the leaf e
(.5) Blaee the leaf in the eut out seetien of the eardboard*
($% $la©@ the leaf and eardboard between two pieees of very ©lean* ©lear glass®. Bake ©ertain to inelmde a olear plasti© ruler to measure the leaf 0
{?)• fo take the pietmre* set up a hundred watt
■light bulb in a, light proof box® Em front of the open side of the box* plaee the plate glass' and inclosed leaf * lb ® ' sure all the light is being transfered through the leaf® 1© not allow any outside light to enter the' photographing area® 10 (B.) I'alce a light meter reading direetly on the leaf area and set the earnera to this reading0
(9 ): ®he camera, Hamiya €3 , is set to seven inehe® from the plate glass, foemsed properly, and the shatter- snapped o
The method of measuring the leaves was as followst
ClI- The hlades were measured for length and width, at their longest and widest point for ©aeh, from the ah scission zone between petiole and blade to the point of the leaf o- C2:)' The petioles were measured in the same manner@ ill measurements were started from the abscission zone between the blade and petiole and extended to the base of the petiole 6- (3 ); if ter all measurements were taken, the ratios for the blade andpetiole were obtained* These ratios were length divided by the width for both the blade and petiole®.
In order to obtain the proper prospective of these ratios both an analysis of variance and the Duncan8s
Multiple Hange Test were performed on each set of data®.
The method for obtaining the oil gland count -waas to detach a leaf and punch a hole with a paper punch® The area of the paper punch was- <,3315 square centimeters.® 11 F@x greater uniformity, the hole was punehei. on the right side of the "blade» To simplify the eounting process it was neeessary to nse a dissecting microscope with ten and twenty power lenses0 Ten leaves of each variety were used to obtain the oil gland counte The analysis of variance and Duncan6;s Multiple Mange Test were employed to establish significant differences© RESULTS. £ S B DISCUSS!OK
111© gpeeiee* Gi-trug sinensis„ G-'itrns tetieulata, GJitrttS naradigio dHtriie Ilmen, and. tlie kyteidSj limeqmat. Tange 1©.$, and Tangos ean "be distinguished "by visual inspeetien of the photographs of Figaros 3 throagh f *
The faeiag- page,. Tables I through Til, eentains i list ©f eharaeteristies whieh should aid in further separation ©f varieties within speeies0
Of&J TA 1 m m u 0 83 © ffi M b) bS 8 . . II I1 III IV V VI Oranges i r~c 11 ■' ..." ecoacao Mandarins , VII VIII IX X r i ^ XII XIII XIV XV Lemons 1 XVI XVII XVIII Mmeoiiat XIX XX ' - Tangelos ------—- -y- •- XXI Tangors FIELD CBUPABISOH OF SPECIES M B HYBEIDS1 /./A - Wery diffieult t® tell apart in the field 12 13 The field eoxaparison of speeies and. hybrids is a compilation of the methods which hare "been tised "by the citrus grower in identification of the citrus speeies0 Bhtchelor and Webber (2 ) note that„ identification of the species and sometimes the varieties of citrus ©an be based on the foliage and the odor of the ©rushed leaves-0 Figure 1 is an aid in locating the comparisons of species* Combination I is mandarin versus oranges9 Combination II. is grapefruit versus ©ranges etce This first section of results and discussion is the results of field identification works. The next section includes- the photographs, listed as figures, and the facing pages, listed as tables* Figure 1 illustrates the difference as discussed in this section; each combination refers to a photograph which illustrates the discussed material 0 l4 (I) Oranges versus Mandarins In this comparisons, Oranges have a wide round "blade base as compared to the Mandarins, which have narrow blade basest normally, Mandarins are pointed on each end Of the blade; the exception is in the Satsuma, Figure 5 Humber 3 and Einnow, Figure 6 Humber 4 which have shapes similar to that of Oranges, Figures 3 and 4 e The major difference observed is in the size and shape of the petiole wing„ The Orange petiole wing is usually obovate and very distinct, where the Mandarin is most often indistinct, to almost absent© The oil glands are, as a group about the same, but individual differences can be observed as indicated in Table VIII © The taste test is also a factor© In the nursery, the experienced workers- can often select various varieties by chewing on the leaves = The Tangerine leaves taste differently than Grange leaves© The Tangerine leaves have a defnite taste which is all their own, which is similar to the fruit taste© (II) Granges versus Grapefruit One of the easiest methods of identification is to hold the Grapefruit leaf up to the sun and observe the number of oil glands per unit area© Granges have twice as many oil glands, per unit area as the Grapefruit© The Grapefruit leaf. ■15 Figure 7 limiiers 1 and S has a mere distimet ohovate wimg than the ©ranges Figure 3 and 4; the Grapefruit petiole wing, sometimeSj, overlaps the hlade.6 (III)* Oranges versus Lemons There is little ehanee of error in eomparison of these two speeieso The Lemons8 Figure 7 Humbers 3 and 4 have very large oil glands as eompared to Oraneess Figures 3 and 4 and Lemons have no wings on the petiole© Thus, a rapid glamee at the oil. glands of these two species will he sufficient for primary identification of species© Alsog, the leaf margins of Lemons are ©renate* while Granges are entire© . Cll^l Granges versus Limequati The extremely large number of oil glands per unit area of Limegnat, Figure S lumber 3 Is an adequate index to.tell the differ ©nee hetweem these two species© The Llmequat hasi- a# '• average of 149©3® ell glands per ©3315 square eentimeters and the Grange speeles8 Figures 3 and 4 average is per square eentimeters© Thuss a. quiek look through the given leaf will show the above eomparison©. The Mmequat leaves; are shorter and thinner than any of the Oranges© (¥'): Oranges versus Tangel©s The oil gland eounts of these two speeies are not statistically different © The Mineola T.aagelOj Figure 8 16 Ziimber k has a somewhat cut led leaf and is very faintly veined 5, as seen, on the' under side of the leaf 0 The Orlando Tangelo» Figure 9 Kraher 1 has a remarkable curled leaf which is another prevalent item in the observation of differenceso The Orangesg Figures- 3 and 4 do not tend to curl and are boldly veined* {VIX Oranges versus Tangers The petiole wings' of'T.angers* Figure f Humber 2 average almost twice as narrow as the Oranges* Figures 3 and 4 d The veins of the Tangor appear to stand out and are dark in colors from the rest of the leaf0 The oil gland count is statistically different from the Tangelos average* and have one and ahalf times more oil glands per area than the Grange speeies0 (VII) Mandarins versus Grapefruit In all the varieties* of these- two species* the oil gland count per area will sort out the species very easily* .In the field* the observed oil gland count * by holding the leaf mp to the sun* will show the inquirer that Mandarins* Figure 6 have about three times more oil glands per upit area as; Grapefruit * Figure 7' lumbers 1 and 20 Also * the petiole wing attachment to the blade of the Grapefruit will demonstrate further differences* The pronounced obovate petiole of the Grapefruit is a major distinction from any Mandarin* 17 lYIi'Il.) Mandarias Terms Bemens Bt is very notieeaBle that the oil glands of Lemons % Figure 7 Sumhers 3 and k are nraeh larger and more dispersed than in the Mandarin varieties. Figure 6 ? The edge of the Bemom Beaf is very rough, where the Mandarins have smooth edged leaves@. (IX) Mandarins versus Bimequat The size of the Bimequat leaves. Figure 8 EumTber 3 are one of the important differences0 The leaves of the Bimequat are Tangerine shaped, hut smaller than the average Mandarin, leaf, Figure 6 0 The other mark of difference is in the mumher of oil glands per unit area* .The Bimequat Possesses a large number of oil glands per area; almost twice as many as the Mandarin species® (X):- Mandarin® versus Tangelos The greatest difference will he in the curl of the leaves which are more pronounced in the Sri and©, Figure f Sumber 1 than in the Mineola, Figure 8; lismher Tangelos, a hybrid of Mandarins and Grapefruit, are very close in characteristics to the Mandarins® The greatest difference between the Tangelos and the Mandarins, Figure 6 is in the shape of the leaves® The Tangerine blades; are long and narrow, while the Tangelos have an Grange type blade® (XI) Man&ar ins versus T.'angor s ®:aag©TSy Figure 9 Biuribex 2 are hybrids of a Mandarin^ Figure 6 and sweet Orange, thus it is expected that these two groups are difficult to tell apart in the field® In Table VIII, evidence is presented which will enable laboratory detection.®f the differenees between some varieties of the two species0- The field observation method used up to this point has; not been of help in establishing differences between these two species®. (XXI.)' Grapefruit versus Lemon There is no problem in the field identification of these two species® The oil gland observation alone can do the job® Lemon, Figure ? lumbers; 3 and 4, oil. glands are larger and have twice as; many as- that of the Grapefruit, Figure 7 lumbers 1 and 2 ; also, the Lemon does not have a wing on the petiole® (XIII.) Grapefruit versus Li me gnat The size and shape of the Ximeguat leaf. Figure 8 lumber 3 is a postive index®. ■ The oil gland is another certain!tyv Limequat is shaped like a Tangerine and the limequat oil gland count is six times mere per unit area than. the Grapefruit, Figure"7 lumbers 3 and 4# 19 (XIY'): Grapefruit versus T.angelos The petiole of the Grapefruits Figure 7 Bhmhere 1 and 2 is a distinet difference in comparison of Grapefruit and Taageleso Grapefruit petioles are ehovate* long and sometimes overlap the "blade$ while the Tangelors petioles. Figure 8 Humber k and Figure 9 Humber 1 are similar to danger inesv Grapefruit versus Hangers Observation of oil gland counts by holding leaves of varieties up to the sun, is’an excellent method of visually separating these two species* 011 glands for Grapefruit, Figure 7 lumbers I and 2 averages 27 °9 oil glands per unit area and Hangers, Figure 9 Humber 2 average 9®o2 oil glands for the same size area* Thus, the difference is easily observed* Also, the petioles are very different, the Grapefruit being four times wider than the Hangers* ( XO ) Ziemoiis ver sus Limequat Again, the liimequat species, Figure S: lumber 3 is very distinct and there is no problem in visual separation* The oil glands are four times more numerous per unit area in the liimequat than in the hemon. Figure 7 lumbers 3 and k a (UII) Lemons versus T.angelos If nothing else, the odor or scent of the Lemon leaf, Figure 7 lumbers 3 and 4 will distinguish these two species* The TangelO;, Figure 8 lumber 4 and Figure 9 lumber 1 is a curled leaf hybrid and this will also separate the two groupso Furthermores the taste of the Eemom leaf will establish a marked difference between these two group So The taste of the lemon leaf is similar to the fruit, except the leaf is a little ©ily0 (.XF1U) lemon versus Tangors There are twice as many oil glands in the Tangor, Figure 9 lumber 2 per unit area as in the lemon leavesj, Figure 7 lumbers 3 and 4» Ms©* the lemon oil glands:'- are very largee Another point is that the Tangor has a winged petiole and the lemon is void of any wing on the petiole* (XI3C) Eimequat versus Tangelos In most all cases the oil gland, count per unit area is a visual distinction of the limequat$ Figure 8 lumber 3 which will separate this species from any other species or group* The T'angelo, Figure & lumber 4 and Figure 9 lumber 1 has the curled leaves and Grange like blades and petioles* Thus, these two groups can be very easily separated* (XK) limequat versus Tangor This combination is quite similar to combination XIX9 except that the Tangors, Figure 9 lumber 2 do not have the curled leaves* The number of oil glands per unit area is the most important item in the contrast and identification 21 of these species„ ' The Mmequat leaves. Figure 8 Bomber 3 are much smaller than the Tangors and are Tangerine shapedo (1X1)' Tangelos versus Tangers The comparison of these two hyhrids eonId he a real problem,. One factor which aids in the distinction of these two is the curling tendency of the Tangelos, Figure 8 lumber k and Figure 9 lumber I„ The Tangors, Figure 9 lumber 2 tend to have a prominent type of vein pattern* In addition, the veins appear to be more pronounced then is seen in the Tangelos* - VARIETY No. 4 6 8 10 11 12 7 s 9 i4 I4) 1.6 18 20 24 26 2 . 3. 5. - o 17 19 21 22 23 25 Trovita Orance 1 - 0 1 O . b M i b 0 P t>P . bpo_ P too bo bp po po bo 0 bo 0 bo b Mgfeji bpo Hamlin Orange 2 0 bo 0 bo --tip.. 0 P bp _ to p bp bo bpo po bpo bo 0 bpo o bo b O bpo Campbell Orange 3 . _ — b J K B t L . b - M . 0 P _bp . too J>- bpo bpo bp po po bo PO bo 0 bo b flat bpo Indian River Orange k — b o 0 bo b bpo bpo bp bpo bo p bpo bpo bpo bo bpo bpo bpo bpo b bpo Woods Valencia Orange 5 — b 0 _ tpp. 0 bpo P t o . - P- bpo bo bp po po bo 0 bpo o bo b M l bpo Enterprise Navel Orange - 0 JBL9..bo bp __P. . too bp bpo bo p bpo bpo bo bo bpo bo bo b b bpo — 0 Warren Navel Orange _ 7 P t o t o bpo PO PO bpo bo PO bo 0 bo b 0 bpo Tarocco Orange 8 - bpo b - . to t o . . t o bo PO bpo bpo bpo bo bpo bpo bpo bp bo bpo - Ruby Red Orange _ 9 ..... po too to po to b bpo po po bo 0 bpo 0 bo bo 0 bp King Mandarin 10 to too P too bo bp PO bpo bpo 0 bpo po bpo bp bpo Satsuma 11 too b bo bpo bp bpo bpo bpo bpo bpo bpo bpo bp bp bpo Willow Leaf Tangerine 12 . . . bpo _ to bpo bpo bpo bpo bpo bpo bpo bpo bpo to bpo bo Dancy Tangerine - - - . too bpo bp po PO bpo PO bpo po bpo to p bpo Algerine Tangerine Ik too bpo too bpo bpo bpo bpo bpo po bpo bpo po Wise Tangerine 15. bpo bpo bpo bpo bo bpo bpo bpo bpo bo bp Kinnow Mandarin if — too bpo bpo too bpo bpo bpo bpo bp bo Marsh Seedless Grapefruit 17 m bpo po bpo P bpo bpo PO bpo Red Blush Grapefruit 18 PO PO bpo bp bpo po _pp bpo Eureka Lemon _ 19 bp ■it b bo 0 bpo bpo Lisbon Lemon 20 bp P bpo bpo 0 bpo Mi 11 sweet Lemon 21 b bo 0 bpo bpo Cucuzzaro Lemon 22 _ bo bo PO bpo Limeauat 23____ — bo bpo po Minneola Tangelo 24 — bp bpo Orlando Tangelo bpo Temple Tangor4 26 ! - FIGUBE 2 COMPARISON OF CHARACTERISTICS IN DETERMINING VARIETY OF UNKNOWN TREES Key To Characteristics p = petiole ratios b = blade ratios o = oil gland counts per unit area B B = not able to differentiate between varieties by use of blade, petiole, oil gland characteristics. Numbers 1 through 2 6 correspond to number of varieties in above Figure. To Use Figure 2: (a) find varieties to be compared in column on left margin t of the c}ort (b) Arabic numbers opposite the varieties, are the same as the numbers 1 (c) to compare Satsuma and Lisbon Lemon; use numbers 11 and 20 n+al column OitxiiB sinensis The inter specie comparison of Oltrns sinensis is complicated hy six comparisons, that cannot he identified hy -use of the blade, petiole, or oil gland separation characteristieso Trovita ©.range can he separated from Hamlin, Warren lavel, and Buby Bed Orange hy the oil gland ratios only; and from Indian liver and Enterprise Havel Orange hy the blade and ratios only0. T.aroeeo Orange is the only comparison, with Trovita that, can he identified hy use of . all three characteristics; hlade, petiole, and oil gland counts6 Campbell Orange and Woods Valencia ©range cannot he separately Identified from Trovita hy use of these characteristics^ Hamlin Orange can he identified from Campbell Woods.; Valencia, and Ruby' Bed Orange hy use of the oil gland counts only* Both Indian River - and Enterprise Havel Orange are separated from Hamlin Orange hy the blade ratios and the oil gland count Sc. Taroceo Orange is the only one that is separated by use of the blade and petiole ratios0 Hamlin Orange and Warren Havel Orange are so similar that they cannot he separated hy use of any of the characteristics blade and petiole ratios and oil gland count per unit area* 24 GJamplbeli Orange is easily separated from Indian River and Warren Havel Orange by the blade ratios only, and from Taroeeo Orange by use of both the blade and petiole ratioso Rmby Red Orange is the only one that can be separated from Qiampbe! 1 Orange by the oil glands per unit area* Woods Valencia and Warren Havel Orange have not been found distinct enough to be separated from Campbell by any of these characteristics, • Indian River■Orange can be separated from Warren Havel Orange and Taroeeo Orange by the oil gland counts per unit area, and from Ruby Red Orange by both the blade and the oil gland count „ Woods-; Valencia is separated by the blade ratios only. Enterprise Havel Orange is not distinct enough to be separated from Indian River by any of these characteristics. Woods Walencia Orange can be separated from Warren Havel'Orange and Ruby Red Orange by oil gland counts only, and from Enterprise Havel-Grange- by the blade ratios only, Taroeeo Orange is a very distinct variety and can be separated from Woods Valencia by all three characteristics;' blade, petiole, and oil gland counts. Enterprise Havel Orange can be identified from Warren Havel Orange by comparing their oil gland counts per unit area. Also, Enterprise Havel Orange can be separated from Taroeeo by the petiole and the oil gland counts per 25 unit area6 Ruby Bed Orange is separated from Enterprise Havel Orange "by the "blade ratios and the oil gland counts per unit area* Warren Havel Orange and Taroceo Orange differ only in the petiole ratios and Baby Bed Orange differs from Warren Havel Orange by the oil gland eounts only* -The Taroee© and Buby led Orange differ in all areas of consideration0 These two oranges can be separated by blade and petiole ratios and by oil gland counts per unit area* Gitrus reticulata All varieties in this specie can be identified from each other by at least one of the characteristics used in this papero King Mandarin can be separated from Kinnow and Sat sums, by use of the blade and petiole ratios only, and from Dancy Tangerine- by use of petiole ratios only. Wise Tangerine and King Mandarin are separated by use of the blade and the oil gland eounts onlya The Willow Leaf and the Algerine Tangerines are very distinct and can be separated from King Mandarin by all the characteristics employed here; blade, petiole ratios, and oil gland eounts per unit area. The Satsuma is very unique and can be identified from Dancy Tangerine by blade ratios only, and from 2 6 Alger in© Tangerine "by the "blade ratios and oil gland counts per unit areae Einnow Mandarin is separated by blade and petiole ratios* Willow Iteaf and Wise Tangerine are again, very unique and separate themselves from Satsuma by all three characteristics; blade, petiole, and oil gland counts per unit area* The Willow leaf Tangerine is a very unique variety and is separated from Algerine Tangerine by blade and petiole ratios* Baney Tangerine, Wise Tangerine, and Einnow Mandarin are separated from Willow. Leaf Tangerine by all three characteristics; blade and petiole ratios and oil ■ gland counts per unit; area* The Baney Tangerine is separated from Einnow Mandarin by blade and petiole ratios, and from Algerine and Wise Tangerines by all three characteristics; blade and petiole ratios and oil gland counts per unit area* Algerine Tangerine is a singular type variety and is separated from Wise Tangerine and Einnow Mandarin by the blade, petiole ratios, and oil gland counts per unit area* Vise Tangerine and Einnow Mandarin are also separated by all three of the above indicated leaf characteristics* git nag paradisi $.lie varieties of © i t m s paradisi cannot "be distingmished from each other 0 Both the Red and White gtapefrnit are very similar in all three characteristieso Pit ms limon The Eareka Lemon cannot "be separated from Mi 11sweet Eemon by any of these three leaf characteristics. The Lisbon Lemon is differentiated by the blade and petiole ratios from the Eureka Lemon0 , The Guenzzaro Lemon has a.blade ratio that is different and is considered a means of separation between it and the Eureka Lemon6 The Lisbon Lemon can be differentiated from both Ml 11 sweet and Giacnszaro Lemons by the petiole ratios and from Mi 11sweet by the blade ratios also. Mi 11sweet and Gueuzzaro can be separated by blade ratios only* the petiole and oil gland counts being so similar that they are not considered significant difference. Hybrids Limequat,Minneola Tangel©? Orlando Tangelo,and Temple Tangor The Limequat can be isolated from the Tangelos and the Tangor by oil gland counts. I'm addition, the Orlando Tangelo is separated from Limequat by the blade and petiole ratios. The Hinneola and Limequat are also separated by the blade ratios. The Temple Tangor has the petiole ratio to add to the oil gland eoonts in separating this variety from himequa10 The Hinneola Tange1© is statistically different from Orlando Tangelo in the Made and the petiole ratios. The Temple Tanger is different in all three areas from Mimmeola Tangelo. The Orlando Tange 1© and Temple, Tangor are very different and all the leaf characteristics suhstanelate this observation, These two varieties are separated by blade? petiole, and oil gland characteristics. This concludes the comparison of varieties within species. In the following section the presentation of photographs and their facing pages, Tables I through.SII, will help define the characteristics of the leaves. The major divisions of these tables are defined here as: Shape: the general characteristic proportion of the blade of the leaf. Petiole Wing: the shape of the wing of the petiole of the leaf. Oil Gland Count: the average oil gland count of ten leaves for each given variety, as per section of leaf by a paper punch. Leaf Margins is the type @£ the average leaf* Leaf Base and Tips, further explain the shape of the M a d e of the leaf „ e:oiPABi.smr o f f o i e o b a k g e y a e i e t i e s ; fcEAF CHAEAOTEEISTIGS s h i p s ; Shape Lanceolate Ovate-. Petiole Wing-Qt)ovate Almoet Absent. Bent ate • Go relate r i Oil Gland G opj Per o3315 G a t Mean 30 TABLE II COMPARISON OF FQUK ORANGE VARIETIES LEAF CHAIiACTERISTICS SHAPE Shape Lanceolate Ovate Oval Petiole Wing-Qbovate Ovate Almost Absent Absent Leaf Margins-Serrate Entire Crenate Dentate Leaf Base Acute Acuminate Cordate Leaf Tips Acute Obtuse Ari state Truncate Oil Gland Count Per .3315 Cm " Mean 6l«8 3 / ^Yr" C o/^^iL^aoM of /~otAi^ C ^ i r t k A s ^ e V k r i e l i e z TABLE III COMPARISON OF ONE ORANGE AND THREE MANDARINS X \ XT LEAF OHABACTEBISTICS SHAPE 1 2 3 4 Shape Lanceolate 0 i— Ovate 0 Oval 0 u/ 1/ 1/ Petiole Wing-Obovate 0 Ovate 4 Almost Absent f L/ Absent / Leaf Margins-Serrate . f _ Entire f t Crenate Dentate Leaf Base Acute V Bounded vjy Acuminate Y Cordate q j Leaf Tips Acute A L^ ^ ' Obtuse n Aristate n - Truncate n Oil Gland Count Per .3315 Cm 2 Mean 87.2 65.1 .. ^7_.6 . . 78.5. <32 hjurt S'- Coi»f>*r< ioAf a? O"* a M / 7X^*e /i«/r EAF CHARACTERISTICS SHAPE Shape Lanceolate Ovate Oval Petiole Wing-Obovate Ovate Almost Absent Absent Leaf Margins-Serrate Ent ire Crenate Dentate Leaf Base Acute Rounded Acuminate Cordate Leaf Tips Acute Obtuse Aristate Truncate Oil Gland Count Per .1115 Cm Mean 82.5 96.0 5.6.? 33 or* Pa rt % ow o f ~ o u ^ TABLE V COMPARISON OF TWO GBAPEFBUITS AND TWO LEMONS LEAF CHABACTEBISTIQS SHAPE Shape Lanceolate Ovate Oval Petiole Wing-Ohovate Crenate Dentate Acut eLeaf Base AcuteLeaf Bounded Acuminate Cordate Leaf Tips Acute Obtuse Aristate Truncate Oil Gland ( Per .3315 Cm Mean | 27.3 I 28.6 | 41.9 |4l.l Table VI COMPARISON OF TWO LEMON AND TWO HYBRID VARIETIES LEAF CHARACTERISTICS SHAPE Shape Lanceolate Ovat e Oval Petiole Wing-Ohovate Ovate AbsentAlmost Absent Leaf Margins-Serrate Entire Crenate Dentate Leaf Base Acute Rounded- Acuminate Cordate Leaf Tips Acute Obtuse Aristate Truncate Oil Gland Count Per .1315 Cm 2 ALeaJi 3 U p •€ ~ C. 6 5" tw* LeAAOAt O.A4< TABLE VII COMPARISON OF ONE TANGELO AND ONE TANGOH LEAF CHARACTEKISTICS SHAPE 1 2 Shape Lanceolate 0 Ovate 0 Oval 0 Petiole Wing-Obovate Ovate Almost Absent 7 Absent / Leaf Margins-Serrate f Entire «z Crenate r Dentate \S Leaf Base Acute y Bounded Acuminate y Cordate <— Leaf Tips Acute A Obtuse . n Aristate n Truncate n Oil Gland Count Per .3315 Cm ^ Mean 58.9 9 0 . 2 uvc. cl — c < ^A/C ^/vee/o tizv Test for all three types of measurement data* Within this Table are the ratio means for blade and petiole, of each variety, and the mean for number of oil glands per .3315 square centimeters. The varieties which have the same letter in the grouping column are not different statistically for the given characteristic, Table IX is a suggested method for obtaining a quick identification. In this Table, the mean of ratios for the blade and petiole, and the mean for oil glands per unit area are presented. This Table is similar to Table VIII, but in Table IX the mean averages are in descending numerical order for each characteristic, for all the varieties in this paper. Thus, in the process of variety identification, through this method, it is easy to insert the mean, for the blade of an unknown variety, in the blade column, and obtain the aproximate variety. Bepeat this process for each of the other two characteristics and a definate identification can be obtained. TABLE' 1X11 B'0ZCA5:«'S MULTIPLE EMG-E GROUPINGS EOS RATIOS' OE' BLADE? PETIOLE AMD HEIM GROUPINGS EOS !OfL GLANDS: BLADE PETIOLES^ ■ . OIL ■g l a n d s : TASIETF MEAN GEOUPINGS' HEAM GROUPING MEAN GROUPINGS 1 Trovita Oxange 2 o0510 C;,D 4.6812 B,0,D,E,E 63.9 G;,D,EfP 2 Hamlin Oxange 201136 D 4.7236 G:rB,EsE 75 = 2 g:9,hs;i 3 Gfampbell Oxange 2.0794 Gj»D 4 . 5 6 0 6 65 = 9 G,D,E,F,G 4 Indian Sivex Oxange 2.2384 E,E 5*1218 B jE,FrG,Ifi 55=7 G 5 Woods Walenoia Oxange 2 o04i4 G,D 4.7500 G:,D,E,F 6 1 . 8 C,D,F 6 Enterprise Navel 2 . 2 8 2 2 E,G 4.8024 0,D,E,E,G 6 2 . 3 C;,D,E 7 Warren Navel Orange 2.1544 D,F 4.6076 7 4 0 6 G,E,I 8 T.aracco Orange 2.3014 E jG jH s 5=4214 H 75=0 G ?E,I 9 Buby Bed Oxange 2 . 0 8 1 2 G»D 4.8158 g:'»b»e9f»g__ 8 ?o2 A,.K,L . ... 1 0 King Mandarin 2.0948 D- .5 .4964 H,I 6 5 . 1 0,D,E,E,G 1 1 Satsrana 2 . 3 5 8 2 G 5.H: 6 . 2 5 7 2 J»K 6 7 . 6 B,E,F,G 1 2 Willow Leaf Tangerine 2 . 9 2 6 0 K 7 . 6 1 3 8 L 78.5 H,I,J 13 Daney Tangerine 2 . 0 7 2 2 GAD 6.0342 J 65.3 G^BjEjE l4 Algerine Tangerine 2 . 5 2 8 8 I 6 .6842 K 8 2 . 5 1 ,J,E 15 Wise Tangerine 2 . 7 3 5 6 J 5 = 2 1 1 8 F,G,H 9 6 . 0 1 l6 Kimiow Mandarin 2.2390 E,E 9 . 2 8 1 2 M .56.7 17 Marsh Seedless 2.0432 0 »D 2.9372 A 27=3 A 1 8 __ Bed Blush Grapefruit 1.9648 B,€? 2.6254 A 2 8 * 6 A 19 Eureka Lemon 1.9094 AjB 4.2172 B:,0 43=9 B| 2 0 Lisbon Lemon! 2.0334 5=2074 EjG^.K 4i.i B 2 1 Millsweet Lemon 1 .8452 A 4.1088 B 42.5 B 2 2 Gueuzzaro Lemon . 2 . 1 2 0 6 B 4.3872 B.G! 3 k s 3 A,Bi M 23 Limegnat 2.4670 I 4.2440 BjG 49 o3 24 Minneola Tangelo 1.9044 A,m 4 . 2 3 2 8 B?$1G: 6 9 0.6 E,F,G,» 25 Orlando Tangelo 2 . 0 7 6 8 0,D 5=0290 B,E,F5G, m _58=.2__ G L ^ E ___ 2 6 Temple Tangox 2.5278 I . 7 = 8 3 9 2___ L,M 90.2 KeL t o & E I X AYES1G-E BLADE, M B PETIOLE PATIOS (LENGTH/WIBTH) ASS OIL GLASS- BOOSTS: (PER *3315 SQ- GIT..) FOR 26 GjlTRUS •TARIETIIS Y a r e . " "far. far 0 -fari Blade So. Petiole So. Oil Gland So. i far'iety So. 2 0 9 2 6 0 1 2 * _ 9 «2 8 l2 _.__l6 1___ 149T3 . 23 1 Siovita Orange. ' 1 2.7356 15 7 0 8 3 9 . 2 26 ; ^ S T o 15 Hamlin 0range. 2 2 . 5 2 8 8 14 rrz^il38_ 1 2 i. 9 0 . . 2 2 6 BampLeli ©range ...... ■ ,.3„,.„. 2.5278 26 0 S 4 2 i4 8 7 = 2 ,, 9 Indian River 'Orange 4 2=4670 2 3 6.2572 1 1 82.5 — i r i Woods faieneia Orange 5.. S 2 .3582; _ 11 r o s p . . 1 3 1 ^ ^ 8 7 5 . . ' 1 2 Enterprise Save! Orange , 6 2=3014 8 5 4 4 9 8 4 1 0 V 75.2 2 Warren Save! Orange 7 2.2822 6 5.4214 8 75=0 8 Tarocco Grange . 8 2.2390 1 6 5 = 2 1 1 8 15 74.6 Ruby led Orange 2.2384 _ 4 45.2074 20 _____ 69.6 , 24 Ring Mandarin l“ 2 . 1 5 4 4 •7 5.1218 4 6 7 a£ 11 Sat snsia 11 2.1206 2 2 5 = 0 2 9 0 . 2 5 , _____ 65*9. _ 3. Willow Leaf Tangerine 12 2.1136 2 T 4 B l 5 8 ^ 9 6 5 . 3 ..,.-..13 -.1 Baney Tangerine m . . 2.0948 10 ! 4.8024“ 6 ; 6 5 . 1 1 0 Algerine Tangerine i4 j2.0812. 9 4447500“ ,,.5, 1 Wise Tangerine ..... 15 3 .l 4X723,6. _ 2 62.3 . 6 K'iraiow Mandarin , r i6 ! 2 .0768 ...25.. ; 4.6812 1 . 6 1 . 8 : ... -...- 5_. Marsh Seedless Grapefruit 1 7 18 ! 2.0722 13 O 0 ? 8 .?.. 1_____ 58x9__ ..— 25 , Red Blush Grapefruit 2.0510 1 3 4 .5 6 0 6 “ , 3„ _ ... . 56_o 7__ 16 iEur eka Lemon . .______19 ,| 2.0432 ,17 , 4.3872 _ 2 2 ^_____ 55^7 42 Lisbon Lemon ., ,m 1 !F=o 4 i4 “ 5 4 . 2 4 4 0 2 3 41=2 Mi 11sweet Lemon 2.0334 2 0 4.2328 24 :____ 92_.5___ 21 Bucuzzaro Lemon 22 : T%9648TT 1 8 4.2172 19 4i.i 20 Lime auat 23 1.9094" 19 4.1088 2 1 ' 36 .S' 22 Mlnneola Tangelo : : 1.9044 24 2.9372, 17__ 2 8 7 6 1 8 Orlando Tangelo 2 5 2 6 21 2I 6 2 W 18 ____ 22=3 , , 12— i Temple Tangor S ' l H E l B W Twenty-six eoiameroial varieties of citrus^ eommon in Sri zona, have "been eomparedo Photographs are presented, illustrating that trees of different spooles can he separated on the basis of observable leaf ©haraeteristieso The species, Qiltrus sinensis, reticulata., paradisi * 1imon, and the hybrids; limequat, tangelos, and tangor were studied ia detail, The.above species and hybrids are effectively separated by visual eomparison of leaf characteristics. The differentiation of tangor versus Gitrus reticulata is the. only combination which fails to ■produce a very distinct field identification between specieso 40 MTESITUSE' CITED Batelaelor j, lie on Dexter and Herbert Webber 6 19^-8 0 The Citrus Industryj Wblume, 2;- $$ie University of California F r e s ;@0 page l49» Bitters, W e F 0 lr ® 1948, Boot stock Menttf leation For ©rangese Citrus LeavesD July, 1948a Esau, Katherine Br0 19^5 = Plant Anatomy; John Wiley # Sons $h@o- Sew Tibrk, London, and Sidneye. page 540 o Hume, Harold HL 1957« Citrus-: Fruit o. The Hae Millan Company0 pages 10— =27 o Humphries, E. C r8. and A®. W«. Wheeler0. 1 9 6 3 e The Physiology of Leaf Clowth ~ Annual Review of Plant Physiology, Wolume 14®. pages: 385— 410 „ Ee s ter son,. J. W » , Po- Plerenger, C - 6, J T * Edwards, and BV Hbndrieksons. 1964®. Application .of Cas-Liguid Chromatography to the Citrus Leaf Oils for the Identification of Hinds:: of Citrus» Proceedings of AMeriean Society for Horticultural 8501 fence® Wolmme" 84; ,pages 199— 203a Pi ©ringer, S® E», CL JT®. Edwards:, R e. W®, Hi If or d0 1964® The Identification of Citrus:- Species; and Varieties by Instrumental Jhalysis of Citrus Oils®. Proceedings of American Society for Horticultural Science® Fblume 84$ pages’ 2'o4— - 2 1 2 0 Robins Wilfred, W® and T®. Elliot. Weier® 195©® Botany Am Introduction to Plant Science® John Wiley Sons Inc® Mew lork, London, and Sidney6 page 154 o- Webber, Herbert and L e a n Dexter Batchelor0 19480 The Hitxufe’ Industry, Wolume 1;; The Hhiversity of California, Eresst pages 676— 677 »