Relative absorption of some nutrient elements by the tomato plant as affected by the stage of growth

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REL.~TI\'E .~B~OnC'Tl(~i~ OF SO~IE NUTRIENT


ELE~IENTS HY THE 'rOMATO PLANT AS


.~FFECTEL) R~' THE STAGE OF GROWTH










~: Dli~~l: L!~.I IIMENEZ S.


~ TiiEij r'i.E~L~uTEir Ti3 illi: GBADUATE COUNCIL OF
~Hi: U:;iiER~li\' OF FLORIDtl
r lu I' uiTi.\L F~lil~lLLlil~uT rlT THE RE$UIREMENTS FOR THE
~rEI.H1L ~~` ~I,\~TEF. (I~ SCIENCE IN AGRICULTURE


UNI\' F: 1;31T\' cjF FLORIDA
.IUh'E. 19j~











ACKNOWLEDGE~[ENT


The author wishes to ex~ress his deepest appre-

ciation to Dr. C. B. Hall for the wise direction and su~er-

vision of this investigation; to Dr. T. W. Steams and

Dr. G. J. Stout, the other members of the Committee, for

their valuable suggestions and reading of the manuscript;

to Dr. D. B. Duncan, professor of Statistics, for his con-

tribution made through the numerous advices in the use of

the statistical methods; to Mr. R. D. Roush, technician of

the Vegetable Products Laboratory, and to all those members

of the Florida Agricultural Experiment Station at

Gainesville, who in some way or another contributed to

make possible the accomplishment of this work.

The author sincerely wishes to express his indebt-

cdness to Dr. R. A. Dennison, Interim Head of the Horticul-

ture Department of the Florida Experiment Station,

Gainesville, and Dr. W. Popenoe, Director of the Panamerican

School of Agriculture, Honduras, for their part in obtain-

ing the required economical support.











TABLE OF CONTENTS

Page

INTRODUCTION.....,.,.................... 1

REVI~I OF LITERATUHE..............................

METHODS................................. 10

RESULTS................................. 14

Total Absorption. .........,,,.., ....... 14

Percentage of Dry Matter................... 16

Potassium............................... 20

Calciwn................................. 24

Magnesium............................... 24

Phosphorus. .........,,,..., ............. 31

Nitrogen................................ 31

DIsCvssIoN.............................. 36

sVMMARY................................. 39

APPENDIX................................ 41

BIBLIOGRAPHY. ................... ................... 79

















INTHODUCTION


A large amount of research work hzs been done In the

field of plant nutrition since 1804, when de Saussure estab-

lished that the plant depends upon the soil for the supply

of nitrogen and the mineral components of the ash. A better

knowledge about the nutrient elements was gained after

Llebig's work, published in 1840, which demonstrated that

the soil furnishes the growi~ plant with the elements

czlciun, potassium, sulfur, and phosphorus. But the great

advances in the field of mineral nutrition came after the

introduction by Sachs and Knop, in 1860, of the methods of

liquid culture which have been ever since the basis of this

type of experimentation (1).

k marked tendency toward the study of the rate of

absorI~tion of nutrient elements by different plants began

late in t~e nineteenth century. The idea has always been

to gather sound Information that can be applied practically

in the attempt to make crop production a more successful

enterprise, both from the economic and scientific points of

view.

Several factors have induced the undertaking of the

present investigation: the need for more detailed










information concerning the relative absorption of some of

the nutrient elements by the tomato plant at different

stages of development; a complete recognition of the various

factors that affect the nutrient absori~tion by different

species of plants; end finally, the fact that most of the

studies performed up to date have not considered the mineral

absorption in terms of the amounts taken up by the plant per

unit produced of fresh and dry weights respectively,

It is, therefore, the purpose of this ~r~ork to pre-

sent data concerned primarily with the relative absorption

of some nutrient elements by the toinato plant at five stages

of growth. Emphasis is placed on the cations calcium,

potassium, and magnesium. Other elements also included in

this study were phosphorus and nitrogen.
















~tEVI~I Or" LITEWiTU~E


The earliest work published in the line of mineral

uptake by plants of economic importance has been ascribed to

Hernberg, 1822, who worked with corn. He was able to note

that abrupt changes take place In the rate of absorption of

various elements at definite stages of the development of

corn plants. Hernberg reported that when the tassels were

beginning to form there was a marked reduction in the rate

of absorption followed by a period of rapid uptake which was

then succeeded by the ripening period. At this point he

noted that there was some loss of practically all nutrients

due perhaps to outward diffusion of solutes and to the loss

of leaves and roots (2). It should be mentioned here that

the concept of outward movement of nutrients from the plant

to the external medium has been also sustained by other

workers such as Hoagland (2) and Burd (3). More recently

MacCillivray (1C) could not detect any loss of phosphorus

from tomato plants to the surrounding medium which was much

lower in phosphorus concentration, and Amen (5) has proved

that there is a redistribution of this element in the tomato

plant. Steward (6) says that ali~arently the release of

elements to the external solution occurs only in extreme











cases. ~i~~agi~id (7) has stated in more recent publications

that normally metabolizing cells are highly impermeable to

salts, and that the electrostatic balance bet~ieen the root

and the solution is maintained externally by the release of

bicarbonate, or hydrogen ions or perhaps others and inter-

nally by readjustment of the organic acid content.

Burd (3), studying the rate of absorption of soil

nutrients by barley plants, found that a slight loss of cal-

cium, potassium and nitrogen appears to take place ,ihen the

heads are beginning to form, and he further concluded that

the forces acting upon the mentioned elements may also

affect others.

Eester, Shelton and Issacs (8) studied the rate and

the amount of plant nutrients taken up by various vegetables

--from the horticultural point of view. The data for tomato

indicate that this plant begins to absorb nutrients in con-

siderable amounts following the fourth week after trans-

planting. The largest absorption is during the latter part

of the grorring season when the fruit is forming. It is also

indicated that the amounts present in the top portion of the

plant (expressed in pounds per acre of the crop), followed

constantly up to the twelfth week this sequence:

K20 ) N ) Ca ) P 205 ) Mg. The summarized form in which these

authors present their data makes its applicability of

limited value.

Collander (9) studied the selective absorption of










several plant species without considering their stage of

development. He grew the plants in different nutrient solu-

tions of known composition, after which the cation composi-

tion of the plants was determined. Among his conclusions

there is one of particular interest. That is that "single

plant species are constantly, irrespective of the year of

cultivation and composition or the culture solutions, found

to be relatively rich in certain catfons and other species

as constantly relatively rich in other cations."

McCall and Richards (10) investigated the salt

requirements of wheat pla~ts at three different stages of

growth. These workers considered the absorption of the

salts as such, and this may lead to the conclusion that they

overlooked the fact that the constituent ions of a salt are

not necessarily absorbed in equivalent amounts which means

that any attempt made to correlate the salt uptake with the

growth made by those plants feeding upon such salt solutions

has no sound basis. It is impossible, therefore, to separate

from this sort of data the effect of the ions involved, or

the amounts of them absorbed.

Shive and Martin (11) have reported that buckwheat

plants produced their maximum yield of tops and roots during

the latter stage of development (from the fourth to the

eighth week) in a medium having a lower osmotic proportion

or potassium phosphate, a much higher proportion of calcium

nitrate, and a much lower one of magnesium sulfate than had










the medium which produced the highest yield during the early

growth period (from germination to the fourth week). Again,

this work tells nothing about the relative amounts of ions

absorbed by the plant from the two solutions used at the two

stages of growth.

Jones and Huston (12) working with maize found r;hat

a very rapid absorption of potassium occurred four weeks

after germination. This was followed by a period of

relatively slow absorption which in turn was succeeded by

another period of high uptake at the time the grains were

developing. They also observed that the uptake of phospho-

rus did not undergo any appreciable variation throughout the

life cycle. It may be noted in their data that an increase

in the amount of phosphorus absorbed on a dry weight basis

occurs, as comnared to the relative uptake of potassium and

nitrogen after the blooming stage.

Pember (1~), and Pember and McLean (14) observed

that barley, oats, and whea~ were able to make a more effec-

tive use of a limited amount of potassium if tne element was

supplied early in their growth period. The time of the

application of phosphorus made little difference, but small

amounts of nitrogen were most beneficial if supplied gradu-

ally over the entire growth period.

Gerickels ruork (15) with wheat agrees ~~ith the

findings of the investigators just mentioned in respect to

n~trogen` and potassiun, but differs somewhat in regard to











the conclusions reached for phosshorus. Gericke says that a

good supply of nitrogen is essential throughout the growth

period of wheat, and the proper supply of potassium, magne-

slum, sulfur and phosphorus appearsto be required by this

plant during the first four-week period of growth.

Brenchley (16), using barley, found results similar

to those obtained by Gericke in relation to the absorption

of phosphorus at early stages of growth. He found tl~t bar-

ley plants grew normally and produced a good yield of grain

if supplied with phosphorus during the first six weeks or

longer. If the phosphorus was withheld for the first four

weeks and then restored to the solution, the "tiller" pro-

duction was not affected but no heads were produced.

Brenchley also noted that the amount or phosphorus absorbed

by the plant increased steadily in more or less direct ,uro-

portion to the length of time the element was given at the

beginning or growth; then, the uptake ceased during the

latter stages of ripening of the grain.

Gile and Carrero (17) worked with rice and found a

decrease in the percentage of potassium, phosphorus, end

sulfur in the ash, and of nitrogen in the dry matter as the

plant matured. They also observed that the percentage dry

matter in the green plant did not rise until the plant had

begun to form seeds.

"According to Chizhov (1926) all the necessary ash

and nitrogenous compounds are accumulated by winter and











spring crops about the period of blooming or grain forming.

In the sunflower this accumulation is complete at about the

same time of ripening, while in beans and potatoes it is

completed at the end of the vegetative gro~~th" (2). In the

particular case of the tomato plant it may be expected that

such accumulation of nutrients will not stop until the plant

reaches senility. MacGillivray (4) considers the type of

growth of the tomato plant as being of an intermediate type,

where the vegetative growth Is concurrent with the develop-

ment of fruits at all stages.

Bartholomew and Janssen (18) included tomato plants

among several other species in their experiment. They found

a high initial level of concentration of potassium in the

plants during the early stages of growth. The height of

this level was in proportion to the amount of potassium

available to the plant. Nevertheless, they found that as

the amount of gror~th increased, there was a very decided

decrease in the potassium content of the plant. The authors

considered that the supply of this element was short and

thus concluded "that the plants~ had taken up more potassium

than was actually needed to perform normal life processes

and had reutilized this potassium when the incomine supply

became insufficient for Its normal growth."

Overstreet, Jacobson and Handley (19) studied the

effect of calcium on the absorption of potassium by barley

roots. They noted that the uptake of potassium was











considerably greater than the ui~take of calcium, and as the

potassium concentration increased in the solution there was

a reduction in the absor~tion of calcium. The authors also

mentioned a reciprocal effect, in which case the absorption

of potassium was markedly stimulated by the presence of cal-

cium. Even relatively small concentrations of calcium

exerted a stimulating effect which increased as the calcium

concentration increased. For a given calcium concentration

the effect diminished as the potassium concentration in-

creased. As the potassium concentration decreased, calcium

had an increasir~ly stimulating effect down to a concentra-
-4
tion of 2 x 10 N KC1. Below this value the stimulating

effect diminished and eventually the calcium depressed the

absorption of potassium at very low concentrations of potas-

sium chloride.

Fisher (20), working with tomato, observed that

plants which had been grown for four weeks (fIom the cotyle-

donary stage) in complete solutions before they were sui3-

plied with calcium deflcient solutions, took three to five

days to exhibit the symptoms denoting the lack of this

element.


















PiETtiODS


A strain of the Rutgers variety of tomato was

planted In flats filled with sterilized soil; the flats

were ~ratered regularly r~ith tap water. When the seedlings

passed the cotyledonary stage they were washed of the soil

and transferred to solutions in two-gallon glazed crocks,

the inside of which had been coated with asphalt paint.

The plants were pruned to one stem. As the plants reached

the desired stage of maturity, five uniform plants were

selected and transferred to similar crocks in a room in

which the light, temperature, and humidity were controlled.

Due to equipment limitations only one stage of growth could

be run at a time.

The room used was an insulated storage room in which

the relative humidity was maintained at about 30 percent.

The temperature was about 75 degrees F during the illumi-

nated period, and 70 degrees during the dark period. The

liyht was supplied by three sets of 12 slimllne fluorescent

tubes 8 feet in length. One set was suspended at a height

of one and one-half feet above the toy of the plants. The

other two sets were suspended to the front and to the rear

of the plants about one foot from the outer leaves. Three








11

100-watt mazda lamps were placed just under the upper set of

fluorescent tubes in order to increase the amount of red

light. The intensity of light at the plant surface was

about 800 foot candles as measured by a Weston light meter.

The illuminated period was 12 hours daily.

The crocks in the room were numbered from 1 to 5, so

that the plant growing in each one of them could serve as a

replicate in the experiment. Each crock contained 8 liters

of solution of the composition suggested by Hoagland (No. 2),

as given in the Appendix, with the exception that the con-

centration of ammonium phosphate ~~as increased 50 percent

over that recommended by the author.

The solutions were continually aerated by means of

diffusion stones attached to a comoressed air line. The

volume of the solution was kept constant by the addition of

distilled water; the nutrient contentsof the solutions were

very much the same in all the crocks. Wooden covers were

used for the crocks and in order to maintain the plants in a

vertical position they were fastened to stakes.

The plants were in the room for 3 days before begin-

ni~ the studies. Three samples were drawn from the solu-

tion of each crock during every treatment (stage of growth).

The first samole was taken just after the addition of fresh

solution; the second, at the end of the third day; and the

last one, at the end of the seventh day when the period of

observation was over. The results of the analysis of the








12

second sample were discarded. The elements whose absorption

was measured were potassium, calcium, magneslum, phosphorus

and nitrogen. The techniques used for their determinations

were the quantitative spectral analysis for calcium and

potassium, and colorlmetric methods for phosphorus and

magnesium. k Beekman Model B Spectrophotometer was used for

this purpose. The nitrogen was determined as total nitrogen

according to the Micro-Kjeldahl-GuMing method. The methods

are given in the Appendix.

The absorption of the various elements made by each

plant-repl~cate was obtained from the difference between the

concentration of the 8 liters of solution at the beginning

and the end of the seven-day period of observation as given

in the Appendix.

At the end of each treatment, the plants were re-

moved from the culture solutions and divided Into leaves,

stems, roots, and fruits for the determination of the fresh

weight. Whenever flowers were present they were included in

.the same group with the leaves. The material was dried in

a forced draft oven at 70 degrees F for a week; then, the

dry weight of each plant portion was determined.

The design of the present experiment is that of a

randomized block type with five treatments (stages of

growth) and five replications. The variable to be analyzed

is the logarithm of a number representing the milligrams of

the element absorbed per unit of fresh, or dry weight of the











whole plant. The use of logarithms was dictated by the

nature of the data; further explanation for their use is

given in the Appendix.

The stages of growth which served as a basis of

study in the present investigation were arbitrarily chosen.

For a better understanding of what is meant by the different

stages of growth, the following descriptions are given:

i. Seedling stage. The plants were about six inches

high from the base of the stem to the top, and suitable for

tran6planting.

2. Stem Elongation stage. The plants were making

rapid growth and still did not show any flower buds.

3. Flowering stage. The plants showed clusters of

flowers.

4. Fruit Setting stage. The plants had fruits of

less than one inch in diameter.

5 Fruit Enlargement stage. The plants had fruits

of any size above one inch in diameter, but no one of which

reached the mature green stage of development.

















EiESULirS


Although fresh and dry weights were determined for

the various parts of the sampled plants, as given in the

Appendix, only the data for the rate of absorption per unit

of fresh, or dry weights of the whole plant that were ana-

lyzed statistically will be discussed. In addition to the

unit rates of absorption, the results or total absorption of

the elements (Table 1) and the average percentage of dry

matter at various stages of growth (Table 2) are presented.


Total Absorption

The total absorption of potassium, calcium, magnesi-

um, phosphorus, and nitrogen (Table 1) was found to increase

almost constantly with maturity of the plant, as has been

noted by other workers (2, 5, 8, 12, 13, 14, 15, 16). Ex-

cept for nitrogen and magnesium, the uptake of nutrients is

markedly accelerated as the plant approaches Its reproduc-

tive period, and continues Increasing until the fruits are

set. Once this point is reached, the absorption of potassl-

un decreases considerably while the reduction in the uptake

of phosphorus arr~rl magnesium Is not so pronounced. Only

nitrogen and calcium are still absorbed in larger amounts at

the fruit enlergemene sta~e. a complsce picture of the

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total absorption of these elements is given in Figure I. In

general, it may be said that during the vegetative stages of

development the absorption of K> Ca) NP ,Mg, while after

the flowering stage, phosphorus is absorbed in larger

amounts than nitrogen resulting in this other relationship:

KCa>P>N.Mg. Throughout the life cycle of the tomato

plant, potassium and calcium are absorbed in the largest

prosortions, and magnesium is absorbed the least. The

period of highest total absorption corresponds to the fruit

setting stage, when there is a large proportion of actively

metabolyzlr~ cells in the plant. This last observation

agrees with the results reported by Hester et al (8).


PercentaRe of Dry Matter

In regard to the percentage distribution of the dry

matter of the tomato plant it may be observed (Tab'le 2 and

Figure 2) that the Increase in percentage takes place very

slowly during the periods or more active growth, namely,

before the plant blooms, and then, when the fruits are

developing. The explanation for this lag in the accumula-

tion of dry material may be that during those periods of

active growth there is a more rapid increase of fresh weight

due to the formation of ns~r vegetative tissue and expansion

of the young fruits which results in small gains in percent-

age of dry wei~ht. Considering that the enlargement of the

tonaco fruits occurs without any further addition of dry






























Fli~ure i. Total absor;jtion, in milli-
~rhms, or" potassium, caicluril,, mab?7esium,
phosphorus, ~nd nitrogen made by tomato
Ibnts iuri~ ~erlode of seven 8ays st
the following stages of growth: (1) Seed-
ling; (2) Ste~ elongation; (~) Floweri~;
(4) Fruit set~ir~; (5) Fruit enlsrgeoent.
(The points on the curves represent fhe
average absor~~lon of five plants.)

























TABLE 2

AVERAGE FRESH AND DRY WEIGHTS, AND PERCENTAGE
DRY MATTER Or' FIVE TOMATO PLANTS
Al' VARIOUS STAGES OF GROWTH



Stages Weight in Grams p..e ent age
of Growth I I I Dry Matter
Fresh Dry

Seedling 72.3 4.7 6.50

Stem
Elongation 150.1 10.2 6.82

Flowering 521.8 36.6 7.00

Fruit
Setting 1283.7 113.8 8.86

Fruit
Enlargement 2118.2 190.1 8.98



















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20

matter (Zi), it nsy reem reaconsble to ei:~,ecr ~nst tne Fer-

cen~6~e of dry matter a~ ttle ~19nt does not cn~irrge ~pprecl-

ably dLlrl~~ the last r;wo Et~7ges of Erorlth. iln the otner

nzni. the r~i? bccumulsr;lon o~ dry mn~erlsi i~tl3T; is found

between tne ~iorierl!~ and t;ne I'rult cettlrr2 sc~t~e~ Is in

agreement iritn tne opinion oi' clle ~rid C;rrrero (17) Hno

~oilild f!iir in rice the ~ercerits6e or' dry matter did not rise

L~ntll tne F~ihnt nad 'DBL~L~LU~ ~C' form seeds. Arlotner Otcer\rB-

tlon Is that the leaves I`orm ~ha portion of t~~e plant that

follows more cioeel;: ~ne cnmSee: tiP~ec~lr~ the percentat~e

o~ dr; matter oi' thEE ~jhoie plarit r;~irougno~t tne stat~es o~

If msy also be added that the leaves snow the

nlghecr; yercenthfe of drj matter as c~mfered to tne orner

por~ione o~ tne plant.


PottiEFlum

Tne rare o~ aDsorptlon of ~Ol;~sEl~l[il expressed on a

rresn, or dr.i' irelEnt basis (Ttitle j) Is 1'Jund to decrease

~~lth s~e. The ~hl~F1C 01' VBrlCr~iCe (Tsbie 4) indicates

t~l~l tne red~lcrlon lri tne rate of 6tcor3~icn ~rorr~ one 'tage

to sr~otr.er is clgnltlcut at the 1-; level, as cno~lrr by the

~ii~nl, slg~lrlchnt Ili~eer el'~ecr: and non-Elenl~lc~t quod-

retlc e~~ect and reeldual variation berireen EG3E~S. SIIIC~

Dotn joiynomlal regressions (Fl~ure j! show tne same cntir-

sct;rrlstic Elotje, It msg be concluded tnat ni~ Slrl~ilrlChlit

dil'l'erence could De detected in the riay of er~recslnc, ~ne

































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TABLE 4

ANALYSIS OF VARIANCE OF THE DATA (IN LOGARITHWS) FOR
THE RATE OF ABSORPTION 07 POTASSIUDI EXPRESSED ON
FRESH, OR DRY PIEIGHT BASIS OF THE ~IHOLE YLANT1
----
r~resh Weight Basis


Degrees Sum of Mean
Source of Variation F
Freedom Squares Square

Treatments2 1.898 0.475 52.84"

Linear Effect 1 1.871 1.871 207.94*
~adratic Effect 1 0.003 0.003 0.3
Residual 2 0.024 0.012 1.3

Rep lic nation 4 0.031 0.008 o.g

Error 16 0.147 O.oog

Total 24 2.076


Dry Weight Basis


Treatments2 4 2.735 0.547 54.7""

Linear Effect 1 2.719 2.719 271.9""
~adratic Effect 1 0.007 0.007 0.7
Residual 2 0.009 0.005 0.5

Replications 4 0.052 0.013 1.3

Error 16 0.153 o.oio

Total 24 2.940


1 The calculations are given in the Appendix.
2 The d~fferencesbetween any tMo consecutive treat-
ments (stages of growth) are also significant at the
1~ level.
v+ Significant at the 1~ level.
































Fl~ure 3. RateE of aDsarption of
potssslum st the follor;lr~s! stages
of ~rorrth: (1) SPedling; (2) Stem
plon;atlon; (3) Flowerii~; (4) Fruit
settl~ig; i5) Fruit enlargement.
(The points on the curves represent
the observed mean values.l











24

rate of absorption of this element. The fact that the rate

of absorption of potassium is higher during the early stages

of growth of the tomato plant is found to agree with the

idea sustained by several corkers (8, 12, 13, 14, 17, 18).


Calcium

The decrease in the rate of absorption of calcium

(Table 3) on fresh, or dry weight basis also takes place

throughout the life cycle of the tomato plant. The analysis

of variance (Table 5) indicates that the decrease in rate is

significant at the 1~ level, as shown by the highly signff-

icant linear effect and non-significant quadratic effect

and residual variation between stages of growth. The trend

of the rate of absorption of calcium on a fresh, or dry

weight basis Is found to show the same characteristic slope

(Figure 4); as it was the case for potassium, the rate of

absorption of calcium can be equally determined on either

fresh, or dry weight basis. Apparently, the tomato plant

also has a tendency to absorb large amounts of calcium

during the early stages of growth.


MaRnesium

Even though the overall tendency for the rate of

absorption of magnesium is to decrease with maturation of

the plant (Table 3), from the analysis of variance is

deduced that the variations in the rate of absorption are

different among the stages of growth as indicated by the










TABLE 5

ANALYSIS OF VARIANCE OF THE DATA (IN LOGARITHMS) FOR
THE RATE OF ABSORPTION OF CALCIUM EXPRESSED ON
FRESH, OR DRY WEIGHT BASIS OF'17HE WHOLE PLANT1


Fresh Weight Basis

Degrees Sum of Mean
Source of Variation F
Freedom Squares Square


Treatments2 4 1.923 0.481 30.1""

Linear Effect 1 1.890 1.890 118.1YY
&uadratic Effect 1 0.025 0.025 1.6
Residual 2 0.008 0.004 0.2

Replications 4 0.077 0.019 i. 2

Error 16 0.254 0.016

Total 24 2,254


Dry Weight Basis


Treatments2 4 2.782 0.696 43.5YY

Linear Effect 1 2.744 2.744 171.5"+
&uadratic Effect 1 0.015 0.015 o.g
Residual 2 0.023 0.012 0.8

~ceolications 4 o. 097 0.024 1.5

Error 16 0.251 0.016

Total 24 3130


1 The calculations are given in the Appendix.
2 The dlfferencenbetween any two consecutive treat-
ments (stagec of growth) are also significant at the
l;g level.
Y" Significant at the 1;% level.
































r'l~t~ure 4. Iiatec- of abzcir~~ion of
calcium at the follo~din3 sts~os of
Srorrth: (i) Sepdlinb; 12) Stem
elon~a~ion; (~) F1~Heriize_; (4) aruit
Eetting; (j) 7rul~ enlar~ement.
('i~Re points on ~hp curves re~rBSent
ihe oboerved me~i~ values.)













significant linear and quadratic effects and non-s~~nifi-

cant residual variation between stages (Table 6). The

trend of the rate or absorption of magnesium (Figure 5)

shows that the rate tends to Increase, although not signif-

icantly at the 5~ level, between the seedling and the stem

elongation stages; soon after this stage is passed the

trend starts to decrease up to the last stage of growth.

When the rate is expressed on dry weight basis, all the

reductions are significant at the 1~ level, but if the rate

is expressed on fresh weight basis the decrease between the

stem elongation and the flowering stages is not significant

at the 5~ level (Table 7). This divergency observed be-

t~een the two rates at this point may be due to differences

in the accumulation of fresh and dry matter by the plant at

the flowering stage which show up only when the nutrient

elements are absorbed in relatively small proportions

during the vegetative stages of the development of the

tomato plant. k similar case to this of magnesium will be

also observed for the rates of absorption of phosphorus.

To test the significance of the difference between

any two consecutive stages or growth it was necessary to

develop a new technique" which involves the use of a

t-test. The steps followed in testing the significance of



QThe technique was developed by Dr. David B.
Duncan, professor of Statistics of the University of
Florida, based on an idea suggested by the writer.











TABLE 6

ANALYSIS OF VARIANCE OF THE DATA (IN LOGARITHMS) FOR
THE RATE OF ABSORPTION OF FII1GNESIUD'I EXPRESSED ON
FRESH, OR DRY WE~GHT BASIS OF THE WHOLE PLANT1


Fresh Weight Basis


Source of Variation Degrees Sum of Mean
Freedom Squares Square

Treatments 4 2.238 0.560 7.6""

Linear Effect 1 1.636 1.636 22.1Y"
&uadratic Effect 1 0.601 0.601 8.1"
Residual 2 0.002 0.001 0.01

Replicatiolls 4 0.073 0.018 0.24

Error 16 1.176 0.074

Total 24 3.487


Dry Weight Basis


Treatments 4 3.122 0.780 10.4++

Linear Effect 1 2.446 2.446 32.69+
&uadratic Effect 1 0.671 0.671 8.q""
Residual 2 0.005 0.003 0.04

Replicationg 4 0.087 o.oz2 0.3

Error 16 1.207 0.075

Total 24


I The calculations are given i:
Significant at the 5~ level.
"" Significant at the 1~ level.


n the Appendix.































7irure ~. Rates of absb~tian of
mhJnecium at the followln, stages
of growth: (1) Seedling; (2) Stem
elonsatlon; (3) FlouFrin-J; (L~) Fruit
settIng~; (~) Fruit enlargement,
(The points on the curves represent
ttre observed mean values.)























TABLE 7

SIGNIFICANCE OF THE DIFFERENCES BETWEEN ANY TWO
CONSECUTIVE TREATMENT MEANS (STAGES OF GROWTH)
ON THE RESPECTIVE POLYNOMIAL REGRESSIONS
FOR THE RATE OF ABSORPTION OF MAGNESIUM


Fresh Weight Basis Dry Weight Basis
Stage of Growth
Differencel II ta Dif~erencel II t II
ldl ldl


Seedling- 0.og8 0.93 0.073 0.69
Stem Blo~Pation

Stem Elongation- 0.088 173 0.123 2.4""
Flowering

Flowering- 0.274 5.49" 0.?19 6.3""
Fruit Setting

Fruit Setting- 0.460 4.4~rt+ 0.515 4.8+a
Fruit Enlargement


3'Significant at the 1~ level.











those differences are illustrated in some detail In the

App endix.


Phosphorus

The rate of absorption of phosphorus (Table 9) also

has the tendency to decrease as the plant grows older. The

analysis of variance (Table 8) indicates that the rate of

absorption of this element, expressed on a fresh, or dry

weight basis has an overall tendency to decrease, and the

variations among the stages are different as shown by the

higr~y significant linear and cubic effects and the non-

significant residual variation between stages. The trend

of the rate of absorption of phosphorus (Pigure 6 and

Table 9) indicates that the rate, when expressed on a dry

weight basis, decreases significantly at the 1~ level up to

the last stage of growth, but a tendency for the rate to

level off is observed between the stem elongation and fruit

setting stages. This flattening is better shown by the

curve for the rate of absorption on fresh weight basis. in

either case, the leveling of the curves indicates that the

tomato plant absorbed more phosphorus when it was blooming

and setting fruit.


Nitronen

Since the data for the absorption of nitrogen could

not be analyzed statistically, It was impossible to get any

results concornsd with the rate of absorption of this











TABLE 8

ANALYSIS OF VARIANCE OF THE DATA (IN LOGAEiITH~IS) FOR
THE RATE OF ABSORPTION OF PHOSPHORUS EXPRESSED ON
FRESH, OH DRY WEIGHT BASIS OF THE WHOLE PLANT1~


Fresh Weight Basis

Degrees Sum of ~ean
Source of Variation F
Freedom Squares Square

Treatments 4 1.624 0.406 40.6""

Linear Effect 1 1.487 1.487 148.74"
~uadratic Effect 1 0.006 0.006 0.6
Cubic Effect 1 0.110 0.110 ll.O"Y
Residual 1 0.021 0.021 2.1

Replications 4 0.006 0.002 0.2

Error 16 0.161 o.oio

Total 24 1.791


Dry Weight Basis


Treatments 4 2.381 0595 45.89Y

Linear Effect 1 2.248 2.248 172.94"
&uadratic Effect 1 0.013 0.013 i.o
Cubic Effect 1 0.074 0.074 5.7"
Residual 1 0.046 0.046 2.0

Replications 4 0.033 0008 o.i

Error 16 0.203 0.013

Total 24 2.617


1 The calculations are given in the Appendix.
Significant at the 5~ level.
"" Significant at the 1~ level.





i:
/
/iiiiii


~ -
i i


Flfiure 6. rcates of abso~ption of
phosphorus at the folloning stages
of gro*rth: (1) Seedling; (2~) Stem
elongation; (~) Flowerir~g; (4) FruSt
setting; (51 Fruit enlareement,
(The points on the curves represent
tne observed nean o~a~~uesr)

























SIC1IIFICWI~E OF THE GIF~PEF~EilCES EEnjEEI! ~11Y TIlO
Ci~llSEiU~i~l'lE 'I'FtE;k'i'jlEI1T i1EAliS (S~TACES OF c;F~~7~1'I'H)
OIj THE RE~P~CIIV~ P3iR1SIII.iL F\ECRESSICIIIS
FOFi 'T'~E ~TE OP;rtiSO~TIOli OF PHOSPHO~US


Fr~~~ ~slght Basis Dry Weight Basis
S~~~c o~ ~l~o:r~n
Diff~rerrc4 r t (I Dilferencelr t II
Ldl ldl

S~edilrLt~- 0.286 4.2++ 0.287 4.4r~+
S~en ElorL~ation

S~en ~:iorlj~tiori- 0.069 1.7 0.120 3. 11"
Flo~rerlritl

Plowering- 0.087 2.2* 0.148 3.8YY
=ruic Setting

Fruit SeCtliy- 0.340 5.0"" 0.371 5.6++
Fruit Cnlarrem~~it


*SIErilflciine at the 5e level.
*"5laniflc~t at the 1~ level.


'T'PL~LE q








35

element. Table 3 can onlg give a sl~ght idea of the pat-

tern of such absorption.

















DISCUSSION


In the light of ~he results obtained from this

experiment it may be said that the nutrient elements

potassium, calcium, ma5nesium, phosphorus, and probably

nitrogen are absorbed selectively by the tomato plant

throughout its life cycle.

Even though the plant absorbs the nutrients in

larger amounts as it gets older, the amount taken up of

each element on a unit weight basis decreases as the plant

matures.

The rates of absorption of potassium and calcium

were found to decrease uniformly with age, and the respec-

tive trends for the rates of absorption were found to be

linear as indicated by the significant linear effect (at

the 1~ level) and non-significant quadratic effect and

residual variation between stages of growth.

The rate of absorption of magnesium showed an

overall tendency to decrease with maturation of the plant,

but the changes in rate from one stage to another were

found to be different in significance; between the seed-

line and the stem elongation stages the rate had a tendency

to increase although not significantly at the 5;g level;











soon after the stem elongation stage the rate started to

decrease significantly at the 1~ level, if it was expressed

on a dry weight basis; on the other hand, if the rate was

expressed on a fresh weight basis, the decrease between the

stem elongation and the flowering stages was not signifi-

cant at the 5~ level. The divergency observed between the

rates at this point may be due to differences in the

accumulation of fresh and dry matter by the plant at the

flowering stage which showed up only when the nutrient

elements were absorbed in relatively small proportions

during the vegetative stages of growth of the tomato plant.

A similar case to this was also observed for the rates of

absorption of phosphorus.

The rate of absorption of phosphorus was also round

to have an overall tendency to decrease with age. Never-

theless, the significant reductions in rate at the 1~ level

that were observed when the rate was expressed on the dry

weight basis tended to level off somewhat between the stem

elongation and the fruit setting stages. This tendency was

more pronounced ~ihen the rate was expressed on a fresh

weight basis. In either case, the flattening of the curves

indicates that the tomato plant absorbed more phosphorus

during the periods of blooming and setting of the fruit.

Due to a shortage in supply of nitrogen at the

flowering and fruit setting stages, the data for nitrogen

could not be analyzed statistically.








38

In every case, the fitted polynomial regressions of

the rates of absorption on the stages of growth were found

to be the best estimates of the respective trends, as indi-

cated by the non-significant residual variation between

stages of growth.
















SUMMARY


kn experiment was set up to study the effect of

maturation of the tomato plant upon the rates of absorption

of potassium, calcium, magnesium, phosphorus, and nitrogen

expressed on fresh or dry weight basis.

It was found that even though the tomato plant had

a marked tendency to absorb the nutrient elements in larger

amounts as it grew older, the rates of absorption per unit

of fresh or dry weight basis had a general tendency to de-

crease throughout the life cycle.

The rates of absorption of potassium and calcium

were found to decrease linearly throughout the five stages

of growth under study. This linear decrease was statisti-

cally significant at the 1~ level. The changes in rate

were, therefore, also significant at the same level.

The rate of absorption of magnesium was found to

increase slightly from the seedling to the stem elongation

stages, and then to decrease more and more through the

later stages. Both the linear and the quadratic trends

were statistically significant at the 1~ level. The ~n-

crease in rate of absorption from the seedling to the stem

elongation stages was not significant at the 5~ level. The









40

subsequent decreases, however, were all significant at the

1~ level except for the decrease between the stem elongatlan

and the flowering stages, when the rate was expressed on

fresh weight basis.

The rate of absorption of phosphorus followed a

more complex curve. In general, there was a linear down-

ward trend (significant at the 1P level) together with a

tendency to level off between the stem elongation and the

fruit setting stages which indicates that the tomato plant

absorbed more phosphorus between these two stages of

growth. The departures from linearity gave a cubic trend

which was significant at the 1~ level.

The fitted polynomial regressions of the rates of

absorption on the stages of growth of the tomato plant were

found, under the conditions of this experiment, to be the

best estimates for the respective trends.

The data for the absorption of nitrogen could not

be analyzed statistically because of a variation introduced

by a shortage in supply found at the flowering and fruit

setting stages.









































APPENDIX


















I. METHODS FOR THE QUANTITATIVE ~NAT~YSIS OF POTASSIUM,
CALCIUM, MAGNESIUM, PHOSPHORUS AND NITROGEN


Potassium (22)"

Standard: Dry potassium chloride in the oven and weigh out

exactly o.3el~ gr. Dissolve and make to one liter. This

gives a standard of 200 p.p.m. For the working standard

dilute to 20 p.p.m.


Procedure: (Using the Beekman ~lodel B flame photoneter. )

Use the red phototube and 10,000 megohm resistor. Set

sensitivity at 4 and wave length at 768 m~. Adjust dark

current to zero until steady. Obtain a 100~ transmission

using the potassium standard of 20 p.F.m. Place water into

flame and record transmission. Place the sample into flame

and record transmission.


To record: Subtract transmission of water from trans-

mission of sample; look up results In standard curve and

correct for dilution.


Standard Curve: Place 25, 50, 75, and 100 aliquots of the

20 p.p.m. potassium standard in 100 mi. volumetric flasks.




+Referencenumber.








43

~ilake up to volume and read on photometer. This Nill give a

curve for 5, io, 15 and 20 p.p.m. Plot the net percentage

transmission on plain graph paper.


Calcium (22)'

Same procedure as for potassium except for:

i. Wave length 554 m~.

2. Blue phototube and 10,000 megohm resistor.

3. To avoid the interference of high concentra-

tions of phosphorus in the readings for cal-

ciwn, the nutrfent solution has to be diluted

so that the phosphorus concentration is around

2 p.p.m.

4. Working standard for calcium is 200 p.p.rr.,


Standard: Dry calcium chloride in the oven and weigh out

exactly 0.5538 gr Dissolve and make to one liter. This

gives a standard of 200 p.p.m.


Standard Curve: Place 25, 50, 75, and 100 mi. aliquots of

the 200 p.p.m. calcium standard in 100 mi. volumetric

flasks. Make up to volume and read on photometer. This

will give a curve for 50, 100, 150 and 200 p.p.n. Plot the

net percentage transmission on plain graph paper.


Maffnesium (29)+

ReaRents: H~droxglamine hgdrochloride 5~. Dissolve

"Reference number.








44

10 gr. of the reagent in 200 mi. of water and store in dark

bottle.

Sodium hydroxide 2.5 N. Dissolve 50 gr. of

the reagent In 500 mi. of water.

Thiazole yellow 0.02~. Dissolve 0.10 gr. of

the reagent in 500 mi. of water and store In dark bottle.

Prepare fresh batch every 2 weeks.

Compensatln~ solution. Dissolve 3.7 gr. of

calcium chloride (CaC12~2H20), 0.74 gr. aluminum sulfate

(A12(S04)3'18H20), 0.36 gr. manganous chloride (MnC12'4H20),

and 0.60 gr. sodium phosphate (Na3P04) In about 500 mi. of

water containing 10 mi. of concentrated HC1. Dilute to

1 liter.

Starch solutlonl 2~. ~ix 50 mi. of glycerol

and 50 mi. of water and bring to boil. Add a mixture of

1 gr. soluble starch with 2 to 3 mi. or water, stir, and

continue the boiling for 3 minutes. Cool to room tempera-

ture and use or store. This starch solution may show no

signs of deterioration after at least 6 months.

Starch ConPensatin~ reaffent. Mix equal volumes

of the starch solution and compensating solution. Prepare

daily as needed.


Procedure: (Using the colorimetric set up of a Beekman


LI~aKen ~rom Chmi~t Analyst, 42: 70, 1953











Model Bphotometer. )

Tra~lsfer a 2 mi. aliquot of the nutrient solution to a

50 mi. volumetric flask and enough water to bring the vol-

ume to about 25 mi. Add 1 mi. of the hydroxilamine hydro-

chloride solution from a burette. Then add 5 mi. of starch

compensating solution and shake well. Add exactly 5 mi. of

thiazol yellow solution from a pipette and mix. Add 5 mi.

of sodium hydroxide solution. Shake and bring to volume

with water. I'lix again and allow to stand about 15 minutes

before reading on colorimeter at ~lave length 540 mu.,

sensitivity i. Use a blue phototube and 500 megohm resis-

tor. With each set run a blank which is used for 100~

transmission.


Standard Curve: Treat two 5 mi. aliquots of 20 p.p.m.

standard magnesium solution in the same manner as the

unkno~ns. This gives a 2 p.p.m. sample. The line passing

through the origin point and the average reading of the two

knorm samples constitutes the standard curve. Plot on

semi-log paper if ~ transmission is read, or on plain graph

paper if optical density is read.


Standard: Dissolve 250 mg. of reagent grade magnesium

metal in dilute hydrochloric acid solution (150 mi. of

water and 10 mi. of concentrated HC1) and bring to volume

in a 250 mi. volumetric flask. Dilute 10 mi. of this

solution to 500 mi. for the working standard of 20 p.p.m.










of magnesium.


Phosphorus (2LC)+

Reagents: Ammonium molybdate solution. Heat 25 gr. of the

reagent in about 200 mi. of water at 600C. and filter.

Dilute 280 mi. of concentrated sulfuric acid to about

800 mi. When cool, add the ammonium molybdate solution to

the sulfuric acid slowly with constant stirring. Cool the

mixture, transfer to 1000 mi. volumetric flask and make up

to volume. This is a 2.5;8 solution of ammonium molybdate

in 10 N H2SOlC.

_1_.2.4~ aminonaphthol sulfonic acid. Dissolve

0.5 gr. of the reagent and ~ gr. of sodium sulfite in

about 200 mi. of water. Add 30 gr. of sodiun bisulfite and

dissolve. Filter and make the final volume of 250 mi.

Prepare a fresh batch at least every two weeks.


Procedure: Transfer a 2 mi. aliquot of the nutrient solu-

tion into a 50 mi. volumetric flask. Add about 20 to

25 mi. of water and shake. Add 2 mi. of molybdate solution

from a burette and shake. Add 2 mi. of 1,2,4, aminonaph-

tholsulfonic acid also from burette and shake. Make up to

volume, shake, and allow to stand 10 to 12 minutes before

reading on colorlmeter at wave length 700 mu. and sensi-

tivity 3 against a blank for zero optical density. Use a

blue phototube and 500 megohm resistor.

*Reference number.










Standard Curve: Transfer i, 2, 4, and 10 mi. aliquots of

the 10 p.p.m. phosphorus standard into 50 mi. volumetric

flasks and Droceed in the same manner as the unknowns.

This will give a curve for 0.2, 0.4, 0.8, and 2 p.p.m.

Plot optical ~density on plain graph paper.


Standard: Dissolve 0.11394 gr. of KH2,P04 (dried over sul-

furic acid) in water. Add 10 mi. of 1:3 H2SO4 and dilute

to 1 liter. This solution contains 100 p.p.m. of phos-

ishorus equivalent to 229 p.p.m. of P205. Dilute 100 mi. of

this solution to 1 liter, thus making a standard solution

of 10 p.p.m.


Micro-KJeldahl-Gunnin~: Methoa

Total nitrogen is determined by this method to in-

clude nitrates end nitrites.


ReaRents: Concentrated sulfuric acid with 34 gr. of

salycllic acid per liter.

Sodium thiosulfate, 50 mg.

Sodium hydroxide solution. Dissolve 400 gr.

per liter.

Eerie acid, 2~.

0.02 N standardized HC1.

Catalyst. ~'Iix 2 parts of CuSOLe and 1 part of


K2S04..










Indicator:

Methylene blue,0.248 gr.

Methyl red, 0375 gr

Ethanol 95i~, 300 ml


Procedure: Transfer 20 mi. aliquots of nutrient solution

to 30 mi. Kjeldahl flask. Add 2 mi. of the sulfuric acid

and'salycilic acid to the sample, stopper and allow to

stand at least 30 minutes. Add approximately 50 mg. of

sodium thiosulfate, place on KJeldahl rack, heat 5 minutes

over a low flame and cool. Add a knife point of catalyst,

mix and heat gently until the reaction subsides. Prevent

any loss of the material due to frothing. When frothing

has ceased, increase heat so that a sulfuric acid condensa-

tion ring is formed in the neck of the flask. Continue

digestion until the liquid becomes water-white.

Distillation is carried out as follows: The micro

still is thoroughly cleaned out by allowing steam to pass

through for 10 or 15 minutes. Open all stopcocks, place a

150 mi. beaker containing 10 mi. of boric acid solution,

20 mi. of water, and a few drops of the indicator, under

the condenser. Have the water in the steam generator hot.

Transfer the digested material to the distillation flask,

using 40 mi. of water. Add 10 mi. of sodium hydroxide

solution, put flame under steam generator and close the

stopcocks. All the ammonia is distilled over in 5 minutes








49

from the time the first distillate appears.

Titrate the solution to color produced by 10 mi. of

boric acid and same amount of indicator made to approximate

the volume of distillate.

p.p.m. N = (ml. HC1)(Bormality HC1)(14)(10DO)
Volume of sa~o-~le in mi.









50

II. TOTAL CONCENTRATIONS OF THE VARIOUS NUTRIENT ELEMENTS
SUPPLIED IN EIGHT LITERS OF SOLUTION TO FIVE TOIIATO
PLANTS AT FIVE STAGES OF GROWTH



Stages of Growth


d
Repli- o
cations ci a
c~ a,
rd F
rl eb~ a~
a)o rlc, r((d
~e~
a, F~a, kF:
V3 c~W EW


Potassium


1 420.0 410.4 1112.0 1504.0 1488.0
2 240.0 500.0 988.0 2240.0 1520.0
3 260.0 460.0 1316.0 1816.0 1896.0
4 460.0 440.0 912.0 1976.0 1608.0
5 540.0 460.0 1024.0 2256.0 1696.0
Total.. 1920.0 2270.4 5352.0 9792.0 8208.0


Calcium


1 ioo.o 200.0 320.0 720.0 680.0
2 320.0 200.0 440.0 840.0 800.0
3 220.0 200.0 800.0 824.0 1320.0
4 ioo.o 200.0 440.0 720.0 840.0
5 320.0 200.0 520.0 600.0 920.0
Total.. 1060.0 1000.0 2520.0 3704.0 4560.0


Magnesium

1 29.6 41.6 90.4 59.2 66.4
2 4.0 24.8 104.8 131.2 120.8
3 18.4 49.6 95.2 175.2 86.4
4 32.0 29.6 60.0 123.2 36.8
4.8 95.2 121.6 204.0 70.4
Total.. 88.8 180.8 472.0 692.8 380.8













Nitrogen


1 59.6 92.0 259.2" 148.0" 258.4
2 59.2 124.0 1~6.Lc)t 221.6" 259.2
3 64.8 146.4 127.2* 156.0+ 245.6
4 52.0 123.2 180.8' 221.64 220.0
5 89.6 113.6 123.2" 216.OY 228.8
Total. 319.2 599.2 836.8 963 .2 1212.0


Phosphorus

1 62.4 42.4 178.4 216.8 260.8
2 45.6 53.6 180.8 393.5 376.0
3 48.8 69.6 240.8 322.4 236.8
4 63.2 56.0 158.4 923.2 146.4
5 49.6 47.2 185.6 955.2 337.6
Total.. 269.6 268.8 944.0 1611.2 1357.6


"Figures based on periods of absorption of approxi-
cately five days.


II. (continued)









52.

III. HOAGLAND'S NO. 2 FOR~,~IULA FOR NUTRIENT SOLUTION (25)"


A.


gm/llter
o.q5

0.61

0.49

0.18*"


Ca(No3)2'4Hz0

KN03

MgS04~7H20

NH1CHzP04


B. Composition of the

supplied the minor

H3B03

MnS04' 2H20

znso11'?Hz0

CuS04'5H20


C. Sequestrene NaFe


stock solut~on that

elements:

0.g15

0.543

0.07

0.05


13.4


25 mi. of

taini~ 8


solutions B and C were added to each crock con-

liters of nutrient solution.


*RPference I~umber.
**Tnl-- Ein~ount is one and one-half that originally
recommended by the author.











IV. r'EiESH AND DRY WEIGHTS (IN GRAP~S) ANI) PERCENTAGE
DRY MATTER OF THE PORTIONS, AS WELL AS THE
WHOLE PLANT, OF FIVE TOMATO PLANTS AT
FIVE STAGES OF GROWTH



Seedling Stage

LEAVES STEM
Plant
No. Fresh Dry P ere entage Fresh Dry IP e re ent ag e
WeightlWeightlDry Matter WeightlWeightlDry Matter

I 30.9 2.4 7.77 113 0.6 5.31
11 36.9 2.9 7.86 12.8 .7 5.lc7
111 43.2 9.8 8.80 14.7 .9 5.44
Iv 45.0 9.7 8.22 14.1 .8 5.67
v 49.4 3.4 6.84 16.9 .8 4.73
Ave.. 41.1 3.4 790 14.0 .8 532

ROOT WHOLE PLANT

I 0.6 ~.oo 57.1 3.6 6?0
I1 18.5 .7 3.78 68.2 4.3 6.30
111 20.1 .8 3.98 78.0 5.5 7.05
Iv 13.0 .7 5.38 72.1 5.2 7.21
v 19.3 .8 85.9 5.0 5.82
Ave.. 17.2 .7 ~.26 723 47 6.50















Stem Elongation Stage

LEAVES STEM
Plant
No. Fresh Dry Percentage Fresh Dry Percentage
Weigh WeightlDry Matter Weight elgh Dry Matter

I 74.5 5.5 7.38 22.5 1.W 6.22
11 94. O 7.5 7.98 23.5 i. 61 6.81
111 ioo.o 8.2 8.20 24.5 1.71 6.94
Iv 87.5 71 8.16 22.5 6.67
v 85.5 6.4 7.49 23.5 1.5 6.38
Ave.. 88.2 6.9 7.84 23.3 1.51 6.60

ROOT I WHOLE PLILNT

I 31.5 1.5 4.76 128.1 8.41 6.55
11 40. o 2.0 5. oo 157.5 11. 11 7.05
111 49.5 2.1 4.24 174.0 12.0 6.90
Iv 40.5 1.9 4.69 150.0 10.5 7.00
v 31.5 14 4.44 1~0.5 9.2 6.62
kve.. 38.6 1.8 4.63 150.1 10.11 6.82


IV. (contlnued)














Flowering Stage

LEAVES STEM
Tlant
No. Fresh Dry Percentage Fresh Dry IP e re entage
WeightlWeightlDry Matter WeightlWeightlDry Matter

I 334.0 24.5 7.34 86.0 5.5 6.40
11 297.0 23.0 7.74 72.0 5.0 6.94
1II 363.0 29.5 8.13 97.0 6.5 6.70
Iv 270.0 24.0 8.89 82.0 6.0 7.32
v 359.0 26.5 7.38 94.0 5.0 5.32
Ave.. 324.6 255 790 86.2 5.6 6.54

ROOT 'WHOLE PLANT

I Iii.o 5.0 4.50 531.0 35.0 6.59
11 103.0 5.0 4.85 472.0 330 6.99
111 138.0 6.5 598.0 42.5 7.11
Iv gi.o 5.0 5.49 443.0 35.0 7.90
v 112.0 6.0 5.36 565.0 375 6.55
Ave.. 111.0 5.5 4.98 521.8 36.6 700


IV. (continued)















Fruit Setting Stage

LEAVES STEi~
Plant
No. (Fre sh Dry (P e re entage Fresh Dry (P e re entage
eight IT~Jeight IDry Matter Weieht IWelght IDry Matter

I 817.0 83.2 10.18 264.0 22.4 8.48
11 799.0 78.8 9.86 228.0 21.5 9.43
111 762.0 72.~ 9.48 243.0 22.8 9.38
Iv 847.0 85.6 10.Il 236.0 21.5 9.11
v 654.0 57.2 8.75 225.0 18.7 8.31
Ave.. 775.8 75.4 9.68 239.2 21.4 8.94

FRUIT ROOT

I 26.5 1.9 7.17 231.0 Ib.i 6.10
1I 4.1 0.3 7.32 293.0 18.0 6.14
111 30.3 2.1 6.93 260.5 14.5 5.58
Iv Il.o 0.9 8.18 280.0 18.6 6.64
v 7.7 0.6 7.79 200.0 13.9 6.35
Ave.. 15.9 1.2 7.48 252.8 15.8 6.28

WHOLE PLANT

I 11398.5 121.6 9.08
11 1324.1 118.6 8.96
111 1295.3 111.7 8.62
Iv 1374.0 126.6 9.21
v 1086.7 90.4 8.32
Ave. 11283.7 113.8 8.86


IV. (coritinued)















Fruit Enlargement Stage

LEAVES STE~I
Plant
Fresh Dry Percentage Fresh Dry Percentage
No.
WeightlWelghtlDry Matter WeightlWelghtlDry Matter

I 1179.0 101.2 8.62 364.0 30.1 8.26
11 1223.0 Izz.o 9.98 487.0 43.6 8.95
111 13~0.0 138.0 10.30 424.0 39.6 93~
Iv 891.0 120.re 13.51 315.0 95.6 11.30
v 1160.0 100.7 8.68 428.0 42.7 9.98
Ave..11157.4 116.5 10.22 403.0 38.3 957

FRUIT ROOT

I 132.0 7.9 5.98 363.0 20.0 551
11 613.a 36.2 5.91 270.0 17.6 6.52
111 98.0 5.8 5.92 3250 211 6.49
Iv 143.0 10.2 7.13 346.0 24.1 6.96
v 244.0 13.9 5.70 252.0 19.9 7.90
Ave.. 246.0 14.8 6.19 311.2 20.5 6.68

WHOLE PLANT

I 2032.0 159.2 7.83
11 2593.0 219.4 8.46
111 2187.0 204.5 9.35
Iv 1695.0 190.3 11.23
v 2084.0 177.2 8.50
Ave.. 2118.2 190.1 8.98


IV. (continued)












V. THE STATISTICAL ANALYSES OF THE DATA, IN LOGA-
RITHPIIS, FOit TtiE F(A'TE OF ABSORPTION OF
SOiIE ELEIIEIITS IIADE BY FIVE TOMATO
PLkll'i'S AT DIFFERENT STAGES
OF G~ilWTH



The Use of Logarithms+

A randomized block analysis assumes that the error

variance of any observation is the same throughout the

plots; if the error variance for a given observation is

proportional to the respective true mean, then, the correct

procedure is to analyze the logarithm or the observation.

Since in this particular experiment it was found

that the rate of absorption of any of the studied elements

decreased considerably in magnitude with the treatments,

this indicates that the observations of the first treat-

ments may have larger true means than the observations of

the last treatments, and hence, different observations may

have different error variances which in turn may be pro-

portional to the respective true means. Therefore, the

conversion of the original data into logarithms was impera-

tive in order to have the same error variance in all the

treatments.


'A private communication from Dr. D. B. Duncan to
the writer.









VI. COilIPUT~TIONS FOEI THE ANALYSES OF VARIANCE, AND
FITTING OF THE POLYNOMIAL REGRESSIONS FOR
TtiE RATE OF ABSORPTION OF POTASSIUM
EXPRESSED ON FRESH, OR DRY
WEIGHT BASIS OF THE
WHOLE PLANT

Data for Unit Fresh Weight
tin logarithms)
Treatments


Repli- d a,
cztion c, rl E
rl (d
"a E~ a, I c~ rl I rl
a, mO O~ rlcl deb (d
,,, ii ~5 c~
vl cllW aw R

1 2.867 2.504 2.321 2.051 1.864 11.607
2 2.546 2.502 2.321 2.228 1.768 11.365
3 2.523 2.422 2.342 2.147 1.938 11.372
2.805 2.467 2.314 2.158 1.977 11.721
5 2.798 2.515 2.258 2.317 1.911 11.799
Total. 1 13539 12410 11.556 10.901 9.458 5786Le
Mean... 2.708 2.482 2.311 2.180 1.892 2.315


CO~UTIPIG THE SUM OF SQU~RES
2
Correction Factor: C P G
N


57.8642 5 199.990
25


Total: F y~-C'1~6.006- 137.930= 2.076

Treatments: f rp~ c = 135.828 133930 = 1.898

Rellcations: ~ ~5-C=133961- 199970= 0.031

Error: (total s.s.)-(treatments s.s.)-(re~licatlons s.s.)
2.076 1.929 = 0.147









VI. (contlnued)

Contribution of the Linear Hegression to the s.s.

zl = (-2)(13.539) ~ (-1)(12.410) + 0(11.556)+ 1(10.901) ...
...-e 2(9.458) = -9.671
"12 -9,6712 ~f PZ~28 = 1.871
sszl D1 5x10


Contribution of the r~uadratic Regression to the s.s.

22'2(13539)+ (-1)(12.410)t (-2)(11.556) + (-1)(10.901)
... + 2(9.458) = -0.429
222 -0.4292 0.184
s.s.z2 D2 5x14 70 0.003


Regression Coefficient: bl Z1 14L6~ -0.193
D1 50

General Mean: ~L~' 122~t25
2.315


ComI~uting ~: ~y

Y1



Y3
Y4

Y5 I


y + bl~Ei'
2.315 +(-2)(-0193) = 2701

2.701 0.193 = 2.508

2.508 0.193 = 2.315

2.315 0.193 = 2.122

2.315 + 2(-0.193)













Data for Unit Dry Weight
tin logarithms)
Treatments
F: 1~
4 a,
Repll- b~ cil k
cation s ~ a, ck
rlcs d~
a, mo o ~cl
e, rl ka, ~F: o
rnW ~I ~cn W E-l

1 4.079 3.689 3.502 3.092 2.971 17333
2 9.747 9.654 3.476 3.276 2.841 16.994
3 3.674 3.584 3.491 3.211 2.367 16.927
4 3.94~7 3.622 3. lt16 3.193 2.927 17.105
5 4.033 3.694 3.436 3.397 2.981 17.541
Total.. 19.480 18.243 17.?21 16.169 14.687 85.900
ILIean. .. 3 896 3 649 3 404 3 2?4 2. 937 3 113 6


COMPUTING THE SUM OF S&UARES
O2 85,9002
Correction Factor: C P 295152
N 25

Total: fyy2-C=298.09e- 295.152= 2.440

Treatments: ~ ~t c = 297.887 295.152 12.775


Replications: t ~
J c = 295.204 295.152 r 0.052


Error: (total s.s.)-(treatments s.s.)-(replications s.E.) =


VI. (continued)


2.941 2.787 ~ 0.15~










VI. (contlnued)

Contribution of the Linear Regression to the s.s.

z, = (-2)(19.480) ~ (-1)(18.243) -t 0(17.321) + 1(16.169) ...
...+ 2(14. 687)= -11.660

s.s.z, .12 ~11.6602 2.719
D1 5x10 50


Contribution of the Quadratic Regression to the s.E.

z, ~ 2(19.480) + (-1)(18.243) + (-2)(17.321) + (-1)(16.169)
...+2(14. 687) -0.720
2 2
"2 -0.720 _0.518
s-sz2' ~=5x14 70 0.007


-11.660
50 -0.233

3.436



).233) = 3.902

,.233 = 3.669

,.233 = 3.436

,233 e 3,203

!33) = 2.970


Regression Coefficient: bl = Z1
D1
G 85.900
General Mean: ~ E i3 25


Computing yi:


Y

Y1'

Y2 =


Y4 =

Y5


Y + bl ~~
3. LC36 ~(-2)(-C

3.5~02- C

3.669 -e

3.436- c

3.436 -t 2(-0.;










VII, COMPUTATIONS FOR THE ANALYSES OF VARIANCE, AND
FITTING OF THE POLYNOMIAL REGRESSIONS FOR
THE RATE OF ABSORPTION OF CALCIUM
EXPRESSED ON FRESH, OR DRY
WEIGHT BASIS OF THE
WHOLE PLANT

Data for Unit Fresh Weight
tin logarithms)

Treatments

Reoli- a,
~
i I~ U~
E1~ aT -lo
a, a~O O
a, rl ~F: O
vl ~lil crl

1 2. 243 2. 19 2 1. 780 1. 731 1.525 a. 471
2 2.671 2.104 1.969 1.802 1.490 1~ 036
3 2.450 2. 060 2. 126 1.801 i. 781 to. 220
4 2.142 2.125 1.997 1.719 1.695 9.678
5 2.571 2.153 1.964 1.741 1.644 10.073
Total.. 12.077 10.634 9.836 8.:96 8.1?5 49.478
Mean... 2.415 2.127 1.367 1759 1.627 1.979


COI~PU~ING THE SUDI OF S&UAHES
G2 49.4782
Correction Factor: C
N 2j '97923

Total: 100.177 97.923 P 2.254

T21
Treatments: f C = 99.846 97923 = 1923

RePllcations: 4 Zi~ 98.000 97.923 = 0.077

Error: (total s.s.)-(treatments s.s.)-(replicetions s.s.)

2.254 2.000 = 0.254










VII, (continued)

Contribution of the Linear Regression to the s.s.

zl = (-2)(12.077) + (-1)(10.634) + 0(9.836) + 1(8.796) + ...
... $ 2(8.135) = -9.722
2 2
sszl=Z1 ~e~2~1 e~i~i~ 1.890
5x10 50
"1


Contribution of the Quaarztle Regression to

22 = 2(12.077) + (-1)(10.634) ~ (-2)(9.836)
... $ 2(8.135) = 1.922
2 2
22 1.322 1.748
S.s.Z
2-D 5x14 70 0.025

Regression Coefficient: bl ; 21 -9.722
o, ~o


the s.s.

~ (-~)(8.796) ~






-o.194


c 49.478 = 1979
N 25

Y+bl~'
= 1.97~ + (-2)(-0.194) = 2.367

2.367 0.~~4 2.173

2.173 0.194 3 1.979

1979 o.~g4 = 1.785

1.979 4 2[-O.194) = 1531


General Mean: ~

Computing y;: y

Y1

Y2

Y3
Yq

Y5












Data for Unit Dry Weight
tin logarithms)
Treatments

E: ~
Repli- "
cation rl a~
a s ,~
a~ o~ ,, I .rl m g
~~ Ef ~vl Fm R

1 3 115 6 3.377 2.961 2.772 2. 631 15 197
2 9.872 3.256 3.125 2.850 2.562 15.665
3 3.602 3.222 3.275 2.868 2.810 15.777
4 3.284 3.280 3. 099 2.:55 2. 645 1-5.063
5 9.806 ~331 3.142 2.822 2.715 15.816
Total.. 18.020 16.466 15.602 14.067 13363 77.518
Mean... 3.604 3.293 3.120 2.813 2~73 3101


CO~IPUTING THE SU~1 OF S&UARES
2 77.5182
240.362
Correction Factor: C N

Total: t JTij 243.492 240.362 = 3.130


(continued)


f 't = 243.144 240.362 = 2.782
r


Treatments:


Heplications: ~j 24O.L~j9 24~0.362 = 0.097

Error: (total s.s.)-(treatments s.s.)-(replications s.s.)

~.1~0 2.888 = 0.251







66

(conclnrl~3)
Contribution of the Linear bsr~r~ion to the s.s.

zl (-2)(18.020) + (-1)(16.466) + 0(15.602 + 1(14.067 + ...
... ~ 2(13.363) = -11.713

"1 -11.713 137.194
1 2.744
s.S.Z
D1 Sxl0 50

Contribution of the ce~adratic Regression to the s.s.

z2 = 2(18.020) + (-1)(16.~66) + (-2)(15.602) t (-1)(14.067)
... t 2(13.363) = 1.029
2 2
S.S.Z "2 1.029 1.059 0.015
2 ,, 5x1L, 70
Regression Coefficient: bl I zl -11.713
50 -0.234
D1
oenera~ ilean: ~-G ~2~8
N 25 3.101

+bl-E~l
Corqouting yi: Y Y

3;1 = 3.101 t (-2)(-0.234) = 3.569

jr, = 3.569 0.234 3.335

Y3 = 9.335 0.294 3.101
y4 = 9. ioi -0.234 = 2.867

Ji5 = 3.101 t 2(-0.2341 = 2.633










VIII. TEST OF THE SIGNIFICANCE OF THE DIFFERENCE
BETI~EEN ANY TWO CONSECUTIVE POINTS
IN A ~UADRATIC OR CUBIC REGRESSION


The ratio of the difference (d = y; y;) between

any two consecutive points (y; and y;, which are the best

estimates of the treatment means as given by the polynomial

regressions) and its standard error follows the Student's t

distribution.

t d
d'
Sd

where sd is the standard error of the difference.

To obtain the standard error or the difference,

first calculate the variance of the difference according to

the following formula:

d^2 C 1 s 2
D1 Dz (1)

where 4,1 -2; 5~1j.-1; 4:;il; and ~d'-2 are the
a~~roprlate ortnogonal polynomial coefficients according to

Fisher and Yates (26); and D1 and D2 are the corresponding

divisors. The error variance (s") is obtained from the

analysis of variance.

For each of the differences
Rinally, sd_~s~
compute the respective standard error.

When the cubic effect is significant the formula

for the variance of the difference is:

2 ri 2
s d- If~i- ~~j) 2 3 Se
D1 D2 D3








68

VIII. (continued)

where 5:i; -1; and 5~U. 2 are the additional

ortho~onal polynomials coefficients; and D3 is the addi-
tional divisor.

The computed l't" value for each difference is then

compared with the values for "t" given by the table with

"n" degrees of freedom (n= d. f. for error), and the chosen

level of si~nificance.










IX. COFIPUTkTIONS FOR THE ANALYSES OF VARIANCE, AND
FITTING OF THE POLYNOMIAL REGRESSIONS FOR
THE RATE OF ABSORPTION OF iYkcNESIUM
EXPRESSED ON FRESH, OR DRY
WEIGHT BASIS OF THE
WHOLE PLANT


Data for Unit Fresh Weight
tin logarithms)
Treatments

F: ~
Repli-
cation ri
,f~
Ei~ r1~3 ~(d
mm vlWa, o o ka, R
Fr~ F

1 1.714 1,511 1.230 0.643 0.518 5.616
2 0.771 1.196 1.346 0.996 0.672 4.981
3 1.379 1.455 i. 201 1.130 o. 602 5.761
4 1.647 1.294 1.130 0.954 0.342 ~.367
5 0.748 1.400 1.332 1.274 0531 5.285
Total.. 6.253 6.856 6.239 4.997 2.665 27.010
Mean... 1.251 1371 1.248 0.999 0533 1.080



COMPUTING THE SUM OF SQIJARES
2 2
Correction Factor: C G 22~ 29. 182
N 25

Total: Yij C = 32.669 29.182 = 3.487


Treatments: f IO- C = 31.420 29.182 = 2.238


aeplioations: ~ ~~ C = 29.255 29.182 = 0.073

Error: (total s.s.)-(treatments s.s.)-(replicat~ons s.s.) I

3.487 2.311 = 1.176









IX. (contin~red)
Contribution of the Linear ~eer~erion to the s.s.

z, = (-2)(6.253) + (-1)(6.856) + 0(6.239) + 1(4.997) c .....
... + 2(2.665) = -9.045

212 -9,0452 1 81.818 1.636
S.6.Z1 D1 5X10 50


Contribution of the &uadrstic Regression to

z, = 2(6.253) + (-1)(6.856) + (-2)(6.239) +
~ 2(2.665) = -6.485

222 ,6,4852 = 42.055 0.601
s.s.z2 D2 5 x14 70


the s.s.


= Z1 = -9.04~5
Regression Coefficients: bl
D1 50


-0.181


b2= "2 = -6.485 -0.093
"2 70

G 27.010 1.080
General Mean: a( N 25


~ = ;Y t blF;1+ b2f\2 (b2 is included
because the quadratic effect is si~nificant)
/z 1.256
y, = 1.080 + (-2)(-.181) ~ 2(-.093)
1.080 -t (-1)(-.181) (-1)(-.093)1 1.3~4

33 = 1.080 +0(-.181)~ (-2)(-.093) = 1.266
1.080 + 1(-.181) t (-1)(-.093) : 0.992

35 = 1.080 + 2(-.181) + 2(-.093) = 0.532


Computing y;:












Data for Unit Dry b~eight
tin logarithms)
Treatments

d
~tepll- ~ i
cation rl
~ m k M
8~ a, ccar m
"" 4 "
a,
vl vlW ~W ~

1 2.927 2.695 2.412 1.687 1.620 11.341
2 I.q68 2.349 2.502 2.044 1.741 10.604
3 2.524 2.616 2.350 2.195 1.626 11.311
4 2. 789 2.450 2. 294 1.988 1.285 10.746
5 1.982 2.578 2.511 2.354 1.599 lloz~
Total.. 12.190 12.688 12.009 10.268 7.871 55.026
Mean... 2.438 2.538 2.402 2.054 1.574 2.201


COMPUTING THE SUM OF S&UARES

Correction Factor: C G2 1 55.0262 121.114
N 25

'Patal: f y~- C-125.590- 121.114= 4.416

Treatments: f Ip~ c = 124.236 121.114 = 3.122


Repiicetions: ~-q C = 121.201 121.114 e 0.087

Error' (total s.s.)-(treatments s.s.)-(reslicatlons s.s.)

4.468 3.241 = 1.207


IX. (continued)









IX. (continued)

Contribution of the Linear Reg~ession to the s.s.

z, = (-2)(12.190) + (-1)(12.688) + 0(12.009) + 1(10.268) +..
... + 2(7.871) = -11.058
2 2
s.s.z "1 -11.058 122.224 2.446
1 D1 JX10 50

Contribution of the quadratic regression to the s.s.
z, = 2(12.190) + (-1)(12.688) + (-2)(12.009) + (-1)(10.268)
... + 2(7.871) = -6.852
2 2
22 '6.852 46_t950 0.671
S.S.Z2 D2 5X1~ 70

"1 11.058 -0.221
Regression Coefficients: b
1 D1 50

b 22 1 -~-r852 _0 ~098
2 D, 60

General Mean: y G = 55.026 = 2.201
N 25

Com~utlng y;: y y+ blTrl c b2~ 2

y; = 2.201 + (-2)(-.221) + 2(-.098) 1 2.447
j;2=2.201+ (-1)(-.221)+ (-1)(-.098)= 2.520
^ P 2201 + 0(-221) + (-2)(-098) = 2~97
Y3
y4=2.201+1(-.221) ~ (-1)(-.098) = 2. 078
1.563
Y5 2.201 ~ 2(-.221) + 2(-.098)










X. COMPUTATIONS FOH THE rlNALYSES OF VARIANCE, AND
FITTING OF TEE POLYNOMIAL REGRESSIONS FOR
THE RATE OF ABSORPTION OF PHOSPHORUS
EXPRESSED ON FRESH, OR DRY
WEIGHT BASIS OF THE
WHOLE PI~NT

Data for Unit Fresh Weight
tin logarithms)
Treatments


Rei~li-
cation d Ei
ct 7;j a,
B dcd rd
6~ D I Y-i Y~
P)O
rl I ~O HO
~IW Fr~ ~E~vl ~ZI

1 2.039 1.518 1.526 1.210 1.107 7.400
2 1.825 1.531 1.583 ~.~73 1.161 7573
3 1.796 1.602 1.605 1.396 1039 7.432
l.9LC3 1.572 1.554 1371 0.934 7.374
5 1.761 1.526 1.516 1.51~ 1zlo 7527
Total.. 9.364 7.749 7.784 6.904 5.445 37.306
Mean... 1.873 1550 1557 1393 1.089 1.1192


COMPUTING THE SUM OF S~UAHES
2 2
C 6
Correction Factor: C 77.30
N 25


55.669


Total: 6. yi)j- C=57.460-55669= 1791
Treatments: L TP 1.624
0 57.293 55.669

R2
Replications: ~ 0 = 55675 55.669 = 0.006

Error: (total s.s.)-(treatments s.s.)-(replications s.s.)

1.791 1.630 0.161










X.

Contribution of the Linear Regression to the s.s.

z, = (-2)(9.364) + (-1)(7.749) + 0(7.784) + 1(6.~64) +


+ 2(5.445) = -8.623
,8,6292 74 156 1.487
5x10 50


the diuadratic Hegresslon to the s.s.

(-1)(7.749) + (-2)(7.784) ~ (-1)(6.964) + ..

... + 2(5.445) = -0.663

-0.663" = 0.440 0.006
5x14 70

the Cubic Regression to the s.s.

f 2(7.749) + 0(7.784) ~ (-2)(6.964) + ......

... ~ 1(5.445) = -2.349

-2.?492 5.518 0.110
5x10 50


= Z1
sszl
D1

Contribution of

z, = 2(9.364) )



s.s.z 22
2 D2

Contribution of

23 = -1(9.364)


s.s.z 23
3 D3


Regression Coefficients: bl
D1
b
L-D2
23
b3 t
D3


-8.627 -0.172
50
-~.C67
-o.oog
'ic,

-0.047
50


G~77.?0i
General Mean: y = 3 1492
N 25









X. (continued)

Com~uting ~j~i : Ij~ = y + blil + b2~2 + b3E~3 (b3 is in-
cluded beczuse the cubic effect is

significant)

= ~.492 + (-2)(-.172) + 2(-.009) + ......
... + (-1)(-.947) = ~.865

= ~.492 + (-1)(-.172) + (-1)(-.009) + ...
... + 2(-.0~7) -- 1.579

1.492 + 0(-.172) ~ (-2)(-.009) + ......
5~'3
... 4 0(-.047) = 1.510

j~ =1.492 -~ 1(-.~72)+ (-1)(-.oo~)+ ......
... + (-2)(-.047) = 1.423

j;j 1.492+ 2(-.172)+ 2(-.009)+ .........
... + 1(-.0'c7) = 1.083













Data for Unit Dry Weight
tin logarithms)
Treatments


Repli-
cation rl
d
Ld F~
E!~ a, I
E ,,
64 4 E~ c?
~IW F E~a R

1 3.251 2.703 2.707 2.251 2.214 13.126
2 3.025 2.684 2.739 2.521 2.234 13.203
3 2.948 2.769 2753 1 2.460 2. 064 1 12.988
4 3.084 2.727 2.656 2.407 1.886 12.760
5 2.996 2.705 2.694' 2.5q4~ 2. 280 13.269
Tota1.~15.304 13.582 13549 12.233 10.678 65.946
Mean..~ 3.061 2.716 2.710 2.447


X. (continued)


COPSUTING THE SUM OF SQUARES
c2 65.9462
Correction Factor: C N


170.804


Total: 4 yi~- C = 173.421- 170.P04 1 2.617

Treatments: f rp~ 0 = 173.185 170.804 = 2.381

Replications: f ~j 0 = 170837 170.804 = 0033

Error: (total s.s.)-(treatments s.s.)-(repllcations s.s.)


2.617 2.414 = 0.203









X. (continued)
Contribution of the Linear Regression to the s.s.

z, = (-2)(15.304)+ (-1)(13.582)+ 0(13.549) + 1(12.233) +..
... + 2(10.678) E -10.601
2 2
"1 -10.601 112,381 = 2.248
s.s.Z1'
D1 5x10 50

Contribution of the &uadratic Regression to the s.s.

z2 = 2(15.304)+ (-1)(13.582) -t (-2)(13.549) +.............
... + (-1)(12.233) + 2(10.678) = -0.9~9
,22 -0.9492 0 a01
s.s.22 D2 1L 0~1~
70

Contribution of the Cubic Regression to the s.s.

"3 = -1(15.So4) + 2(13.582) + 0(13.549) + (-2)(12.233) +..
... t 1(10.678) = -1.928

s.s.zg = ~2 = -1.9281 = 3.717 P 0.074
Dg 5x10 50

"1 -10.601
Regression Coefficients: bl -0.212
"1 50
3 22 = -0949 -0014
b2
"2 70

b~ cZ3 ~P~ --0.0?9
"7 50


G 65.346 = 2.614
General Mean: y r N 25










X. (continued)
n
Comduting y;: Y y+blSI l+b25L2+h?~E119

~1 = 2.614 + (-2)(-.212) + 2(-.014) + .........

3.049

j~ 2.614 + (-1)(-.212) ~ (-1)(-.014) ......
... + 2(-.039) 1 2.762

2.614 + 0(-.212) + (-2)(-.014) + .........
Y3
... + o(-.ogg) r 2.642

34 = 2.614 + 1(-.212) ~ (-1)(-.014) + .........
2.494

~j~5 = 2.614 + 2(-.212) + 2(-.014) + .........,
... + 1(-.039) = 2.123










BIBLIOGRAPHY


i. Bonner, J., and Galston, A. P1. Principles of Plant
Physioloag. Preeman and Company. Pp. 47 and
48. 1952.

2. Miller, E. C. Plant Pngsiolo~S. McGraw-~ill Book
com~ any;-i~nc~-~p~j-; 231 and 371. 193 8

3. Burd, J. S. Rate of absorption of soil constituents
at successive stages of plant growth. Jour.
ARr. Res. 18: 51-72. 1919.

4. MacGillivray, J. H. Effect of phosphorus on the
com,3osition of the tomato plant. Jour. Aar.
Res. 74: 97-127. 1927.

5. Arnon, D. I., et al. Radioactive phoshorus as an
indicator of phos_3horus absorption of tomato
fruits at various stages of development.
Am. Jour. Bet. 27: 791-98. 1940.

6. Steward, F. C. ~ineral Nutrition of Plants. Am. Rev.
Biochemistr~. 4: 519-544. 1935

7. Hooalland, D. R. Inorganic Plant Nutrition, Prather
Lectures. Pp. 50 and 61. 1948.

8. Heater, J. B., et al. The absorption of nutrients by
the tomato plant at different stages of
growth. Proc. Am. Sec. Hort. Sci. 36: 720-2.
1939.

g. Collander, Ii. Selective absorption of cations by
higher plants. Plant Phgs. 16: 691-720. 1941.

10. McCall, 8. G., and Richards, P. E. Mineral food
requirements of the wheat plant at different
stages of its development. Jour Am Soc
uvur rril vuu
Agron. 10: 127-34. 1914.

11. Shive, J. W., and Martin, W. H. A comparative study of
salt requirements for young and for mature
buckwheat plants in solution cultures. Jour.
A~r. Res. 14: 151-176. 1918.

12. Jones, W. J., and Huston, H. A. Composition of maize
at various stages of its growth. Ind. Sta.
Bull. 175. 1914.











13 Pember, F. R. Studies by means of both pot and solu-
tion culture of the phosphorus and potassium
requirements of the barley plant'during Its
different periods of growth. R. I. Sta. Bull.
169. 1917.

lie. and McLean, F. T. Economical use of
nitrogen, phosphorus and potassium by barley,
oats, and wheat in solution cultures. R. I.
sta. Bull. 199. 1925.

15. Gerlcke, W. F. The beneficial effect to wheat growth
due to depletion of available phosphorus in the
cultural media. Science 60: 297-98. 1924.

16. Brenchley, W. E. The phosphate requirement of barley
at different periods of Growth. Ann. Bet. 43:
89-110.

17 Gile, P. L., and Carrero, J. O. Ash composition of
upland rice at various stages of growth.
Jour. ARr. Res. 5: 357-64. 1915.

18. Bartholomew, R. P., and Janssen, G. Luxury consumption
of potassium by plants and its significance,
Jour. Am. Sec. Aar. 21: 751-65. 1929

19. Overstreet, R., et al. The effect of calcium on the
absorption of potassium by barley roots.
Plant Phys. 27: 583-90 1952

20. Fisher, P. L. Responses of the tomato in solution
cultures with deficiencies and excesses of
certain essential elements. Md. Sta. Bull.
~i~fi 1935.

21. Hayward, H. E. The Structure of Economic Plants.
McMillan company. Page 565. 1938.

22. Methods of Analysis used in the Total &uantitative
Determinations of the Mineral Elements in
Tung Leaves at the U.S.D.A. Field Laboratory
for Tung Investigations, Gainesville, Florida.
(Private communication)

23. Drosdoff, et al. ~uantitatlve kilcrodetermlnation of
ilb~rrt~-lum In Plant Tissue and Soil Extracts,
tlrLc~l. Inom. ~C~: 679-4. 1948.










24. Snell and Snell. Page 503 Truog and Meyer, Indus.
and Eng. Chem. Anal. Ed. i: 136-39 1929

25. Curtis, O. P., and Clark, D. G. Principles of Plant
Physiology. McGran-Hill Book Company, Inc.
1950


'6. Fisher,


R. A., and Yates, F. Statistical tables for
bioloRical, agricultural and medical research.
Oliver and Boyd, Edinburg, 3rd ed., 1948.











DI OJ RAP H i'


Eduardo Jimenez Saenz was born in Guadalupe,

San Jose, Costs Rica, the 13th of July, 1929.

He completed his High School studies in 1946 in

San Jose.

In 19Lc7 he entered the Panamerican School of

Agriculture in Honduras; in 1950 he satisfactorily ful-

filled the requirements and obtained a Diploma, and went

back to Costa Rica where he spent two years working for

the P(inistry of Agriculture.

In 1952 he was granted with a scholarship by the

Panunerican School of Agriculture and entered the Univer-

sity of Florida that same year after having completed a

short trainir~g course with The Rockefeller Foundation in

Mexico. It was In 1954 when he obtained his B. S. degree

in Agriculture.

He has pursued his graduate work at the University

of Florida, and expects to receive his degree of Master

of Science in Agriculture in June, 1955.

He was nominated as a member of the Honorary

Fraternities Alpha Zeta and Phi Kappa Phi in 1954~, and

C;amma Sigma Delta in 1955.












This thesis was prepared under the direction of the

chairman of the candidate' s supervisory committee and has

been approved by all members of the committee. It was

submitted to the Deain-of the College of Agriculture and to

the Graduate Council and was approved as partial fulfill-

ment of the requirements for the degree of Master of Science.



Date







Dean, College of Agriculture




Dean, Graduate School



SUPERVISORY COMMIUITTEE:




Chairman

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PAGE 1

RELATIVE ABSORPTION OF SOME NUTRIENT ELEMENTS BY THE TOMATO PLANT AS AFFECTED BY THE STAGE OF GROWTH By EDUARDO JIMENEZ S. A Thesis Presented to the Graduate Council of The University of Florida In Partial Fulfilment of the Requirements for the Degree of Master of Science in Agriculture UNIVERSITY OF FLORIDA JUNE, 1955

PAGE 2

^^ ACKNOWLEDGEMENT The author wishes to express his deepest appreciation to Dr. C. B. Kail for the wise direction and supervision of this investigation; to Dr. T. W. Stearns and Dr. G. J. Stout, the other members of the Committee, for their valuable suggestions and reading of the manuscript; to Dr. D. B. Duncan, professor of Statistics, for his contribution made through the numerous advices in the use of the statistical methods; to Mr. R. D. Roush, technician of the Vegetable Products Laboratory, and to all those members of the Florida Agricultural Experiment Station at Gainesville, who in some way or another contributed to make possible the accomplishment of this work. The author sincerely wishes to express his indebtedness to Dr. R. A. Dennison, Interim Head of the Horticulture Department of the Florida Experiment Station, Gainesville, and Dr. W. Popenoe, Director of the Panamerican School of Agriculture, Honduras, for their part in obtaining the required economical support.

PAGE 3

TABLE OP CONTENTS Page INTRODUCTION 1 REVIEV; OP LITERATURE 3 METHODS 10 RESULTS Ik Total Absorption 14 P ercentage of Dry Matter l6 Potassium 20 Calcium Zk Magnesium 24 Phosphorus 31 Nitrogen 31 DISCUSSION 36 SUMMARY 39 APPENDIX 41 BIBLIOGRAPHY 79

PAGE 4

INTKODUCTION A large amount of research vvork has been done in the field of plant nutrition since 1804, when de Saussure established that the plant depends upon the soil for the supply of nitrogen and the mineral components of the ash. A better knowledge about the nutrient elements was gained after Liebig' s work, published in 1840, which demonstrated that the soil furnishes the growing plant with the elements calcium, potassium, sulfur, and phosphorus. But the great advances in the field of mineral nutrition came after the introduction by Sachs and Knop, in i860, of the methods of liquid culture which have been ever since the basis of this type of experimentation (1). A marked tendency toward the study of the rate of absorption of nutrient elements by different plants began late in tne nineteenth century. The idea has always been to gather sound information that can be applied practically in the attempt to make crop production a more successful enterprise, both from the economic and scientific points of view. Several factors have induced the undertaking of the present investigation: the need for more detailed

PAGE 5

2 Information concerning the relative absorption of some of the nutrient elements by the tomato plant at different stages of development; a complete recognition of the various factors that affect the nutrient absorption by different species of plants; and finally, the fact that most of the studies performed up to date have not considered the mineral absorption in terms of the amounts taken up by the plant per unit produced of fresh and dry vjeights respectively. It is, therefore, the purpose of this v^ork to present data concerned primarily with the relative absorption of some nutrient elements by the tomato plant at five stages of growth. Emphasis is placed on the cations calcium, potassium, and magnesium. Other elements also included in this study were phosphorus and nitrogen.

PAGE 6

REVIEVJ OF LITERATUhE The earliest work published in the line of mineral uptake by plants of economic importance has been ascribed to Hemberg, 1822, who viorked with corn. He was able to note that abrupt changes take place in the rate of absorption of various elements at definite stages of the development of corn plants. Hemberg reported that when the tassels were beginning to form there was a marked reduction in the rate of absorption followed by a period of rapid uptake which was then succeeded by the ripening period. At this point he noted that there was some loss of practically all nutrients due perhaps to outward diffusion of solutes and to the loss of leaves and roots (2). It should be mentioned here that the concept of outward movement of nutrients from the plant to the external medium has been also sustained by other worxers such as Hoagland (2) and Burd (3). More recently MacGllllvray (4) could not detect any loss of phosphorus from tomato plants to the surrounding medium vmich was much lower in phosphorus concentration, and Arnon (5) has proved that there is a redistribution of this element in the tomato plant. Steward (6) says that apparently the release of elements to the external solution occurs only in extreme

PAGE 7

k cases. Hoagland (7) i^as stated in more recent publications that normally metabolizing cells are highly impermeable to salts, and that the electrostatic balance betvieen the root and the solution is maintained externally by the release of bicarbonate, or hydrogen ions or perhaps others and internally by readjustment of the organic acid content. Burd (3)» studying the rate of absorption of soil nutrients by barley plants, found that a slight loss of calcium, potassium and nitrogen appears to take place when the heads are beginning to form, and he further concluded that the forces acting upon the mentioned elements may also affect others. Hester, Shelton and Issacs (8) studied the rate and the amount of plant nutrients taken up by various vegetables — from tne horticultural point of view. The data for tomato indicate that this plant begins to absorb nutrients in considerable amounts following the fourth week after transplanting. The largest absorption is during the latter part of the growing season when the fruit is forming. It is also Indicated that the amounts present in the top portion of the plant (expressed in pounds per acre of the crop), followed constantly up to the twelfth week this sequence: K2O > N > Ca >P205 >Mg. The summarized form in which these authors present their data madces its applicability of limited value. Collander (9) studied the selective absorption of

PAGE 8

5 several plant species without considering their stage of development. He grew the plants in different nutrient solutions of known composition, after which the cation composition of the plants was determined. Among his conclusions there is one of particular interest. That is that "single plant species are constantly, irrespective of the year of cultivation and composition of the culture solutions, found to be relatively rich in certain cations and other species as constantly relatively rich in other cations." McCall and Richards (10) investigated the salt requirements of wheat plants at three different stages of growth. These workers considered the absorption of the salts as such, and this may lead to tne conclusion that they overlooked the fact that the constituent ions of a salt are not necessarily absorbed in equivalent amounts which means that any attempt made to correlate the salt uptake with the growth made by those plants feeding upon such salt solutions has no sound basis. It is impossible, therefore, to separate from this sort of data the effect of the ions involved, or the amounts of them absorbed. Shive and Martin (11) have reported that buckwheat plants produced their maximum yield of tops and roots during the latter stage of development (from the fourth to the eighth week) in a medium having a lower osmotic proportion of potassium phosphate, a much higher proportion of calcium nitrate, and a much lower one of magnesium sulfate than had

PAGE 9

6 the medium wnicJi produced the highest yield during the early grovvth period (from germination to the fourth v.eek). Again, this work tells nothing about the relative amounts of Ions absorbed by the plant from the two solutions used at the two stages of growth, Jones and Huston (12) working with maize found that a very rapid absorption of potassium occurred four weeks after germination. This was followed by a period of relatively slow absorption which in turn was succeeded by another period of high uptake at the time the grains were developing. They also observed that the uptake of phosphorus did not undergo any appreciable variation throughout the life cycle. It may be noted in their data that an Increase in the amount of phosphorus absorbed on a dry weight basis occurs, as compared to the relative uptake of potassium and nitrogen after the blooming stage. Pember (13), and Pember and McLean (lA-) observed that barley, oats, and wheat were able to make a more effective use of a limited amount of potassium if tne element was supplied early in their growth period. The time of the application of phosphorus made little difference, but small amounts of nitrogen were most beneficial if supplied gradually over the entire growth period. Gericke's work (15) with wheat agrees with t he findings of the investigators Just mentioned in respect to nitrogen and potassium, but differs somewhat in regard to

PAGE 10

7 the conclusions reached for phosphorus. Gericke says that a good, supply of nitrogen is essential throughout the growth period of wheat, and the proper supply of potassium, magnesium, sulfur and phosphorus appears to be required by this plant during the first four-week period of growth. Brenchley (16), using barley, found results similar to those obtained by Gericke in relation to the absorption of phosphorus at early stages of growth. He found that barley plants grew normally and produced a good yield of grain if supplied with phosphorus during the first six weeks or longer. If the phosphorus was withheld for the first four weeks and then restored to the solution, the "tiller" production was not affected but no heads were produced. Brenchley also noted that the amount of phosphorus absorbed by the plant increased steadily in more or less direct proportion to the length of time the element was given at the beginning of growth; then, the uptake ceased during the latter stages of ripening of the grain. Gile and Carrero (1?) worked with rice and found a decrease in the percentage of potassium, phosphorus, and sulfur in the ash, and of nitrogen in the dry matter as the plant matured. They also observed that the percentage dry matter in the green plant did not rise until the plant had begun to form seeds, "According to Chizhov (I926) all the necessary ash and nitrogenous compounds are accumulated by winter and

PAGE 11

8 spring crops about the period of blooming or grain forming. In the sunflower this accumulation is complete at about the same 'time of ripening, while in beans and potatoes it is completed at the end of the vegetative growth" (2). In the particular case of the tomato plant it may be expected that such accumulation of nutrients vvill not stop until the plant reaches senility. MacGillivray (^) considers the type of growth of the tomato plant as being of an intermediate type, vjhere the vegetative grovjth is concurrent with the development of fruits at all stages. Bartholomew and Janssen (18) included tomato plants among several other species in their experiment. They found a high initial level of concentration of potassiiim in the plants during the early stages of growth. The height of this level was in proportion to the amount of potassium available to the plant. Nevertheless, they found that as the amount of growth increased, there ivas a very decided decrease in the potassium content of the plant. The authors considered that the supply of this element was short and thus concluded "that the plants, had taken up more potassium than was actually needed to perform normal life processes and had reutilized this potassium when the incoming supply became insufficient for its normal growth. " Overstreet, Jacobson and Handley (19) studied the effect of calcium on the absorption of potassium by barley roots. They noted that the uptake of potassium was

PAGE 12

9 considerably greater than the uptake of calcium, and as the potassium concentration Increased in the solution there was a reduction in the absorption of calcium. The authors also mentioned a reciprocal effect, in which case the absorption of potassium was markedly stimulated by the presence of calcium. Even relatively small concentrations of calcium exerted a stimulating effect which increased as the calcium concentration increased. For a given calcium concentration the effect diminished as the potassium concentration increased. As the potassium concentration decreased, calcium had an increasingly stimulating effect down to a concentration of 2 X lO""*" N KCl, Below this value the stimulating effect diminished and eventually the calcium depressed the absorption of potassium at very low concentrations of potassium chloride. Fisher (20), working with tomato, observed that plants which had been grown for four weeks (from the cotyledonary stage) in complete solutions before they were supplied with calcium deficient solutions, took three to five days to exhibit the symptoms denoting the lack of this element.

PAGE 13

METHODS A strain of the Rutgers variety of tomato was planted in flats filled with sterilized soil; the flats were viatered regularly with tap water. When the seedlings passed the cotyledonary stage they were washed of the soil and transferred to solutions in two-gallon glazed crocks, the inside of which had been coated vjith asphalt paint. The plants were pruned to one stem. As the plants reached the desired stage of maturity, five uniform plants were selected and transferred to similar crocks in a room in which the light, temperature, and humidity were controlled. Due to equipment limitations only one stage of growth could be run at a time. The room used was an insulated storage room in which the relative humidity was maintained at about 30 percent. The temperature was about 75 degrees F during the illuminated period, and 70 degrees during the dark period. The light was supplied by three sets of 12 slimline fluorescent tubes 8 feet in length. One set was suspended at a height of one and one-half feet above the top of the plants. The otner two sets were suspended to the front and to the rear of the plants about one foot from the outer leaves. Three 10

PAGE 14

11 lOO-watt mazda lamps vjere placed just under the upper set of fluorescent tubes In order to increase the amount of red light. The intensity of light at rne plant surface was about 800 foot candles as measured oy a VIeston light meter. The illuminated period was 12 hours daily. The crocks in the room were numbered from 1 to 5i so that the plant groi-jing in each one of them could serve as a replicate in the experiment. Each crock contained 8 liters of solution of the composition suggested by Hoagland (No. 2), as given in the Appendix, with the exception that the concentration of ammonium phosphate was increased 50 percent over that recommended by the author. The solutions were continually aerated by means of diffusion stones attached to a compressed air line. The volume of the solution was kept constant by the addition of distilled water; the nutrient contents of the solutions vjere very much the same in all the crocks. Wooden covers were used for the crocks and in order to maintain the plants in a vertical position they v^ere fastened to stakes. The plants were in the room for 3 days before beginning the studies. Three samples were drawn from the solution of each crock during every treatment (stage of growth). The first sample was taken just after the addition of fresh solution; the second, at the end of the third day; and the last one, at the end of the seventh day when the period of observation was over. The results of the analysis of the

PAGE 15

12 second sample were discarded. The elements whose absorption was measured were potassium, calcium, magnesium, phosphorus and nitrogen. The techniques used for their determinations were the quantitative spectral analysis for calcium and potassium, and colorimetric methods for phosphorus and magnesium. A Beckman Model B Spectrophotometer was used for this purpose. The nitrogen was determined as total nitrogen according to the Micro-KJeldahl-Gunning method. The methods are given in the Appendix. The absorption of the various elements made by each plant-replicate was obtained from the difference between the concentration of the 8 liters of solution at the beginning and the end of the seven-day period of observation as given in the Appendix. At the end of each treatment, the plants were removed from the culture solutions and divided into leaves, stems, roots, and fruits for the determination of the fresh weight. Whenever flowers were present they were included in the same group with the leaves. The material was dried in a forced draft oven at 70 degrees F for a week; then, the dry weight of each plant portion was determined. The design of the present experiment is that of a randomized block type with five treatments (stages of growth) and five replications. The variable to be analyzed is the logarithm of a number representing the milligrams of the element absorbed per unit of fresh, or dry weight of the

PAGE 16

13 whole plant. The use of logarithms was dictated by the nature of the data; further explanation for their use is given in the Appendix. The stages of growth which served as a basis of study in the present investigation were arbitrarily chosen. For a better understanding of what is meant by the different stages of growth, the following descriptions are given: 1. Seedling stage . The plants were about six inches high from the base of the stem to the top , and suitable for tr an'sp lant ing . 2. Stem Elongation stage . The plants were making rapid growth and still did not show any flower buds. 3. Flowering stage . The plants showed clusters of flowers. 4. Fruit Setting stage. The plants had fruits of less than one inch in diameter. 5. Fruit Enlargement stage . The plants had fruits of any size above one inch in diameter, but no one of which reached the mature green stage of development.

PAGE 17

RESULTS Although fresh and dry weights were determined for the various parts of the sampled plants, as given in the i^pendix, only the data for the rate of absorption per linit of fresh, or dry weights of the whole plant that were analyzed statistically will be discussed. In addition to the xinit rates of absorption, the results of total absorption of the elements (Table 1) and the average percentage of dry matter at various stages of growth (Table 2) are presented. Total Absorption The total absorption of potassium, calcium, magnesium, phosphorus, and nitrogen (Table 1) was found to increase almost constantly with maturity of the plant, as has been noted by other workers (2, 5, 8, 12, 13, 1^, 15, 16). Except for nitrogen and magnesium, the uptake of nutrients is markedly accelerated as the plant approaches its reproductive period, and continues increasing until the fruits are set. Once this point is reached, the absorption of potassium decreases considerably while the reduction in the uptake of phosphorus and magnesivira is not so pronounced. Only nitrogen and calcium are still absorbed in larger amounts at the fruit enlargement stage. A complete picture of the 14

PAGE 18

15

PAGE 19

16 total absorption of these elements Is given in Figure 1. In general, it may be said that during the vegetative stages of development the absorption of K>Ca>N>P>Mg, while after the flowering stage, phosphorus is absorbed in larger amounts than nitrogen resulting in this other relationship: K>Ca>? > N ->Mg. Throughout the life cycle of the tomato plant, potassium and calcium are absorbed in the largest proportions, and magnesium is absorbed the least. The period of highest total absorption corresponds to the fruit setting stage, when there is a large proportion of actively metabolyzlng cells in the plant. This last observation agrees with the results reported by Hester et al (8), Percentage of Dry Matter In regard to the percentage distribution of the dry matter of the tomato plant it may be observed (Table 2 and Figure 2) that the increase in percentage takes place very slowly during the periods of more active growth, namely, before the plant blooms, and then, when the fruits are developing. The explanation for this lag in the accumulation of dry material may be that during those periods of active growth there is a more rapid increase of fresh weight due to the formation of new vegetative tissue sind expansion of tne young fruits which results in small gains in percentatic of dry weight. Considering that the enlargement of the tomato fruits occurs without any further addition of dry

PAGE 20

Figure 1 . Total absorption, in milligrams, of potassium, calcium, magnesium, phosphorus, and nitrogen made by tomato plants during periods of seven days at the following stages of growth: (1) Seedling; (2) Stem elongation; (3) Flowering; (4) Fruit setting; (5) Fruit enlargement. (The points on the curves represent the average absorption of five plants.)

PAGE 21

c c o. c 00 < bC OB > < 2000 r 1600 lP-00 STAGE OP GROWTH

PAGE 22

TABLE 2 AVERAGE FRESH AND DRY WEIGHTS, AND PERCENTAGE DRY MATTER OF FIVE TOMATO PLANTS AT VARIOUS STAGES OF GROWTH 18 Stages

PAGE 23

Figure 2 . Percentage distribution of the plant dry weight at the following stages of growth: (1) Seedling; (2) Stem elongation; (3) Flowering; (4) Fruit setting; (5) Fruit enlargement.

PAGE 24

10 4J u p
PAGE 25

20 matter (21), it may seem reasonable to expect that the percentage of dry matter of the plant does not change appreciably during the last two stages of growth. On the other hand, the rapid accumulation of dry material that is found between the flowering and the fruit setting stages is in agreement with the opinion of Gile and Carrero (1?) who found that in rice the percentage of dry matter did not rise until the plant had begun to form seeds. Another observation is that the leaves form the portion of the plant that follows more closely the changes affecting the percentage of dry matter of the whole plant throughout the stages of its growth. It may also be added that the leaves show the highest percentage of dry matter as compared to the other portions of the plant. Potassium The rate of absorption of potassium expressed on a fresh, or dry weight basis (Table 3) is found to decrease with age. The analysis of variance (Table 4) indicates that the reduction in the rate of absorption from one stage to another is significant at the 1% level, as shown by the highly significant linear effect and nonsignificant quadratic effect and residual variation between stages. Since both polynomial regressions (Figure 3) show the same characteristic slope, it may be concluded that no significant difference could be detected in the way of expressing the

PAGE 26

21 < MCQ CO CO W « ;z> M M 54 WO §^ w >

PAGE 27

TABLE 4 ANALYSIS OP VARIANCE OP THE DATA (IN LOGARITHMS) FOR THE RATE OF ABSORPTION OP POTASSIUM EXPRESSED ON FRESH, OR DRY WEIGHT BASIS OF THE WHOLE PLANTI 22 Fresh Weight Basis Source of Variation

PAGE 28

Figure_l, Rates of absorption of potassium at the following stages of growth: (1) Seedling; (2) Stem elongation; (3) Flowering; (4) Fruit setting; (5) Fruit enlargement, (The points on the curves represent the observed mean values. )

PAGE 29

c o •H -P D, c m < -P o ce c o +3 rH GD t£) CD > I4..O 5.0 2.0 1.0 Dry Weight Fresh Welf^ht 5 k STAGS OP GROWTH

PAGE 30

2i^ rate of absorption of this element. The fact that the rate of absorption of potassium is higher during the early stages of grovjth of the tomato plant is found to agree with the idea sustained by several viorkers (8, 12, 13, 1^, 17, 18). Calcium The decrease in the rate of absorption of calcium (Table 3) on fresh, or dry weight basis also takes place throughout the life cycle of the tomato plant. The analysis of variance (Table 5) indicates that the decrease in rate is significant at the 1% level, as shown by the highly significant linear effect and nonsignificant quadratic effect and residual variation between stages of growth. The trend of the rate of absorption of calcium on a fresh, or dry weight basis is found to show the same characteristic slope (Figure 4) ; as it was the case for potassium, the rate of absorption of calcium can be equally determined on either fresh, or dry weight basis. Apparently, the tomato plant also has a tendency to absorb large amounts of calcium during the early stages of growth. Magnesium Even though the overall tendency for the rate of absorption of magnesium is to decrease with maturation of the plant (Table 3), from the analysis of variance is deduced that the variations in the rate of absorption are different among the stages of grovjth as Indicated by the

PAGE 31

25 TABLE 5 ANALYSIS OF VARIANCE OP THE DATA (IN LOGARITHMS) FOR THE RATE OP ABSORPTION OF CALCIUM EXPRESSED ON FRESH, OR DRY V;EIGHT BASIS OP THE WHOLE PLANT^ Fresh Weight Basis Source of Variation

PAGE 32

Figure 4 . Rates of absorption of calcium at the following stages of growth: (1) Seedling; (2) Stem elongation; (3) Flowering; (4) Pruit setting; (5) Fruit enlargement. (The points on the curves represent the observed mean values.)

PAGE 33

L|..o r c o •ri a u m n 51 «-> o u CD a: t£ *3 o OBrH ««H cc a. 2.0 1.0 Dry Wolqjit Frpsh T/elght STAGE OP GROWTH

PAGE 34

27 significant linear and quadratic effects and non-significant residual variation between stages (Table 6). The trend of the rate of absorption of magnesium (Figure 5) shows that the rate tends to increase, although not significantly at the 5% level, between the seedling and the stem elongation stages; soon after this stage is passed the trend starts to decrease up to the last stage of growth. When the rate is expressed on dry weight basis, all the reductions are significant at the 1% level, but if the rate is expressed on fresh weight basis the decrease between the stem elongation and the flowering stages is not significant at the 5% level (Table 7). This divergency observed between the two rates at this point may be due to differences in the accumulation of fresh and dry matter by the plant at the flowering stage which show up only when the nutrient elements are absorbed in relatively small proportions during the vegetative stages of the development of the tomato plant, A similar case to this of magnesium will be also observed for the rates of absorption of phosphorus. To test the significance of the difference between any two consecutive stages of growth it was necessary to develop a new technique* which involves the use of a t-test. The steps followed in testing the significance of *The technique was developed by Dr. David B. Duncsja, professor of Statistics of the University of Florida, based on an idea suggested by the writer.

PAGE 35

28 TABLE 6 ANALYSIS OF VAKIANCE OF THE DATA (IN LOGARITHMS) FOR THE RATE OF ABSORPTION OP MA.GNESIUH EXPRESSED ON FRESH, OR DRY WEIGHT BASIS OF THE WHOLE PLANT^ Fresh Weight Basis Source of Variation

PAGE 36

Figure 5 . Rates of abs6rption of magnesium at the following stages of growth: (1) Seedling; Jz) Stem elongation; (3) Flowering; (4) Fruit setting; (5) Fruit enlargement. (The points on the curves represent the observed mean values.)

PAGE 37

Ij-.O r Dry Ti'elght Fresh Yv'plp;ht o o, O ID CQ E O OS bC C C OB K C •r< W) GB C > < 5.0 2.0 1.0 ^ STAGE OP OROViTH

PAGE 38

TABLE 7 SIGNIFICANCE OF THE DIFFERENCES BETV\fEEN ANY TWO CONSECUTIVE TREATMENT MEANS (STAGES OF GROWTH) ON THE RESPECTIVE POLYNOMIAL REGRESSIONS FOR THE RATE OF ABSORPTION OF MAGNESIUM 30 Stage of Growth

PAGE 39

31 those differences are Illustrated in some detail In the Appendix. Phosphorus The rate of absorption of phosphorus (Table 3) also has the tendency to decrease as the plant grows older. The analysis of variance (Table 8) indicates that the rate of absorption of this element, expressed on a fresh, or dry weight basis has an overall tendency to decrease, and the variations among the stages are different as shown by the highly significant linear and cubic effects and the nonsignificant residual variation between stages. The trend of the rate of absorption of phosphorus (Figure 6 and Table 9) indicates that the rate, when expressed on a dry weight basis, decreases significantly at the 1:^ level up to the last stage of growth, but a tendency for the rate to level off is observed between the stem elongation and fruit setting stages. This flattening is better shown by the curve for the rate of absorption on fresh weight basis. In either case, the leveling of the curves indicates that the tomato plant absorbed more phosphorus when it was blooming and setting fruit. Nitrogen Since the data for the absorption of nitrogen could not be analyzed statistically, it was impossible to get any results concerned with the rate of absorption of this

PAGE 40

32 TABLE 8 ANALYSIS OF VARIANCE OF THE DATA (IN LOGARITHMS) FOR THE RATE OF ABSORPTION OF PHOSPHORUS EXPRESSED ON FRESH, OR DRY \V EIGHT BASIS OF THE WHOLE PLANT^ Fresh Weight

PAGE 41

Figure 6 . Rates of absorption of phosphorus at the following stages of growth: (1) Seedling; (2) Stem elongation; (3) Flowering; (^) Fruit setting; (5) Fruit enlargement. (The points on the curves represent the observed mean values, )

PAGE 42

li.O — Dry Weight — Fresh \7elght o -P o. {-,'— c
PAGE 43

TABLE 9 SIGNIFICANCE OF THE DIFFERENCES BETWEEN ANY TWO CONSECUTIVE TREATMENT I4EANS (STAGES OF GROWTH) ON THE RESPECTIVE POLYInTOMIAL REGRESSIONS FOR THE RATE OF ABSORPTION OF PHOSPHORUS 3^

PAGE 44

35 element. Table 3 can only give a slight Idea of the pattern of such absorption.

PAGE 45

DISCUSSION In the light of the results obtained from this experiment it may be said that the nutrient elements potassium, calcium, magnesium, phosphorus, and probably nitrogen are absorbed selectively by the tomato plant throughout its life cycle. Even though the plant absorbs the nutrients in larger amounts as it gets older, the amount taken up of each element on a unit weight basis decreases as the plant matures. The rates of absorption of potassium and calcium were found to decrease uniformly with age, and the respective trends for the rates of absorption were found to be linear as indicated by the significant linear effect (at the 1.% level) and non-significant quadratic effect and residual variation between stages of growth. The rate of absorption of magnesium showed an overall tendency to decrease with maturation of the plant, but the changes in rate from one stage to another were found to be different in significance; between the seedling and the stem elongation stages the rate had a tendency to increase although not significantly at the 5% level; 36

PAGE 46

37 soon after the stem elongation stage the rate started to decrease significantly at the 1% level, if it was e:5>ressed on a dry vjelght basis; on the other hand, if the rate was expressed on a fresh weight basis, the decrease between the stem elongation and the flowering stages was not significant at the 5,^ level. The divergency observed betvjeen the rates at this point may be due to differences in the accumulation of fresh and dry matter by the plant at the flowering stage which showed up only when the nutrient elements were absorbed in relatively small proportions during the vegetative stages of growth of the tomato plant, A similar case to this was also observed for the rates of absorption of phosphorus. The rate of absorption of phosphorus was also foiind to have an overall tendency to decrease with age. Nevertheless, the significant reductions in rate at the 1% level that were observed when the rate was expressed on the dry weight basis tended to level off somewhat between the stem elongation and the fruit setting stages. This tendency was more pronounced when the rate was expressed on a fresh weight basis. In either case, the flattening of the curves Indicates that the tomato plant absorbed more phosphorus during the periods of blooming and setting of the fruit. Due to a shortage in supply of nitrogen at the flowering and fruit setting stages, the data for nitrogen could not be analyzed statistically.

PAGE 47

38 In every case, the fitted polynomial regressions of the rates of absorption on the stages of growth vfere found to be the best estimates of the respective trends, as indicated by the nonsignificant residual variation between stages of growth.

PAGE 48

SUMMARY An experiment was set up to study the effect of maturation of the tomato plant upon the rates of absorption of potassium, calcium, magnesium, phosphorus, and nitrogen eagjressed on fresh or dry weight basis. It was found that even though the tomato plant had a marked tendency to absorb the nutrient elements in larger amounts as it grew older, the rates of absorption per unit of fresh or dry weight basis had a general tendency to decrease throughout the life cycle. The rates of absorption of potassium and calcium were found to decrease linearly throughout the five stages of growth under study. This linear decrease was statistically significant at the ifo level. The changes in rate were, therefore, also significant at the same level. The rate of absorption of magnesium was fovuid to increase slightly from the seedling to the stem elongation stages, and then to decrease more and more through the later stages. Both the linear and the quadratic trends were statistically significant at the 1% level. The increase in rate of absorption from the seedling to the stem elongation stages was not significant at the 5^ level. The 39

PAGE 49

40 subsequent decreases, however, were all significant at the 1% level except for the decrease between the stem elongation and the flowering stages, when the rate was expressed on fresh weight basis. The rate of absorption of phosphorus followed a more complex curve. In general, there was a linear downward trend (significant at the Ifo level) together with a tendency to level off between the stem elongation and the fruit setting stages which indicates that the tomato plant absorbed more phosphorus between these two stages of growth. The departures from linearity gave a cubic trend which was significant at the 1% level. The fitted polynomial regressions of the rates of absorption on the stages of growth of the tomato plant were found, under the conditions of this experiment, to be the best estimates for the respective trends. The data for the absorption of nitrogen could not be analyzed statistically because of a variation introduced by a shortage in supply found at the flowering and fruit setting stages.

PAGE 50

APPENDIX

PAGE 51

I. METHODS FOR THE QUANTITATIVE ANALYSIS OP POTASSIUM, CALCIUM, MAGNESIUM, PHOSPHORUS AND NITROGEN Potassium (22)* Standard : Dry potassium chloride In the oven and weigh out exactly 0.3B13 gr. Dissolve and make to one liter. This gives a standard of 200 p. p.m. For the working standard dilute to 20 p. p.m. Procedure : (Using the Beckman Model B flame photometer.) Use the red phototube and 10,000 megohm resistor. Set sensitivity at k and wave length at 768 m^. Adjust dark current to zero until steady. Obtain a 100;^ transmission using the potassium standard of 20 p. p.m. Place v;ater into flame and record transmission. Place the sample into flame and record transmission. To record : Subtract transmission of water from transmission of sample; look up results in standard curve and correct for dilution. Standard Curve : Place 25, 50, 75, and 100 aliquot s of the 20 p. p.m. potassium standard in 100 ml. volumetric flasks. •Reference .number. i•2

PAGE 52

43 Make up to volume and read on photometer. This vjill give a curve for 5, 10, 15 and 20 p. p.m. Plot the net percentage transmission on plain graph paper. Calcium (22)* Same procedure as for potassium except for: 1. Wave length 35^ hm. 2. Blue phototube and 10,000 megohm resistor. 3. To avoid the interference of high concentrations of phosphorus in the readings for calcium, the nutrient solution has to be diluted so that the phosphorus concentration is around 2 p. p.m. ^, Working standard for calcium is 200 p. p.m. Standard : Dry calcium chloride in the oven and weigh out exactly 0.5538 gr. Dissolve and make to one liter. This gives a standard of 200 p. p.m. Standard Curve : Place 25, 50, 75, and 100 ml. aliquots of the 200 p. p.m. calcium standard in 100 ml. volumetric flasks. Make up to volume and read on photometer. This will give a curve for 50, 100, 150 and 200 p. p.m. Plot the net percentage transmission on plain graph paper. Magnesium (23)* Reagents : Hydroxylamine hydrochloride 5% . Dissolve Reference number.

PAGE 53

10 gr. of the reagent In 200 ml. of water and store in dark bottle. Sodium hydroxide 2.5 N . Dissolve 50 gr. of the reagent In 500 ml. of water. Thlazole yellow 0.02^ . Dissolve 0.10 gr. of the reagent In 500 ml, of water and store In dark bottle. Prepare fresh batch every 2 weeks. Compensating solution . Dissolve 3»7 gr. of calcium chloride (CaCl2*2H20) , 0.?^ gr. aluminum sulfate (Al2(S0i|,)3'18H20) , 0.36 gr. manganous chloride (MnCl2'^H20), and 0,60 gr. sodium phosphate (Na3P024,) in about 500 ml. of water containing 10 ml. of concentrated HCl. Dilute to 1 liter. Starch solution 2^ . Mix 50 ml. of glycerol and 50 ml. of water and bring to boll. Add a mixture of 1 gr. soluble starch with 2 to 3 ml. of water, stir, and continue the boiling for 3 minutes. Cool to room temperature and use or store. This starch solution may show no signs of deterioration after at least 6 months. Starch Compensating reagent . Mix equal volumes of the starch solution and compensating solution. Prepare daily as needed. Procedure : (Using the colorimetrlc set up of a Beckman ^aken from Chemist Analyst . k2: 70, 1953.

PAGE 54

^5 Model B photometer.) Transfer a 2 ml. aliquot of the nutrient solution to a 50 ml. volumetric flask and enough water to bring the volume to about 25 ml. Add 1 ml, of the hydroxilamine hydrochloride solution from a burette. Then add 5 ml. of starch compensating solution and shake well. Add exactly 5 ml. of thiazol yellow solution from a pipette and mix. Add 5 ml. of sodium hydroxide solution. Shake and bring to volume with water. Mix again and allow to stand about 15 minutes before reading on colorimeter at vjave length 5^0 mu, , sensitivity 1, Use a blue phototube and 500 megohm resistor. VJith each set run a blank which is used for 100^ transmission. Standard Curve : Treat two 5 ml. aliquots of 20 p. p.m. standard magnesium solution in the same manner as the unknowns. This gives a 2 p. p.m. sample. The line passing through the origin point and the average reading of the two knoi'jn samples constitutes the standard curve. Plot on semi-log paper if % transmission is read, or on plain graph paper if optical density is read. Standard : Dissolve 250 mg. of reagent grade magnesium metal in dilute hydrochloric acid solution (I50 ml. of water and 10 ml. of concentrated HCl) and bring to volume in a 250 ml. volumetric flask. Dilute 10 ml. of this solution to 500 ml. for the working standard of 20 p. p.m.

PAGE 55

of magnesium. Phosphorus (2^^)* Reagents : Ammonium molybdate solution . Heat 25 gr. of the reagent In about 200 ml. of water at 60 C. and filter. Dilute 280 ml. of concentrated sulfuric acid to about 800 ml. VJhen cool, add the ammonium molybdate solution to the sulfuric acid slowly with constant stirring. Cool the mixture, transfer to 1000 ml. volumetric flask and make up to volume. This Is a 2.^% solution of ammonium molybdate in 10 N H2SO4. 1.2.4. aminonaphthol sulfonic acid . Dissolve 0.5 gr. of the reagent and 6 gr. of sodium sulfite in about 200 ml. of water. Add 30 gr. of sodium bisulfite and dissolve. Filter and make the final volume of 250 ml. Prepare a fresh batch at least every two weeks. Procedure ; Transfer a 2 ml. aliquot of the nutrient solution into a 50 ml. volumetric flask. Add about 20 to 25 ml. of water and shake. Add 2 ml. of molybdate solution from a burette and shake. Add 2 ml. of 1,2,4, aminonaphtholsulfonic acid also from burette and shake. Make up to volume, shake, and allow to stand 10 to 12 minutes before reading on colorimeter at wave length 700 mu. and sensitivity 3 against a blank for zero optical density. Use a blue phototube and 500 megohm resistor. •Reference number.

PAGE 56

47 Standard Curve : Transfer 1, 2, k, and 10 ml. aliquot s of the 10 p. p.m. phosphorus standard Into 50 ml. volumetric flasks and proceed in the same manner as the linknovnas. This will give a curve for 0.2, 0.^, 0.8, and 2 p.p.m. Plot optical density on plain graph paper. Standard : Dissolve 0.^394 gr. of KRz^Oi^ (dried over sulfuric acid) in water. Add 10 ml. of 1:3 HgSOij, and dilute to 1 liter. This solution contains 100 p.p.m. of phosphorus equivalent to 229 p.p.m. of P2O5. Dilute 100 ml. of this solution to 1 liter, thus making a standard solution of 10 p.p.m. Mlcro-Ktleldahl-Gunnlng Method Total nitrogen is determined by this method to include nitrates and nitrites. Reagents ; Concentrated sulfuric acid with 3^ gr. of salycilic acid per liter. Sodium thio sulfate, 50 mg. Sodium hydroxide solution. Dissolve ^00 gr. per liter. Boric acid, 2%, 0.02 N standardized HCl. Catalyst. Mix 2 parts of CuSO/j, and 1 part of K2SOi4..

PAGE 57

48 Indicator : Methylene blue, O.ZifS gr. Methyl red, 0.375 gr. Ethanol 95%, 300 ml. Procedure ; Transfer 20 ml. allquots of nutrient solution to 30 ml. Kjeldahl flask. Add 2 ml. of the sulfuric acid and "salyclllc acid to the sample, stopper and allow to stand at least 30 minutes. Add approximately 50 mg. of sodliim thlosulfate, place on Kjeldahl rack, heat 5 minutes over a low flame and cool. Add a knife point of catalyst, mix and heat gently until the reaction subsides. Prevent any loss of the material due to frothing. When frothing has ceased. Increase heat so that a sulfuric acid condensation ring Is formed In the neck of the flask. Continue digestion lontll the liquid becomes water-white. Distillation Is carried out as follows: The micro still Is thoroughly cleaned out by allowing steam to pass through for 10 or 15 minutes. Open all stopcocks, place a 150 ml. beaker containing 10 ml. of boric acid solution, 20 ml. of water, and a few drops of the Indicator, under the condenser. Have the water In the steam generator hot. Transfer the digested material to the distillation flask, using ^0 ml. of water. Add 10 ml. of sodium hydroxide solution, put flame under steam generator and close the stopcocks. All the ammonia Is distilled over In 5 minutes

PAGE 58

^9 from the time the first distillate appears. Titrate the solution to color produced by 10 ml. of boric acid and same amount of indicator made to approximate the volume of distillate. p. p.m. N = (ml. HCl) (Normality HCl) (14) (lOOC) Volume of sample in ml.

PAGE 59

50 II. TOTAL CONCENTRATIONS OF THE VARIOUS NUTRIENT ELEMENTS SUPPLIED IN EIGHT LITERS OP SOLUTION TO FIVE T0I4AT0 PLANTS AT FIVE STAGES OP GROWTH

PAGE 60

II. (continued) 51 Nitrogen 1

PAGE 61

52 III. HOAGLAND'S NO. 2 FORMULA FOR NUTRIENT SOLUTION (2^)* '•

PAGE 62

IV. FRESH AND DRY WEIGHTS (IN GRAI^IS) AND PERCENTAGE DRY MATTER OP THE PORTIONS, AS V/ELL AS THE WHOLE PLANT, OF FIVE TOMATO PLANTS AT FIVE STAGES OF GROWTH Seedling Stage 53 Plant

PAGE 63

IV. (continued) 54 Stem Elongation Stage

PAGE 64

IV. (continued) 55 Flowering Stage

PAGE 65

IV. (coritinued) 56 Fruit Setting Stage

PAGE 66

IV. (continued) 57 Fruit Enlargement Stage

PAGE 67

V. THE STATISTICAL ANALYSES OP THE DATA, IN LOGARITHMS, FOR THE RATE OF ABSORPTION OF SOME ELEMENTS MADE BY FIVE TOMATO PLANTS AT DIFFERENT STAGES OF GROWTH The Use of Logarithms * A randomized block analysis assumes that the error variance of any observation is the same throughout the plots; if the error variance for a given observation is proportional to the respective true mean, then, the correct procedure is to analyze the logarithm of the observation. Since in this particular esqperiment it was found that the rate of absorption of any of the studied elements decreased considerably in magnitude with the treatments, this indicates that the observations of the first treatments may have larger true means than the observations of the last treatments, and hence, different observations may have different error variances which in turn may be proportional to the respective true means. Therefore, the conversion of the ori^iinal data into logarithms was imperative in order to have the same error variance in all the treatments. *A private communication from Dr. D. B. Duncan to the writer.

PAGE 68

VI. COI^IPUTATIONS FOR THE ANALYSES OP VARIANCE, AND FITTING OF THE POLYNOMIAL REGRESSIONS FOR THE RATE OF ABSORPTION OF P0TASSIUI4 EXPRESSED ON FRESH, OR DRY. VJEIGHT BASIS OF THE WHOLE PLANT 59 Data for Unit Fresh Weight (in logarithms)

PAGE 69

60 VI. (continued) Contribution of the Linear Regression to the s.s, zi = (-2)(13.539) 4 (-1)(12.410) + 0(11.556)+ 1(10.901) ... ...+ 2(9.^58) = -9.671 s.s.zi = zi^ ^ -9»671^ , 93.528 ^ ^ g^^ ^ dI 5x10 50 '^ Contribution of the Quadratic Regression to the s.s. Z2 = 2(13.539) + (-1)(12.410) + (-2)(11.556) + (-1)(10.901) ... + 2(9.^58) = -0.^29 s.s.zp = i2 ^ -0.^29^ _ 0.18^ , 003 Regression Coefficient: bn = ^1 "9-671 » -0.193 ^ dJ 50 General Mean: ^ = f = ^^ '^f"^ 2.315 Computing y-: y = y + b]^^. ^y 1 = 2.315 + (-2)(-0. 193) = 2.701 ^2 2.701 0.193 = 2.508 ^^ = 2.508 0.193 = 2.315 ^4 = 2.315 0.193 = 2.122 -y^ » 2.315 + 2(-0.193) » 1.929

PAGE 70

61 VI. (continued) Data for Unit Dry Weight (In logarithms)

PAGE 71

62 VI. (continued) Contribution of the Linear Regression to the s.s. z^ = (-2)(19.^80) + (-1)(18.243) + 0(17.321) + 1(16.169) ... ... +2(1^.687) = -11.660 s c; Z-, = zi^ = -11.660^ , 1^S96 , 2 719 s.s.zi _ ^^^^ ^Q ^./X9 Contribution of the Quadratic Regression to the s.s. Z2 = 2(19.^80) + (-1)(18.243) + (-2)(17.321) + (-1)(16.169) ...+ 2(14.687) » -0.720 Z2 -0.720 ^ 0.518 _ ^ ^^„ ^•^•^2Di = "liar "tT" = ^'^^^ Zn -11.660 Regression Coefficient: bj^ = _i = Jq — = -0.233 G 85.900 , ^ General Mean: ^ = n " 25 = 3.^36 Computing y-: "y" = y + b^ ^, yi 3.436 -V (-2) (-0.233) = 3.902 y 2 = 3.902 0.233 = 3.669 'y^ = 3.669 0.233 = 3.436 "y^ = 3.436 0.233 = 3.203 '?3 = 3.436 +2(-0.233) = 2.970

PAGE 72

63 VLI. COMPUTATIONS FOR THE ANALYSES OP VARIANCE, AND FITTING OF THE POLYNOMIAL REGRESSIONS FOR THE RATE OP ABSORPTION OP CALCIUM EXPRESSED ON FRESH, OR DRY V/EIGHT BASIS OP THE WHOLE PLANT Data for Unit Fresh Weight (in logarithms)

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64 VII* (continued) Contribution of the Linear Regression to the s. s, Zi = (-2)(12.077) (-1)(10.634) + 0(9.836) + 1(8.796) + ... ... 4 2(8.135) = -9.722 s.s.z. =^1^= 4-?|^^= %^ = 1.890 1 ^ 5x10 50 Contribution of the Quadratic Regression to the s.s, Z2 = 2(12.077) + (-1)(10.634) + (-2)(9.836) f (-1)(8.796) + ... 4 2(8.135) = 1.322 ^•^•^2^D~ " ^xl4 70 ' ^'^^^ Regression Coefficient: bi = ^1 = -9.722 = -0.19^ Dl 50 General Mean: H = 9. = ^9 -^''7 8 1.979 On 25 Computing yj,: "y = y 4 b3_'^i "yi = 1.971 + (-2)(-0.194) = 2.367 '^2 = 2.367 0.194 = 2.173 'y3 = 2.173 0.194 «= 1.979 1^4 = 1.979 0.194 = 1.785 '75 = 1.979 4 2(-0.194) = 1.591

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65 Vn. (continued) Data for Unit Dry V/eight (in logarithms)

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66 Vn. (continued) Contribution of the Linear Regression to the s.s, zi = (-2)(lb.020) + (-1)(16.466) + 0(15.602 + 1(14.06? < ... ... \ 2(13.363) = -11.713 '•^•^1 D-L 5x10 " 5 3^ = 2.744 Contribution of the <^adratic Regression to the s.s. Z2 = 2(18.020) 4(-1)(16.466) + (-2)(15.602) + (-1)(14.067) ... t 2(13.363) = 1.029 s.s.z, =^2^ Hf^^ = h^0.015 2 D2 5x14 70 Regression Coefficient: bn fl = ''^^'Jr?''^ = -0.234 General Mean: J " f = '^'^'^•'-^ = 3.101 Computing Yi.: "y = y + bi"^, yi = 3.101 f (-2)(-0.234) = 3.569 ?2 = 3.569 0.234 = 3.335 93 = 3.335 0.234 3.101 'y/4. = 3.101 0.234 = 2.867 95 = 3.101 + 2(-0.234) = 2.633

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67 VIII. TEST OP THE SIGNIFICANCE OP THE DIPPERENCE BETl^EEN ANY TV/0 CONSECUTIVE POINTS IN A QUADRATIC OR CUBIC REGRESSION The ratio of the difference (d = yi yj ) between any two consecutive points (y^ and yj ^ which are the best estimates of the treatment means as given by the polynomial regressions) and its standard error follows the Student's t distribution, where s^^^ is the standard error of the difference* To obtain the standard error of the difference, first calculate the variance of the difference according to the following formula: "i !_ Dl D2 J * (1) where ^,t = -2;^,jr-l; "^ilc-1; and^i.j--2 are the appropriate ortnogonal polynomial coefficients according to Fisher and Yates (26); and D3_ and D2 are the corresponding divisors. The error variance (Sq) Is obtained from the analysis of variance. Finally, s,^z y b^ . For each of the differences compute the respective standard error. When the cubic effect is significant the formula for the variance of the difference is: ~l Dl D2 D3 j

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68 VIII. (continued) where ^31= -1; and 73j-2 are the additional orthogonal polynomials coefficients; and Do is the additional divisor. The computed "t" value for each difference is then compared with trie values for "t" given by the table with "n" degrees of freedom (nr d. f. for error), and the chosen level of significance.

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69 IX. COMPUTATIONS FOR THE ANALYSES OP VARIANCE, AND PITTING OP THE POLYNOMIAL REGRESSIONS POR THE RATE OP ABSORPTION OP I4AGNESIUiyi EXPRESSED ON PRESH, OR DRY WEIGHT BASIS OP THE WHOLE PLANT Data for Unit Presh Weight (in logarithms)

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70 IX. (continued) Contribution of the Linear Regression to the s.s. z-L = (-2)(6.253) + (-1)(6.856) 1-0(6.239) + 1(4.997) •• ... + 2(2.665) = -9.045 s.s.Zt = ^1^ = r£^OM^ . 81-812 = 1.636 ^ dI 5x10 50 Contribution of the Quadratic Regression to the s.s. Z2 = 2(6.253) + (-1)(6.856) + (-2)(6.239) + (-1)(4.997) + .. ... 4 2(2.665) = -6.485 ,2 . ..„.2 '2 s.s.zp =12= -6.485^ = 42.055 = 0.60I ^ Do 5x14 70 Regression Coefficients: bn = fi = "^'^^^ = -O.I8I Di 50 b2 = 12 = =:6jm = -0.093 ^ D2 70 General Mean: J = | = ^7-010 :; i^Qgo Con5)uting yi: y = y bl^l •^ b2^2 (^2 is included because the quadratic effect is significant) y"-L = 1.080 + (-2)(-.l8l) 4 2(-.093) = 1.256 % 1.080 4 (-1)(-.1&1) 4 (-l)(-.093) 1.354 1^3 = 1.080 + 0(-.l8l) 4 (-2)(-.093) = 1.266 % = 1.080 4 1(-.181) 4 (-l)(-.093) = 0.992 ?3 = 1.080 42(-.lbl) 4 2(-.C93) = 0.532

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71 IX. (continued) Data for Unit Dry V/eight (in logarithms)

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72 IX. (continued) Contribution of the Linear Regression to the s.s. z^ = (-2)(12.190) + (-1)(12.688) 0(12.009) + 1(10.268) .. ... + 2(7.871) = -11.058 s.s.Zt=^^= -11-0^8^ = 122.279 = 2.4/+6 1 D-L 5x10 50 Contribution of the quadratic regression to the s.s. Z2 = 2(12.190) + (-1)(12.688) + (-2)(12.009) + (-1)(10.268) ... + 2(7.871) = -6.852 s s zo = ^ = -^-Q^^^ = ^^'950 = 0.671 ^•^•2 Do 5x14 70 ^•°^'Regression Coefficients; b-^ = -i = -^-^'Ji^ = -0.221 D-i J'-) General Mean: y = | = ^^^^^6 = 2.201 Computing yi, • y = y ^i^ 1 »• ^2^ 2 y-L = 2.201 + (-2)(-.221) + 2(-.098) 2.44? y2 = 2.201 (-1)(-.221) + (-l)(-.098)= 2.520 y^ « 2.201 + 0(-.221) + (-2)(-.098) = 2.397 y/^ = 2.201 + 1(-.221) + (-l)(-.098) = 2.078 y^ = 2.201 4 2(-.221) + 2(-.098) = 1.563 ^r

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73 X. COI'IPUTATIONS FOR THE ANALYSES OP VARIANCE, AND FITTING OF THE POLYNOMIAL REGRESSIONS FOR THE RATE OF ABSORPTION OF PHOSPHORUS EXPtffiSSED ON FRESH, OR DRY WEIGHT BASIS OF THE WHOLE PLANT Data for Unit Fresh Weight (in logarithms)

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7^ X. (continued) Contribution of the Linear Regression to the s.s. 2^ = (-2)(9.364) + (-i)(7.72j.9) + 0(7.784) + 1(6.964) + .... ... 4 2(5.^45) = -8.623 s.s.z. = ^1 = -8.623 ^ = 7^.356 = 1.487 ^ dJ 5x10 50 Contribution of the
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75 X. (continued) Computing yc J y ~ y "• ^1^ 1 • ^2^ 2 "• ^3 ^ 3 (b-^ is included because the cubic effect is significant) 'y-L = 1.^92 + (-2)(-.172) ^ 2(-.009) + ... + (-!)(-. 947) = 1.865 "yg = 1.^-92 + (-!)(-. 172) + (-l)(-.009) + ... ... + 2(-.047) = 1.579 y3 = 1.492 + 0(-.172) + (-2)(-.009) + ... -V 0(-.047) = 1.510 'Yi^ = 1.492 -» 1(-.172) + (-l)(-.009) + ... + (-2)(-.047) = 1.^23 f^ s 1.492 + 2(-.172) + 2(-.009) + ... -tl(-.047) = 1.083

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76 X. (continued) Data for Unit Dry Weight (in logarithms)

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77 X, (continued) Contribution of the Linear Regression to the s.s. z-L = (-2)(15.304) + (-1)(13.582) + 0(13.5^9) +1(12.233) 4.. ... + 2(10.678) = -10.601 s.s.z. ^ = -10-601^ = 112.381 = 2.2i+8 1 D-L 5x10 50 Contribution of the Quadratic Regression to the s.s. Z2 = 2(15.304) + (-1)(13.582) + (-2)(13.549) + ... + (-l)(12.233) • 2(10.678) = -0.9^9 s . z. = ^ = -Q-949^ = 0.901 = 0.013 S.S.Z2 d; 70 70 '^^ Contribution of the Cubic Regression to the s.s. Z3 = -1(15.304) + 2(13.582) + 0(13.549) 4(-2)(12.233) ... t 1(10.678) = -1.928 z 2 2 s.s.z^=^ = -1.928 = 3.717 = 0.074 ^ D3 5x10 50 Regression Coefficients: t)]_ = ^ = ^ — = -0.212 = f2 = -0.949 = _o.oii+ b 2 70 V = ^ = =1^ = -0.039 ^ D3 50 General Mean: y = f = ^^||^ = 2.614

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78 X. (continued) Computing y: : y = y
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BIBLIOGRAPHY 1. Bonner, J. , and Galston, A. y. Principles of Plant Physiology . Freeman and Company. Pp. 4? and ^8. 1952. 2. Miller, E. C. Plant Pnysiology . McGraw-Hill Book Company, Inc. Pp. 369, 231 and 371. 1938. 3. Burd, J. S. Rate of absorption of soil constituents at successive stages of plant growth. Jour . Agr. Res. 18 ; 51-72. 19194. MacGillivray, J. H. Effect of phosphorus on the comoosltion of the tomato plant. Jour. Agr . Res^. 34 : 97-127. 1927. 5. Arnon, D. I., et al. Radioactive phosphorus as an indicator of phosphorus absorption of tomato fruits at various stages of development. Am. Jour. Bot. 27 : 791-98. 19-^0. 6. Steward, P. C. Mineral Nutrition of Plants. Am. Rev . biochemistry . 4: 519-544. 1935. 7. Hoagland, D. R. Inorganic Plant Nutrition, P rather Lectures . Pp. 50 and 6l. 1948. 8. Hester, J. B. , et al. The absorption of nutrients by the tomato plant at different stages of growth, Proc. Am. Soc. Hort. Sci. 36 : 720-2. 1939. 9. Collander, R. Selective absorption of cations by higher plants. Plant Phys. 16 : 691-720. 1941. 10. McCall, A. G. , and Richards, ?. E. Mineral food requirements of the wheat plant at different stages of its development. Jour. Am. Soc . Agron. 10 : 127-3^. 1914. 11. Shive, J. W., and Martin, W. H. A comparative study of salt requirements for young and for mature buckwheat plants in solution cultures. Jour. Agr. Res. l4 : 151-176. 1918. 12. Jones, VJ. J., and Huston, H. A. Composition of maize at various stages of its growth. Ind. Sta . Bull. 175 . 191^. 79

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13. Pember, F. R. Studies by means of both pot and solution culture of the phosphorus and potassium requirements of the barley plant 'during its different periods of growth. R. I. Sta. Bull . 169 . 1917. 1^. and McLean, F. T. Economical use of nitrogen, phosphorus and potassium by barley, oats, and wheat in solution cultures. R. I, Sta. Bull. 199 . 1925. 15. GericKe, W. F. The beneficial effect to wheat growth due to depletion of available phosphorus in the cultural media. Science 60 : 297-98. 192^. 16. Brenchley, V/. E. The phosphate requirement of barley at different periods of growth. Ann. Bot. 43 : 69-110. 1929. 17. Glle, ?. L. , and Carrero, J. 0. Ash composition of upland rice at various stages of growth. Jour. Agr. Res. 5 : 357-64. 19 15. 18. Bartholomevj, R. P., and Janssen, G, Luxury consumption of potassium by plants and its significance. Jour. Am. Soc. Agr. 21 : 751-65. 1929. 19. Overstreet, R. , et al. The effect of calcium on the absorption of potassium by barley roots. Plant ?hys. 27 : 583-90. 1952. 20. Fisner, P. L. Responses of tne tomato in solution cultures with deficiencies and excesses of certain essential elements. Md. Sta. Bull , 121. 1935. 21. Hayward, H. E. The Structure of Economic Plants . McMillan Company. Page 565. 1938, 22. Methods of Analysis used in the Total Quantitative Determinations of the Mineral Elements in Tung Leaves at the U.S.D.A. Field Laboratory for Tung Investigations, Gainesville, Florida. (Private communication) 23. Drosdoff , et al. Quantitative Hicrodetermination of Magnesium in Plant Tissue and Soil Extracts, Anal, Chem. 20: 673-4. 1948. 60

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24. Snell and Snell. Page 503. Truog and Meyer, Indus . and En^. Chem. Anal. Ed. 1 : 136-39. 1929. 25. Curtis, 0. P., and Clark, D. G. Principles of Plant Physiology . McGraw-Hill Book Company, Inc. 1950. 26. Fisher, R. A. , and Yates, P. Statistical tables for biological, agricultural and medical research . Oliver and Boyd, Edinburg, 3rd ed. , 19^8. 81

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BIOGRAPHY Eduardo Jimenez Saenz was born in Guadalupe, San Jose, Costa Rica, the 13th of July, I929. He completed his High School studies in 1946 in San Jose. In 19^7 iie entered the Panamerican School of Agriculture in Honduras; in 1950 he satisfactorily fulfilled the requirements and obtained a Diploma, and went back to Costa Klca where he spent two years working for the Mini B try of Agriculture. In 1952 he was granted with a scholarship by the Panamerican School of Agriculture and entered the University of Florida that same year after having completed a short training course with The Rockefeller Foundation in Mexico. It was in 195^ when he obtained his B. S. degree in Agriculture. He has pursued his graduate work at the University of Florida, and expects to receive his degree of Master of Science in Agriculture in June, 1955. He was nominated as a member of the Honorary Pratemitles Alpha Zeta and Phi Kappa Phi in 195^, and Gamma Sigma Delta in 1955. 82

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This thesis was prepared under the direction of the cnairraan of the candidate's supervisory committee and has been approved by all members of the committee. It was submitted to the Dean of the College of Agriculture and to the Graduate Council and was approved as partial fulfillment of the requirements for the degree of Master of Science. Date SUPERVISORY COMMITTEE; Dean, College of Agriculture ^AV Dean, Graduate School d:/?. Chairman ^ ' 6~n^M^