THE

 

 

 

1-H:

 

 

THE MINERAL COMPOSITION OF T CLIPA GESNERIANA AS RELATED

 

 

TO GROWTH AND NUTRITION

B y

HAROLD WILLIAM SCI-IMALFELD

AN ABSTRACT

Submitth to the College of Agriculture, Michigan State University
of Agriculture and Applied Science in partial fulfillment of the
requirements for the degree of

DOCTOR OF PHILOSOPHY

Department of Horticulture

1964

ABSTRACT

THE MINERAL COMPOSITION OF TIfLIpA GESNERIANA
AS RELATED TO GROWTH AND NUTRITION

 

By Harold William Schmalfeld

Mineral contents of the. plant parts Of Tulipa gesneriana cv.

 

'Blizzard' were determined periodically during the growth cycle to
ascertain the extent to which stored nutrients may be utilized in
growth, then redistributed tO new storage tissue. The effect of
applied N, P, and K, two growth media and a combined application Of
Ca, Mg, and B on plant nutrient content and bulb yield was investigated.
Effects Of varying defoliation practices on bulb production were also
examined. ,5

Bulbs were planted in pots in either a 3:1 Inixture. of Plainfield
sand and arcillite, or in a 3:1:1 mixture Of loam, sand, and manure
and grown in a OOOF. minimum ten‘Iperature greenhouse. after having
received the cold treatni'nit necessary to break flower dormancy.

Plants grown in the sand—arcillite mixture without added nutrients
were evaluated at two week intervals for their dry weight and 13
Inineral elements. Dry weight, N, P, and K contents continually de-
creased in the original bulb tissue, increased in the green parts to the
time of full bloom and then decreased, and continually increased in the
new bulb tissue. Of the minor elements varying quantities Of Mg, Zn,
Cu, B, and Mn were redistributed to the new storage tissue from

(1)

Harold W'illiam Schmalfeld Abstract - 2

senescent foliage, while the major portion of Ca, Na, Fe, lVlI). and Al
was retained in the foliage.

The bulb weight yield of plants receiving no nutrients, low or
high levels of all three major nutrients, applications Of Ca, Mg, and
B, or none, and harvested after full bloom or at maturity was ex-
amined. Differences in harvest dates were responsible for 91% Of the
variation observed. Nutrient applications in this study had no signifi-
cant effect On yield.

When nine N, P, and K combinations were applied to plants grown
in the sand-arcillite medium, harvest date again was reSpOnsible for

I...
most Of the Observed variation in bulb production, but an effect of
nutrients and an interaction between nutrient level, Ca—Mg—B applica-
tion, and harvest date on Inain bulb production was found. Plants re-
ceiving the high level of N, P, and K, or the high level Of any one in
combination with the low level of the other two, produced weights Of
main bulbs above the average for all treatrn3nts. Plants receiving
treatments which lacked one or all of these elen‘ients produced weights
Of main bulbs which were below the average. In the early harvest
main bulb yields were increased by the application of Ca-Mg-B. This
beneficial effect was not evident when the plants were harvested at
maturity. Compared with the effect on main bulb yield, the effect On
Offset bulb weight yield was reversed, with the Ca—Mg-B application
increasing their weight in the harvest at maturity, but not in the

earlier harvest.

Harold W'illiani Schnialfeld Abstract - 3

Applied nutrients had the following effects on bulb production:
lVlain bulb percentage weight increases: High N vs. no N-—l3%, high
P vs. no P—-b%, high K vs. no K--Z%; Offset bulb production: High N

vs. no N-—19% decrease, high P vs. no P--3% decrease, and high K

I
".
I

vs. no K——31% increase.

The contents of 12 essential elements in foliage and new bulbs
were. determined on the tulips grown in the two media, and which re-
ceived no, high, or low applications of all three major nutrients.
Nutrient level affected N, P, and K contents of the foliage and new
bulbs, and the Cu content of the new bulbs. The growth medium signi-
ficantly affected the. residual foliar contents of N, P, K, Ca, Mg, Na,
l\*ln, Cu, B,Zn, and Mo, but only the K, Ca, Cu, B, and Zn contents
of the bulbs. The plant Fe contents were not affected by either nutrient
level or growth medium.

At various nutrient levels growth medium had a differential effect
on the residual foliar P contents and new bulb N, P. and Ca contents.
In general the. plant contents of N, P, and K increased as the level of
fertilization with these elements was increased. Most striking dif—
ferences were in the residual P contents of the foliage. The—re was
only a slight change. between the low N—P-K application and no nutrient
application. but with the high N-P-K application the foliar P resid-
uum increased five- and six-fold. At the sam: time the P contents of
new bulbs increased by 57% and 19% from the nil treatment to the low

N-P-K treatment, and by 18% and 29% from the low to the high level

Harold \Villiani Sc unalfeld Abstract - 4

of nutrient application in the sand-arcillite and soil respectively.

The percentage of applied nutrient that was recovered in the new
bulbs was always greater in the plants grown in the sand—arcillite niix—
ture, and at the low level of nutrient application.

Plants grown in the soil ni-‘diuni which contained large amounts
of Ca and M31, contained larger quantities of Ca and Mg than did plants
grown in sand-arcillite.

The Na remaining in the foliage of plants grown in both media,
and the bulb Na contents of plants grown in the sand-arcillite increased
with increased N-P-K application. Plants grown in both media con—
tained approximately the sa1ne.amount of Na, but sand-arcillite—grown
bulbs contained a higher percentage than did those grown in soil.
Plants grown in the sand—arcillite m edium, containing 20 p. p. m. of
lVln, had a residual foliar Mn content 7. 4 tim-‘s that of soil—grown
plants, while bulb Mn contents were essentially the same for plants
grown in both media.

The Cu contents of sand-arcillite-grown plants showed no apparent
relationship to the level of N—P-K fertilization. The Cu contents of
soil—grown plants increased as the rate of N-P-K application was in—
creased. Rate of N-P-K application did not affect the B contents of
plants grown in either medium. Plants grown in the soil did, however,
contain less B than those which were grown in the sand—arcillite niix—

ture.

Harold William Schnialfeld Abstract _ 2

wt

i\=l:)re Zn was found in the bulbs of plants grown in sand—arcillite
than in those of plants grown in soil. Residual. foliar Zn was at the
same level for plants grown in either medium. Residual foliar l\/Io was
greater for soil-grown plants, but the. average lvlo concentration was
identical in bulbs from plants grown in either medium.

When nine nutrient combinations were applied to plants grown in
sand—arcillite. plant N contents were related to the quantity of N
applied. The bulb content of N was a more sensitive indicator of the
quantity of N applied to the soil than was the residual leaf content.
Plant N contents were enhanced when P and K were at the low rather
than the high levels. The quantity of N in the bulbs was reduced when
K was at the high level. I

Bulb P was remarkably increased by P application, residual
foliar P by the high P application and also by the high N application.
Bulb P contents were slightly increased when N was high rather than
absent.

Residual foliar K was increased by high soil N, but new bulb K
levels were unaffected. When N was high, or P absent, the low K
application did not increase bulb K over the nil treatznent. However,
when N was low, or absent, or when P was high, the low K application
increased bulb K contents by 10% to 14%.

The residual foliar Na, relative to non—fertilized plants, was re-
duced when one of the three major elements was not supplied, or when

p was at the high level. All other treatxhents greatly increased

Harold William Schmall'eld ’ Abstract — o

residualfolharlfla. (Zonyersely, wlmnione ofthe Hireeirmgcn‘elenients
was notsupplhwh residualfohar Cu‘wasincreased. PYfliarCSuxxas
alsoincreasedln'hnfliP’or anPQAP K apphcafions, whikén:was re—
duced by the high N-P—K application.

ifotal bulb prcxhicthan by plants corntfltwcdy'dtdtdiated ininiediately
after petal fall was significantly lower than from plants that were de-
fifliated fliree wmwfluslater, or winch had onlytludi°fhmwers and ped-

uncles re moved .

 

THE RI’NERAL COMPOSITION OF ELIPA GESNERIANA AS RELATED

TO GROWTH AND NUTRITION

B y

HAROLD WILLIAM SCI-IMALFELD

A THESIS

Submitted to the College of Agriculture, Michigan State University
of Agriculture and Applied Science in partial fulfillment of the
requirements for ‘the degree Of

DOCTOR OF PHILOSOPHY
Department of Horticulture

1964

-‘———..—.‘¢

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Q 7 K,’\.\!‘J‘

u Q,L£""

"Ivlan takes interest in an object just in so far as he fashions
an idea for it. It has therefore to pass into his mode of apprehension.
In lix ing nature nothing happens except what stands in relation to
the wh(_)le, and if phenomena appear to us as if isolated, and we. have
to look on our inyestigations as isolated facts, this does not mean
that they are isolated; it only raises the question how are we to
ascertain the connection of these. phenomena and these circuin-
H

stances.

Goetheil‘

*Quoted by Visc0unt Haldane (29)

AC KNOWLEDGM ENTS

The members of my advisory comn‘i‘ttee, Drs. R. L. Carolus,
D. P. Watson, C. E. Wildon, R. F. Stinson, H. C. Beeskow, and
R. L. Cook are sincerely thanked for assistance rendered and advice
given in the course of this study. Dr. A. L. Kenworthy and members
of the Horticulture. I—‘lant Analysis Laboratory are thanked for their
assistance in performing the cheinlcal and spectrographic analyses.
The aid of the Associated Bulb Growers of Holland, who provided the
tulip stock used in these studies, is also sincerely appreciated.

Special thanks are extended to Dr. R. L. Carolus for his en-
couragement and extreme. patience through a very trying period, and
to Dr. D. P. Watson for his encouragement and counselling.

Words cannot express my deep feelings of gratitude for the
financial assistance, faith and moral support that has been given to
me by my parents, Mr. and Mrs. William Schnialfeld, my uncle and
aunt, Mr. and Nlrs. George A. C. Mueller, and my good friends,

Mr. and l\/II'S. Floyd A. Thew.

TABLE OF CONTENTS

INTRODUCTION .
REVIEW OF LITERATURE
Early Cultural Recommendations for the tulip

Fertilizer Recommendations for Commercial
Bulb Production.

Mineral Nutrient Experimentation with Bulb Crops
The Effects of Defoliation and Flower Removal .

GENERAL IVIATERIALS AND METHODS .

CHANGES IN COMPOSITION OF TULIP PLANTS DURING A
GROWING SEASON

Dry lVIatter Content .

Nutrient Distribution Pattern.

THE EFFECT OF DEFOLIATION ON TULIP BULB
PRODUCTION

THE EFFECT OF VARYING LEVELS OF N, P, AND K ON
NUTRIENT REDISTRIBUTION AND BULB PRODUCTION
IN THE TULIP

The Effect of Nutrient Level and Ratio and Time of
Harvest on Bulb Yield

The Effect of Nutrient Level and Ratio on the IVI neral
Composition of the Tulip .

Major Element Composition

Mi nor Element Composition

GENERAL DISC USSION .
SUM MAR Y

LIT ERAT URE CIT ED

Page

13

17

21

21

39

41

INTRODUCTION

From the time of its introduction into Europe in the middle of the
XVI Century the tulip has delighted gardeners and fanciers with its
variety of color, shape, size, and time of bloom. With modern pro—
duction techniques and transportation facilities even the dilettante can
have success in producing their Winch—desired spring display.

Yet the. tulip retains somewhat of an air of mystery appropos of
its origin in the Levant and Asia. First, optimum "dormant" period
temperatures required to produce blossoms varies with the growth
stages of the floral priniordia. After the flower parts have been dif—
ferentiated there are yet other temperature requirements to be met
before blossoming can occur. These requirements have. been eluci—
dated by Dutch workers after many years of research,

IVIineral nutrition requirements remain to be clearly defined.
There has been no dearth of fertilization experimentation with this
plant over the years. But many experin‘ients have produced conflicting

.
information. The investigations reported in this work concerning the
movement of mineral nutrients within the plant itself may aid in the

resolution of such disagreements.

REVIEW OF LITERATURE

Earlv Cultural Reconiinendations for the Tulip.

The tulip was first described in 1560 by Conrad Gesner (d'Ardene, 8)
who had seen it blooming in a garden in Augsburg (Doorenbos, 21).
lVlost tulips originated around the Mediterranean and through Asia to
Japan (Gould, 25, Post, 51). The tulip became an extremely popular
garden flower, especially in the Netherlands, partly due to the efforts
of Carolus Clusius who spent the years 1593—1609 in Leiden actively
propagandizing for the plant (Doorenbos, 21).

Early cultural recommendations for the tulip are. somewhat vague.
IVI'Jrin (~16) in 1682 stated that "tulips do not want much sun nor a Very
dense soil. " Valnay (68) in 1696 recommended fertilizing in June and
\\V'<.')rking the soil five or six times before planting the bulbs. In 1754 I
d'Ardene (7) cautioned that the gardener risked losing a large part of
his stock by not lifting the bulbs annually.

Except for N10 rin's inference that tulips grow better when shaded,
these I‘CCOlillhafl‘ldathHES persist. Barr (10), Griffiths (27), and
Crossley (20) agree that. annual lifting is to avoid overcrowding be-
cause of rapid proliferation of the bulbs. Nisbet (—18) feels, and
Crossley (20) concurs that this is a prophylactic measure for the con—
trol of "f’ire'l disease. They indicate the desirability of a time lapse

betWeen plantings in the same location of from four to eight years.

Ilabershon (Z8), Synge (62), and Crossley (20) following Morin stress
thorough preparation of the soil to achieve good drainage and fine
tilth.

To recommend the use of fresh manure in home gardens is ana—
thema (l‘labershon, 28, Synge, 62, Belin, 11, and Everett, 24), al-
though organic fertilizers such as well-rotted cow manure, bone meal
and dried blood are recon‘irnended by Belin and Synge. Everett (2-1)
calls for the use of slow acting fertilizer, and, if chemical fertilizer
is to be used, one of a 5-10-5 analysis. Crossley (2.0) states that fall
applied N should be in a slowly available form, but that rapidly
available N can be applied as a side dressing in spring. Belin (11)
suggests the use. of 25—30 grams of superphosphate per square n'ieter

when cow manure is used.

Fertilizer Recommendations for Commercial Bulb Production.-
General fertilizer recommendations for commercial tulip bulb
production are somewhat more specific. In Washington and Oregon
the fertilizer rec-Oinmendations on an acre basis are: 30—50 pounds of
N, 100—200 pounds of PZOF, 60—80 poufiids of K20 (preferably as the
sulfate), and 30 pounds of IVIgO as the sulfate. This in addition to 40-
80 pounds of N per acre to be worked in with a preceding cover crop,
(Crossley, 20). Suggested fertilization for British Columbia by

Crossley is 1000 pounds of a 6—8-6 analysis fertilizer per acre in the

fall with 120 pounds of NH4NO3 per acre as a spring side dressing.

Nisbet (48), writing on bulb growing in the islands off the western
coast of Britain, notes that fertilizers with up to 600 pounds of K2804
and 200 pounds of hoof and horn meal to supply N are normally applied
per acre after planting, but may be delayed to November on light soils.
Little phosphate is used although a light dressing may be applied if the

soil phosphate level is low. ,

Griffiths (27) has stated, "That tulips are an exacting crOp, as

commonly supposed, lilJSt be most emphatically denied.’ Certainly,
the wide. divergence of recommendations here would seen'i to indicate

that the soils are extremely different, and that the tulip itself can grow

and mdiltiply satisfactorily under a wide variety of conditions.

Niineral Nutrient Experimentation with Bulb CrOps.

Investigations of the nutrient requirement of bulbous crops have
been conducted over the years to ascertain the effect of quantity, ratio,
and time of application of mineral nutrients on subsequent bulb and
flower production. Algera (l) analyzed tulip bulbs seven times at
intervals of five to nine weeks during the plants' growth cycle, and
concluded that in the Netherlands the tulip begins to take up mineral
nutrients in Nlarch. The Polish worker Woycicki (71) concurs with
this observation saying that in autumn when tulips are planted they

.
absorb only small amounts of mineral nutrients, and that in spring
there is an initial intensive absorption of N. He compares the tulip

with the onion in suggesting fertilization practices. Both crops absorb

similar quantities of the three major nutrients——the tulip somewhat
more N and K, and the. onion somewhat more P. Since the onion has a
growing period of about twice the length of the tulip, he recommends
giving the tulip abundant mineral elements in an easily assimilated
form.

lVlulder (47) was concerned with N fertilization in the Netherlands.
Although he found the cultivar 'Krelage's Triuniph' to grow filOSt
rapidly between the beginning of lV'larch and niid-lVIay, he found that
N03 applications were most satisfactory when applied both in Novem—
ber or December, and in February or .March. He also found that bulbs
which had received ample N while growing forced better than those
which had been produced with insufficient N.

Swanborn (bl) was concerned mainly with the problem of K leach-
ing from dune sands in the bulb district of the Netherlands. Plants
that received high or late. applications of K showed a slight increase in
K content, otherwise analyses of plants at intervals during the season
showed only a slight influence from amount or time of K application.
His results show that tulips have a high requirement for N and K, but
a small requiren'ient for P.

The Japanese workers Amaki and Hagiya (3) compared applications
of varying amounts of N, P, and K using ammonium sulfate, calcium
superphosphate and potassium sulfate and found bulb weight and num-
ber was influenced most by N and least by P. it was also their obser—

vation that the water content of bulbs tended to increase with

 

lul-‘Illllallull l! J lllllll'l' ll."

 

 

 

 

increasing N or K, and to decrease with increasing P.

In a subsequent report (4), on forcing of the bulbs produced,
these investigators observed that as each of the three elei‘nents had
been increased for the previous generation, the plants bloomed earlier,
and the occurrence of "blind" plants was reduced. As N and K supply
to the previous generation decreased, the production of bulbs the suc—
ceeding year was remarkably decreased. These same effects were
noted in field trials. The effect of K applied in the preceding genera-
tion was less than that of N. The amount of P fertilizer seemed to be
of little effect. The dry matter content of second generation bulbs
increased with increased fertilization of the, first generation.

In sand, Bould (13), in 1934-1936 investigated the effect of nutri-
tional deficiencies on growth, flowering, bulb weight increase, and
compostion of tulip bulbs. Fertilizer treatments that did not contain
N, K, or all three major nutrients, resulted in significantly lower
weight increases as cmnpared with full nutrient treatn'ients, while the
absence of P from the fertilizer had no effect on bulb weight increase.
In the second year all treatments resulted in lower bulb weight increase
as compared with the treatments that received the complete fertilizer.
The absence of P in the second year considerably reduced bulb weight
increase while production in the -K treatment equalled that of the full
N-P—K treatment.

Regarding field trials in England, Shepherd (*5) has stated that

the only way to obtain results is over a long period of time, since bulbs

‘

grown on agricultural land of average fertility show no n'ieasureable
response to manures of any kind the first year, and little response the
second. Accordingly, his reports on the use of bulky manures and
mulches applied to King Alfred narcissus and Golden Harvest tulips
cover a seven year period. l\/Ianure and seaweed applied eight to ten
months before planting resulted in small increases in growth for both
bulbs, with a slight further increase in the growth of tulips with addi—
tional N. In a factorial experiment using 27 combinations of no,
moderate, or high applications of ammonium sulfate, superphosphate
and potassium sulfate the narcissi reSponded startlingly to K with the
high rate producing more and larger bulbs than the moderate rate.
Neither N nor P had any great effect on the narcissi. Tulips behaved
similarly, but also showed some slight response to N and P.

In yet another experiment Shepherd (55) applied K2504 in five
increments from none to 600 pounds per acre with generous applica-
tions of N and P. The differences between the nil treatment and 100
pounds of K2504 were striking, but increases were recorded for both
tulips and narcissi to 400 pounds per acre. In an eight year trial with
narcissi no effect of N could be seen or recorded.

Similarly Horton (35) reports that over a five year period tulip,
narcissus and iris bulbs gave a considerably higher response to K
applications than to N or P. Contrarily, Struijis ((30), in trials in—
volving gradually increasing amounts of N, P, and K to tulips, narcissi,

and gladioli showed that N and P had a favorable effect on yield.

In an experiment using the sniall—bulbed Dutch iris (cy. Iniperator),
to minimize the effect of nutrients available in the bulb, Stoughton (59)
ShOWCd that N played the dominant role in the growth of the. plant's
aerial parts, while P played a dominant role in bulb cleyelopnient.
PhoSphorus application was associated with an increase in the number
of large bulbs and a decrease in the number of small bulbs. Potassium
had a small effect in itself, but interacted significantly with P. There
was also a significant interaction between P and N.

Hewitt and lvliles (33) designed an experiment to measure the cuniu—
latiye effect of nutrient deficiencies on tulips and narcissi over a three
year period. A treatment of an excessively high lVln level was in-
cluded in their study. They found that tulips were first most drastic—
ally affected by N, Mg and Ca deficiencies. The effects of P and K
deficiencies were comparable to the first year effect of these three.
elements only after three years. The second year yields were re-
duc ed most by N deficiency, then by deficiencies of P, Mg, and K in
that order. The effects on narcissi were much less pronounced over
the entire period of the experiment. Excess Mu was not detrimental
to either the tulips or narcissi. Treatments that were deficient in
Ca produced bulbs that did not survive the second year.

Cheal and Hewitt (17) in a detailed nutrient experiment were not
successful in correlating nutrient deficiency effects on foliage growth

or development with the effect on tulip bulb production. They

9

observed that N and Mg increased bulb yields while the. effects of P
and K were less Inarked.

Tulips used in the experiment by Cheal and Hewitt were from two
different sources, and each source had a definite effect on the plants'
reSponse in the. experiment. These workers feel, therefore, that,
"the determination of mineral content of the bulbs before planting as
well as after lifting them, as suggested by Bould (13) is evidently
necessary to help in elucidating the reasons for the different reactions

to the treatments. "

Nlineral Analyses of Bulbs.

IMineral analysis of tulips and narcissi were made by Bould (13)
before and after the bulbs had been grown in sand in the absence of
either N, P, or K, or all three elements. The analyses were for N,
P, and K contents. None of the bulbs grown in these treatments con-
tained the quantity of nutrients that had been found in the bulbs before
planting. Potash contents of the new bulbs most closely approached
those of the original bulbs when K had been preSent in the nutrient
solution. Nitrogen and P contents, when N and P had been supplied,
were about two—thirds those of the original bulbs. in all cases when
N, P, or K had been omitted from the nutrient solution the bulb
contents of N, P, and K respectively were approximately one-half

those of the original bulbs.

lO

lto, Kato, and Toyoda (36) in studying the \I and carbohydrate
metabolism of the tulip found that the N content of the bulb increases
with increase in fresh weight of the bulb although the final N content is
attained later than that of fresh weight. Another of their findings was
that the percentage of N in the fresh weight also increases with growth.
Bulbs grown in a sandy soil had a higher N content and concentration
on a fresh weight basis than bulbs grown in a paddy field.

Size and morphological site of development of tulip bulbs as fac—
tors influencing their chemical conipostion were investigated by Har-
grave, Thompson and Wood (30). Smaller sized bulbs——those which
had developed from other than the main axillary bud-~were consistently
significantly lower in percent dry matter and in percent N, P, K and
Ca in the dry matter than the larger bulbs which developed from the
central axillary bud. One striking feature was that ”maiden" bulbs
(bulbs which had produced but one leaf, and no flowers in the growing
season) had twice the Ca content of the non—maiden bulbs. The authors
felt that in this case the high Ca content was due to less being used to

produce leaves and therefore, was available to the new bulb that

form ed.

Analyses of Bulbs Other Than Tulip.
Several bulbous crops other than tulips have been the subject of
mineral nutrient experiments. Zink (72) studied field grown garlic in

three California counties in part to determine the crep's nutritional

 

 

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ll ‘1‘ Illil‘slllll

ll

requirements by determining the mineral content of the bulbs. He
found that on an acre basis garlic would absorb approximately 180
pounds of N, 165 pounds of K, 130 pounds of Ca, 37 pounds of P, 18
pounds of Mn and 7 pounds of Na.

Couto (19) studied the effect of nutrient solutions on garlic grown
in quartz sand. The plants were. grown from a uniform clonal line.
One—half of the plants were grown from whole garlic cloves and one-
half from buds dissected from the storage leaf of the clove. Although
bulb weights are not reported in this paper, deficiencies of N, P, K,
Ca, Mg and B all resulted in highly significant reductions in the. mini—
ber of cloves produced per plant. All Ca deficient plants prpduced
bulbs with only one clove. One—cloved bulbs also resulted when
plants grown from buds dissected from the storage leaf were grown in
solutions containing no K or no lvlg.

Again in sand cultures Woodman (70) found that onion yields were
Significantly reduced by the deletion of N, P, K, Ca, or Mg from the
nutrient solution.

Growing Ebenezer and Yellow Globe onions in Plainfield sand or
a 1:1 sandy loam-muck mixture, Downes and Carolus (22) reported
that nutrient applications high in N or all three major nutrients in-
creased the Mn concentration of the leaves three and four times,
reSpectively over normal treatingnts. Significant, but ni-1ch lower in—
creases in the Mn content of the bulbs were also found with these

treatni ents.

lZ

Boodley (12.) grew Croft lilies under three fertilizer regimes and
followed the iutrient content pattern of the plants by taking \\ eekly leaf
samples. The plants were grown in unfertilized sand, sand with a
complete nutrient solution, or a soil n'iixture with a standard green—
house fertilizer procedure. The N content of the leaves declined from
juvenility to maturity and the quantity recovered was in proportion to
that applied. Very small, but about equal, amounts of P were re-
covered in all treatments. Potassium recovery from the leaves was
similar to that of N except for increases during the last three weeks in
those plants receiving the Ccmplete nutrient solution. The quantities of
Ca recovered showed the most striking differences. In thePsand culture
without added nutrients very little was recovered throughout the plants'
life, but'the amount recovered in the other two treatments increased
steadily with maturity. Magnesium showed the same pattern as Ca,
but was of smaller magnitude. Most flower buds were formed on the
plants grown in the soil nilxture with the standard greenhouse fertiliza—
tion practices.

In field experiments with the gladiolus cultivar 'Lorelei' grown in
soil of high fertility, van Diest and Flannery (69), showed that only a
n‘iinor portion of nutrients in the plants at flowering time and at the end
of the season were supplied by the original corni. Percentages of
nutrients still present in old deteriorated corms ranged from 13% for

K to 44% for P.

13

Contrasting with this, Brown, Lawton, and Carolus (14) report
that the yield and total P content of asparagus spears from five-year-
old plants were not affected by P fertilization, indicating that a major
portion of the P required to produce an asparagus crop is supplied
from reserves in the root system. Carolus (16) followed the nutrient
content of senescent asparagus vegetation and found that 47—74% of the
N, 68-76% of the P and 39—89% of the K present in the August foliage
was leached from the plant, or redistributed to more permanent plant
structures by the time the foliage had matured. Depletion of N, P,

and K from onion and rhubarb leaves was also reported by this author.

The Effects of Defoliation and Flower Removal.

The ren'ioval of leaves from any growing plant reduces productivity
since the leaves synthesize the substances stored by the plant. The
extent of such diminution would be dependent upon both the time in the
plant's life cycle when the defoliation occurred, and the severity of the
treatment. Compton (18) clipped 'Beacon' and 'Picardy' gladioli in
varying degrees periodically, or at spike emergence, and found that
corm weights were reduced in proportion to the severity of the leaf
clipping. Significant reductions in corni weights were obtained only
after about 11% of the total leaf area per plant had been removed.

Baker and Wilcox (9) defoliated onion plants 30, 60, and 90%.
When the plants were most sensitive to defoliation yield reductions

were of the order of 25, 45, and 60% respectively. The most critical

14

stage of growth in terms of the effect of defoliation on yield was after
the plant had attained its maximum vegetative development and when the
bulb was enlarging.

The marketing of narcissus blossoms from fields of plants grown
for bulb production prompted Kalin (37) to compare the effects of flower
head removal only with flower and peduncle removal as for commercial
cut flowers. Several discoveries were, made when bulb production and
subsequent forcing quality of the bulbs were examined. First, the
peduncle was found to be an efficient synthesizing organ—-1eaving it on
the plant without the flower head consistently increased bulb production.
Second, the peduncle's effectiveness varied with the type Of growing
season. Complete peduncle removal reduced production 6% in a normal
year, 10% in a poor year, and only 4% in a good year. Finally, there
was a definite cumulative effect. Where only the flower heads were
removed over a three year period, bulb size improved progressively
while. those that had undergone continuous flower cutting continually de—
clined in quality. Horton (34) reported the same effect on tulip bulbs
produced for forcing where "headed" plants produced bulbs which
flowered earlier and had flowers of better color and greater weight.

Grainger (26) suggested removal of narcissus flower buds and
peduncles while they were still in a very early stage to divert to the
bulbs the carbohydrates that would have been used by these parts. This
prOposal was examined in another experiment by Kalin (38). Removing

the buds early did result in a slight increase of total bulb weight

produced, but had no beneficial effect on the production of double-nosed
bulbs and higher quality forced flowers as did the "heading" technique.

The Japanese workers Toyoda and Nishii in a series of experiments
(03, b4, b5, 06) achieved similar effects with tulips. Using the inforina-
tion formulated by Blaauw and his co-workers (thoroughly reviewed by
Hartseina, 32) on the use of cold temperatures to promote flowering,
they found that treating bulbs with heat prior to planting resulted in
flower stalks without flowers. Bulb production from these plants was
20% to 26% greater than for the control plants.

Removing the tulip blossoms serves a double purpose. As noted
above it increases the bulb production. No less vital to bulb production
is its role in the control of disease. Gould (25) identifies the tulip
flower as an infection court for Botrytis blight (tulip ”fire") (Botrytis
tulipae (Lib. ) Lind). One of the control measures be enumerates is

the removal and destruction of all flowers.

Effects of Teihperature on Bulb Growth.

The growth pattern of tulip bulbs has been examined by several
investigators. Pryor (52) made periodic examinations of growing tulips
and concluded that the bulb passes through two exhaustion periods--first
when the tops and flower stems begin to elongate, the. old bulb begins to
disintegrate, and the new bulbs begin to develop. The second when the
tops are rapidly elongating and during maturation of the flowers. He
also stated that the major portion of bulb growth appears to take place

after blooming.

Kraaij enga (-10, 41, 42) followed tulip bulb dt‘rvelopment in relation
to temperature and humidity during the growth period. Weekly increases
1 n weight of the new bulbs and secondary bulblets were positively corre—
lated with temperature until May, and then negatively correlated. Most
rapid bulb growth was found to Occur froi‘n late April or early May until
0. arly or mid-June. To check the finding that very little bulb thickening
occurred in dry weather a growth meter was developed. Use of this
(1 (ax-ice showed that growth was interrupted when transpiration was high.

These findings would tend to corroborate the statement by Sass (54)
that high temperatures early in the growing season might have a bearing
011 the senescence of tulip plantings. Post (-31) also states that if the
Spring is long and cool the plant continues to grow and store food in the
bulb after flowering, and that if the temperature goes from cold to hot

in a short time, bulb growth is very slight because the plant matures

early.

GENERAL MATERIALS AND lVlETHODS

’:
‘

One thousand bulbs of Tulipa gesneriana 'Blizzard', produced by

 

one grower under uniform conditions, were obtained from the Nether-
lands on October 30, 1962 and stored at 450F. for six weeks. Bulbs
\‘V’QI‘O then weighed into uniform 128 i 1 gram lots of four bulbs each and
planted in six—inch sterilized clay pots. Growing media were steam
s terilized mixtures of either one part manure, one sand, and three
loam, or three parts Plainfield sand and one. of arcillite*. The Plain-
fi eld sand had a pH of 5. 6 and contained 4 p. p. In. of P, 80 p. p. m. of K,
74 p. p. m. of Ca, 2 p. p. m. of Mg, 20 p. p. m. of Mn, and traces of Fe
and C1. The manure, sand and loam m‘xture had a pH of 7. l and con-
tained 48 p. p. m. of P, 480 p.p. m. of K, 1128 p.p. In. of Ca, and
1 19 p. p. m. of Mg. Phosphorus in soil samples was determined using
B ray's P—l method while active K and Mg were determined with the
Spurway method (—38), using an extractant. The pH values were obtained
from a soilzwater suspension, using the glass electrode technique (57).
The planted pots were initially well watered with tap water and re-
turned to 45017.. storage for six additional weeks, after which all plants
\V‘ere removed to a COOP. minimum temperature greenhouse. After the

Initial watering additional moisture was proyided by distilled water only.

 

.—

*$\rcillite——an inert calcined niontmorillonitic clay product, trade
riame Turface.

Representative bulbs were analyzed at planting time to determine
their mineral nutrient composition. The bulb scales and incipient
s capes of leaves, stems and flowers (Figure l) were separated and
analyzed to provide a basis with which to compare later analyses of the
d eveloping plants. As the plants developed the parts analyzed were:
Roots, original bulb scales, new bulbs and bulblets, stems with leaves,
a lid flowers with peduncles. The latter two categories were Separated
j List above the uppermost leaf on the plant (Figure 2).

All plant parts were weighed as harvested, dried at lbOOF.,
W’eighed again, ground to pass a ZO-mesh-to-the-inch screen, and ana-
lyzed for their nilneral nutrient contents. Nitrogen was determined by
the Kjeldahl—Gunning—Arnold method (Anonymous,5). Potassium was
(1 etermined by flani e photometry (Anonynious,b) using a Becknian Model
B spectrophotonieter. Phosphorus, Ca, Mg, Fe, Mn, Cu, B, Zn, Mo,
and Al were analyzed with a direct-reading photoelectric spectrometer=1°

(Kenwo rthy, 39).

 

=“"Quantograph" manufactured by Applied Research Laboratories,
Glendale, Calif.

 

ulv Vol
till it!“

19

 
 

 

 

w Storage leaves
\\ Incipient scape of

leaves, stem and

[I] flowers

 

 

I Fragment of tunic

\—\\\\ \\ \\:\\\\\\ ” // Bulb from which new

main bulb develops
I

 

Base with root initials

 

Figure .l. Diagrammatic cross-section of tulip bulb at planting
time. (After Hall, 31 )

l.ll‘.llll'illll.llll.l‘nl lil_llil‘ill.

 

20

 

\\/I // -
\ [l/l/ Flowei

 

 

Leaves

Peduncle
. ’/

\\ \

\\

 

 

Stem

 

 

 

\\ New main bulb

/ Shrivelling scales of
e \\ old bulb
\

Offset

7" N

 

Figure 2. Diagrammatic representation of tulip at flowering
time. (After Hall, 31)

 

‘v—1

U'

pr

3’

Zl

CHANGES IN COMPOSITION OF TULIP PLANTS DURING A
GROWING SEASON

On December 9, 1962, forty-eight 4-bulb lots were planted in the
Plainfield sand-arcillite mixture. No nutrients were added to the
growth medium. Two 4-bulb lots were harvested weekly for 19 weeks
beginning December 17 to observe the plants' deveIOpnient. lV'lineral

analyses were determined on lots harvested on alternate weeks.

Results and Discussion
A. Dry Matter Content.

The fresh weight and dry matter content of the various plant parts
are presented in Table I. The changes in the dry matter in the original
bulbs, the new bulbs and the combined green organs of stems, leaves
and flowers during the 19 week forcing period are graphically shown in
Figure 3.

Average. dry weight per old bulb decreased steadily from 16. 3
grams to O. 6 gram. The dry weight of the stem, foliar and floral
parts, beginning with the scape within the old bulb, increased from O. 4
g. to 5. 3 g. at flowering and then decreased to Z. 2 g. at maturity. The
new bulb presented sufficient material for analysis beginning Febru—
ary 18. Its dry weight increased markedly in the six-week period from
two weeks before until four weeks after flowering. The final average
dry weight of approximately 10 g. was about two-thirds the weight of

the o riginal bulb.

22

 

 

 

 

 

 

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23

 

 

 

 

 

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Na N H mm m ca q m cm as 00 00 NN cm H mm «m m w ma om o a o
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g. per plant

160
140

 

120
100

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+8 80 +3 80
C3 :3
3n .3
p.60 p.60
33 4o 33 4o
9- a.
a 20 b}, 20
E s
/
5 9 13 19 5 9 l3 19
Growth Pariod (Weeks) Growth Period (Weeks)
Figure 3. Composition of unfertilized Orig . 3.1le
tulip plants sampled at bi-weekly in- New Bllle ' — -
tervals. Average of 8 plants. An— Green Parts --

alyses for dry weight, N, P, K. Full Bloom f

20

The decline in the dry \\ eight of the original bulb scales would be
attributed to natural translocation of carbohydrate and mineral matter
to the new vegetative and reproductive parts, and to provide. respira—
tory energy for plant development. The new plants' leaves would also
have provided newly synthesized carbohydrate material for these pur—
poses. Visually there appeared to be little, if any, decomposition of
the original bulb scales until the very end of the growth cycle.

After flowering, rapid new bulb grd'wth continued for an additional
four weeks. The, abrupt end of bulb dry \\ eight increase and the fact
that there was a large net loss of bulb dry matter contents from the
beginning to the end of the season is partly the result of high green-
house temperatures. Kraaijenga (—12) has noted that increases in bulb
weight in the latter part of the 5! rowing season are negatively correlated

M

with temperature. By inid-April daytime temperatures frequently rose
above 80017. and temperatures of 75°F. were common. Low growth
values for the new bulbs are probably not due to nutrient deficiencies
since concentrations of the elements in the new bulbs equalled or ex-
ceeded those of the original bulbs (Table l).

The decrease in dry matter content of the leaves and stems indi—
cates that most of the carbohydrate material was either translocated to
the new bulbs, or lost through respiration. Since none of the plants set
seed it is futile to speculate on the effect fruiting would have had on

\

carbohydrate use and translocation.

As shown in Table I the original b.1lbs contai ted SO. 9% dry matter
while the new bulbs contained only 41.8%». These bulbs were analyzed
at different tin‘ies--the new bulbs immediately after harvest, the origi-
nal bulbs approximately six months after harvest. The differences in
dry matter content may partly be the result of normal water loss from

the original bulbs during post-harvest storage.

B. Nutrient Distribution Pattern.

The major nutrient content variations of the three tissues Closely
resemble those of the. dry weight. Nitrogen (Figure 3) steadily de-
clined in the original bulbs from 150 mg. to 4 mg. In the green parts
it increased from 16 mg. at planting to 99 mg. at full bloom, and then
declined to 15 mg. at maturity. Sufficient new bulb tissue to pro—yide
material for nitrogen analysis was not available until nine weeks after
planting. Thirteen n’iilligranis were present at that time. Nitrogen
content of the new bulb then increased sharply to 142 mg. on April 15
and declined to 130 mg. at maturity. The new bulbs contained 1.20%
N, the original bulbs (excluding the incipient scape) contained only
0. 92% N (Table 1).

Phosphorus in the dry scales of the mother bulbs measured 0. 4 mg.
(Figure 3) at maturity compared with 31 Ing. at planting. The peak in
leaf—stein-flower P content was measured two weeks before full bloom.
Only 1.5 mg. remained in these. parts at maturity. The final P con-

tent of the new bulbs averaged 30 mg. , or one milligram less than that

of the larger original bulb. The P content of the new bulbs, indicated
in Table l, ayeraged .30% as compared with . 19% for the original bulbs.

There appears to have been an initial absorption of K (Figure 3)
from the sand—arcillite medium while the bulbs were receiying the
flower dorniancy-breaking treatment. Original bulb K rose to 153 mg.
from 135 1112., but then declined to maturity when only one milligram
was found in the dry tissues. In the leaves and flowers the weight of K
increased from an initial low of 7 mg. to a peak at flowering of 93 mg.,
then fell to a level of 24 mg. at maturity. Potassium in the new bulbs
increased sharply over a ten week period to 126 tug. at maturity. The
new bulbs contained 1.26% K as compared with O. 8% K in the original
bulbs analyzed at planting (Table I).

Since the new bulbs were smaller than the original bulbs, and since
their N, P, and K contents were not reduced to the same extent, the
percentages of N, P, and K in the new bulbs all exceeded the percent—
ages in the original bulbs. This contrasts sharply with results reported
by Bould (13) wherein the bulbs not only decreased in size, but also de—
creased in N, P, and K content as percent of dry weight. Bould's ex-
periments were conducted out-of—doors thereby exposing the plants and
growing medium to leaching by rain. Since foliar leaching is acknow-
ledged to be of considerable extent in many crops (Tukey and Tukey,
6?), lack of leaching may in part explain. the high values observed in

this study.

 

 

 

An asPect of Bould's work which tends to agree with this experi—
ment is the K analysis of the new bulbs. None of the bulbs grown by
Bould contained as high a percentage of N, P, or K as the original
stock. But where K was supplied the K content of the new bulbs closely
approached the original content. In the preSent experiment, new bulb
N and P content increaSed by about one-third, while the K content in—
creaSed by about one-half (Table I). The increase in K over the N and
P would partly be due to absorption of K from the medium. It also re—
flects the ease with which it is redistributed in the plant which could,
under Bould's conditions. possibly have prevented it frmn being
leached.

The major element content of the plants in this experiment re—
mained remarkably consistent. If the amounts present in each plant
part are added at any time, the total approximates the original amount
(Figure 3). Removal of major nutrients from the above ground parts
and old bulb scales to the new bulb was very great in the case of N and
K and virtually complete in the case of P.

In Figures 4, 5, and b the periodic analyses of the original bulb
indicate a diminution of the ten other elements to varying degrees
during the period of active growth. Exceptions to this generalization
are apparent increases in the Al and l\/1n contents.

The decrease of the other elements from the original bulbs tends
to be indicative partly of their relative availability in the medium, and

their essentiality. Calcium, which was present in the growth medium,

E3 :3 5; 25

mg. per plant

H
O

 
  
  
  
  
  
 
    
 

on

th

nnnnnnnn

5913 19
Growth Period (woeks)

Orig. Bulbs ""
New Bulbs ' " '
Green Parts """"
Full Bloom

Figure 4. Composition of un-

fertilized tulip plants sampled
at bi-weekly intervals. Aver-
age of 8 plants. Analyses for
Ca, Mg. Na.

H
O

t

mg. per plan

Nfimm

 

HHH
DNA

Nthdfiw

 

mg. per plant

 

£5 9 13 19

Growth Period (WGeks)

400

 

300 300
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3200 .‘3200
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140 70

120 60

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8. 8.

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5 9
Growth Period (weeks)

13 19

Figure 5. Composition of unfertilized tulip
plants sampled at bi-weekly intervals.
Average of 8 plants. Analyses for Fe,
A1, 211. Cu.

400

31

 

 

5

9 13
Growth Period (Weeks
Orig. Bulbs ‘—

New Bulbs

Green Parts
Full Bloom

19

 

32

 

 

 

700 | 160
650 140
600 M" 120
550 4,100
: :2
500 ,2 80
D.
450 g 60
a.
400 - 40
= 32
*3 350 I 20
,3 5
n. 300 I’
a; I
b3 200 ,
3. 5 I
150 I
100 ,’
50 : I,
4.)
“I"... I f 5
a" H
5 9 13 19 °‘
Growth Period (Weeks) a
s1)
=1
Orig. Bulbs -—
New Bulbs -—-
Green Parts -------
Full Bloom f
Figure 6. Compositon of unfertilized
tulip plants sampled at bi -weekly Growth Period (Weeks)

intervals. Average of 8 plants. An-
alyses for Mn, B, Mo.

 

 

33.

was reduced to one-third of the bulb's maximum content, while hie,
which was very low in the substrate, was reduced to one—seventh.
Manganese, which was abundantly available, apparently increased in
the original bulbs. This high value for IVIn resulted partly from the in-
creasing difficulty of removing soil particles from the sl‘irivelling

St ales. Aluminum.showed a slight decrease, and then an apparent in-
creaSe. This increase was again probably the result of contamination.

The role of contamination overall was small and can be attributed
to two sources. Soil particles adherring to the underground portions
would distort Fe, lVln and Al values. Another source of contamination
would be dust from flaking laluminuni paint of the greenhouse. The
opening and closing of ventilators did result in such dust being scattered
over the growing plants. Inability to remove this dust completely may
have. resulted in high Al values for the foliar organs. In all cases the.
new bulbs, which were very smooth, and which were protected within
the original bulb scales, were freest of contamination.

The leaf content of a minor element tended to reflect the niobilitv
of the element, and its availability {from the substrate. Calcium, which
is not mobilized from leaves, continually increased in the leaf tissue.
Calcium was also available from the sand. Foliar Mn content increased
greatly, and although there. was a slight drop-off near maturity, it re-
flected the availability of i\/In to the plant. Although no soil analysis
was made for Na and B these eleni‘snts were evidently available in the

soil as indicated by their high content in the plant.

34

In the new bulbs the quantity of the minor elements with the. excep-
tion of i\/lg, Mo, and B exceeded those of the original bulbs. Since the
concentrations of these three elements in the new bulbs equalled those
of the original bulbs (Table I) it is conceivable that the concentrations
observed represent adequate levels, and that an additional accumulation
might not readily be accomplished by the plant. At any rate, about 20%
of these nutrients remained in the original bulbs, and, supposedly,
still should have been available to the. new bulb.

The analyses of tulips, grown in-a medium of very low nutrient
content illustrate the tendency for nutrients to be utilized in foliar
growth and then to be redistributed and conserved in new bulb growth.
However, this experiment did not facilitate bulb weight increase com-
parable to that which would normally be expected in outdoor culture.
Low production wasalso apparently related to abnormally high green—
house temperature conditions, and not to deficiencies of the elements
analyzed since their percentages in the new bulbs exceeded those in

the original planting stock.

35

THE EFFECT OF DEFOLlATlON ON TULIP BULB PRODUCTION

Materials and Methods

Forty 4—bulb lots of tulips providing eight replications of five.
randomized treatments were planted in the loam-sand-inanure mixture
on December 9, 1962. These plantings were. allowed to develop nor-
mally until just before flowers were in full bloom, and then were
subjected to five defoliation treatments which fall into three main
categories--(l) complete removal of all above-ground parts, (2) re-
inoyal of flowers and peduncles only, and (3) no foliage removal.
Complete defoliations were made at petal fall, or three weeks after
petal fall. Flower and peduncle removals were made as the flowers
came into full bloom, or at petal fall. Foliage that remained on the
plants and intact plants dried down naturally six weeks after full

bloom at which time the bulbs were harvested.

Results and Discussion
The average fresh weights of bulbs produced by four plants are
indicated in Table II. Plants that were.‘ completely defoliated at petal
fall produced lower weights of main bulbs* and total bulbs than any of

the. other treatments. No other treatment influenced main bulb growth.

No treatment affected offset production.

*inain bulb--the bulb produced from the central axillary bud of the

original bulb.

V‘ ) 73......”

wr‘w-oi'fi'"

TABLE 11

The Effect of Defoliation on Tulip Bulb Production

50

 

 

 

 

 

 

Conlplvtv Defoliation Fl«.’)\\o.-I'5 and Pednnt‘los No
at ~ a d DH'
at Pvtal l-‘all 1 ('11)Q\L at (‘ o 1-
Pt-tal Fall +3 Weeks Pvtal Fall Opening ation
Main Bulbs 52. 81 70. o \ 74.1 80.1 77. o
OffSctS 13.6 22.4 21.1 19.0 22.0
Total 60.43“? 92.4 95.2 99.1 99.0
Production ’
Total por-
ccntago of ‘32 72 7—1 77 77
Orig. \Nt-ight
% of Inaxinlam
Main Bulbs 65. 9 87. 4 92. 5 100 90.1
Proclncvd
0,70 of Inaxin‘uln‘n
Total 67.0 93.2 96.0 100 99.9

Production

 

 

1. Fresh \x'cight in granls per 4 plants.
Significantly lower at .01 level.

Plants in this experiment produced approximately two-thirds of
their main and total bulb growth by the time the petals had fallen from
the flowers (Table II). By three weeks after full bloom this had in—
creased to approximately 90% of the maximum fresh weight. This is in
agreement with observations of the dry weight increase pattern show-n
in Figure 3.

The largest fresh weight of main bulbs was produced by the plants
from which the. flowers with peduncles were removed as the flowers
reached full bloom. How ever, this treatment did not result in yields
that were significantly different from the other treatments except where
complete defoliation at petal fall was practiced (Table II). The pro-
nounced reduction of bulb production by plants defoliated at full bloom
is to be expected since they w ere in a vigorous vegetative state when
defoliated. Plants which w ere defoliated three weeks later also ap-
peared to be growing vigorously, but their production of main bulbs did
not differ significantly from that of plants that were allow ed to mature
naturally. Therefore, the plants defoliated three weeks after full
bloom were defoliated only shortly before growth ceased. This is in
agreen‘ient with the results shown in Figure 3 in which dry weight in-
crease ceased four weeks after full bloom.

Some support for Grainer's (26) contention that early removal of
peduncles and flowers will increase bulb production has been indicated.

In this experiment the bulb weights from plants which had had their

flowers removed earliest were slightly, but not significantly, above
those of the other plants.

Simons (56) maintains that if flowers are cut for sale or for in-
door use, leaving two leaves to remain is desirable if the bulbs are to
be kept for growing again. Allen (2) found that leaving only one leaf
per plant reduced bulb production by one-half. Horton (35) states that
stock may be maintained by leaving one leaf on each plant but that two
leaves per plant results in a better increase in bulb weight. It would
appear from the, data presented that gathering tulip flowers without

leaves for home use is probably not a factor in reducing bulb vitality.

39

THE EFFECT OF VARYING LEVELS OF N, P, AND K ON NUTRIENT
REDlSTRlBUTlON AND BULB WEIGHT IN THE TULIP
One-hundred forty-four 4-bulb lots were planted--3/4 in the
sand-arcillite mixture and 1/4 in soil--on December 8, 1962. Twelve
replications of nine nutrient combinations as indicated in, Table 111
were used in the pots containing the sand—arcillite mixture; the O,
IX and 3X N-P-K levels were. repeated in the soil medium. In the

nutrient combinations the "X" level was equivalent to . 25 0. Of N,

b

.50 g. of P and .25 g. of K. The nutrients were supplied by appro—
priate combinations of reagent grade NH4NO3, KNO3, H3PO4,
NH4H2PO4, and KHZPO4. After cold treatment, the planted, treated
pots were randomized in complete blocks in the greenhouse.

The nutrients were applied in solution l/2 one month, 1/4 two
months, and 1/4 three months after planting. One-half of the plants

were additionally fertilized with Ca, N1 and B two months after

planting using gypsum, Epsom salts, and "Safety—Bor" to provide
.25 g. of Ca, 0.83 g. of Mg, and .02 g. of B per pot. Bulbs from

one-half of the plants were harvested following full bloom, the re—

mainder after they had Inatured normally.

v.1

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Results and Discussion

The Effect of Nutrient Level and Ratio and Tin‘ie of Harvest on Bulb Yield.

0
v

A statistical evaluation of the effect of O-O-O,X-X-X, and 3X-3X-3X

 

treatments in the sand-arcillite and the soil media were made. Har-
vest date proved to be the only significant factor affecting bulb produc-

tion in this comparison, and was responsible for 91% of the variance

I
observed. The average total bulb weight per pot of four plants was
65. 9 g. for the first harvest and 104.6 g. for the harvest at maturity. , S.

The analyses of variance for bulb yield of the nine nutrient treat-
ments on the sand-arcillite mixture. are. summarized in Table IV. Har-
vest dates significantly influenced both main bulb and Offset bulb
production. Nutrient treatments had a significant influence on main
bulb weight and there was an apparent interactive influence of nutrient
level, D‘lanI‘ elements and harvest date on both main bulb and offset
bulb production. However, there was no statistical influence attribut -
able to minor element addition p313 or to the various first order ,_
interactions involving minor elements and either harvest date or
nutrient level, with the exception of a Slightly significant influence of
nutrient level with minor elem ants on main bulb yield.

Plants that received the high level of N, P, or K or all three, on
the average of both harvests, produced higher main bulb yields than
the average (Table Ill). Plants that were fertilized with solutions
lacking N, P, or K or all three nutrients in general produced main bulb

weights that were below the average. These observations indicate

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43

that N, P, and K separately or combined w ere beneficial to main bulb
production.

IVIain bulb y~'ields--\\ hen the high level of any or all of the three
major nutrients were applied--\\ ere generally benefitted more by the
addition of minor elements in harvest 1 than in harvest 2 as indicated
by the relative values calculated in Table V. In harvest 1 where no
minor elements were added nutrient additions were apparently of little
benefit to yield, but if N or P were omitted the yield was reduced by 19

‘c
and 10% respectively (Tables III, V).

In the first harvest, high N, and the high level of N-P—K when in
combination with minor elements greatly enhanced Inain bulb production
as indicated by relative yield values of 125 and 121. The high N—P-K
level with minor elements also increased main bulb production as re-
lated to the control treatment in the second harvest, while the high N
treatn‘ient increased production both with and without ni‘nor elements
(Table V).

In general, the increases in main bulb production resulting from
minor element additions in combination \\ ith nutrient application were
eliminated \\ hen the bulbs \\ ere harvested at maturity. This is evidenced
in the treatments deficient in any one of the major elen'ients. In harvest 1
the plants were benefitted by the minor elen‘ients in these treatments,
while in harvest 2 there was no benefit from Ca-iVIg—B (Table III). The
reverse, however, is true in the case of offset production. In harvest 1,
in general, plants without the Ca-IVIg-B application produced more w eight
of offsets than plants receiving the minor elements, but in harvest 2.

minor elements consistently increased production of offset weight.

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The importance of N to main bulb production is indicated by the
treatment averages in Table III--bZ. 0 g. for no N vs. 70. 3 g. for high
N, an increase of about 13%. The yield increase between the —P and
high P treatments was 6%, and the increase from the —K to the high K
treatment was only 2%. This trend is also reversed in the case of off—
set production. High N and high P resulted in offset yield decreases of
19% and 3% from the -\l and -P treatments while high K treated plant
offset production increased 31% Over the —K treatment.

From these observed differences in growth of main bulbs and off-
Sets as a result of nutrient treatment, it appears that when conditions
are favorable for main bulb weight increases, growth is made at the
expense of offset weight increases. It also appears that when minor
elements are present, and bulbs are harvested at maturity, offset
growth adversely influenced main bulb growth.

The Effects of Nutrient Level and Ratio on the Mineral Composition of
the Tulip.

 

The stems with leaves, and the combined main bulbs and offsets of
the plants in the three replications of twelve treatments that were grown
to maturity and which received no minor element applications were.

analyzed for N, P, K and ten other elements.

The Effect of Three. N—P-K Levels on Tulips Grown in Two IVIedia.

 

The chemical analyses of the parallel treatments receiving the 0,

IX and 3X levels of N-P-K on sand-arcillite or soil were statistically

F7“

~16

compared by analysis of variance. Except for Fe the growth medium
significantly affected leaf and stem nutrient contents to varying degrees.
Treatment had no influence on Mg, Na, Mn, Fe, or Mo contents of the
bulbs. The F values, where significant differences were found in
mineral nutrient contents of stems with leaves, and of bulbs, are

listed in Table VI.

Increased N-P-K fertilization of plants grown in either the soil or
sand-arcillite medium in general resulted in an increase in the quantity
of N in the new bulbs with concomitant increases in the residual N con-
tent of the foliage. (Table VII). The N content, however, was larger
in plants grown in soil than in those grown in the sand-arcillite Inix-
ture. This is in part associated with varying bulb size as well as N
concentration. Bulb dry weight from plants grown in soil averaged
11.0 g. while that of plants grown in sand-arcillite averaged 10. 5 g.
The N concentration of soil—grown bulbs was about equal to the N con—
cent ration of those grown in sand-arcillite except in the unfertilized
plants. (Table VIII). The higher 1' concentration in unfertilized, soil-
grown bulbs is accounted for by the natural N content of the soil. In
the fertilized plants, larger bulb weight resulted in the increased
quantity of N.

The N found in new bulbs from fertilized plants compared to that

found in non-fertilized plants is presented in Table IX. The bulbs

grown in sand-arcillite recovered 8. 8% more of the N applied at the 1X

TABLE VI

F7

Summary of Statistical Evaluations of Nutrient Contents in Foliage and
Bulbs as Related to Soil and Nutrient Level Treatment

 

 

Element

Foliage

New Bulbs

 

Nutr.
Level lvleditun NL X IVI

 

lvledium NL X M

 

 

 

N 11 7 ~~~~~ 7. O —-
158 4.13 2 321
K 27 b 4. 7a -—
Ca -- 15.4 """ —-
Mg —- ll.l -—
Na —- 4.6a -—
Mn -- 67.431“? ——
Fe -— -- --
C11 —- 9. 3 --
B —- 6.1 __
Zn —- 6.4* --
M3 —- 10. 213* --
1. F values from the analyses for each element.

xxxxx

Significant at .01 level

Significant at .05 level

a Significant at .10 level

 

48

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49

TABLE V111

Composition of Tulips Grown in Two Soil Media

 

 

 

 

 

 

 

 

 

N-P-K Dry Dr)
Lev (,1 Wt. N 0701:) 070K Wt. ‘70 N 07013 %K
Plainfield Sand-Arcillite Soil

Stems With Leaves
0-0-0 1.20 .322 .030 1.06 1.39 .41 .031 1.47
1-1-1 1.28 .33 .048 1.50 1.23 .36 .028 1.35
3—3-3 1.32 .45 .219 2.12 1.40 .50 .167 2.17

l\~lain Bulbs and Offsets

0-0-0 10.50 .14 .308 1.15 10.39 1.27 .333 1.27
l-1-1 10.80 41 .471 1.27 11.35 1.41 .408 1.29
3-3-3 10.26 73 .589 1.30 11.27 1.69 .543 1.33
1. Dry weight in g. per plant. Average of 4 plants.

2. Weighted averages for 3 replications.

TABLE 1X

Quantity and Percentage. of Applied N, P, and K accumulated in New

Bulbs of Plants Grown in Two Soil Media (Average. of 3 replications).

 

 

 

 

N-p-K Level 1X 3X 1X 3X
1V1ediuni Sand—Arcillite Soil

N Applied 2:301 750 250 750
N Recovered 133.2 232.0 111.6 232.0
% Recovery 53.2 31.4 44.4 31.4
P Applied 500 1500 500 1500
PReCO\'ered 74.0 111.6 29.6 83.6
% Recovery 14.8 7.4 5.9 5.6
K Applied 250 750 250 750
K Recovered 63.6 50.0 55.6 73.2
% Recovery 25.4 6.6 22.2 9.8

 

 

R134. per pot of 4 plants.

 

level than those grown in soil, but at the 3X level bulbs from each
medium recovered identical quantities of the applied N.

Differences in P content of the plant parts caused by differences in
P applications are very striking. Very little residual P was found in
the mature. leaves of plants which received no nutrients or the 1X level
of N-P—K. Between the IX and 3X levels of nutrient application the
residual P content of the foliage increased five- to six-fold (Table V11).
These differences appear to be an indication of P availability to the
plants, and would also indicate that alnwst all of the P in the leaves
and stems was redistributed to the new bulbs until the new bulb P con-
tent reached 50—60 1113;. per plant. The P concentration at this time
averaged .408 to . 471% of the bulbs' dry weight (Table V111).

Without nutrient application the amount of P in the new bulbs was
the same as or slightly higher than in the original bulbs (Figure 3,
Table V11). Phosphorus content of the bulbs increased in a parallel
manner in sand-arcillite and in soil as the level of P fertilization in-
creased (Table Vl1). But in the fertilized plants the percentage of-P in
the new bulbs was consistently lower for soil-grown bulbs than for those
grown in sand-arcillite (Table V111). This difference was not the result
of the slightly greater dry weight of the soil-grown bulbs since sand-
arcillite-grown bulbs contained a greater or equal quantity of P. This
is possibly due to less P fixation in the sand-arcillite compared to soil,

and its consequent increased availability to the plant.

1"}

 

52

Available P in the soil, and the fixation of applied P by the soil,
reduced the recovery of applied P by the plants (Table 1X). Theisand-
arcillite grown bulbs at the low and high levels of fertilization con-
tained 74.0 and 111.6 mg. more P respectively than those from the
non-fertilized plants. In the soil medium only 29. 6 and 83. 6 mg. of
the. low and high P applications were recovered in the bulbs.

Fertilization with N-P-K increased the K content of plants grown
in both media. Soil media significantly affected the residual K content
of the foliage, and highly significantly affected the K contents of the new
bulbs (Table V11). Residual K contents increased in the foliage with
increasing fertilization, but not as regularly for the two media as did
the K contents of the new bulbs. 1n the new bulbs the K contents of
plants grown in soil was consistently above that of plants grown in the.
sand-arcillite mixture. This would in part be due to the higher level
of K in the soil inediun'i.

The. largest percentage of applied K was recovered by the new bulbs
of plants receiving the low treatment in the sand—arcillite medium
(Table 1X). Bulbs from plants receiving the high level of fertilization
grown in sand-arcillite recovered the. lowest percentage of the applied
K. Potassium contents of bulbs from this treatment were about equal
to those of bulbs from unfertilized plants grown in the soil (Table V11).

Foliar and new bulb Ca was not affected by the N-P-K fertilizations,
but the effect of growing media was significant (Table VI). The soil

contained 15 times as much Ca as the Plainfield sand, thus accounting

5‘5.

 

53

for the significance of soil media on the plant Ca contents. Although
Mg was also more. plentiful in the soil than in the sand, more residual
Mg was present in the foliage of plants grown in the sand-arcillite mix-
ture than in those grown in soil (Table VII). There was more Mg in the
bulbs Of unfertilized plants grown in the soil than in those grown in the
sand-arcillite. With nutrient applications, however, bulb lV'lg content
was at the same level froniboth media indicating better utilization, or
greater availability of Mg as a result of N-P—K applications.

In general, quantities of N, P, and K were all increased in the
plants as the level of nutrient application was increased. The amount
of the applied nutrient which was recovered in the bulbs was also re—
lated to the quantity applied, with a higher percentage being recovered
at the lower level of application. The quantity of P in the new bulbs
from the low level of application. was much larger than from the con-
trol treatment. Residual foliar P, however, was only increased at the
high level of its application suggesting that P is reduced to a lower
level in the leaves if adequate quantities of P for bulb growth are not
available.

Statistically significant differences observed in minor element
contents of the tulip plants were mainly associated with soil media.
(Table VI). There are, however, some noticeable trends in minor
element contents of both foliar and storage organs as affected by

. . .
nutrient level or growth filedlljtnl.

Residual Na content increased in the leaves of plants grown in both
media and in bulbs from plants grown in sand—arcillite as the nutrient
level increased from zero to the high level {Table X). The con'ibined
Na contents of both foliar and storage organs grown in either medium
vary by less than 5%. But in soil-grown plants, the Na content
averages 36% greater for foliage and 26% less for bulbs than in plants
grown in the sand—arcillite Inixture. Sodium was evidently about
equally available in either medium, or equally absorbed by the plants.
The differences in the redistribution of this element to the bulbs may
be related to a substitution of Na for Ca in the bulbs grown in the low
Ca content sand—arcillite nuixture.

Foliar Mn of the sand-arcillite-grown plants averaged 7. 4 times

greater than that of soil-grown plants, but caused no apparent toxic
effects. DeSpite the availability of excess Mn in the sand-arcillite
mixture, evidenced by soil and foliar analysis, the bulbs produced in
either medium contain similar quantities of Mn, which generally
followed the same trend, and were apparently satisfactory. The excess
lVlri that was absorbed by the sand—arcillite-grown plants was retained
in the leaves, and n'iay have reduced the possibility of toxic effects to
the bulb from the high Md levels. In both media more Mn was found in
bulbs from the unfertilized plants than from fertilized plants.

The Cu contents of both foliar and storage organs of plants grown
in the sand—arcillite mixture show no definite relationship to the level

of N—P—K application. In plants grown in soil, however, more Cu was

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56

found as the level of fertilization increased. On the average there was
45$brnore Cu hithe fifliage, and 48%)nn3rein finetndbs ofsxfil—growwx
plants than of sand-arcillite-grown plants indicating inc reaSed Cu con-
tent and/or availability in the soil.

l3oron contentsin buNDS\vereINN:appreciablyiffiluencedlyythe
nutrient level. Soil-grown bulbs had a lower B content than bulbs
grovniirithe sand-arcilhte niediuni.

The average Zn accumulation in the sand~arcillite-grown bulbs
was twice that of soil—grown bulbs, while the residual foliar Zn was at
the same low level for each niediun‘i. Since leaf Zn was redistributed
‘u3thelndbs fl appearsthatlngh.knwfls areiun retahuxiintlu:leaves
or that tulip bulbs have a large Zn requirement. As with Mn, the lar-
gest quantities of Zn were found in the bulbs from non-treated plants,
which may partly be the result of differential absorption when nutrients
wwwmrappfied.

kiolybdenurn contents of the bulbs were at equal levels for each
medium and nutrient application level, while foliar contents of soil-
grown plants exceeded those of sand-arcillite-grown plants. Original
bulb h43<nsncentratuni\vas .7jp.p.rn. ofthe dry'weight. (Talfle D.
Using the average dry weight of bulbs grown in sand-arcillite and in
soil (10.5 and 11.0 g. respectively) the average Mo concentration of
these bulbs both equal . 56 p. p. m. indicating again that the leaves may
retain excess minerals when adequate levels have been translocated to

the storage organs.

«1

UI

These minor element con'iposition values tend mainly to reflect the
influence of the growth medium on the plant parts. Sodium was the
only element to be influenced to any large extent by N-P—K nutrient

application.

The Effect of Nutrient Ratio on Composition

The N, P, and K contents of stems with leaves and of the new
bulbs were significantly affected by the nine nutrient treatments on the
sand—arcillite mixture. Of the other elements only the Na and Cu con-
tents of the foliage were significantly affected by the various N-P-K
treatments. The significance of variations in plant part contents of
these minerals were evaluated by Duncan‘s Multiple Range Test (23)
and are presented in Table XI. Contents of m7nerals not significantly
affected are listed in Table XII.

The residual N content of the foliage and the N content of the new
bulbs is clearly related to the level of N applied. The bulb N contents
appear to be a more. sensitive indicator of N application than the resid-
ual N in the mature leaf. In the bulb the N contents varied with the
quantity applied while in the foliage they only showed a significant in-
crease at the'high level of application. Although the plant N contents
appear to be related to the. quantity of N applied, at the high level of
application the N contents were also enhanced when the P and K were
at the low rather than high levels. High K had the effect of reducing

the quantity of N present in the new bulbs (Table XI). This may be

58

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60

related to Lambeth's (~15) finding of reduced lettuce yields due to a
N—K imbalance.

In addition to the increase of P in plants treated with the two levels
Of N—P-K, as discussed previously, the data in Table XI indicate that
high N had the effect of’ increasing residual foliar P of the low' P
treated plants to equal that of those that were treated with the high
level. Bulbs from the high N treatment had slightly, but not signifi-
cantly, more P than bulbs from the -N treatment. These data, there-
fore, suggest increased P uptake with increased N application. This
contrasts with the finding by Patterson, it _a_l_. (50) that applications of
N significantly decreased the P content of onion bulbs from that where
no N was applied.

High N also increaSed the residual foliar K but not new bulb K,
and when compared with the two levels of N-P-K, depressed bulb K.
The low K application did not increase bulb K over no K when N
was high, or P was absent. However, when N was low, or omitted,
or when P was high, bulb K content at the low level of K application
was 10 to 14% higher than in bulbs from plants which did not receive K.

When either N, P, or K was not applied, quantities of residual
foliar Na were smaller than in the non-treated plants. Foliage from
other treatments, except the high P treatment contained quantities of
Na considerably greater than non-treated plants. There is a trend for

the N, P, and K to follow the same pattern (Table XI) indicating that

bl

major nutrient balance may partly influence residual nutrient contents
in the foliage.

When N, P, and K were applied together at the high level foliar Cu
was significantly reduced. With high N and high K the Cu contents were
the same as in untreated plants. High P, the low level of all three
nutrients, or the absence of one of the nutrients considerably increased
foliar Cu. This is partly in agreement with Labanauskas _e_t_a_1. (-13, 44)
who found the Cu concentration of avocado leaves to decrease appre-
ciably with high applications of chemical N. However, when foliar and
bulb Cu contents are added, plant Cu appeared to have been inc reaSed
by the -P treatment and decreased by the -N treatment. COpper con—
tent totals for these treatments are 62 and 33 pg. respectively while
those of the other treatments range from 43 to 54 pg.

Increasing the level of N—P-K, resulted in increases in plant N, P,
and K content. Different nutrient ratios interacted to influence the
quantity of these elements in the plant. Sodium uptake appeared to be
decreased when one of the elements was n'i.‘ssing, while reduction of

foliar Cu was induced by high levels of N or K or all three major ele-

ments.

()2

GENERAL DISC USSION

Periodic analyses showed that the dry weight of the original bulbs
decreased steadily from planting time until they were reduced to brown,
shrivelled scales shortly before the plant matured. Developing bulbs
began to increase rapidly in dry weight in the period two weeks prior to
full bloom, and continued to develop for a total period of approximately
six weeks. During these six weeks increases occurred at a slightly
greater rate immediately following blossoming than during other
periods. This is in agreement with observations by Kraaijenga (40)
who found the most rapidgbulb growth period to be the four to five days
following blossom removal. Pryor (52) found that bulbs increased 85%
over the planted weight within eight days following the blooming period,
but that until then bulb weights had only increased slightly over the
planted weights.

Four weeks after full bloom the periodic measurements indicated
little or no growth continuation. Tulip; that had been completely de-
foliated three weeks after full bloom achieved 93% of the maximum
total bulb weight produced. This also is in accordance with Kraaijenga
(41) who found that bulb weight increases were small in the final week
before harvest.

In plants grown in a Iiiediuin very low in nutrients, major nutrient

contents in the new bulbs began to increase about four weeks before full

 

(>3

bloom. lxnmediately after full bloom new bulb nutrient contents in-
creased very sharply as nutrients were translocated from the foliage.
Just prior to blossoming the foliage itself had increased rapidly in
nutrients derived from the old bulb.

Rogers, Still. (53) followed the seasonal trend of nutrient element
contents in apple leaves and found that the dry weight, N, P, and K
contents reached a peak and then decreased before abscission. They
estimated that approximately one pound of N and 0. 1 pound of P were
returned to the tree in this manner. Calcium increased in the apple
leaves up to the time of abscission, and MK; contents remained about
constant from the time that the first samples were taken 20 days after
full bloom. Bukovac, et al. (15) could demonstrate no basipetal Inove-

ment of Mg28 in Phaseolus vulgaris. In the tulip foliage Ca remained

 

irnwriobile, but the lVIg contents declined about 30%. Zinc, Cu, Mn, and
B also tended to decrease considerably in the tulip leaves as they
Inatured.

Nutrient applications to the tulip plants elicited a number of
responses. Main bulb growth was benefitted by the addition of Ca, Mg,
and B when plants were harvested immediately after flowering, but not
when plants were allowed to grow to maturity, possibly in part the re—
sult of redistribution of Mg and B from the leaves.

Bulb weights have been reported by Ainaki and Hagiya (3) to be
increased most by applications of N, and least by P. Results obtained

in this study agree in part, with N increasing main bulb weight, but with

“m.

(34

P appearing to be more beneficial than K. The reverse occurred in the
case of offset production where K applications resulted in the largest
weight increases and N was least beneficial. This may in part be the
reason for conflicting reports in the literature (3, 33, 35, 55, 70, and
61) as to which of the three major elements elicits the best tulip bulb

growth response .

 

l
1“
In this experiment main bulb and offset production tended to comple—
' E
ment each other-~one being high when the other was low, and vice versa. ._‘
V

This had the effect of obscuring the reSponse to added nutrients if only
total bulb production was examined. Hargrave, §_t__a_l_. (30) found that
bulbs produced from lateral buds were lower in percent dry weight and
in percent of N, P, K, Ca, and lVlg in the dry weight than the bulbs pro-
duced from the main axillary bud, which finding may also be related to
the differences observed in bulb weight increases in this investigation.

The differential effects of N and K may be of practical interest to.
both those who use tulips for landscape purposes, and to those who
produce them commercially. Additional investigation may disclose
optimum levels of N applications necessary to maintain main bulbs in
good vigor, while discovery of the proper levels of K fertilization to
insure Inaxiinuni offset growth would increase production for bulb
growers.

Increasing the amount of a nutrient applied to the growth Inedium

Increased the quantity of that element in the plant. The percentage of

. . '0 .
applied nutrient that was recovered 1n the new bulbs was always

 

largest in bulbs from plants which were grown in the sand-arcillite niix-
ture, and which received the lower level of applied nutrients.

The N contents of new bulbs were not only related to the quantity
of N applied, but also to the quantity of K applied. Residual foliar N
was not affected by increased K levels. Applied N tended to have. the
reciprocal effect on plant K contents, i. e. with high N applications new
bulb K was reduced, and residual foliar K was increased.

Paterson et a1. (50) report that applied N reduced the P contents of

onion bulbs. This relationship was not found in the tulip, with bulb P

contents at high and low N levels being statistically the same. High N
did significantly increase residual foliar P. The. great increase noted
in residual foliar P contents when P was applied illustrates the extent
of P redistribution which takes place. This redistribution of P in plants
is probably in part the reason for lack of uptake by asparagus of applied
P as described by Brown, Lawton and Carolus (14).

In general the quantity of Ininor elements in the plant was affected
to a larger extent by the growth medium than the differential N-P-K
nutrient applications. This is especially noticeable where plant Ca and
iVIg were highest for soil-grown plants and M'] and Zn were highest for
sand—arcillite-grown plants.

Although total plant i\/In contents for sand-arcillite-grown plants
greatly exceeded those of soil-grown plants,. bulb Mn contents were at
the same level for both media. The. retention of excess Mn in the

foliage removed the mineral frOIn the plant by normal foliar abscission

PL

be

at the end of the season. This would in part explain the lack of injury

to tulips from excessively high Mn levels as found by Hewitt and

lVliles (33)-

SLTIVIMJ\RY

When the. various parts of unfertilized tulip plants grown in a
medium very low in nutrient contents were periodically analyzed it was
found that most of the N and K, and virtually all of the P that had been
utilized in foliar growth was redistributed to the new bulbs after the
blossoming period. This recycling phenomenon may occur in other
plants with storage organs thus reducing the amount of applied nut ri-
ents needed to maintain their growth. Redistribution of Mg, Zn, Cu,

B, and Mn from the foliage to the new bulbs also occurred, while Ca,
Na, Fe, Mo, and Al remained immobile.

Complete defoliation of tulip plants immediately after flowering re-
duced total bulb production by one-third. Complete defoliation three
weeks later, or removal of peduncles and flowers at opening or at petal
fall did not significantly alter bulb production from that of plants which
were allowed to grow intact to Inaturity.

The relative importance of the major nutrients to main bulb and
offset production differ. High N was most beneficial to main bulb and
least beneficial to offset bulb yield. High K was least beneficial to
main bulb and most beneficial to offset bulb yield. lVlain bulbs and off-
set yields were also differentially affected by harvest date and an appli-

cation of Ca-MU-B. When harvested immediately after flowering these

6"

Ininor elements benefitted main bulb yield and did not affect offset bulb

5‘

(38

yield. When harvested at maturity offset yield was benefitted and main
bulb yield was not affected.

Plant contents of N, P, and K were increased by application of
these nutrients to the growing medium. Large increases were noted in
foliar P contents at the high level of P application. The N-P-K ratio
applied also affected the N-P-K contents. More N was found in the
plants when P and K were applied at low rather than at high levels,
and the quantity of N in the bulbs was reduced when the K application

'

was high. \

Phosphorus in the bulbs was increased by high N applications.

Bulb K contents were not affected when the application of N was high or
when P was omitted, however when N was omitted or when the high
level of P was applied bulb K was increased.

The amount of lVIn and the concentration of M3 in bulbs grown in two
media were very similar. At the same time leaves of plants grown in
soil contained more Mr) than those of plants grown in sand-arcillite,
and leaves of sand-arcillite-grown plants contained 7. 4 times more Mn
than those of soil-grown plants. This illustrates a possible function of

plant leaves in diSposing of excess levels of nutrients at the end of the

season.

 

III! Ill

’ ‘5)!lllif’i

 

10.

ll.

69

LITERATURE CITED

Algera, L. 1944. Over de Opname van voedingstoffen uit den
boden door de tulp. Inst. Phytopath. Lab. Bloembollenonderz,
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Allen, R. C. 1937. Factors affecting the growth of tulips and
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Amaki, W. and K. Hagiya. 1960. Studies on fertilizer supply to
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29: 157-162.

1960. Studies on fertilizer supply to tulips.

 

11. The differences in growing of tulip bulbs produced by supplying
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Anonymous. 1945. Official and tentative methods of analysis of the
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A.O.A. C. Washington, D. C. —

\

1955. Official Methods of Analysis of the Association

 

of Official Agricultural Chemists. 8th. Ed. Chap. 6. A.O.A.C.
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d‘Ardene, P. R. 1754. Traite de la culture des renoncules, des
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1760. Traite des tulipes. Louis Chanibeau,

 

Avignon.

Baker, R. S. and G. E. Wilcox. 1961. Effect of foliage damage.
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Barr, G. R. 1955. The cultivation of tulips. The Daffodil and
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Belin, G. 1952. Les Plantes Bulbeuses. Bailliere et fils. Paris.
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:r“ mgr .__-. _.__'

12.

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Brown, L. D., K. Lawton and R. L. Carolus. 1961. Utilization
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Bukovac, 1V1. J. , F. G. Teubner and S. H. VVittwer. 1960. Ab-
sorption and mobility of niagnesiun'i28 in the bean (Phaseolus vul-
garis. L.) Proc. Am. Soc. Hort. Sci. 75: 429-434.

 

 

Carolus, R. L. 1962. Distribution and redistribution of nutrients
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Cheal, W. F. and E. J. Hewitt. 1962. Effects of major nutrients
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Compton, O. C. 1960. Effects of leaf clipping upon the size of
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Crossley, J. H. 1957. Handbook on Growing and Forcing. North-
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Doorenbos, J. 1954. Notes on the history of bulb breeding in the
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Proc. Am. Soc. Hort. Sci. 78: 393-399.

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Everett, T. H. 1954. The American Gardner's Book of Bulbs.
Random House, New York. pp. 24-1.

 

Gould, C. J. 1957. The flower bulb industry. Wash. Agr. Exp.
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Haldane, Viscount. 1922. The Philos0phy of Humanism and of
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Hargrave, J., F. C. Thompson, and J. Wood. 1940.’ Size as a
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Hall, Sir A. D. 1929. The Book of the Tulip, Martin Hopkinson,
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Hartsema, A. 1%. 1957. Influence of temperatures on flower for-
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1956. Further studies on field cuttings and its in-

 

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r——-—1

 

 

'11,}.I‘l" ill.’ I

 

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, and W. W. Jones. 1958.

 

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1958. Studies on the high temperature

 

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1958. Studies on the high temperature

 

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'66.

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1958. Studies on the high temperature

 

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