Generalized fertilizer recomme...
 Factors determining fertilizer...
 Special disorders

Group Title: Mimeo report - Gulf Coast Station - 56- 2
Title: Fertilizing gladiolus
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00067638/00001
 Material Information
Title: Fertilizing gladiolus
Series Title: Gulf Coast Station mimeo report
Physical Description: 8 leaves : ; 28 cm.
Language: English
Creator: Woltz, S. S
Gulf Coast Experiment Station (Bradenton, Fla.)
Publisher: Gulf Coast Station
Place of Publication: Bradenton Fla
Publication Date: 1956
Subject: Gladiolus -- Fertilizers -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
Statement of Responsibility: S.S. Woltz.
General Note: Caption title.
Funding: Florida Historical Agriculture and Rural Life
 Record Information
Bibliographic ID: UF00067638
Volume ID: VID00001
Source Institution: Marston Science Library, George A. Smathers Libraries, University of Florida
Holding Location: Florida Agricultural Experiment Station, Florida Cooperative Extension Service, Florida Department of Agriculture and Consumer Services, and the Engineering and Industrial Experiment Station; Institute for Food and Agricultural Services (IFAS), University of Florida
Rights Management: All rights reserved, Board of Trustees of the University of Florida
Resource Identifier: oclc - 71355541

Table of Contents
    Generalized fertilizer recommendation
        Page 1
    Factors determining fertilizer needs
        Page 2
        Page 3
        Page 4
        Page 5
    Special disorders
        Page 6
        Page 7
        Page 8
Full Text


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source

site maintained by the Florida
Cooperative Extension Service.

Copyright 2005, Board of Trustees, University
of Florida



S. S. Woltz, Assistant Horticulturist

No single fertilizer recommendation can be made for gladiolus for all condi-

tions under which they may be grown in Florida. It is probably best, therefore, to

select a general fertilizer program that will insure against serious deficiencies

-r excesses of the various nutrient elements, and then vary the program to meet

local nerds.

Generalized Fertilizer Recommendation

The following applications of fertilizer makes up a general program to be va-

ried according to needs, as discussed later in this report.

1. 400 pounds of 4-8-8 containing secondaries, mixed in the bed. Nitrogen sour-

ces are specified as 25 percent organic, 40 percent nitrate, and 35 percent ammoni-

acal. The secondary elements and the percentages to be supplied in the 4-8-8 ferti-

lizer are: 1 percent water soluble MgO, 0.5 percent Fe2 0 0.5 percent MnO, 0.2

percent CuO, 0.2 percent ZnO, and 0.2 percent B103. Notes: If dolomitic limestone

is not used in conditioning the land, then increase MgO to 2 percent in applications

1 and 2. ZnO and MnO may be reduced or omitted if furnished in fungicidal sprays


2. 500 pounds of the above mixture sidedressed and worked into moist soil about

3 weeks after planting.

3. 400 pounds of 5-10-10 containing 0.2 percent B203, with nitrogen from inor-

ganic sources, approximately 60 percent ammoniacal and 40 percent nitrate. This

is to be applied two weeks after No. 2 above.

4. 400 pounds of the mixture in No. 3, applied two weeks later.

5. 200 pounds of 8-0-16 with 50 percent nitrate and 50 percent ammonium nitrognr

and 0.2 percent EBp, to be sidedressed immediately following the completion of

flower cutting.

If the grower prefers to use only one fertilizer mixture, he may vary the

formula given for applications 1 and 2 by halving the percentages of secondary ele-

rsnts, except for B203 which should not be reduced. This mixture may then be

applied at the rate of 400 pounds mixed in the bed, followed by three 500 pound

sidedressings before flower harvest and another after flower harvest.

Factors Determining Fertilizer Needs

Following is an outline of the factors affecting fertilizer requirement of


I. Soil Conditions.

1. Fertilizer retaining capacity

If the soil has a high cation-exchange capacity, or in other words, is a

heavier soil than the sands, nutrient elements other than nitrates are retained

somewhat against leaching. This is true in mucks and certain phases of Bladen

and Manatee soils, for example.

In heavier soils it will be possible to omit one of the fertilizer applica-

tions or to reduce the amount of each application. Also, the fertilizer analy-

sis may be adjusted on the basis of important reserves of nutrients in the soil

or on -.he basis of the fertilizer retaining capacity of the soil, With most

gladic.us soils, however, there is not generally any large reserve of nutrients

at planting time.

The lc.,r the moisture-holding capacity of a soil, the greater will be the

loss of nr.i-rients to leaching. Irrigation or rain water carrying dissolved nu-

trients vijll move them out of the root zone before the roots have a chance of

absorbing a good share of the fertilizer application. The remedy for the loss

of nutrients due to excessive drainage is more frequent application of ferti-

l2zer, repeating fertilizer applications made just before heavy rains, and ar-

rsnging :irrigation to cause the least leaching loss. In order to reduce this

loss of nutrients in irrigation water it is desirable to avoid the practice, as

r;Lh as possible, of saturating the soil to a very high level and then quickly

dra.iining it out. With heavier soils containing greater clay and organic matter

contents, more of the water from a given rainfall or irrigation is retained in

thl root zone.


2. Root Disturbances.

Any factor that limits the expansion and functioning of the root system de-

creases the efficiency of applied fertilizer and thus makes special treatments

necessary, in the form of increased rates of fertilization, nutritional sprays,

and variations in fertilizer placement and irrigation to bring the nutrients

to the damaged root system. The factors that are known to damage the roots are:

nematodes, fuigi, and toxic levels of chemical elements in the soil.

Preliminary experience with soil 6terilants such as Crag Experimental Fungi-

cide 974 and Vapam indicates that the response to fertilizer will be different

when they are effectively used on soils infested with destructive fungi and nema-

todes. The root system will be more extensive and there will be more active

feeder roots which will result in greater uptake of nutrients, both native and

applied. In many soils that have been repeatedly planted to gladiolus, the roots

are much restricted by nematodes and fungi working together and the growth of the

tops of plants is limited by the poor up-take of fertilizer.

cr-tiliier experiments have shown that it is necessary to use more fertilizer

to get nor-mal flower and bulb production when damage by fungi and nematodes to

roots is serious. Little or no fertilizer under these conditions resulted in

extremely low flower production as well as poor bulb production. The use of

abnormally high levels of fertilization, such as one ton of 8-8-16 per acre

resulted in greatly improved yields, but these yields were still sub-normal.

The formulation of fertilizers will need to be changed when partial soil

sterilization is practiced, in order to compensate for the temporary decrease

in conversion of organic nitrogen to ammoniacal compounds and also the conver-

sion of the latter to nitrates. Thus, fertilizers for partially sterilized

s-il should contain more nitrate and less organic and ammoniacal nitrogen, at

lost during the first month or so after treatment.

Two other types of root disturbances encountered are physical damage from

cnlt', i;vion operations and chemical burn by concentrated fertilizer applications

in the root zone. The first of these is avoided by cultivating with sweeps set


so they will do the least amount of root pruning while still providing effective

weed~6ntrol ..To reduce fertilizer birn onj;dots; distribute :the application in

a fairly wid6 bandiand work into moist soil.

3. Soil pH

Low soil pH values, especially below 5.0, cause increased leaching of most

nutrient elements and thus decrease the efficiency of applied fertilizer. Where

accumulated soil copper causes toxicity to plants, such toxicity is much worse

at lower pH levels and may be reduced by adequate liming. Very high pH levels

reduce the availability of minor elements, except molybdenum, to plants. It is

desirable to keep the soil pH within the range of 5.5 to 6.5. In order to do

this, pH measurements should be made well in advance of planting and liming ma-

terials should be applied in time to allow them to react. The nature of the

soil and the liming material will determine the length of time required. Con-

sult Florida Circular S-39.

Frequently, after applying fertilizer at the beginning of the crop season,

it is found that the pH will drop a half to one unit below the value found be-

fore fertilizing. The 'alcitim. cllbride'lmethod4.f' detenmting' soil pH perriss

the tise of larger amounts of lime when needed for soils with greater reserve or

ez'.hangenr.le acidity. Soils that have been fertilized regularly do not usually :.

have lae-e reserve aciditygcontent, while heavier soils that are being cultivated

for the first time usually do.

1,. Climatic Conditions.

Cold, wet weather decreases the rate at which organic nitrogen becomes avail-

Oble to plants. Consequently, nitrogen supplied to gladiolus in such weather

should be derived mainly from inorganic sources, especially nitrate. Nitrate of

potash or soda to supply 15 to 20 pounds of nitrogen per acre is frequently ben:-

fl.ial during periods of cold, wet weather, as a supplement to the regular ferti-

lizer program.

In warmer weather, especially when considerable rainfall is expected, a great-

er percentage of the nitrogen should be furnished from ammoniacal and organic

sources to reduce leaching losses. Organic nitrogen requires time to become a-

vailable, however, and applications made near the flowering sta-e may be only

partly available before flowers are cut. Special care should be exercised with

the placement of fertilizers containing organic nitrogen to be sure that the

fertilizer will be in contact with moist soil since moisture is necessary for

the breakdown process.

The effect of rainfall on fertilizer practices is discussed under other sec-

tions of this report, but it should be emphasized that during long dry periods

special care must be taken to insure that sufficient moisture is present to dis-

solve the fertilizer. Otherwise, it may lie dormant and several applications

may accumulate to become available at the same time following a good rain, with

undesirable effects. Irrigation and placement methods should be coordinated to

insure the fertilizer coming in contact with moist soil.

III. Quality of Irrigation Water.

Very little work has been done on this subject as it pertains to gladiolus,

but it would be well to discuss it briefly on the basis of available information.

The total salt content of irrigation water should be below 1800 ppm for best

results. If possible, it is better to use wells with high salt content in the

late su.mimeb and early fall and those with lower salt content in the winter and

spring since rain in August, September and October will leach salts and also

mrke it unnecessary to irrigate so often.

The chemical nature of the salts in the water has a bearing on fertilizer

practices to be employed. Large amounts of sodium and chloride are especially

undesirable. The effects of calcium, magnesium, sulfate, and bicarbonate ions

are not as serious. To compensate for high sodium, the grower should broadcast

1000 pounds of gypsum per acre to prevent an unbalance in calcium nutrition. The

general level of potassium and magnesium required will also be increased somewhat

since sodium competes both in the soil and in the plant with these elements.

TV. Diseases

The degree of damage resulting from Fusarium bulb rot is affected by ferti-


lizer practices and this should be considered in planning the fertilizer program.

High levels of nitrogen will increase the incidence and severity of Fusarium

bulb and neck rot. Certain sources of organic nitrogen, such as blood tankage,

mixed in the bed will have an especially bad effect. Low levels of phosphorus

will also increase the attack of Fusarium. Theoretically, calcium and potassium

in good supply should decrease the susceptibility while high chloride should

increase it. Other diseases attacking bulbs and leaves are probably also made

worse by high levels of nitrogen and ameliorated by the presence of adequate

calcium and potassium.

Since Fusarium bulb rot is the most serious disease problem, the nitrogen

supply must be limited in order to prevent undue effect. Any normal fertilizer

program involving the use of not more than about 80 to 100 pounds of nitrogen

per acre in a crop season should not cause undue loss unless the soil provides

large amounts of nitrogen. If a good muck soil is planted to gladiolus, it is

advisable to use no nitrogen in the fertilizer except under cold and wet condi-


Gladiolus plants, especially from planting stock and bulblets, have an im-

portant nitrogen requirement, and, in order to realize the best crop, adequate

nitrogen must be supplied. If heavy leaching losses occur, it is advisable to

repeat the application of fertilizer. When Fusarium is not a serious problem,

d'e to varietal resistance or clean bulbs and soil, the grower may fertilize

more liberally with nitrogen so long as he maintains the calcium and potassium

at a good level.

Special Disorders
1. Bud rot. We have experimental evidence that physiological bud rot may be caused

by relatively low calcium content of the spikes. Preventive measures include (1)

adequate liming, (2) avoiding a nutritional imbalance due to excess magnesium, po-

tassiam, sodium, or nitrogen, (3) spraying with 4 pounds of calcium nitrate per

hundredd gallons of water two to four times between the stage spikes first begin to

slip and the time flower cutting starts, and (4) broadcasting 1000 pounds of gypsum


per acre before planting.

2. Topple of Gladiolus, the breaking over of spikes as they open in vases, is

caused by low calcium content of the spikes and may be largely prevented by the

methods used for bud-rot control above.

3. Iron Deficiency is identified by a yellowing of new leaves, especially the

fourth to seventh leaves. Spikes will also be yellow or pale green-;. 'If:the condi-

tion is severe, the first to the third leaf may also be affected. Iron deficiency

is found mostly on older soils that have a history of copper accumulation. Control

measures include adequate liming, to the pH range 6.0 to 6.5 before planting and

soil treatment with iron ethylene diamine tetracetic acid (iron EDTA) at the rate

of 20 pounds active ingredient per acre at the time the deficiency is found. This

material, with trade names of Sequestrene and Versene, should be worked into moist

soil. If severe iron deficiency is expected on the basis of the history of the

soil, it is well to include 20 to 30 pounds of iron EDTA per ton of fertilizer to

be used in all applications before flower harvest.

4. fCopper deficiency is encountered principally on new land. This deficiency is

identified by an abnormal wilting of leaves, especially noticeable in Valeria. Con-

trol methods involve broadcasting 20 to 40 pounds of copper sulfate per acre on new

land before planting. The heavier rates are to be used on soils with greater or-

ganic matter content. If the deficiency develops during the growing season, a

sicZdress fertilizer application supplying 10 pounds of copper sulfate per acre

shoJld be made.

5 B7ron deficiency is recognized by a characteristic notching on edges of leaves

anid by translucent streaks along the veins of Hopman's Glory variety. The deficien-

cy is more likely to occur in the one to three-leaf stage and may result from an

abnormally low boron reserve in the bulb. In addition to having 0.2 percent borax

in the fertilizer, the grower may spray with 1 1/2 pounds of borax in 100 gallons

of water 2 or 3 times if boron deficiency symptoms are found. It is reported, how-

ever, that spraying too frequently with borax may cause brittle spikes. Borax is

very easily leached from the soil which makes repeated applications of borated fer-


tilizer necessary. Less than about 15 ppm boron in recently matured gladiolus

leaves is an indication that boron may be a limiting factor.

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