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 Copyright
 Time of leaf sampling
 Method of leaf sampling
 Results and interpretation
 Application of results
 Analytical laboraties














Group Title: AREC-H research report - Agricultural Research and Education Center-Homestead ; SB-73-1
Title: Leaf analysis as a guide for fertilisation of limes
CITATION PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00067835/00001
 Material Information
Title: Leaf analysis as a guide for fertilisation of limes
Series Title: Homestead AREC research report
Physical Description: 3 leaves : ; 28 cm.
Language: English
Creator: Orth, Paul G
Agricultural Research and Education Center, Homestead
Publisher: University of Florida, Agricultural Research and Education Center
Place of Publication: Homestead Fla
Publication Date: 1973
 Subjects
Subject: Foliar diagnosis -- Florida   ( lcsh )
Limes -- Fertilization -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: Paul.G.Orth, C.W Campbell
General Note: "April 3, 1973"
 Record Information
Bibliographic ID: UF00067835
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 72441208

Table of Contents
    Copyright
        Copyright
    Time of leaf sampling
        Page 1
    Method of leaf sampling
        Page 1
    Results and interpretation
        Page 1
    Application of results
        Page 2
    Analytical laboraties
        Page 2
        Page 3
Full Text





HISTORIC NOTE


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
(EDIS)

site maintained by the Florida
Cooperative Extension Service.






Copyright 2005, Board of Trustees, University
of Florida










S-) LEAF ANALYSIS AS A GUIDE FOR FERTILIZATION OF LIMES


-W) P. G. Orth and C. W. Campbell-


Lime leaves have been sampled and analyzed for nitrogen, potassium, phosphorus, and
magnesium (N, K, P, and Mg) at three locations in the lime production area for almost
ten years. From the data we have developed guidelines for sampling leaves and inter-
pretation of leaf analysis. They are presented here for the use of growers who wish
to use leaf analysis to measure the effectiveness of their fertilizer program.


TIME OF LEAF SAMPLING

Lime leaves should be sampled in June or July, when natural fluctuations in nutrient
concentrations in the leaves are least. (Samples can be taken in May or August if
necessary without sacrificing too much accuracy.) Leaves should be sampled 3 to 4
weeks after a new flush has started when the new leaves have reached full size but
still can be visually distinguished from earlier flushes.


METHOD OF LEAF SAMPLING

Collect a young leaf from the new flush and a mature leaf from the next older flush
* on the same twig or branch as the young leaf. Only one pair of leaves should be
taken from a tree, one young and one mature. Put the young leaves in one bag and the
mature leaves in another to give two samples. Petioles should not be included.
Twenty-five leaves makes an adequate sample but 50 or even 100 trees could be sampled
to get a more representative sample from a large grove. The size of the area sampled
is not critical but trees should be uniform in appearance, age, rootstock, and recent
fertilization history. A grove should be divided into at least two units for sampl-
ing so that any errors in sampling or chemical analysis will be detected.

Wash leaves in distilled water soon after sampling, and dry them in a forced air oven
at 1250F.


RESULTS AND INTERPRETATION

Table 1 lists criticalvalues for N, K, and Mg* in lime leaves an the response ex-
pected from changes in fertilization. I ljqy e mp 4 kfr grove consistently
test less than the critical value and th< t*U~VME )DfiaTed, additional ferti-
lizer should give greater yields. If leaves test higher than the critical value,
more fertilizer may increase yields, but it is less



_.F.A.S.- Univ. of Florida

SAssistant Soils Chemist and Horticulturist, University of Florida, IFAS,
Agricultural Research and Education Center, Homestead, Fla. 33030.

In our experiments P fertilization had little effect on yield or leaf analysis,
but we estimate the critical value for P in young leaves as 0.25% and in mature
leaves 0.15%.


Homestead AREC Research Report SB73-1


April 3, 1973










S-) LEAF ANALYSIS AS A GUIDE FOR FERTILIZATION OF LIMES


-W) P. G. Orth and C. W. Campbell-


Lime leaves have been sampled and analyzed for nitrogen, potassium, phosphorus, and
magnesium (N, K, P, and Mg) at three locations in the lime production area for almost
ten years. From the data we have developed guidelines for sampling leaves and inter-
pretation of leaf analysis. They are presented here for the use of growers who wish
to use leaf analysis to measure the effectiveness of their fertilizer program.


TIME OF LEAF SAMPLING

Lime leaves should be sampled in June or July, when natural fluctuations in nutrient
concentrations in the leaves are least. (Samples can be taken in May or August if
necessary without sacrificing too much accuracy.) Leaves should be sampled 3 to 4
weeks after a new flush has started when the new leaves have reached full size but
still can be visually distinguished from earlier flushes.


METHOD OF LEAF SAMPLING

Collect a young leaf from the new flush and a mature leaf from the next older flush
* on the same twig or branch as the young leaf. Only one pair of leaves should be
taken from a tree, one young and one mature. Put the young leaves in one bag and the
mature leaves in another to give two samples. Petioles should not be included.
Twenty-five leaves makes an adequate sample but 50 or even 100 trees could be sampled
to get a more representative sample from a large grove. The size of the area sampled
is not critical but trees should be uniform in appearance, age, rootstock, and recent
fertilization history. A grove should be divided into at least two units for sampl-
ing so that any errors in sampling or chemical analysis will be detected.

Wash leaves in distilled water soon after sampling, and dry them in a forced air oven
at 1250F.


RESULTS AND INTERPRETATION

Table 1 lists criticalvalues for N, K, and Mg* in lime leaves an the response ex-
pected from changes in fertilization. I ljqy e mp 4 kfr grove consistently
test less than the critical value and th< t*U~VME )DfiaTed, additional ferti-
lizer should give greater yields. If leaves test higher than the critical value,
more fertilizer may increase yields, but it is less



_.F.A.S.- Univ. of Florida

SAssistant Soils Chemist and Horticulturist, University of Florida, IFAS,
Agricultural Research and Education Center, Homestead, Fla. 33030.

In our experiments P fertilization had little effect on yield or leaf analysis,
but we estimate the critical value for P in young leaves as 0.25% and in mature
leaves 0.15%.


Homestead AREC Research Report SB73-1


April 3, 1973










S-) LEAF ANALYSIS AS A GUIDE FOR FERTILIZATION OF LIMES


-W) P. G. Orth and C. W. Campbell-


Lime leaves have been sampled and analyzed for nitrogen, potassium, phosphorus, and
magnesium (N, K, P, and Mg) at three locations in the lime production area for almost
ten years. From the data we have developed guidelines for sampling leaves and inter-
pretation of leaf analysis. They are presented here for the use of growers who wish
to use leaf analysis to measure the effectiveness of their fertilizer program.


TIME OF LEAF SAMPLING

Lime leaves should be sampled in June or July, when natural fluctuations in nutrient
concentrations in the leaves are least. (Samples can be taken in May or August if
necessary without sacrificing too much accuracy.) Leaves should be sampled 3 to 4
weeks after a new flush has started when the new leaves have reached full size but
still can be visually distinguished from earlier flushes.


METHOD OF LEAF SAMPLING

Collect a young leaf from the new flush and a mature leaf from the next older flush
* on the same twig or branch as the young leaf. Only one pair of leaves should be
taken from a tree, one young and one mature. Put the young leaves in one bag and the
mature leaves in another to give two samples. Petioles should not be included.
Twenty-five leaves makes an adequate sample but 50 or even 100 trees could be sampled
to get a more representative sample from a large grove. The size of the area sampled
is not critical but trees should be uniform in appearance, age, rootstock, and recent
fertilization history. A grove should be divided into at least two units for sampl-
ing so that any errors in sampling or chemical analysis will be detected.

Wash leaves in distilled water soon after sampling, and dry them in a forced air oven
at 1250F.


RESULTS AND INTERPRETATION

Table 1 lists criticalvalues for N, K, and Mg* in lime leaves an the response ex-
pected from changes in fertilization. I ljqy e mp 4 kfr grove consistently
test less than the critical value and th< t*U~VME )DfiaTed, additional ferti-
lizer should give greater yields. If leaves test higher than the critical value,
more fertilizer may increase yields, but it is less



_.F.A.S.- Univ. of Florida

SAssistant Soils Chemist and Horticulturist, University of Florida, IFAS,
Agricultural Research and Education Center, Homestead, Fla. 33030.

In our experiments P fertilization had little effect on yield or leaf analysis,
but we estimate the critical value for P in young leaves as 0.25% and in mature
leaves 0.15%.


Homestead AREC Research Report SB73-1


April 3, 1973










Table 1. Guide for interpreting analyses of lime leaves.


Nutrient Leaf Age Critical Value Response Value
(%) (per 100 lbs/A)

N Young 2.4 0.2
Mature 2.3 0.1

K Young 1.5 0.1
Mature 1.4 0.15

Mg Young 0.18 0.01
Mature 0.16 0.02


The response value is the approximate increase in concentration expected in the
leaves with an increase in fertilization of 100 pounds of a nutrient per acre. We
have consistently found that more fertilization with a nutrient will produce a small
increase in the concentration of that nutrient in the leaves. This effect is greatest
below the critical value and decreases as the concentration rises above it.


APPLICATION OF RESULTS

A grower should have leaf sample analyses from two consecutive years before changing
the fertilizer program, unless the results are extremely low. Analyses from two
years frequently differ by 0.1 to 0.2% without any change in fertilization.

With a 2 year history of leaf analysis a grower can make changes in the fertilizer
program and measure response in two ways -- yield and leaf analysis. In time the
grower can determine the relationship between fertilizer, yield, and leaf analysis
and can select the most profitable fertilization rate for his grove.

There is an effect of N fertilizer on K concentration in lime leaves which should be
considered when interpreting leaf analyses. We have found an increase of 100 Ibs
N/A may cause a decrease in K concentration of 0.1% in young leaves and 0.2% in
mature leaves. This effect is not as predictable as the effect of N fertilizer on
leaf N. (Increases in K fertilizer may decrease leaf N, but we have found this to
be a small, unpredictable effect.


ANALYTICAL LABORATORIES

We conclude with a word of caution about analytical laboratories. There are dif-
ferent analytical methods, and results from several good laboratories may differ by
0.1 or 0.2%. Such differences can be crucial when interpreting leaf analyses. In
order to utilize the data in Table 1, it is necessary to determine the correlation
between laboratories by exchanging reference samples. Then Table 1, prepared for our
laboratory, could be revised to apply to methods used by another laboratory.










Table 1. Guide for interpreting analyses of lime leaves.


Nutrient Leaf Age Critical Value Response Value
(%) (per 100 lbs/A)

N Young 2.4 0.2
Mature 2.3 0.1

K Young 1.5 0.1
Mature 1.4 0.15

Mg Young 0.18 0.01
Mature 0.16 0.02


The response value is the approximate increase in concentration expected in the
leaves with an increase in fertilization of 100 pounds of a nutrient per acre. We
have consistently found that more fertilization with a nutrient will produce a small
increase in the concentration of that nutrient in the leaves. This effect is greatest
below the critical value and decreases as the concentration rises above it.


APPLICATION OF RESULTS

A grower should have leaf sample analyses from two consecutive years before changing
the fertilizer program, unless the results are extremely low. Analyses from two
years frequently differ by 0.1 to 0.2% without any change in fertilization.

With a 2 year history of leaf analysis a grower can make changes in the fertilizer
program and measure response in two ways -- yield and leaf analysis. In time the
grower can determine the relationship between fertilizer, yield, and leaf analysis
and can select the most profitable fertilization rate for his grove.

There is an effect of N fertilizer on K concentration in lime leaves which should be
considered when interpreting leaf analyses. We have found an increase of 100 Ibs
N/A may cause a decrease in K concentration of 0.1% in young leaves and 0.2% in
mature leaves. This effect is not as predictable as the effect of N fertilizer on
leaf N. (Increases in K fertilizer may decrease leaf N, but we have found this to
be a small, unpredictable effect.


ANALYTICAL LABORATORIES

We conclude with a word of caution about analytical laboratories. There are dif-
ferent analytical methods, and results from several good laboratories may differ by
0.1 or 0.2%. Such differences can be crucial when interpreting leaf analyses. In
order to utilize the data in Table 1, it is necessary to determine the correlation
between laboratories by exchanging reference samples. Then Table 1, prepared for our
laboratory, could be revised to apply to methods used by another laboratory.








-3-


We are willing to exchange samples with any commercial laboratory to establish cor-
relation values. The Extension Service plans to begin analyzing tissue samples on a
fee basis this year.

Contact your County Extension Agent for further information on sampling leaves,
analytical laboratories, and interpretation of results.





























SB73-1
350 copies




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