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Group Title: Agronomy research report - University of Florida Institute of Food and Agricultural Sciences ; AY 89-10
Title: Crop nutrition investigation of an on-farm problem with peanut in Columbia County, Florida in 1988
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Permanent Link: http://ufdc.ufl.edu/UF00056082/00001
 Material Information
Title: Crop nutrition investigation of an on-farm problem with peanut in Columbia County, Florida in 1988
Physical Description: 15, 8 leaves : ; 28 cm.
Language: English
Creator: Stocks, Glenn Ralph, 1963-
Gallaher, Raymond N
Whitty, E. B.
University of Florida -- Agronomy Dept
Publisher: Agronomy Department, IFAS, University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 1989?
 Subjects
Subject: Peanuts -- Field experiments -- Florida -- Colombia County   ( lcsh )
Peanuts -- Soils -- Florida -- Colombia County   ( lcsh )
Genre: bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references (leaves 14-15).
General Note: Agronomy research report - University of Florida Institute of Food and Agricultural Sciences ; AY 89-10
Statement of Responsibility: by G.R. Stocks, R.N. Gallaher, and E.B. Whitty.
 Record Information
Bibliographic ID: UF00056082
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 62412971

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I. 6Library


FEB 28 199C
AGRONOMY RESEARCH REPORT AY-89-10|




Crop Nutrition Investigation of an On-Farm Problem with
Peanut in Columbia County, Florida in 1988


By

G. R. Stocks, R. N. Gallaher, and E. B. Whitty
Graduate Research Assistant and Professors of Agronomy,
respectively, Agronomy Department, Inst. of Food and Agriculture
Science, Univ. of FL, Gainesville, FL 32611.


Abstract

Peanut (Arachis hyvDoaea L.) is sensitive to nutrient
imbalances. Zinc is an essential micronutrient but can be toxic
to peanuts in any but small quantities. Zinc toxicity is usually
not a problem when proper pH and nutrient balances are maintained
in the soil, however, when Zn does accumulate in high levels the
result is severe necrosis and stunting with devastating yield
loss and even death of plants. Problem areas were identified in
a grower's field that had symptoms resembling Zn toxicity. The
stem tissue was split at the base of the plant and plants were
chlorotic, necrotic, and severely stunted. The affected areas
were small and elliptical in shape with an abrupt change from
stunted plants to healthy plants over a 1 m distance. Whole
plant samples were taken from the affected areas and areas that
had no visual symptoms near the affected spots. The whole plant
samples were partitioned into stem, leaf, root, and seed parts.
Also, leaves were picked from the top of the plant (youngest
mature leaves), middle of the plant (most recent fully expanded
leaves) and base of the plant (oldest leaves). Soil samples were
taken from the sample rows at depths of 0-15 cm and 15-30 cm.
All plant tissue and soil samples were analyzed for N, P, K, Ca,
Mg, Cu, Fe, Mn, and Zn for evaluation of any imbalances. From
the soil test results it was found that the stunted plant areas
had lower concentrations of N, P, K, Mg, Ca, and Mn. The stunted
areas had appreciably higher levels of Fe and Zn. The soil Zn
was above the critical level for toxicity. The plant tissue
mineral analysis revealed that although the healthy plants did
not have optimum concentrations of all nutrients, the levels were
more balanced than those for the stunted plant tissue. The
stunted plant leaf tissue from the whole plant samples had a Zn






concentration of 255 mg kg'1 which was well above the critical
range for toxicity. Most of the nutrient levels for the stunted
plant tissue were out of the sufficiency range. The data
indicates that Zn toxicity was caused by an imbalance of the
other nutrients in the soil of the affected areas and Fe
deficiency occurred due to excessive Zn uptake which made the Fe
unavailable in the plant.
Literature Review

Zinc is a micronutrient that functions in the plant as a
metal activator of many enzymes (Tisdale and Nelson, 1975). Like
most micronutrients Zn is toxic to plants in any but small
quantities. Zinc toxicity is not a major problem to peanut
growers, but to the producers that do have a Zn toxicity problem,
the results are devastating. Practically no yield resulted from
a three ha field of peanut (Arachis hvypoaea L.) in Columbia
County, Florida in 1988. The soil in this field had a low pH and
high Zn levels and the peanut plants were stunted throughout
their growth (personal communication with Mr. Bill Thomas,
Columbia County, FL Extension Agent).

Zinc toxicity occurs over a wide array of crops. In South
Carolina, cotton (Gossypium hirsutum L.), soybean (Glycine max
L.), and peach (Amygadalus persica L.) trees did not grow
normally on Coastal Plain soils following the removal of old
peach trees (Lee and Page, 1967). High Zn levels in the soil
were due to use of Zn-containing fungicides on the peach trees.
In areas where the old trees were burned, the cotton grew
normally. The fact that cotton grew normally was attributed to
the ash from the trees raising the soil pH to 7.0.

Polson and Adams (1970) found that navy bean (Phaseolus
vulqaris L.) displayed extreme Zn toxicity symptoms when grown in
a nutrient solution containing 5 mg kg'1 of Zn. Furthermore,
interaction studies with other micronutrients revealed that
increased Cu and Fe concentrations decreased Zn concentrations in
the root and leaf tissue. Increasing Zn concentration increased
the Fe and Cu concentration in the roots, but decreased Fe and Cu
in the leaves. They speculated that Zn affected Cu and Fe
translocation, and Cu and Fe interfered with Zn uptake.
Increased soil Zn was also found to increase Mn concentration in
barley (Hordeum vulgare L.) plants (Singh and Lag, 1976).

Rogers and Wu (1948) evaluated Zn uptake of oat (Avena
sativa L.) as affected by lime and phosphate application. They
found that Zn concentration in plant tissue was highest at the
lowest phosphate rates and higher rates of P caused a significant
decrease in Zn concentration in the barley plant tissue. The
application of lime did not increase soil pH greatly, but did
significantly decrease Zn concentration in the barley tissue.
Gall and Burnette (1940) found that use of calcium carbonate on





sandy soil types increased the soil concentrations at which Zn
was harmful to corn (Zea mays L.).

Keisling et al. (1977) examined Zn toxicity of peanut in
both field and greenhouse studies. They found that pod yield
began to decline at soil Zn concentrations greater than
8 mg kg'1. Zero pod yields resulted at soil Zn levels of
9 mg kg' and greater due to the severe necrosis associated with
Zn toxicity. Zinc toxicity occurred at about 200 mg kgI of Zn
in plant tissue (whole plant samples) in both greenhouse and
field studies. There was a significantly higher soil Zn
concentration in affected peanut plots (24.9 mg kg-1) than in
unaffected peanut plots (5.3 mg kg'1). They concluded that the
critical values for Zn toxicity on peanut plants were 12 mg kg"
and 220 mg kg-1 for soil Zn and plant tissue (whole plant
samples) Zn, respectively. Their Zn critical values confirmed
those suggested by Jones (1974). Keisling et al. (1977)
cautioned that soil pH influenced Zn uptake so greatly for the
same Zn soil values that the soil test values for Zn should not
be used alone in predicting Zn toxicity. They suggested that
maintaining a higher pH in acid, sandy soils might help reduce Zn
toxicity to peanuts.

Burkhart and Page (1941) sampled peanut plant parts at three
stages of growth. They found that at early fruiting stage K
concentration increased from the lowest to the top leaf
positions. Calcium and Mg concentrations decreased from top to
bottom leaf positions, while P concentrations did not vary
appreciably by leaf position.

Hallock and Martens (1974) evaluated the nutrient
concentrations in leaves for 10 peanut cultivars. The mineral
concentration ranges for the top leaves of the 10 peanut
cultivars are as follows:

P 2.2 to 2.6 g kg"1
K 14.0 to 20.8 g kg"
Ca 25.6 to 29.0 g kg'
Mg 4.9 to 7.3 g kg'
Mn 24.0 to 32.0 mg kg"
Zn 22.0 to 26.0 mg kg-
Cu 5.8 to 6.7 mg kg-"

The peanuts displayed no nutrient deficiency symptoms and soil
test levels of the respective minerals would indicate good soil
growing conditions. One would expect the above concentrations to
be typical of peanuts grown in a proper environment.

Hallock et al. (1969) studied the concentrations of B, Cu,
Mn, and Zn during the growing season of three market type
peanuts. The soil pH was low at 5.4, but the soil micronutrient
levels were also low for Cu (0.6 mg kg'1), Mn (4.4 mg kg'1), and






Zn (0.8 mg kg-1). Consequently, despite the low pH, the
concentrations of Cu, Mn, and Zn were not excessive in the leaf
tissue due to the low levels in the soil.

Materials and Methods

The peanut cultivar 'Florunner' was planted on June 11, 1988
on the producer's farm in Southern Columbia County, Florida. The
seed were planted at a rate of 123 kg ha'1 with a row spacing of
0.92 m. The soil type was a Bonneau fine sand (loamy, siliceous,
thermic Arenic Paleudult). Prior to planting the soil was turned
with a moldboard plow and disked three times. With the third
disking benefin [N-Butyl-N ethyl-a,a,a-trifluoro-2,6-dinitro-P-
toluidine], and metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-
N-(2-methoxy-l-methylethyl) acetamide] were incorporated at rates
of 1.4 and 2.8 kg a.i. ha respectively. Also 250 kg ha"' of
both fertilizer grades 0-7-28 and 3-9-18 were incorporated with
the final harrowing. No lime was applied to the field. After
planting alachlor [2-Chloro-2-'6'-diethyl-N-(methoxymethyl)-
acetanilide] and chloramben [3-Amino-2,5-dichlorobenzoic acid]
were broadcast at rates of 2.8 kg a.i. ha-', respectively.
Carbofuran [2,3-Dihydro-2,2-dimethyl-7-benzofuranyl
methylcarbamate] was applied over the row at planting at a rate
of 4.5 kg a.i. ha Gypsum was applied at the early flower
stage at the rate of 500 kg ha"1.

The experimental design used in this study was a split plot
design with four replications. Main plots were always healthy or
stunted peanut plants, but sub-plots were either plant parts
(stem, leaf, root, pods), leaf position (top, middle, bottom), or
soil depth (0-15 cm, 15-30 cm). In the plant parts study 1 m of
row was taken from the healthy and stunted plant areas of the
field. Each plant was separated into its component parts,
leaves, stems, roots, and pods. Leaves were also taken from
healthy and stunted plants by position on the plant. The top
leaves were the most recently developed leaves at the top of the
plant. The middle leaves were the most recently fully expanded
leaves and occurred below the top leaves. The old leaves were
taken from the bottom of the plant on the main stem. Soil
samples were taken from the rows where the whole plant samples
were acquired. One sample was taken from the upper 15 cm of soil
and the soil probe was inserted into the same hole to take a core
from the 15 to 30 cm depth of soil. The soil samples were air
dried and screened before being analyzed. The soil sample
minerals were extracted by the double acid procedure described by
Mehlich (1953). The minerals were then analyzed by the IFAS
Extension Soil Testing Laboratory using an Inductively Coupled
Argon Plasma Soil Analyzer (ICAP). Phosphorus concentration was
determined by colorimetry, K by flame emission spectrophotometry,
and Ca, Mg, Cu, Mn, Fe, Zn, and Al by atomic absorption
spectrophotometry. Organic matter and pH were tested by
procedures defined by Rhue and Kidder (1983). Nitrogen






concentration of the soil was determined by taking a 2.0 g
sample, adding 3.2 g of a prepared catalyst (9:1 2S04:CuS04) and
10 ml of H2SO4, and vortexing the solution in a 100 ml Pyrex
test-tube. The solution was then loaded onto an aluminum
digester block (Gallaher et al., 1975) and digested at 370 C for
3.5 hours. During the digestion period 2 ml of 30% H202 was
added in small increments to prevent excessive foaming due to the
reaction. The tubes were capped with small funnels allowing
evolved gases to escape while preserving the reflexing action.
After cooling, the digested solutions were vortexed with
approximately 50 ml of deionized water, allowed to re-cool for
two hours, then brought to 75 ml volume. Nitrogen was analyzed
on a Technicon Autoanalyzer II system (manifold,colorimeter)
linked to an automatic Technicon Sample Pump III; N was trapped
as NH4SO4. A standard of known N concentration was used as a
control for the procedure. After the plant samples had been
separated all tissue was tripled washed in deionized water. The
washed samples were then placed in paper bags and dried at 70 C
for 48 hours in a forced air dryer. The whole plant samples were
weighed by individual parts on a Mettler PN2210 top-loading
scale. All dried plant tissue was ground in a Wiley mill using a
2 mm stainless steel screen. The ground samples were stored in
plastic Whirl-Pak bags. Plant sample P, K, Ca, Cu, Zn, Mn, and
Fe concentrations were determined by ashing 1.00 g of plant
material in a muffle furnace at 480 C for six hours. The ashed
samples were diluted with 10 ml of deionized H20 and 2 ml of
concentrated HC1. The solution was boiled to dryness on a hot
plate. The water:acid procedure was repeated and dried residue
was suspended in deionized H20, then brought to a 100 ml volume
for a solution strength of 0.1 N HC1. The solutions were
analyzed for minerals by the IFAS Extension Soil Testing
Laboratory. Solution P concentrations were determined by
colorimetry, K concentrations by flame emission
spectrophotometry, and Ca, Mg, Cu, Fe, Mn and Zn concentrations
by atomic absorption spectrophotometry using a Perkin-Elmer
Atomic Absorption Spectrophotometer. Plant tissue N
concentrations were analyzed identical to soil N except 0.1 g of
plant tissue was used and two glass beads were put into the test
tubes to prevent foaming.
Results

Soil Tests

The soil samples revealed some interesting differences
between the soils which supported the healthy and stunted peanut
plants. Table 1 shows the organic matter, pH, and Al
concentration of the soil. There are no striking differences in
these measures. The pH was lower than what is recommended for
peanuts, but was not low enough to usually cause significant
problems. The macronutrient concentrations in the soils (Table
2) of the healthy and stunted peanuts reveal some striking






differences. All macronutrient concentrations tended to be
lower, although not statistically significant at the 0.05 level
of probability, in the soils where the stunted plants were
growing. Neither soil was agronomically adequate in nutrient
balance but the healthy peanut soil areas certainly would provide
more nutrients than the soils taken from the stunted peanut soil
regions. The soil samples used in this study were taken no more
than two or three meters apart. Table 3 shows the concentrations
of the micronutrients for respective treatments. There were no
differences in the Cu levels. The Mn concentration of the upper
15 cm of soil in the healthy peanut areas was significantly
higher than the stunted peanut soils. The Fe and Zn
concentrations were significantly higher in the stunted peanut
soil areas. In both soil areas the Fe levels declined as soil
depth increased. The Zn concentration increased slightly with
soil depth in the stunted peanut areas, but declined with depth
in the healthy peanut regions. The Zn concentration in the
stunted peanut soils was above the critical level of 9 mg kg"
found by Keisling et al. (1977) that was found necessary to
induce a Zn toxicity on peanuts in field situations. The fact
that these problem areas in the field are of such small size and
have an abrupt boundary would indicate that this is not a natural
phenomenon. The discrepancies in the soil test levels would
suggest that the differences were induced by some practice on the
field over its history. The history of the field is not known,
but it can be speculated that these areas in the field were used
to feed and shelter swine which could partially explain the high
levels of Zn and Fe due to precipitation rundown from the
galvanized metal feeders and/or shelters.

Plant Parts

The macronutrient concentrations (Table 4) for plant parts
reveal that there was an interaction between plant parts and
plant status. The N concentration was higher in the leaf tissue
of the healthy plants, but stem and root tissues were not
different. It should be noted, however, that the stem and root
tissue of the stunted plants had a higher N concentration. This
result would imply a translocation inhibition in the stunted
plants due to the lack of growth which would result in dilutions
of the elements. The plant parts were inherently different in
their nutrient composition and the data show that the leaves were
higher in N concentration while root and stem tissues were not
different for either stunted or healthy tissue.

The Ca concentration followed the same trends as the N
results. The healthy leaves were higher in Ca than the stunted
leaf tissue. Root and stem Ca levels were not different between
plant status treatments. The healthy plant stem and root tissues
were not different in Ca composition, but stem tissue was
slightly higher. The root tissue in the stunted plants was






higher in Ca than the stem tissue implying again translocation
inhibition from lack of normal growth.

Healthy plant leaf Mg concentration was higher than the
stunted peanut leaves. Stem and root tissues were essentially
equal in Mg concentration between healthy and stunted plants and
between the plant parts.

The leaf K level was higher in the healthy plant tissue.
Stem and root K concentrations were not different between plant
status treatments. The healthy root K level was lower than leaf
or stem tissue which would be expected because K is a mobile
element. The stunted plant parts K levels were not different
which indicated the plant was not mobilizing K to the necessary
parts.

The P concentrations for plant parts reversed the results
from the other macronutrients in that stunted plant leaf tissue
was higher than healthy leaf tissue. Stem and root tissue from
stunted plants were also higher than the respective healthy plant
parts. However, the fact that all other macronutrients were
below the sufficiency range for the stunted plants would indicate
an imbalance in the plants skewed toward P.

The micronutrient concentrations for the plant parts
(Table 5) reveal that Fe, Cu, and Mn were within the sufficiency
range for leaf tissue (Jones, 1974). There was a significant
interaction between plant parts and plant status for Cu and Mn.
The stunted plant leaf Cu levels tended to be higher than the
healthy plants, but statistical significance was not observed at
the 0.05 level of probability. Stem Cu concentrations were not
different between plant status treatments, but the stunted plant
roots were higher in Cu. No differences were observed between
leaf Mn concentrations. Stem and root tissues for the stunted
plants were higher in Mn than the healthy plants.

The Fe concentration was not different between the healthy
and stunted plants. The leaf tissue was higher in Fe than the
stem or root tissue in both stunted and healthy plants. No
differences between the stem and root tissue were observed.

Zinc concentration for stunted plant tissue was higher than
the Zn levels found in the healthy plant parts. The leaf and
stem Zn concentrations was higher than the root tissue, while
there were no differences between leaf and stem tissue. Both
plant status treatments had excessively, high Zn concentrations
in the leaves.

Leaf Position

Table 6 displays the macronutrient concentrations for the
three leaf positions evaluated in this study. There was an






interaction between plant status and leaf position for N, Mg, K,
and P. No interaction was observed for Ca.

The Ca level found in the leaf tissue of the healthy plants
was higher than Ca levels of stunted leaves. Between leaf
positions, Ca was highest in bottom or oldest leaves and lowest
in the top or youngest leaves. The middle leaves were
intermediate in Ca concentration and were not different in
concentration from bottom or top leaves. Bottom leaves were
higher in Ca than top leaves. Jones (1974) defined the
sufficiency range for Ca of the upper most mature peanut leaves
to be 12 to 20 g kg'1. In our study the middle leaves were the
upper most mature leaves. The healthy plants middle leaves were
within the sufficiency range at 15.2 g kg'" Ca while the stunted
plant middle leaves were below the range at 9.6 g kg" .

Nitrogen is a mobile element and would be expected to be in
higher concentrations in the top of the peanut plant. In the
healthy plants the top and middle leaves were essentially equal
in N concentration and were higher in N levels than the bottom
leaf tissue. The stunted plants displayed no differences between
leaf positions. The upper leaf tissue was slightly higher than
the bottom leaf tissue, but the differences were not of the
magnitude expected for N. Between plant status treatments, the
top and middle leaves of the healthy plants had higher N
concentrations than did the respective stunted plant leaves. The
healthy plant bottom leaves tended to be higher in N than the
stunted plant bottom leaves but was not significant at the 0.05
level of probability. Jones (1974) gave the sufficiency range
for N of peanut leaves to be 35 to 45 g kg'. Neither healthy
nor stunted plant middle leaves were within this range, but the
healthy plant leaves were nearer the range than the stunted plant
leaves.

Magnesium is also a mobile element in plants. The healthy
plants leaves had Mg levels that ranged from highest in top
leaves to lowest in bottom leaves with top leaves being higher
than the middle or bottom leaves. The stunted plant leaves had
the reverse trend. The bottom leaves had the highest Mg
concentration and the top leaves had the lowest Mg concentration.
The bottom and middle leaves of the stunted plants were higher in
Mg concentration than the top leaves. All leaf positions of the
healthy plants were significantly higher in Mg when compared to
the respective leaf positions of the stunted plants. Jones
(1974) gave the sufficiency range for Mg of peanut leaves to be 3
to 8 g kg-1. Both healthy plant leaves (4.43 g kg'1) and stunted
plant leaves (3.03 g kg"') were within this range, but the
stunted plants leaves had the reverse concentration trend than
would be expected indicating a mobilization problem.

The K concentrations of the healthy plant leaves showed that
the top leaves were higher than the middle leaves, but were not






different from the bottom leaves, while the middle and bottom
leaves were not different as well. Potassium is a mobile element
and would be expected to be highest in the upper leaf issue. The
K concentrations measured in the stunted plant leaves were
essentially the some for all leaf positions. Between plant
status treatments, top and bottom leaves of healthy plants were
higher than the same leaves of the stunted plants. No
differences were observed between the middle leaves of healthy
and stunted plants. The sufficiency range for K in peanut leaves
is 20 to 30 g kg1 (Jones, 1974). Both healthy (15.7 g kg') and
stunted (13.1 g kg ) plant middle leaves were well below this
sufficiency range.

The P concentration of healthy plant leaves was highest in
top leaves and lowest in bottom leaves with differences among all
three leaf positions. The top and middle leaves of the stunted
plants were essentially the same in P concentration and were
higher than the bottom leaves. The top leaves of the healthy
plants were higher in P than the respective top leaves of the
stunted plants, but no differences were observed in the middle
and bottom leaves. The sufficiency range for P in Peanut leaves
is 2.5 to 5.0 g kg'" (Jones, 1974) and the healthy plant leaves
were within the range at 2.60 g kg1 while the stunted plant
middle leaves were just below this range at 2.42 g kg.

Table 7 gives the micronutrient concentrations measured in
the top, middle, and bottom leaf tissues from the healthy and
stunted plants. An interaction between plant status and leaf
position was detected for Mn.

The Mn concentrations were highest in the bottom leaf tissue
and lowest in the top leaf tissue for both healthy and stunted
plants. In both healthy and stunted plants differences were
observed between the top, middle, and bottom leaf positions. The
top and middle leaf positions of the healthy plants were higher
than the same leaf positions of stunted plants. No differences
were found between bottom leaves of healthy or stunted plants.
The sufficiency range for Mn of peanut leaves is 50 to 350 mg
kg'. Both healthy (107.0 mg kg ) and stunted (87.5 mg kg )
plant leaves were sufficient for Mn.

The stunted plant leaves were higher in Fe concentration
than the healthy plant leaves. The bottom leaves were higher
than top or middle leaf positions in Fe concentration. The
sufficiency range for Fe was given to be 50 to 300 mg kg-1
(Jones, 1974). Both healthy (77.1 mg kg'') and stunted (79.5 g
kg-') plant middle leaves were sufficient in Fe.

Copper levels of healthy plant leaves were higher than
leaves of stunted plants. No differences between leaf positions
were observed. The sufficiency range for Cu in peanut leaves has
not been determined, but Jones (1974) stated that it probably





should be greater than 5 mg kg'. Both healthy and stunted plant
middle leaves contained Cu levels of 4.75 mg kg'" which is
slightly below the critical point suggested by Jones (1974).
Zinc concentration were higher in stunted plant leaves.
Comparison of leaf positions revealed that the bottom leaves were
higher in Zn than middle leaves and middle leaves were higher in
Zn than top leaves. The sufficiency range for Zn in peanut
leaves is 20 to 50 mq kg"'. Both healthy (112.5 mg kg'') and
stunted (205.1 mg kg ) plant middle leaves were well above this
Zn range. Zinc was the only nutrient analyzed which was above
the sufficiency range.

Plant Part Yield

There were extreme differences in the visual appearances of
the healthy and stunted peanut plants in the field. The healthy
plants had a full canopy and vigorous growth was apparent. The
stunted plants had no plant canopy and growth was severely
retarded. Table 8 gives the yields of the plants parts taken
from the whole plant samples. The results confirm the visual
observations in the field. All parts of the healthy plants are
higher in yield than the respective parts of the stunted plants.
The total plant yield was also higher for healthy plants.

Discussion

Soil Test

The soils which supported the growth of both healthy and
stunted plants were sandy in nature and slightly acidic for
peanut production. The soil test results reveal that at the time
of sampling the soils were low in nearly all elements essential
for proper peanut development. .The soil was not limed prior to
planting which can explain in part the low pH and low Mg and Ca
concentration in the soil. Gypsum was applied to the peanuts so
Ca should not have been low. The exact rainfall amounts were not
known, but excessive precipitation did occur during July and
August which likely leached out mobile elements in the soil such
as Mg, K, and N.

The micronutrients Fe and Zn were in high concentrations in
the soil. The history of the field used in this study was not
known, but it is speculated that swine may have been raised in
this field at some point. If so, galvanized feeders and/or
shelters may have been placed to feed and shelter the animals and
precipitation would have removed Fe and Zn from the metals. The
combination of low levels of the macronutrients in the soil with
the high Fe and Zn concentrations could have caused imbalances in
plant uptake of nutrients.

Plant Parts






Because of the functional nature of nutrients in plants and
the inherent differences in the role plant parts play in the
growth of the plant, leaves, stems, and roots tend to have
varying concentrations of minerals. The roots are the major site
of nutrient uptake, and the leaves are the major site of nutrient
assimilation to functional compounds. The nutrient balance in
the soil plays a tremendous role in the mineral concentrations in
the plant.

In this study, the healthy and stunted plant areas were
growing in soils that contained less than a desirable balance of
nutrients. The healthy plants were growing in soils that were
slightly more agreeable to crop production. The slightly better
nutrient balance in the soil which supported the healthy plants
made a difference in the mineral status of the plant parts. In
our study, the healthy plants consistently had a better nutrient
balance between plant parts. The macronutrient levels in the
healthy plant parts were higher for all mineral except P. The
higher macronutrient levels corresponded directly with the soil
test results which showed healthy plant area soils to be higher
in all macronutrients except P. The P concentrations were
essentially equal. The P concentrations were higher in stunted
plant parts. This likely is a result of the gross macronutrient
imbalance in the soil in which the stunted plants were growing.

The micronutrient accumulation in plant parts followed
closely the levels in the soil as well, with the exception of Mn.
The Fe concentrations found in the soils supporting the stunted
plants were higher than the healthy plant area soils. Although
statistical significance was not observed at the 0.05 level of
probability between healthy and stunted plant part Fe levels, the
stunted plants tended to be higher in Fe. Zinc was much higher
in the stunted plant soils. The plant parts of the stunted
plants were much higher in Zn concentration. Soil Mn levels were
higher in healthy plants, but plant Mn was higher in the stunted
plants.

Micronutrient tend to be taken up in small amounts, but when
the macronutrients are lacking coupled with a low pH,
availability of micronutrient to the roots is increased. Most
micronutrients are not as readily leached as macronutrients and
the combination of high precipitation, low pH, and relatively
high soil micronutrient levels most likely caused the imbalance
in uptake.

Leaf Position

The leaves of a plant tend to reflect the growing status of
that plant. When there are nutrient imbalances the leaves
usually will show it first. In evaluating nutritional problems,
the leaves are most often used for diagnosis.






The leaves of the healthy and stunted peanut plants in this
study reflected the problems that occurred. The soil levels of
nutrients once again played a significant role in the leaf
position mineral nutritional status. The macronutrients were
lower in the soils supporting the stunted plants and consequently
the leaves are lower in macronutrient concentration.

The mobile elements N, Mg, and K tended to be higher in the
upper leaves, but in the stunted plants no differences in these
nutrients by leaf position were observed indicating a
translocation inhibition or lack of dilution associated with
normal growth. Also, the concentrations of the macronutrients in
the stunted plant leaves were not adequate for proper growth
which could be a causal agent in the poor growth and nutritional
status. The Mg concentration was lowest in the top leaves of the
stunted plants and highest in the top leaves of the healthy
plants. The low Mg concentration of the stunted plant leaves
could be affecting the photosynthesis of the stunted plants
because Mg is the center of the chlorophyll molecule.

The micronutrient levels in the leaves of both healthy and
stunted plants were adequate for proper growth with the exception
of Zn. The soil Zn levels of the stunted plant areas were above
the range set by Keisling et al. (1977) to cause excessive Zn
uptake. Consequently, the leaves had excessive Zn
concentrations. The peanut plants in the stunted areas displayed
the standard Zn toxicity symptoms e.i. lesions on basal stem,
stunting, and chlorosis. The Zn concentrations in the leaves of
the stunted plants were in excess of the 220 mg kg- critical
point found by Keisling et al. (1977) to cause a Zn toxicity to
peanuts. Certainly, this was a Zn toxicity, but the chlorosis
appeared to be an Fe deficiency. The Fe level in the leaves of
the stunted plants were adequate for proper growth, but it has
been found that excessive Zn uptake will induce Fe deficiency
even though the Fe status in the leaves is adequate (Olsen,
1972).

Conclusions

The soils supporting growth for both healthy and stunted
plants were low in the major nutrients required for proper
growth. The soils where stunted plants were grown had lower soil
test levels for macronutrients. The stunted plants displayed
symptoms resembling Zn toxicity and Fe deficiency. The soil test
levels of Zn exceeded the critical levels for Zn toxicity. Zinc
concentrations in the leaves of stunted peanut plants also
exceeded critical values for toxicity. The Fe concentration of
the stunted plant leaves were adequate for proper growth, but the
high Zn levels induced the deficiency.









Recommendations


If peanuts are to be grown in this field again, the soil
fertility should be amended so that the soil has a better balance
of nutrients for proper peanut growth. As for the stunted peanut
plant spots in the field, it may be necessary to treat these
separately. Phosphorous is known to tie up Zn in the soil
therefore applying triple super phosphate to the high Zn areas
may sufficiently tie up the Zn to allow proper peanut growth.










Literature Cited


Burkhart, L., and N. R. Page. 1941. Mineral nutrient
extraction and distribution in the peanut plant.
J. Am. Soc. Agron. 33:743-755.

Gall, O. E. and R. M. Barnette. 1940. Toxic limits of
replaceable zinc to corn and cowpeas grown on three Florida
soils. J. Am. Soc. Agron. 32:23-32.

Gallaher, N., C. O. Weldon, and J. G. Futral. 1975. An
aluminum block digester for plant and soil analysis.
Soil Sci. Soc. Amer. Proc. 39:803-806.

Hallock, D. L., C. Martens, and M. W. Alexander. 1969.
Nutrient distribution during development of three market
types of peanuts. II. -B, Cu, Mn, and Zn contents.
Agron. J. 61:85-88.

Hallock, D. L., and D. C. Martens. 1974. Contents of eight
nutrients in central stem leaf segments of ten peanut
cultivars and lines. Peanut Sci. 1:53-56.

Jones, J. B. 1974. Plant analysis handbook for the Georgia
Cooperative Extension Service, Univ. of Ga., Athens,
Bulletin 735. pp. 21-22.

Keisling, T. C., D. A. Lauer, M. E. Walker, and R. J. Henning.
1977. Visual, tissue, and soil factors associated with Zn
toxicity of peanuts. Agron. J. 69:765-769.

Lee, C. R., and N. R. Page. 1967. Soil factors influencing
the growth of cotton following peach orchards. Agron. J.
59:237-240.

Mehlich, A. 1953. Determination of P, Ca, Mg, K, Na, and
NH4. North Carolina Soil Test Division (Mimeo, 1973).
North Carolina State Univ. Raleigh, N. C.

Olsen, S. R. 1972. Micronutrients in Agriculture.
Chapter 11-Micronutrient interactions. Soil Sci. Soc. Am.
33:743-755.








Poison, D. E., and M. W. Adams. 1970. Differential response
of navy beans Phaseolus vulqaris L. to zinc. I. Differential
growth and elemental composition at excessive zinc levels.
Agron. J. 62:557-560.

Rhue, R. D. and G. Kidder. 1983. Procedures used by the IFAS
extension soil testing laboratory and interpretation of
results. Florida Coop. Extn. Service, Inst. Food and
Agr. Sci., University of Florida. Circular 596.

Rogers, J. H., and Chih-Hwa Wu. 1948. Zinc uptake of oats as
influenced by application of lime and phosphate. J. Am.
Soc. Agron. 40:563-566.

Singh, B. R., and J. Lag. 1976. Uptake of trace elements by
barley from indigenous and applied zinc and the effect of
excessive zinc on the growth and chemical composition of
barley. Soil Sci. 121:32-37.

Tisdale, S. L., and W. L. Nelson. 1975. Soil Fertility and
Fertilizers. Chapter 3-Elements required in plant nutrition.
Macmillan Publishing Co. New York. pp. 93-95.



















Table 1. Mechlich I extractable
and healthy Deanut.


Al, organic matter, and pH of soils with stunted


Soil Depth
0-15 cm
15 30 cm
Mean


---------Plant
Healthy
1.52
1.38
1.45


Status-------
Stunted
1.58
1.41
1.50 NS


0-15 cm 5.80 6.00 5.91 a
15 30 cm 5.80 5.90 5.85 a
Mean 5.80 6.00 NS

0-15 cm 0.20 0.17 0.19 a
15 30 cm 0.21 0.16 0.18 a
Mean 0.20 0.17 NS
Means with the same letter between soil depths are not significantly
different at the 0.05 level. *=0.05, **= 0.01 significance levels
between columns. NS = not significant.


Soil Test
CM
(%)


pH



Al
(g/kg)


Mean
1.55 a
1.39 a











Table 2. Kjeldahl N and Mehlich I extractable Ca, Mg, K, and P in the
soils of stunted and healthy peanut.


Soil
Horizon
0-15 cm
15 30 cm
Mean


-------Plant


I


Healthy
0.44
0.42
0.43


Status-------
Stunted
0.39
0.41
0.40 NS


0-15 cm 0.048 0.045 0.046 a
15 30 cm 0.043 0.044 0.043 a
Mean 0.045 0.044 NS

0-15 cm 0.014 a 0.009 a ** 0.012
15 30 cm 0.011 b 0.011 a NS 0.011
Mean 0.013 0.010

0-15 cm 0.009 0.005 0.007 b
15 30 cm 0.014 0.008 0.011 a
Mean 0.011 0.006 NS

0-15 cm 0.334 0.224 0.279 a
15 30 cm 0.296 0.228 0.262 a
Mean 0.315 0.226 NS
Means with the same letter between soil depths are not significantly
different at the 0.05 level. *=0.05, **= 0.01 significance levels
between columns. NS = not significant


Nutrient
(a/kg)


I


Mean
0.42 a
0.41 a


















Table 3. Mehlich I extractable Cu, Fe, Mn, and Zn in the soils of stunted and healthy
peanut..


Horizon
0-15 cm
15 30 cm
Mean


I


-------Plant
Healthy
0.09
0.09
0.09


Status-------
Stunted
0.09
0.09
0.09 NS


0 -15 cm 8.00 9.50 8.75 a
15 30 cm 7.80 9.10 8.45 a
Mean 7.90 9.30 *

0-15 cm 5.60 a 5.01 a 5.31
15 30 cm 5.03 b 5.01 a NS 5.02
Mean 5.32 5.01

0-15 cm 6.14 9.18 7.66 a
15 30 cm 5.17 9.53 7.35 a
Mean 5.66 9.36 *
Means with the same letter between soil depths are not significantly
different at the 0.05 level. *=0.05, **= 0.01 significance levels
between columns. NS = not significant


Nutrient
(mg/kg)


Mean
0.09 a
0.09 a


I .














Table 4. Concentrations of N, Ca, Mg, K, and P in peanut plant parts.


--------Plant
Healthy
32.1 a
15.4 b
12.7 b
20.1


Status--------
Stunted
22.3 a **
18.5 b NS
16.7b NS
19.1


Mean
27.3
16.9
14.4


Leaf 4.85 a 3.15 a ** 4.01
Stem 2.23 b 2.10 b NS 2.16
Root 1.75 b 1.85 b NS 1.81
Mean 2.94 2.37

Leaf 20.7 a 16.1 a ** 18.4
Stem 18.8 a 16.1 a NS 16.1
Root 12.1 b 13.2 a NS 14.1
Mean 17.2 15.1

Leaf 2.71 a 3.50 b NS 2.86
Stem 2.12 ab 3.59 a 2.65
Root 1.80 b 3.51 a 2.61
Mean 2.21 3.21
Means with the same letter among plant parts for each nutrient
are not significantly different down the column at the 0.05 level.
*= 0.05, **= 0.01 significance levels between columns.
NS = not significant.


Nutrient
(a/kq)

N


Plant
Part
Leaf
Root
Stem
Mean


]


,












Table 5. Concentrations of Fe, Cu, Mn, and Zn in peanut plant parts.

Nutrient Plant --------Plant Status--------
(mg/kg) Part Healthy Stunted Mean


Leaf
Fe Root
Stem
Mean


160.1
88.0
72.1
106.7


200.1
87.5
103.8
130.4 NS


180.0 a
87.9 b
87.8 b


Leaf 5.75 a 8.75 a NS 7.25
Stem 4.75 ab 4.75 b NS 4.75
Root 4.00 b 6.00 b 5.01
Mean 4.83 6.51

Leaf 100.8 a 110.0 a NS 105.4
Stem 31.5 b 58.3 b ** 44.9
Root 26.3 b 40.8 c 33.5
Mean 52.8 69.7

Leaf 145.1 255.1 200.0 a
Stem 81.1 247.5 164.3 a
Root 54.5 187.5 121.0 b
Mean 93.5 230.0 **
Means with the same letter among plant parts for each nutrient
are not significantly different down the column at the 0.05 level.
*= 0.05, **= 0.01 significance levels between columns.
NS = not significant.


|











Table 6. Concentration of N, Ca, Mg, K, and P in peanut leaves by leaf
position.


Nutrient Leaf
(g/kg) Postion
Top
N Mid
Bottom
Mean


I


........Plant
Healthy
34.8 a
33.4 a
25.5 b
31.2


Status--------
Stunted
22.3 a *
23.9 a *
20.4 a NS
22.2


Top 11.1 5.6 8.4 b
Mid 15.2 9.6 12.4 ab
Bottom 18.0 11.8 14.9 a
Mean 14.8 9.0 **

Top 5.35 a 2.33 b ** 3.84
Mid 4.43 b 3.03 a 3.37
Bottom 4.08 b 3.43 a 3.76
Mean 4.62 2.93

Top 20.2 a 12.2 a ** 16.3
Mid 15.7 b 13.1 a NS 14.4
Bottom 17.0 ab 12.7 a 14.9
Mean 17.7 12.5

Top 3.47 a 2.57 a 3.02
Mid 2.60 b 2.42 a NS 2.51
Bottom 2.12 c 2.01 b NS 2.06
Mean 2.73 2.33
Means with the same letter among leaf positions for each
element are not significantly different down the column
at the 0.05 level. *= 0.05, **= 0.01 significance levels
between columns. NS = not significant.


Mean
28.6
28.7
23.1


11












Table 7. Concentration of Fe, Cu, Mn, and Zn in peanut leaves by leaf
position.


Nutrient Leaf
(mg/kg) Postion
Top
Fe Mid
Bottom
Mean


Ii


--------Plant
Healthy
63.3
77.1
117.8
86.1


Status--------
Stunted
73.3
79.5
120.1
90.9 **


Top 4.75 4.75 4.75 a
Mid 4.75 4.75 4.75 a
Bottom 5.01 4.51 4.75 a
Mean 4.83 4.67

Top 80.8 c 63.3 c 72.1
Mid 107.0 b 87.5 b 97.3
Bottom 127.5 a 125.0 a NS 126.3
Mean 105.1 91.9

Top 69.8 112.5 91.1 c
Mid 112.5 205.1 158.8 b
Bottom 260.1 322.5 291.3 a
Mean 147.4 213.3 **
Means with the same letter among leaf positions for each
element are not significantly different down the column
at the 0.05 level. *= 0.05, **= 0.01 significance levels
between columns. NS = not significant.


Mean
68.3 b
78.3 b
118.9 a


















Table 8. Stem, pod, leaf, and root weights from
stunted and healthy peanut plants.

--------Plant Status------
Plant Part Healthy Stunted
(kg/ha)
Stem 2320 a 320 b


Pod 1310 a 20 b


Root 190 a 50 b


Leaf 1660 a 360 b


Total 5470 a 740 b

Means with different letters are significantly different
between columns at the 0.05 level.




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