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Group Title: Agronomy research report - University of Florida Institute of Food and Agricultural Sciences ; AY 89-04
Title: Plant disorder diagnosis of 'southern runner' peanut in nematode infested soil
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Permanent Link: http://ufdc.ufl.edu/UF00056118/00001
 Material Information
Title: Plant disorder diagnosis of 'southern runner' peanut in nematode infested soil
Physical Description: 11, 11 leaves : ill. ; 28 cm.
Language: English
Creator: Rice, Ronald W., 1958-
Gallaher, Raymond N
Dickson, Donald W ( Donald Ward )
University of Florida -- Agronomy Dept
Publisher: Department of Agronomy, Institute of Food and Agricultural Sciences, University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 1989?
 Subjects
Subject: Peanuts -- Field experiments -- Florida   ( lcsh )
Peanuts -- Soils   ( lcsh )
Genre: bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references (leaves 10-11).
General Note: Agronomy research report - University of Florida Institute of Food and Agricultural Sciences ; AY 89-04
Statement of Responsibility: R.W. Rice, R.N. Gallaher and D.W. Dickson.
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Bibliographic ID: UF00056118
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 62586669

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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









Agronomy Research Report: AY-89-04

Plant Disorder Diagnosis of 'Southern Runner' Peanut
in Nematode Infested Soil


R. W. Rice (1), R. N. Gallaher (1) and D. W. Dickson (2)
(1) Graduate Research Assistant and Professor of Agronomy,
respectively, and (2) Professor of Nematology,_-Institute
of Food and Agricultural Sciences, Departihrne osief Agronomy
and Entomology and Nematology, UniversitI~y p orida,
Gainesville, FL 32611
FF3 28 199(

ABSTRACT,~ "_ of F ori-a


Soil population densities of second-stage juvenile (J2)
Meloidoqyne arenaria and leaf/soil nutrient concentrations were
determined for 'Southern Runner' peanut (Arachis hypocaea)
planted on a Grossarenic Paleudult in Levy County, FL. 'Localized
patches of deficiency symptoms were present within an overall
healthy-looking stand. M. arenaria J2 counts in soils supporting
deficient plants were 44% higher than for soils with healthy
plants. Severe symptoms appeared as pale yellow to white leaves
with necrotic spots. Decreasing severity of chlorosis with
progressively older leaf tissue was symptomatic of an immobile
element deficiency such as Mn. Both extractable soil Ca and
tissue concentrations were high, while tissue K was present at
deficient levels. Visual K deficiency was not observed. It may
have been masked by the phenotypic expression of Mn deficiency.
Soil pH with deficient plants was 8.2, coinciding with reduced Mn
uptake.

DESCRIPTION OF THE PROBLEM


A stand of 'Southern Runner' peanut (Arachis hvpocaea L.)
observed 61 days after planting displayed erratic, seemingly
random patches of nutrient deficiency symptoms. Deficient areas
defined sharply demarcated zones of yellow to pale green plants
within the larger, healthy field of green plants. A range of
leaf tissue chlorosis was present, the most severe appearing in
the terminal buds and newly emerging leaves. This suggests a
possible deficiency of an immobile macro- or micro-nutrient.
Mild deficiency symptoms included light green veins with
interveinal tissue of an even paler color, moderate deficiency
symptoms were somewhat reversed with veins of a paler color than
surrounding interveinal tissue and severe cases had necrotic
spots along the midrib. Top terminal buds were light yellow to
almost completely white/yellow color over the entire leaf. Roots









from both sufficient and deficient areas were infected with the
root-knot nematode (Meloidoqyne arenaria).

INTRODUCTION


One of the major costs incurred in peanut production has
been that of pest control. Leafspot (Cercospora spp.) diseases
have been particularly troublesome, causing economic losses that
sometimes exceed 50% (Gorbet et al., 1986). The 'Southern
Runner' cultivar was developed from 'Florunner' crosses with
experimental pedigrees exhibiting resistance to Cercospora spp.
in order to produce a high-yielding runner-market-type peanut
variety demanding less fungicide to control Cercospora spD.
In experimental trials where fungicides were not used,
Southern Runner produced almost twice the yields of Florunner due
to infection of the latter cultivar by Cercospora spp. (Gorbet et
al., 1987). Because Southern Runner has only recently appeared
on the market, production data over a variety of soils and
climates is not yet available. It is likely that its production
and management needs will be similar to other runner varieties
such as Florunner.
Reported essential element sufficiency ranges for upper
mature leaf tissue (taken before or at bloom stage) are: N (35 -
45 g kg'), P (2.5 5.0 g kg'1), K (20 30 g kg ), Ca (12.5 -
-1 -
20 g kg'), Mg (3 8 g kg ), Fe (50 300 mg kg ), Mn (50 350
mg kg'1), and Zn (20 50 mg kg ") where all concentration ranges
are based on one kg of dry leaf tissue (Jones, 1974).
Uptake of an element and its accumulation in plant tissue
can affect (both positively and negatively) the subsequent uptake
and accumulation of other essential elements. Nitrogen
applications can depress response to P fertilization.
Recommended ranges of element ratios in leaves are: N/N+P+K =
0.58 to 0.65, P/N+P+K = 0.03 to 0.05, and K/N+P+K = 0.32 to 0.40
(Reid et al., 1973). Imbalances between K, Ca, and Mg can induce
plant nutrient deficiency symptoms through negative or
antagonistic interaction effects. The K:Ca:Mg ratio of 4:1:1 in
terminal buds and young tissue is associated with optimum peanut
growth (Reid et al., 1973). When not limited in available form,
K uptake in peanut can greatly exceed the plant's physiological
requirement for a given level of low-yield management inputs, a
phenomena called luxury consumption.
Soil pH and element soil test values influence final plant
tissue nutrient concentrations. Many researchers conclude that
regulating soil pH between the range of 5.5 6.2 provides the
optimum compromise in terms of adequate availabilities of both
macro- and micro-nutrients for peanut production in the
southeastern United States. At soil pH less than 5.5, Al and Mn
toxicities often develop and nitrification rates are sharply
reduced. High pH is implicated in several micro-nutrient
deficiencies. Increasing Mn application rates in soils with pH









6.8 produced favorable responses in Florunner (Parker et al.,
1986). Of all the micro-nutrients, Mn availability is probably
the most sensitive to soil-water pH (Jones, 1974). The benefit
of liming acid soils in the southeastern United States include
reducing Al and Mn toxicity, increasing Ca, Mg, and Mo
availability, and generating a soil habitat favoring rhizobia
that tend to be sensitive to low-pH soils (Adams et al., 1980).
Factors other than soil pH may affect nutrient uptake.
Damage to roots by M. arenaria race 1 may reduce a plant's
ability to take up nutrients, causing deficiency symptoms and
reduced yields. There is evidence that adult M. arenaria females
residing in roots compete for nutrients. Whether or not this
removal is harmful to the plant is open to question. Infection
encourages partitioning of photosynthate from shoots to roots
where they are used for nematode nutrition. Again, it is unclear
to what extent the plant is harmed by nematodes from a nutrient
sufficiency or deficiency point of view. Evidence suggests that
some plant species will compensate for altered root growth by
actually increasing rates of nutrient uptake (Hussey, 1985).
Yield losses of peanut at initial population densities (at
planting) of 10 to 50 M. arenaria/100 cm soil were reported
(Candanedo et al., 1985). Nematodes caused substantial yield
losses in peanuts throughout Texas. Initial population densities
of M. arenaria were studied to determine their effect on final
peanut yields. Based on linear regression models, initial
population densities of 44 to 83 eggs and J2/500 cm soil reduced
pod yields by 10% (Wheeler et al., 1987).
The objectives of this study were:
1) To assess for nutrient deficiencies or toxicities by
examining nutrient concentrations in leaf tissue from three
different positions along the main stem.
2) To examine soil pH and extractable nutrient
concentrations in order to identify relationships between these
soil fertility parameters and the observed plant deficiency.

MATERIALS AND METHODS


The Southern Runner peanut crop in Williston, Levy County,
Florida was planted on 2 June 1988 at a seeding rate of 89.6 kg
ha'1 (5 cm depth, 76 cm row spacing) with a Covington planter.
Prior tillage included deep plowing (36 cm) with a moldboard plow
followed with cross-disking. Fertilizer was concurrently applied
during disking at a single application rate of 336 kg (0-10-20)
ha'1 or 0 kg N ha', 14.7 kg P ha', and 48.6 kg K ha The soil
was a sandy, siliceous, hyperthermic Grossarenic Paleudult,
commonly called an Arredondo fine sand.
Pre-plant applications of herbicides included Vernolate (S-
Propyldipropylthiocarbamate) at the rate of 2.24 kg a.i. ha1
and Benefin (N-butyl-N-ethyl-a,a,a-trifluoro-2,6-dinitro-
p-toluidine) at the rate of 1.68 kg a.i. ha'1. Post-plant weed









control was accomplished with Bentazon (3-isopropyl-l H-2,1.3-
benzothiadiazin(4)-3H-one-2,2-dioxide) at a rate of 0.56 kg a.i.
ha"' along with Paraquat (1,1'-dimethyl-4,4'-bypiridinium ion) at
a rate of 0.14 kg a.i. ha'. The fungicide Chlorothalonil
(Tetrachloroisophthalonitrile) was applied at a rate of 0.49 kg
a.i. ha'I on 12 July 1988 and approximately every 21 days
thereafter. Insecticides and nematicides were not applied.
Irrigation was not available. The winter cover crops included
experimental plots of rye ['Wrens Abrazzi' (Secale cereale L.)],
'hairy vetch' (Vicia villosa) and weed fallow.
Sampling
A randomized complete block design was used with five
replications of two treatments identified as 1) Sufficient -
plants displaying phenotypic nutrient sufficiency symptoms, and
2) Deficient plants displaying phenotypic nutrient deficiency
symptoms. Leaves within each plant treatment replication were
sampled in three different locations along the main stem; bottom
(oldest) leaves, middle (mid-age) leaves, and terminal (youngest)
leaves, for a total of 30 leaf samples. Soil samples were taken
from two depth increments (0-0.15 m and 0.15-0.30 m) for each
plant treatment replication for a total of 20 soil samples. Soil
samples were collected from the root-zone directly under the
canopy displaying the particular phenotypic symptoms of interest.
For N and mineral analysis, soil samples were air dried, sifted
through a 2-mm stainless steel mesh (to avoid Fe contamination),
well mixed and stored in air-tight bags. Plant leaves were
vigorously rinsed in water, dried at 70 oC, ground through a
Wiley Mill fitted with a 1-mm stainless steel screen, redried to
remove accumulated moisture during grinding and stored in air-
tight bags.
Soil N Analysis
A 2.0 g sample was vortexed in a 100 ml Pyrex test-tube
under a hood with 3.2 g of prepared catalyst (9:1 K2S04:CuSO4) and
10 ml of H2SO4, loaded onto an aluminum digester block (Gallaher
et al., 1975) and digested at 370 oC for 210 minutes. To reduce
frothing, 2 ml 30% HO2 was added in small increments during the
initial digestion period. Tubes were capped with small funnels,
allowing evolving gases to escape while preserving reflexing
action. Cool digested solutions were vortexed with approximately
50 ml of deionized water, allowed to cool for two hours, brought
to 75 ml volume, transferred to square Nalgene storage bottles
(sand residue was filtered out), sealed, mixed and stored.
Nitrogen was analyzed on a Technicon Autoanalyzer II system
(manifold, colorimeter) linked to an automatic Technicon Sample
IV (solution sampler) and an Alpken Corporation Proportioning
Pump III; N was trapped as NH4SO4. A 0.100 g of prepared
laboratory plant sample with a long history of recorded N
concentration values was subjected to the same procedure and used
as a control.
Soil Mineral Analysis
Soil samples were extracted by a double acid procedure
(Mehlich, 1954) and analyzed by the IFAS Extension Soil Testing









Laboratory on their Inductively Coupled Argon Plasma Soil
Analyzer (ICAP). Phosphorus was determined by colorimetry, K by
flame emission and Ca, Mg, Cu, Mn, Fe, Zn, and Al by atomic
absorption.
Plant N Analysis
The procedure was identical to soil N analysis except 0.100
g of plant sample was used and two glass beads were introduced to
the digestion tubes to attenuate violent frothing. The
laboratory control sample was also used as a check.
Plant Mineral Analysis
Exactly 1.00 g of plant sample was weighed into 50 ml
beakers. Samples were ashed in a muffle furnace at 4800C for
approximately six hours. Cool ash contents were carefully
saturated with 10 ml deionized H20, mixed with 2 ml of
concentrated HC1 and gently boiled to dryness on a hot plate.
This water/acid procedure was repeated, dried residue was
suspended in deionized H0O, and brought to a 100 ml volume for a
solution strength of 0.1 N HCl. Solutions were sent to the IFAS
Extension Soil Testing Laboratory for P (colorimetry), K (flame
emission), and Ca, Mg, Cu, Mn, Fe and Zn (atomic absorption)
concentration analysis on a Perkin-Elmer Atomic Absorption
Spectrophotometer.

RESULTS


Plant Analysis
Dry matter yields of leaf (leafdm), stem (stemdm) and pods
(poddm) in plants displaying nutrient sufficiency symptoms were
roughly 2.5 times greater than the corresponding dry matter
components in plants displaying nutrient deficiency symptoms in
above-ground foliage (Fig. 1). Sufficient plant leafdm was 159%
greater than that in deficient plants. Sufficient plants
produced stemdm and poddm that were 137% and 154% higher,
respectively, than the corresponding dry matter yields in
deficient plants. Although root dry matter (rootdm) yield
appeared to be higher in sufficient plants, the difference was
not significant (P=0.05). A visual inspection of roots suggested
that nematode infection was more severe in plants with deficiency
symptoms.
Nitrogen and P accumulation in leaf tissue was similar in
both sufficient and deficient treatments (Table 1). Terminal
leaf tissue N concentrations were somewhat below the recommended
sufficiency range reported by Jones (1974). Phosphorus
concentrations in terminal leaf tissue for both treatments were
within Jones' sufficiency range (Fig. 2). Average P
concentrations increased with decreasing age of leaf (1.9 g kg'
in lower, oldest leaves; 2.3 g kg'1 in middle, mid-age leaves;
2.7 g kg'1 in terminal, youngest leaves), reflecting its status
as a mobile nutrient that is readily redistributed to distal
plant parts.









Leaf K in both treatments was well below the reported
sufficiency range although the particular deficiency symptoms
observed did not suggest deficient levels of K. Leaf Mg
concentrations in terminal leaves were at the extreme lower
margin (3 g kg"' ) of the sufficiency range (Fig. 3). Like P,
the decline in leaf Mg levels with increasing age reflects its
mobility and tendency to be translocated to younger growth (Table
1).
Iron levels were similar in both treatments and not
deficient. Copper levels in deficient plants were considerably
higher than in healthy plants but the average 10 mg kg' is not
considered a toxic level (sufficiency range for Cu not reported).
Both Mn and Zn terminal leaf concentrations were below the
reported sufficiency ranges. Manganese in both treatments was
considerably more deficient, present at about only two thirds the
critical, 50 mg kg'1 level (Fig. 4). However, differences in Mn
levels across the three leaf positions in phenotypically healthy
plants displayed the classic gradient expected of an immobile
element, a decrease in concentration with a decrease in tissue
age (Table 2). No such trend was observed for the unhealthy
plants which displayed nutrient deficiency symptoms remarkably
similar to classic Mn deficiencies.
Calcium was the only nutrient present in quantities
exceeding the reported sufficiency range for peanuts. Whereas Ca
was within range for sufficient plants, it exceeded the upper
limit (20 g kg ) by almost 25% in terminal leaves of deficient
plants (Fig.3). A comparison across different leaf positions for
the sufficient treatment demonstrates a general decrease in Ca
leaf levels with progressively younger leaf tissue, an expected
trend with an immobile element such as Ca. Data for plants
suffering deficiency symptoms do not reflect such a trend,
displaying instead high to very high Ca levels in all three leaf
positions.
Soil Analysis
All extractable macro-nutrient and micro-nutrient
concentrations in soils supporting both sufficient and deficient
plants were statistically similar with the exception of Fe which
was higher in sufficient plants (Tables 3, 4). The only notable
change in soil element concentrations with depth was observed
with N which was present in lower concentrations in the 0 to 0.15
m surface increment. Fertilizer recommendations from the IFAS
Extension Soil Testing Laboratory at the University of Florida
indicated that soil test K values were very low, Mg values were
medium, whereas Ca levels were very high. Soils supporting
unhealthy plants had approximately 71% greater amounts of
extractable Ca than did soils with sufficient looking plants in
the upper 0.30 m. This differential increased to 159% for the
top 0.15 m. The hypothesis that plants suffering a nutrient
deficiency were in soils with significantly greater amounts of
extractable Ca was not supported (Table 3) (P=0.05). However, it
is clear that overall soil Ca levels across both treatments were
unusually high. Aluminum levels were very low, most likely









because soil pH was quite high at about 7.6 for sufficient plots
and about'8.2 for deficient plots (Table 5).
Nematode Analysis
Average root-knot nematode counts were higher in deficient
plots (545 J2/250 cm3 soil) than sufficient plots (378 J2/250 cm3
soil). A much smaller disparity existed for average ring
nematode 3Criconemella ornata) counts, deficient plots being 270
J2/250 cm soil vs. sufficient plot counts of 249 J2/250 cm3 soil
(Table 7).

DISCUSSION


A casual glance suggests that peanuts were simply under-
fertilized, suffering from N, K, Mg, Mn, and Zn concentration
levels too low to promote optimum growth characteristics.
However, it has already been noted that plants enjoying nutrient
sufficiency characteristics also reflect the same pattern of
element concentrations in ranges deemed deficient (Figs. 2, 3,
4).
More light is shed on the problem when nutrient
concentration ratios in plant leaves are compared (Table 6). The
N/NPK and P/NPK ratios are within the recommended ranges whereas
the K/NPK ratio is slightly lower than ranges recommended from
previous studies (Reid et al., 1973). The examination of the
K:Ca:Mg ratio demonstrates large departures from the recommended
4:1:1 relationship. Sufficient plant leaves displayed a
5.5:5.5:1 ratio whereas deficient plants showed an even greater
disparity in Ca content with a 5:8:1 ratio.
Comparisons of data for mean nutrient concentration levels
in terminal leaves for both deficient and sufficient plants
reveals a notable difference in Ca levels (Fig. 3). While Ca
concentration was within the sufficiency range in sufficient
plants, it substantially exceeded this range within deficient
plants. It is unusual that in a plant identified as deficient,
an element considered as immobile as Ca would register higher
leaf tissue concentrations in mid-age (middle) leaves than old
(bottom) leaves (Table 1). This pattern does not exist for
sufficient plants. Deficiencies in one or more major elements
(N, P, or K) have been implicated in explaining unusually high Ca
levels in plant tissue for corn (Jones, 1974).
Average Ca levels across all three leaf positions indicate
that deficient plants accumulated 28% more Ca in leaf tissues
than did phenotypically healthy plants (Table 1). Calcium
accumulation in the bottom leaves of deficient plants was lowest
of all three leaf ages (positions). This may either suggest a
remobilization of Ca from lower leaves to newer, terminal growth
or a translocation of Ca in disproportionate amounts to terminal
tissues during growth. In any event, the observed phenotypic
deficiency symptoms appear to be a result of a large imbalance
in cation uptake, a possible depression in the uptake of.









important cations (K, Mg, Mn and Zn) induced by unusually high
uptake of divalent Ca.
Plants did not display classic K deficiency symptoms such as
brown firing along the leaf perimeter even though terminal leaf K
concentration in deficient plants was only 77% of the lower
'critical point' of the reported sufficiency range. The yellow
to yellow/white leaf color with pronounced, darker veins is more
typical of a Mn deficiency. The possibility exists that the
expression of K deficiencies are simply being masked by the
stronger deficiency symptoms of another element. An immobile
element such as Mn is also implicated since observed deficiency
symptoms were most acute in upper, more recent leaf growth.
Soil test Al levels were very low at 64 mg kg'" in
sufficient treatments and 56 mg kg'1 in deficient treatments;
corresponding soil pH values were about pH 7.6 and pH 8.2,
respectively (Table 5). High soil pH in deficient plots could
account for the Mn deficiency because Mn availability decreases
sharply with soil pH greater than about 6.8 (Parker et al.,
1986). It is unclear why sufficient plots did not display any
sign of Mn deficiency since pH was considerably higher than pH
6.8. It is possible that the substantially higher Ca uptake in
deficient plants interfered with divalent Mn uptake to such an
extent that a deficiency resulted. Less Ca uptake in healthy
plants and the fact that the expected trends of decreasing Ca and
Mn leaf tissue concentrations with decreasing age was present in
sufficient plants suggests that a cation imbalance was not as
severe, possibly favoring a more orderly uptake of Mn. From this
data it is apparent that the field soil had been under-fertilized
and definitely over-limed at some point in its history.
The relationship between M. arenaria population densities
and the observed deficiency status of plants is less clear.
M. arenaria has been implicated as the most important soil pest
affecting peanuts in Florida (Dickson et al., 1988). Initial
population densities of M. arenaria race 1 of only two J2/100 cm3
soil was enough to cause yield loss in peanut (Candanedo, 1986).
Earlier research demonstrated that initial populations of 10 to
50 M. arenaria J2/100 cm3 were enough to cause significant yield
losses in peanut (Candanedo et al., 1985). Regardless of the
nematode numbers, it appears that very small levels of initial J2
populations are implicated in subsequent yield reduction in
peanut.
Deficient plot counts of 545 J2/250 cm3 soil (or 218 J2/100
cm3) are considerably higher than the reported levels listed
above but these counts were made 61 days after planting and do
not shed any light on what the initial J2 population densities
were prior to planting. Furthermore, sufficient plots also
contained high J2 nematode counts of 378 J2/250 cm3 soil (or 151
J2/100 cm3 soil) yet visually appeared perfectly healthy,
displaying none of the dramatic pigment loss in foliage or mid-
rib chlorosis describing the plants in deficient plots.
It is uncertain whether the 44% increase in J2 densities in
deficient plots relative to sufficient plots is enough to account









for the different phenotypic symptoms observed. Published
information on initial population levels are not altogether
helpful, because J2 densities in this study were not obtained
until 61 days after planting. It is also hard to ignore the fact
that while Candanedo (1986) demonstrated that initial population
densities of only two J2/100 cm3 soil were associated with yield
loss, soils in plots with sufficient or healthy plants contained
a much larger count of 151 J2/100 cm3 soil. Another investigator
also found an association between low spring carry-over
populations of nematodes (initial population) and depressed
yields, but could find no correlation between existing M.
arenaria population densities at harvest with the corresponding
peanut yield (Wheeler et al., 1987).


CONCLUSIONS


1. M. arenaria numbers in deficient plots were 44% higher
than in sufficient plots. This higher population density may
account for deficiency symptoms either by nematodes directly
competing for absorbed nutrients (or by effecting the
mobilization of photosynthate from shoot to root for nematode
use) or by causing enough critical damage in roots to depress
uptake of some nutrients.
2. The fact that very high M. arenaria numbers were present
in soils supporting clearly healthy, sufficient plants is not
immediately explainable, but does suggest that another factor may
be involved.
3. Unusually high Ca concentrations in deficient plant
leaves is responsible for an overall cation imbalance, accounting
for depressed levels of K, Mg and, in particular, Mn.
4. At 61 days after planting, soil fertility (with the
marked exception of Ca) was too low to promote optimum plant
growth.
5. The association between alarmingly high soil pH and
excessive Ca concentrations in plant leaves suggests that the
field had been over-limed.


FUTURE SOLUTIONS/INTERVENTIONS


1. Future planting of peanut in this field should be
preceded by an initial J2 nematode count in order to support
subsequent data regarding population densities and deficiency
symptoms or yield loss.
2. Do not lime the field.
3. Increase N, K, and Mg fertilization and foliar-apply Mn
and Zn in order to reverse the cation imbalance observed with
respect to high levels of Ca in leaf tissue. This management
scheme may be necessary since carry-over of high soil Ca levels











will likely occur, creating opportunities for future imbalances.
4. Choice of fertilizers should include acidic formulations
(such as elemental S) in order to buffer residual CaCO3 that is
present in excessive quantity.

REFERENCES


1. Adams, F., and D. L. Hartzog. 1980. The nature of yield
responses of Florunner peanuts to lime. Peanut Sci. 7:120-
123.
2. Boote, K. J. 1982. Growth stages of peanut (Arachis hypogaea
L.). Peanut Sci. 9:35-40.
3. Candanedo-Lay, E. M. 1986. Penetration, damage, and
reproduction of Meloidogyne arenaria on peanut. Ph. D.
dissertation, University of Florida, Gainesville.
4. Candanedo, E., and D. W. Dickson. 1985. Effect of initial
population densities of Meloidogyne arenaria race 1 on pod
infection and yield of 'Florunner' peanut. Nematologica.
15:116.(Abstr.).
5. Dickson, D. W., and T. E. Hewlett. 1988. Efficacy of
fumigant and nonfumigant nematicides for control of
Meloidoqvne arenaria on peanut. Annals of Applied Nematology
(J. of Nematology 19, Supplement) 1:89-93.
6. Gallaher, R. N., C. O. Weldon, and J. G. Futral. 1975. An
Aluminum block digester for plant and soil analysis. Soil
Sci. Soc. Amer. Proc. 39(4): 803-806.
7. Gorbet, D. W., A. J. Nordan, F. M. Shokes, and D. A. Knauft.
1986. Southern Runner a new leafspot-resistant peanut
variety. Inst. of Food and Ag. Sci. Circ. S-324. University
of Florida, Gainesville.
8. and 1987. Registration of
'Southern Runner' peanut. Crop Sci. 27:817.
9. Hussey, R. S. 1985. Host-parasitic relationships and
associated physiological changes. pp. 148-150 in J. N.
Sasser and C. C. Carter, eds. An Advanced Treatise on
Meloidoqyne, vol I: Biology and Control. Raleigh, North
Carolina State University Graphics.
10. Jones, J. B. Jr. 1974. Plant analysis handbook for Georgia.
Coop. Ext. Work in Ag. Home Econ. College of Adg. Bull. 735.
University of Georgia, Athens.
11. Mehlich, A. 1953. Determination of P, Ca, Mg, K, Na and NH4.
North Carolina Soil Test Division (Mimeo, 1973). North
Carolina State University, Raleigh, NC.
12. Parker, M. B., and M. E. Walker. 1986. Soil pH and manganese
effects on manganese nutrition of peanut. Agron. J. 78:614-
620.









11

13. Reid, P. H., and F. R. Cox. 1973. Soil properties, mineral
nutrition and fertilization practices. pp. 271-297 in
Peanuts-Cultures and Uses. Amer. Peanut Res. and Ed. Soc.,
Inc. Stillwater, OK.
14. Wheeler, T. A., and J. L. Starr. 1987. Incidence and
economic importance of plant-parasitic nematodes on peanuts
in Texas. Peanut Sci. 14:94-96.










Table 1. Comparison of macro-nutrient concentrations in 'Southern
Runner' peanut leaves as affected by relative health of
plants and by position of leaf along main stem of plant.
--------------------------------------------------------------------
Leaf position Plant status relative to nutrition
along main -------------------------------------
plant stem Sufficiency Deficiency Mean +
--------------------------------------------------------------------
-------------------- g/kg -------------------------
Nitrogen

Terminal 31.27 31.48 31.38 b
Middle 36.10 33.16 34.63 a
Lower 32.11 31.56 31.84 b
Mean 33.16 32.07 NS

Phosphorus

Terminal 2.71 2.77 2.74 a
Middle 2.18 2.34 2.26 b
Lower 1.93 1.81 1.87 c
Mean 2.27 2.31 NS

Potassium

Terminal 15.60 15.20 15.40 a
Middle 11.60 13.40 12.50 b
Lower 15.40 13.60 14.50 a
Mean 14.20 14.10 NS

Calcium

Terminal 15.72 b G 24.70 a & 20.21
Middle 20.74 a 27.10 a 23.92
Lower 21.80 a 22.90 b NSi 22.35
Mean 19.42 24.90

Magnesium

Terminal 2.85 3.12 2.99 a
Middle 1.90 2.50 2.20 b
Lower 1.78 1.64 1.71 c
Mean 2.18 2.42 NS
--------------------------------------------------------------------
NS Main treatment (plant status) means not significant (F-test)
P=0.05.
+ Subtreatment (leaf position) means not followed by same letter
are significantly different (Duncan's NMRT) P=0.05.
8 Means within main treatment columns not followed by same letter
are significantly different (Duncan's NMRT) P=0.05 for leaf
position in a 2-way interaction between subtreatments and main
treatments.
& Means within subtreatment rows followed by or NSi are signi-
ficantly different (Duncan's NMRT) P=0.05 or not significant
respectively, for plant status in a 2-way interaction between
subtreatments and main treatments.










Table 2. Comparison of micro-nutrient concentrations in 'Southern
Runner' peanut leaves as affected by relative health of
plants and by position of leaf along main stem of plant.
-----------------------------------------------------------------
Leaf position Plant status relative to nutrition
along main ---------------------------------------------------
plant stem Sufficiency Deficiency Mean +
---------------------------------------------------------------------------------
--------------------mg/kg-------------------------
Copper

Terminal 5.6 10.2 7.9 a
Middle 6.6 12.2 9.4 a
Lower 8.0 8.6 8.3 a
Mean 6.7 10.3 *

Iron

Terminal 86.0 78.0 82.0 b
Middle 86.,0 58.0 72.0 b
Lower 158.0 150.0 154.0 a
Mean 110.0 95.3 NS

Manganese

Terminal 32.4 c @ 33.4 a NSi & 32.9
Middle 41.6 b 35.0 a NSi 38.3
Lower 54.4 a 36.2 a 45.3
Mean 42.8 34.9

Zinc

Terminal 17.4 a b 17.8 a NSi 17.6
Middle 14.8 b 17.0 a NSi 15.9
Lower 18.4 a 15.4 a NSi 16.9
Mean 16.9 16.7
---------------------------------------------------------------
*, NS Main treatment (plant status) means are significantly
different (F-test) P=0.05 or not significant,
respectively.
+ Subtreatment (leaf position) means not followed by same
letter are significantly different (Duncan's NMRT) P=0.05.
@ Means within main treatment columns followed by same
letter are significantly different (Duncan's NMRT)
P=0.05 for leaf position in a 2-way interaction between
subtreatments and main treatments.
& Means within subtreatment rows followed by or NSi are
significantly different (Duncan's NMRT) P=0.05 or not
significant, respectively, for plant status in a 2-way
interaction between subtreatments and maintreatments.










Table 3. Macro-nutrient concentrations in soils supporting
Southern Runner peanut plants with foliage display-
ing sufficient and deficient nutrient symptoms.
--------------------------------------------------------------
Plant status relative to nutrition
Soil ------------------------------------------------
depth Sufficiency Deficiency Mean +
-----------------------------------------------------------------------------
---- m ---- --------------------g/kg----------------------
Nitrogen

0.00 0.15 0.219 0.238 0.228 b
0.15 0.30 0.236 0.266 0.251 a

Mean 0.228 0.252 NS

Phosphorus

0.00 0.15 0.035 0.034 0.035 a
0.15 0.30 0.039 0.030 0.035 a

Mean 0.037 0.032 NS

Potassium

0.00 0.15 0.016 0.018 0.017 a
0.15 0.30 0.016 0.018 0.017 a

Mean 0.016 0.018 NS

Calcium

0.00 0.15 1.630 4.230 2.930 a
0.15 0.30 2.740 3.250 3.000 a

Mean 2.180 3.740 NS

Magnesium

0.00 0.15 0.025 0.044 0.035 a
0.15 0.30 0.034 0.033 0.034 a

Mean 0.030 0.038 NS
--------------------------------------------------------------
NS Main treatment (plant status) means not significant
(F-test) P=0.05.
+ Subtreatment (soil depth increment) means not followed by
same letter are significantly different (Duncan's NMRT)
P=0.05.











Table 4. Micro-nutrient concentrations in soils supporting
Southern Runner peanut plants with foliage display-
ing sufficient and deficient nutrient symptoms.

Plant status relative to nutrition
Soil ----------------------------------------------
depth Sufficiency Deficiency Mean +

---- m ---- ------------------- mg/kg ---------------------
Copper

0.00 0.15 1.51 1.26 1.38 a
0.15 0.30 1.53 1.14 1.34 a

Mean 1.52 1.20 NS

Iron

0.00 0.15 7.24 3.93 5.58 a
0.15 0.30 5.71 5.69 5.70 a

Mean 6.48 4.81 *

Manganese

0.00 0.15 6.36 6.66 6.51 a
0.15 0.30 6.75 6.20 6.48 a

Mean 6.56 6.43 NS

Zinc

0.00 0.15 1.82 2.18 2.00 a
0.15 0.30 2.30 1.84 2.07 a

Mean 2.06 2.01 NS

*, NS Main treatment (plant status) means are significantly
different (F-test) P=0.05 or not significant,
respectively.
+ Subtreatment (soil depth increment) means are not
significant (F-test) P=0.05.











Table 5. Al concentration, organic matter and pH in soils
supporting Southern Runner peanut plants with foliage
displaying sufficient and deficient nutrient symptoms.

Plant status relative to nutrition
Soil ------------------------------------------------
depth Sufficiency Deficiency Mean +
----in-----------------------------mg/kg-------------------------
---- m ---- ------------------- mg/kg -----------------------
Aluminum

0.00 0.15 63.0 60.0 62.0 a
0.15 0.30 66.0 51.0 58.0 a

Mean 64.0 56.0 NS

--------------------- -------------------------
Organic
matter

0.00 0.15 0.57 0.57 0.57 b
0.15 0.30 0.63 0.67 0.65 a

Mean 0.60 0.62 NS

pH

0.00 0.15 7.50 8.10 7.80 a
0.15 0.30 7.60 8.20 7.90 a

Mean 7.55 8.15 *

*, NS Main treatment (plant status) means are significantly
different (F-test) P=0.05 or not significant,
respectively.
+ Subtreatment (soil depth increment) means not sig-
nificant (F-test) P=0.05.












Table 6. Comparison of recommended nutrient ratio relationships
reported in literature with experimental data from
sufficient and deficient "Southern Runner' peanut plants

N, P, K ratios Cation ratios
Plant------------------------------------------------
status N/NPK P/NPK K/NPK K : Ca : Mg


Sufficient 0.67 0.046 0.29 5.5 : 5.5 : 1

Deficient 0.66 0.048 0.29 5 : 8 : 1

Recommended 0.38-0.65 0.03-0.05 0.32-0.40 4 : 1 : 1
ratio range

Conclusion Within Within Low Very large
range range departure

NPK Sum of N + P + K mean concentrations (%) across all
replications and all three leaf positions.










Table 7. Population densities of Meloidogyne arenaria and
Criconemella ornata in soils supporting 'Southern
Runner' peanut with foliage displaying sufficient
and deficient nutrient symptoms.

Plant Nematode species
status & ------------------------------------------------
reps M. arenaria C. ornata

----------- 2 / 250 cm3 ------------
Sufficient

1 336 184
2 16 36
3 584 200
4 640 352
5 312 472

Mean 378 249


Deficient

1 712 416
2 248 276
3 116 344
4 768 88
5 880 224

Mean 545 270

J2 Second-stage juvenile






















50



40



3CM


LEAF


STEM POD


SUFF.
PLANTS

DEF.
PLANTS


ROOT


PLANT TISSUE TYPE

Fig. 1 Dry matter yields of four tissue types for
sufficient and deficient peanut plants.

















































NITROGEN


SUFF.
RANGE


SUFF.
PLANTS


DEF.
PLANTS


PHOSPHORUS


PLANT NUTRIENT

Fig. 2 Tissue N and P concentrations in terminal leaves
of sufficient and deficient peanut plants.


















SUFF.
RANGE
30 ~//3
SUFF.
PLANTS
25-
DEF.
PLANTS




15

|01








POTASSIUM CALCIUM MAGNESIUM

PLANT NUTRIENT

Fig. 3 Tissue K, Ca, and Mg concentrations in terminal
leaves of sufficient and deficient peanut plants.
leaves of sufficient and deficient peanut plants.
















4f0


35T


3M0


i I
SUFF.
RANGE

SUFF.
PLANTS

DEF.
PLANTS


PLANT NUTRIENT

Fig. 4 Tissue Cu, Fe, Mn, and Zn concentrations in terminal
leaves of sufficient and deficient peanut plants.




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