NCDA&CS plant tissue analysis guide

              Plant/Waste/Solution/Media Analysis Section
Agronomic Division
N.C. Dept. of Agriculture & Consumer Services
(919) 733-2655
Michelle McGinnis, Ph.D., Agronomist
Catherine Stokes, Communication Specialist
Brenda Cleveland, Section Chief
February 2012
February 2012 NCDA&CS Plant Tissue Analysis Guide i
1. Overview of the Agronomic Division 1
2. Introduction to Plant Tissue Analysis 2
3. Collecting a Good Sample 2
4. Understanding the Plant Analysis Report 5
5. Summary 6
6. References 7
Appendix A. Sampling procedures for plant tissue analysis 9
Appendix B. NCDA&CS Agronomic Division methods for plant tissue analysis 21
Figure credits:
All figures were developed by the NCDA&CS Agronomic Division, with the exception of
a) the corn diagram in Figure 1, which was adapted, with permission, from the University of
Illinois Cooperative Extension and
b) the cabbage/lettuce diagram in Figure 1, which was adapted from CorelDRAW® clipart.
February 2012 NCDA&CS Plant Tissue Analysis Guide 1
is to provide N.C. residents with site-specific diagnostic and
advisory services to increase agricultural productivity, promote responsible land management
and safeguard environmental quality. The Agronomic Division is comprised of four sections: (1)
Field Services; (2) Soil Testing; (3) Nematode Assay; and (4) Plant, Waste, Solution and Media
Analysis.
The Section has a staff of 13 regional agronomists to advise and educate farmers,
agricultural consultants, fertilizer dealers, homeowners and other state residents regarding
agronomic sampling techniques, responsible and cost-effective fertilization practices,
interpretation of agronomic lab results and the implementation of agronomic recommendations.
For further information, see www.ncagr.gov/agronomi/rahome.htm.
provides soil nutrient levels as well as weight per volume, pH, acidity, percent
humic matter, soil class and soluble salt levels as described in Crop Fertilization Based on North
Carolina Soil Tests. The Soil Test Report provides site-specific lime and fertilizer
recommendations for specified crops. For further information, see
www.ncagr.gov/agronomi/sthome.htm.
identifies plant-parasitic nematodes and estimates population size and relative
hazard to the crop. The Nematode Assay Report provides recommendations for management of
plant-parasitic nematodes. For further information, see www.ncagr.gov/agronomi/nemhome.htm.
measures nutrient levels within crop tissue and identifies nutrient
deficiencies and toxicities. The Plant Analysis Report provides recommendations for monitoring
and adjustment of crop fertilization programs. For further information, see
www.ncagr.gov/agronomi/uyrplant.htm.
determines nutrient levels in farm (such as animal manure), industrial,
municipal and composted waste materials. The Waste Analysis Report provides estimates of
nutrient availability and recommendations for the environmentally sound use of waste material
as a plant nutrient source. For further information, see www.ncagr.gov/agronomi/uyrwaste.htm.
measures nutrient concentrations as well as pH, electrical conductivity
(soluble salts) and total alkalinity levels of water used in agricultural production, such as
irrigation water, nutrient solutions and livestock drinking water. The Solution Analysis Report
provides an assessment of potential problems and recommendations for their management. For
further information, see www.ncagr.gov/agronomi/uyrsoln.htm.
measures nutrient concentrations as well as pH and electrical conductivity
(soluble salts) of soilless media used for containerized plant production. The Media Analysis
Report helps growers troubleshoot problems and fine-tune fertilization programs. For further
information, see www.ncagr.gov/agronomi/uyrmedia.htm.
February 2012 NCDA&CS Plant Tissue Analysis Guide 2
Plant tissue analysis, or tissue testing, is a chemical measurement of essential plant nutrients
within a sample of plant tissue. It can be used to identify nutrient-related problems (deficiencies,
toxicities or imbalances), rule out nutrition as the source of a problem, monitor nutrient status as
a basis for managing a crop fertility program and/or evaluate the effectiveness of a fertility
program. Additionally, plant analysis can help determine the optimal time for harvest of flue-cured
tobacco.
The following 16 nutrients are essential for a plant to complete its life cycle: carbon (C),
hydrogen (H), oxygen (O), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca),
magnesium (Mg), sulfur (S), iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), boron (B),
molybdenum (Mo) and chloride (Cl-). Carbon, hydrogen and oxygen are obtained from air and
water and are not generally limiting factors. The other nutrients are provided by soil minerals,
soil organic matter, limestone, amendments (such as crop residue, animal manure, compost,
agricultural waste and industrial waste) and/or fertilizer.
The NCDA&CS Agronomic Division lab provides interpretive guidelines for 11 of the essential
nutrients (N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, B) as part of its standard plant tissue analysis ($5
per sample). Standard analysis also includes a measurement of sodium (Na) concentration.
Although Na is not a nutrient, it can affect plant growth and may be phytotoxic at concentrations
of 0.25–0.50%.
In addition to standard plant tissue analysis, tests for Mo and Cl- are available, by request, for an
extra fee of $2 per test per sample. For certain crops, measurement of Mo is required because of
its importance to quality. Therefore, tissue tests for samples of poinsettia and crops
(e.g., broccoli, cabbage, canola, kale, mustard, turnip) always cost $7 per sample, even if the test
for Mo is not requested.
Tissue sampling methods depend on the crop and the purpose of the sample. The plant part to
select depends on the crop and sometimes on the stage of growth as well (see Appendix A).
Guidelines for sample collection may differ based on whether you are trying to diagnose a
problem or just monitor nutrient status. In all cases, it is important to collect enough material to
represent the entire area of interest. To receive good interpretations, you must submit a good
sample!
Advisors and growers use tissue analysis to measure concentrations of nutrients in an “indicator”
plant part collected at a specific stage of crop development. Then, they compare those
measurements to established standard values known as sufficiency ranges. Therefore, you must
submit the correct plant part(s) at the correct growth stage to receive valid interpretations and
February 2012 NCDA&CS Plant Tissue Analysis Guide 3
recommendations on a . Sampling incorrectly can result in misleading
findings and inappropriate nutrient management decisions.
For most crops, interpretations are based on sampling the most recent mature leaf (MRML). The
MRML is the most fully expanded or mature leaf and is generally the third to fifth leaf below the
growing point (Figure 1). It is neither dull from age nor shiny green from immaturity. Other
possible indicator plant parts include the whole plant, top of the plant, ear leaf, petiole, outermost
undamaged leaf and harvest leaf (Table 1). The correct plant parts to sample for specific crops
are listed in Appendix A, as well as the corresponding codes to enter on the
form.
For several crops (small grains, corn, forage grasses), the appropriate indicator plant part varies
with the growth stage. However, when the sampling protocol for a specific crop is unknown,
selection of the MRML will generally provide the best indication of nutritional status. Table 1
provides explanatory information about plant-part code choices available on the
form.
In addition to indicator plant part, sufficiency ranges are based on specific growth stage(s).
Interpretations on the Plant Analysis Report will generally be based on established sufficiency
ranges (nutrient levels) for the specific growth stage listed in Appendix A. When samples are
collected at other growth stages, the advisor and/or grower must consider principles of plant
nutrition when reviewing results and interpretations. For example, potassium (K) levels in leaves
of a plant will decrease as the plant moves into reproductive growth, so K sufficiency levels of a
MRML during the early or blooming growth stage will be higher than levels during the fruiting
growth stage.
For the high-value and/or agronomically important crops of strawberry and cotton, criteria have
been developed for the nitrate-nitrogen (NO3-N) concentrations in the petioles associated with
indicator leaf samples (Fig. 1). Petiole analysis provides a snapshot of nutrient uptake from the
soil to the leaves at the time of sampling. Results can be used for fine-tuning in-season nutrient
management. For these crops, an additional $2 per sample is charged for measurement of petiole
NO3-N, even if this test is not requested.
Lab results and interpretations depend on the quality of the sample. A good
is comprised of tissue obtained randomly from multiple plants within the area of interest.
Although only a very small amount of plant material is required for the test (< 1 gram), each
sample must include material to adequately represent the area of interest. For crops with small
leaves (e.g., azalea), 75–100 leaves make a good sample. For larger-leaved crops (e.g., corn or
tobacco), significantly fewer leaves are needed. See Appendix A for the recommended number
of leaves to sample for a specific crop.
The way that plant tissue samples are handled between time of collection and arrival at the
laboratory greatly affects the quality of analytical results. If delivery time to the laboratory (or to
a drying oven) is expected to exceed 12 hours, then it is best to refrigerate or air-dry the samples.
Refer to the publication Plant tissue sampling: proper handling for more detailed instructions.
February 2012 NCDA&CS Plant Tissue Analysis Guide 4
Table 1. Indicator plant-part codes, descriptions and example crops.
M Most recent mature leaf (MRML) Most plants, including cotton & strawberry2
W Whole plant (cut ½–1″ above soil
surface) Seedling or young plants
T Top 3–6 inches or
top 2–4 leaves
Turf; forage grass and small grains prior to
reproductive growth stages
E Ear leaf (opposite and below ear) Corn (from tasseling through silking)
P Petiole3 only Vinifera grape
O Outermost undamaged leaf Lettuce and other leaf vegetables
H Harvest leaf Tobacco
1 This is the code from Appendix A that must be written on the form.
2 Even though cotton and strawberry tissue samples include both leaf blades and petioles (separated),
the appropriate plant-part code is M.
3 Petiole is the leaf stem (Fig. 1).
Figure 1. Some examples of appropriate (indicator) plant parts for tissue sampling.
February 2012 NCDA&CS Plant Tissue Analysis Guide 5
Laboratory results are interpreted by comparing nutrient concentrations within a sample to
known nutrient sufficiency ranges for a specific indicator plant part and/or growth stage. The
sufficiency ranges have been developed from research, survey data, field observations and/or
experience. Reliability varies depending on the extent of research conducted on each crop.
Campbell (2000) provides further detail regarding the history, scientific basis and application of
plant analysis.
For each nutrient measured, the NCDA&CS Plant Analysis Report provides an index value
ranging from 0 to 124 and an interpretation category of deficient, low, sufficient, high or excess
(Table 2) in addition to the actual concentrations. The critical value (Figure 2) is the point at
which a nutrient shortage causes a 5 to 10% loss in yield or growth; the point of mild toxicity
indicates the same degree of loss due to nutrient excess.
 (0–24) and l (25–49) index values indicate that the nutrient concentration is
below the desired level and may be contributing to reduced growth, yield and/or quality.
As the index level decreases, the predicted crop response to nutrient application increases
(Table 2). When nutrient indexes are low or deficient, it is important to determine the
cause before making a corrective action. Causes for low nutrient levels in the indicator
plant part can include low soil nutrient levels or nutrient imbalances in the growing
substrate; low or high soil pH; very wet or dry soils; very low or high soil and air
temperatures; soil compaction; heavy fruit load; insect, disease and/or nematode pressure;
and chemical damage from herbicides or air pollutants (ozone).
 A (50–74) index indicates that the nutrient concentration is optimum for growth
and yield.
 (75–99) and (100–124) index values indicate the nutrient concentrations are
above the desired level. concentrations are not normally detrimental to growth or
yield, but the potential to impact crop quality increases as the index approaches 100.
concentrations may cause problems due to plant toxicity or nutrient imbalances.
Nutrient concentrations can be very high due to high levels in the growing substrate;
contamination from a foliar spray of a pesticide or nutrient; soil contamination; very high
or low soil pH; or as a side effect of limited plant growth caused by another problem.
A look at nutrient ratios can also be informative. Plant reports provide values for ratios of
nitrogen to sulfur (N:S), nitrogen to potassium (N:K) and iron to manganese (Fe:Mn) because of
the effects these nutrients have on each other. As a general guideline, the ratio value should be
1.2–2.2 for N:K and >1 for Fe:Mn.
The most important ratio is N:S, which has an acceptable value of 10–15 for most crops. Values
approaching and exceeding 18 indicate that there is not enough sulfur present for the plant to use
nitrogen efficiently. This situation can occur even when sufficient plant tissue concentrations of
both nitrogen and sulfur are present (Campbell 2000).
February 2012 NCDA&CS Plant Tissue Analysis Guide 6
Plant tissue analysis is a tool used to identify problems and manage nutrients in an economically
and environmentally responsible manner. Other factors to be considered in conjunction with
plant analysis include recent soil pH and fertility levels, fertilization history, soil texture,
environmental conditions (such as soil moisture, soil temperature and recent rainfall events),
cropping history, crop age or growth stage, distribution of problem in the field or greenhouse,
disease, insect and nematode pressure, visual appearance of the crop and pesticide use injury.
Figure 2. Expectation of yield or growth (%) in response to
increasing nutrient concentration and interpretation index
Table 2. Predicted response of nutrient application by index value
Index Interpretation Crop Response
00 – 24 Deficient (D) High
25 – 49 Low (L) Medium
50 – 74 Sufficient Low to None
75 – 99 High None
100 – 124 Excess (E) None
February 2012 NCDA&CS Plant Tissue Analysis Guide 7
Bailey D. 1998. Commercial pansy production. Raleigh (NC): NC Cooperative Extension
Service. Horticulture Information Leaflet 521. 8 p.
www.ces.ncsu.edu/depts/hort/floriculture/hils/HIL521.pdf (verified 2011 Sept 20)
Blackmer AM, Mallarino AP. 1996. Cornstalk testing to evaluate nitrogen management. Ames
(IA): Iowa State University Extension. PM 1584 revised. 4 p.
www.extension.iastate.edu/Publications/PM1584.pdf (verified 2011 Aug 5)
Campbell CR, editor. 2000. Reference sufficiency ranges for plant analysis in the southern
region of the United States. Raleigh (NC): NC Department of Agriculture and Consumer
Services. Southern Cooperative Series Bulletin 394.
www.ncagr.gov/agronomi/saaesd/scsb394.pdf (verified 2011 Jun 27).
Cleveland B. 2007. Submitting a diagnostic soil sample with a problem plant sample. Raleigh
(NC): NCDA&CS Agronomic Division. www.ncagr.gov/agronomi/pdffiles/diagnostic.pdf
(verified 2011 Aug 5)
Cleveland B, McGinnis M, Stokes C. 2008. Sampling for plant analysis. Raleigh (NC):
NCDA&CS Agronomic Division. Agronomic Sampling Folder No. 5. 2 p.
www.ncagr.gov/agronomi/pdffiles/sampta.pdf (verified 2011 Aug 5)
Cleveland BR. 2011. Using tissue analysis to monitor cotton nutrition. Raleigh (NC):
NCDA&CS Agronomic Division. 3 p. www.ncagr.gov/agronomi/pdffiles/11cotton.pdf
(verified 2011 Aug 5)
Farrer D. 2011. Tomato production fertilization guide. Raleigh (NC): NCDA&CS Agronomic
Division. 3 p. www.ncagr.gov/agronomi/pdffiles/tomatoguide.pdf (verified 2011 Aug 5)
Heiniger RW, Spears JF, Bowman DT, Carson ML, Crozier CR, Dunphy EJ, Koenning SR,
Payne GA, Marra MC, Naderman GC, Van Duyn JW, York AC, Culpepper AS. 2000. The
North Carolina corn production guide: basic corn production information for North Carolina
growers. Raleigh (NC): NC Cooperative Extension Service, College of Agriculture and Life
Sciences, NC State University. www.ces.ncsu.edu/plymouth/cropsci/cornguide/ (verified
2011 Aug 5)
Kemble JM, editor. 2011. Vegetable crop handbook for southeastern U.S. — 2011 . Lincolnshire
(IL): Southeastern Vegetable Extension Workers. 284 p.
www.ces.ncsu.edu/fletcher/information-handbooks/2011_SEVG.pdf (verified 2011 Aug 5)
McGinnis MS. 2011. Plant tissue samples: proper handling. Raleigh (NC): NCDA&CS
Agronomic Division. www.ncagr.gov/agronomi/pdffiles/tissuehandling.pdf (verified 2011
Oct 14)
Mills HA, Jones JB Jr. 1996. Plant analysis handbook II: a practical sampling, preparation,
analysis, and interpretation guide (revised). Athens (GA): MicroMacro Publ, Inc. 421 p.
NCDA&CS Agronomic Division. 2005. Production tools for tobacco growers: solution & plant
analyses. Raleigh (NC): NCDA&CS Agronomic Division. Sampling Folder 8. 2 p.
www.ncagr.gov/agronomi/pdffiles/samtob.pdf (verified 2011 Aug 5)
February 2012 NCDA&CS Plant Tissue Analysis Guide 8
NCDA&CS Agronomic Division. 2007. Diagnosing plant growth problems: services available
through the NCDA&CS Agronomic Division and N.C. Cooperative Extension. Raleigh
(NC): NCDA&CS Agronomic Division. Agronomic Sampling Folder No. 3. 2 p.
www.ncagr.gov/agronomi/pdffiles/samprob.pdf (verified 2011 Aug 5)
NCDA&CS Agronomic Division. 2009. Agronomic services for Christmas tree growers. Raleigh
(NC): NCDA&CS Agronomic Division. 2 p. www.ncagr.gov/agronomi/pdffiles/xmas.pdf
(verified 2011 Aug 5)
NCDA&CS Agronomic Division. 2009. Agronomic services for grape production. Raleigh
(NC): NCDA&CS Agronomic Division. 2 p. www.ncagr.gov/agronomi/pdffiles/grape.pdf
(verified 2011 Aug 5)
NCDA&CS Agronomic Division. 2009. Agronomic services for turfgrass management. Raleigh
(NC): NCDA&CS Agronomic Division. 2 p. www.ncagr.gov/agronomi/pdffiles/turf.pdf
(verified 2011 Aug 5)
NCDA&CS Agronomic Division. 2009. Harvesting tobacco based on tissue analysis. Raleigh
(NC): NCDA&CS Agronomic Division. 2 p.
www.ncagr.gov/agronomi/pdffiles/tobaccopta703.pdf (verified 2011 Aug 5)
NCDA&CS Agronomic Division. 2009. Strawberry tissue analysis. Raleigh (NC): NCDA&CS
Agronomic Division. 2 p. www.ncagr.gov/agronomi/pdffiles/sberrypta.pdf (verified 2011
Aug 5)
NCDA&CS Agronomic Division. 2011. Tissue sampling & analysis for greenhouse tomatoes.
Raleigh (NC): NCDA&CS Agronomic Division. 2 p.
www.ncagr.gov/agronomi/pdffiles/gtomato.pdf (verified 2011 Sept 20)
NCDA&CS Agronomic Division. 2011. Understanding the plant analysis report. Raleigh (NC):
NCDA&CS Agronomic Division. 2 p. www.ncagr.gov/agronomi/pdffiles/uplant.pdf
(verified 2011 Aug 5)
Plank CO, editor. 1992. Plant analysis reference procedures for the southern region of the United
States. Raleigh (NC): NC Department of Agriculture and Consumer Services. Southern
Cooperative Series Bulletin 368. www.ncagr.gov/agronomi/pdffiles/scsb368.pdf (verified
2011 Jun 27).
Rideout JW. 2002. SoilFacts—soil and plant analysis for Christmas trees. Raleigh (NC): NC
Cooperative Extension. Publication AGW-439-46. 3 p.
www.soil.ncsu.edu/publications/Soilfacts/AGW-439-46/AGW-439-46.pdf (verified 2011
Oct 13
Whipker B. 1998. Fertility management for geraniums. Raleigh (NC): NC Cooperative
Extension Service. Horticulture Information Leaflet 504. 4 p.
www.ces.ncsu.edu/depts/hort/floriculture/hils/HIL504.pdf (verified 2011 Sept 20)
Yarborough B. 2010. Fertilization. In: Ivors K, editor. Commercial production of staked
tomatoes in the southeast (including Alabama, Georgia, Louisiana, Mississippi, North
Carolina, and South Carolina). Raleigh (NC): NC Cooperative Extension. Publication AG-
405 (revision). p 14–6. ipm.ncsu.edu/Production_Guides/Tomatoes/AG-405Web.pdf
(verified 2011 Aug 5)
October 2011 NCDA&CS Plant Tissue Analysis Guide 9
African violet Mature plants of flowering size B, M Most recent mature leaf M 25 –– $5
Alfalfa Prior to or early bloom E, B Most recent mature trifoliate leaves from
the top 1/3 (6″) of plants T 30 Mo
Apple 5 to 10 weeks after full bloom
(mid-June to mid-July) M
Most recent mature leaf from mid shoot,
leaves near base of current year’s growth,
or leaves from spurs; 4–8 leaves per plant
from 20–30 plants
M 50 –– $5
Asparagus
Mid-summer E Top 4–6″ of most recent mature fronds M
20–30 –– $5 2011 SE Vegetable Handbook
Late-summer M Top 18″ of most recent mature fronds M
Azalea Prior to flowering E Most recent mature leaf M 75–100 –– $5
Bahiagrass Grass (Forage & Pasture)
Barley Small Grain
Bean
Seedlings (less than 12″) S All the above-ground portion W
20–30 –– $5 2011 SE Vegetable Handbook
Prior to, or during initial bloom E, B Most recent mature leaf M
Beet Early to mid-growth E, B Most recent mature leaf M 20–30 –– $5 2011 SE Vegetable Handbook
Begonia
( ) Prior to heavy flower formation E, B Most recent mature leaf (1st leaf from top
that is 2″ wide or greater) M 20 –– $5 ––
Bentgrass Grass (Turf)
Bermuda, coastal
(hybrid) Grass (Forage & Pasture)
Bermudagrass (turf) Grass (Turf)
February 2012 NCDA&CS Plant Tissue Analysis Guide 10
Blackberry Postharvest
(10 to 14 days after final harvest) M Most recent mature leaf on primocane
(nonfruiting laterals) M 20–40 –– $5 ––
Blueberry Early or during bloom E, B Most recent mature leaf from mid-portion
of current season's growth M 50–60 –– $5 ––
Bluegrass Grass (Forage & Pasture)
Bluestem, big Grass (Forage & Pasture)
Boxwood Summer M 2–3″ cuttings from terminal growth M 20 cuttings –– $5 ––
Broccoli Early or prior to head formation E, B Most recent mature leaf M 25–30 Mo $7 Southern Cooperative
Series Bulletin 394
Bromegrass Grass (Forage & Pasture)
Cabbage Early to midgrowth E First mature leaf from center of whorl;
should be oldest undamaged leaf M 25–30 Mo $7 ––
Cabbage, Chinese
(heading types) 8-leaf stage E Oldest undamaged leaf M 25–30 Mo $7 ––
Camellia Summer M Most recent mature leaf M 25–30 –– $5 ––
Caneberries Blackberry or Raspberry
Canola Prior to bloom E Most recent mature leaf M –– $5 ––
Cantaloupe Melons
February 2012 NCDA&CS Plant Tissue Analysis Guide 11
Carnation
Unpinched plants E 4th or 5th leaf pair from base of plant M
20–30 –– $5 ––
Pinched plants B, F, M 5th or 6th leaf pair from top of primary
laterals M
Carrot Early growth (60 days after seeding) E Most recent mature leaf M 20–30 –– $5 2011 SE Vegetable Handbook
Cauliflower Early or prior to head formation E Most recent mature leaf M 25–30 Mo $7 ––
Centipede Grass (Turf)
Cherry 5 to 10 weeks after full bloom M
Leaves near base of current year’s growth
from spurs; 4–8 leaves per plant from
20–30 plants
M 50–100 –– $5 ––
Chinese cabbage
(heading types) 8-leaf stage E Oldest undamaged leaf M 25–30 Mo $7 ––
Chrysanthemum Prior to or at flowering E, B, F Most recent mature leaf from top of plant
upper leaves on flowering stem M 20–30 –– $5 ––
Clover Prior to bloom E Top 4–6 inches of the plant T 40–50 –– $5 ––
Collards Early E Oldest undamaged leaf M 25–30 Mo $7 ––
February 2012 NCDA&CS Plant Tissue Analysis Guide 12
Corn, field
Seedling (<4″) S Entire top of plant cut 1″ above soil W
15–20
plants
–– $5
NC Corn Production Guide (2000)
Early (4–12″) E Entire top of plant cut 1″ above soil W
Prior to tasselling (>12″) E
First fully developed leaf below the whorl;
This leaf should be totally unrolled and
have developed a sheath (collar) on the
stalk.
M
10–15
Tasselling & shooting to silking B, F Leaf opposite and below the uppermost
developing ear (earleaf) E
Maturity M Leaf opposite and below the uppermost
developing ear M
Sampling after silking is not
recommended –– –– –– ––
Corn stalk
(end of season)
1–3 weeks after black layer has formed
on 80% of the kernels of most ears M 8″ segment collected at 6–14″ above the
soil line H 15
Only
test:
NO3-N
$5 Cornstalk Testing to Evaluate
Nitrogen Management
Corn, sweet Prior to tasselling
E
First fully developed leaf below the whorl;
This leaf should be totally unrolled and
have developed a sheath (collar) on the
stalk.
M
15–20 –– $5 2011 SE Vegetable Handbook
At tasselling B, F Leaf opposite and below the uppermost
developing ear (earleaf) E
February 2012 NCDA&CS Plant Tissue Analysis Guide 13
Cotton
Seedling: Four weeks following
emergence of 2–3 true leaves
S
Weeks
1, 2, 3, 4
Most recent mature leaf and petioles.
Separate petioles in the field. M 25–30 Petiole
NO3-N $7
Using Tissue Analysis
to Monitor Cotton Nutrition
NC State Cotton Website
Early: Four weeks following seedling
(S) stage, includes pinhead square
formation
E
Weeks
1, 2, 3, 4
Bloom: Begins when plants have at
least 5 open blooms per 25 row feet
B
Weeks
1, 2, 3, 4
Fruit: Begins 5th week after beginning
of bloom
F
Weeks
1, 2, 3, 4
Mature M
Cucumber Early to early bloom E, B Most recent mature leaf (generally
4th to 5th leaf from a growing point) M 15–20 –– $5 2011 SE Vegetable Handbook
Cucumber,
greenhouse Early to early bloom E, B Most recent mature leaf (generally
4th to 5th leaf from a growing point) M 8–10 –– $5 2011 SE Vegetable Handbook
Fescue Grass (Turf or Forage & Pasture)
Fir During dormancy
(~Sept–Dec) M
Two or three shoots from the upper 1/3 or ½
of 8–12 trees. DO NOT sample from leader
or top whorl.
M 15–30
shoots –– $5
Agronomic Services for Christmas
Tree Growers
SoilFacts—soil and plant analysis
for Christmas trees
Daisy, gerber All growth stages E,B,F,M Most recent mature leaf M 25–50 –– $5 ––
Gammagrass Grass (Forage & Pasture)
Gardenia Summer B Most recent mature leaf M 25 –– $5 ––
February 2012 NCDA&CS Plant Tissue Analysis Guide 14
Garlic Early growth prior to root/bulb
enlargement E Center mature leaves M 20–30 –– $5 ––
Geranium All growth stages E,B,F,M Most recent mature leaf M 25–50 –– $5 Fertility Management for
Geraniums
Grape, muscadine
Mid to late summer but prior to final
swelling of fruit (end of bloom through
Aug); Best Time – June to early July
B, F
Most recent mature leaf opposite fruit
clusters from well-exposed shoots
(generally the 1st or 2nd fruit cluster from
the base of the shoot)
M 60–80 –– $5
Agronomic Services for
Grape Production
Grape, vinifera
Full bloom through veraison (ripening
of fruit)
B, F
PETIOLES ONLY from Most recent
mature leaf opposite fruit clusters from
well-exposed shoots (generally the 1st or
2nd fruit cluster from the base of the shoot)
P 80–100 –– $5
Grass
(Forage & Pasture)
Tillering (Less than 6″ tall) S Entire top of plant cut ½″ above soil T 2 handfuls
–– $5 ––
Greater than 6″ tall and prior to seed
head formation (after tillering to
before boot stage)
E Top 6 inches of plant or the upper half of
the plant (top 4 leaves) T 20 tops
After seed head formation
(recommended only when
troubleshooting)
F Most recent mature leaf
(leaf below seed head) M 20–30
leaves
Grass (Turf)
During normal growing season; at
least two days regrowth
M
Two handfuls of freshly mowed grass (with
trash removed)
T
2 handfuls
––
$5
Agronomic Services for Turfgrass
Management
NCSU TurfFiles Website
Holly Summer M Most recent mature leaf M 30–50 –– $5 ––
Hydrangea Early summer M Most recent mature leaf M 30–50 –– $5 ––
Impatiens All growth stages E,B,F,M Most recent mature leaf M 25–50 –– $5 ––
February 2012 NCDA&CS Plant Tissue Analysis Guide 15
Kale Early or during bloom E, B Most recent mature leaf M 25–30 Mo $7 Southern Cooperative Series
Bulletin 394
Lettuce Anytime during growing season E Outermost undamaged leaf M 10–20 –– $5 2011 SE Vegetable Handbook
Lettuce (leaf),
greenhouse Anytime during growing season E Outermost undamaged leaf M 10–20 –– $5 ––
Lima bean Bean
Marigold All growth stages E,B,F,M Most recent mature leaf M 25–50 –– $5 ––
Melons
(watermelon,
muskmelon)
Prior to or during bloom; prior to fruit
set E, B Most recent mature leaves (generally the
5th leaf from the growing tip) M 12–30 –– $5 2011 SE Vegetable Handbook
Millet Grass (Forage & Pasture)
Milo Sorghum
Mung bean Bean
Muskmelon Melons
Mustard greens Early or during bloom E, B Most recent mature leaf M 25–30 Mo $7 ––
Oats Small Grain
Onion Early growth prior to root/bulb
enlargement E Center mature leaves M 20–30 –– $5
Orchardgrass Grass (Forage & Pasture)
February 2012 NCDA&CS Plant Tissue Analysis Guide 16
Ornamental shrubs
& trees During active growth M Most recent mature leaf on current year’s
growth M 30–100 –– $5 ––
Pansy All growth stages E,B,F,M Most recent mature leaf M 25–50 –– $5 Commercial Pansy Production
Peach Mid-season; 12 to 14 weeks after
bloom F, M Leaves near base of current year’s growth;
4–8 leaves per plant / 20–30 plants M 50–100 –– $5 ––
Peanut Prior to, or at bloom. E or B Most recent mature tetrafoliate leaves
(about 3rd to 5th leaf from growing point) M 25–30 –– $5 ––
Pear 5 to 10 weeks after full bloom M
Leaves near base of current year’s growth
or leaves from spurs; 4–8 leaves per plant
from 20–30 plants
M 50–100 –– $5 ––
Peas (English,
southern) Prior to or during initial flowering E, B Most recent mature leaf (about the 3rd set
of leaf from the growing point). M 30–60 –– $5 2011 SE Vegetable Handbook
Pecan 6–8 weeks after bloom; 8–12 weeks
after catkin fall (July 7 to August 7) M Middle pairs of leaflets from a compound
leaf on a terminal shoot M 30–45 –– $5 ––
Pepper
(bell, hot, banana) Prior to bloom E Most recent mature leaf M 20–30 –– $5 2011 SE Vegetable Handbook
Petunia All growth stages E,B,F,M Most recent mature leaf M 25–50 –– $5 ––
Pine Summer M
Needles from upper 1/3 crown; select
dominant trees with good form and crown;
primary lateral branches from first flush of
past season’s growth; strip needles (include
sheaths and fascicles)
M 200 needles –– $5 ––
Poinsettia Prior to or at bloom E, B Most recent mature leaf M 15–20 Mo $7 ––
February 2012 NCDA&CS Plant Tissue Analysis Guide 17
Potato, Irish
Prior to or during early bloom E, B Most recent mature leaf (3rd to 6th leaf from
the growing tip) M
20–30 –– $5 2011 SE Vegetable Handbook
Early flowering to half-grown tubers M Most recent mature leaf (3rd to 6th leaf from
the growing tip) M
Raspberry Postharvest
(10 to 14 days after final harvest) M Youngest mature leaves on primocane
(nonfruiting laterals) M 20–40 –– $5 ––
Rhododendron Summer M Most recent mature leaf M 20–30 –– $5 ––
Rose During flower production F Upper leaves on the flowering stem
5-leaflet leaf below bud M 20–30 –– $5 ––
Rye Small Grain
Ryegrass Grass (Forage & Pasture)
Small Grain Seedling stage to early jointing;
GS 3–6 (Feekes) or GS 26–31
(Zadoks)
S Entire top of plant cut ½″ above soil W 2 handfuls
–– $5
NCDA&CS Pictorial Guides
to Plant Tissue Sampling
Small Grain Production Guide
Early jointing to just prior to
heading (ie just prior to boot);
GS 7–9 (Feekes) or
GS 32–39 (Zadoks)
E The 2–4 uppermost leaves (Top 4–6″) T 25–40
Just prior to heading (boot stage);
GS 10–11 (Feekes)
GS 45–100 (Zadoks)
[sampling after heading is not
recommended]
B Flag leaf M 30–40
Snap Bean Bean
February 2012 NCDA&CS Plant Tissue Analysis Guide 18
Sorghum (Milo,
Grain sorghum)
Early or Bloom E, B If E, first leaf out of the whorl; if B, second
leaf from the top M 20 –– $5 ––
Sorghum-Sudan Early or Bloom E, B Top 4″ to 6″ of plant T 15–20
plants –– $5 ––
Soybean
Seedlings (less than 12″) S Entire top of plant cut 1″ above soil W
Prior to, or during initial bloom; before 20–30 –– $5 ––
pod set [sampling after pods begin to
set is not recommended]
E, B, F Most recent mature leaf M
Spinach Mid-growth M Most recent mature leaf M 20 Mo $7 2011 SE Vegetable Handbook
Spinach, greenhouse All growth stages M Most recent mature leaf M 20 Mo $7 ––
Spruce Mid-season to late summer M 2–3″ terminal cuttings M 25 cuttings –– $5 ––
Squash Summer B, F, M Most recent mature leaf (about 5th leaf
from the growing point) M 15–20 –– $5 2011 SE Vegetable Handbook
Strawberry, field Early
E
Weeks
1–8
Most recent mature leaf and petioles.
Separate petiole in the field M 20–25 Petiole
NO3-N $7
Strawberry Tissue Analysis
Bloom/Fruit: Initiated when there are
5–10 blooms on >75% of the plants or
2–3 blooms on most plants; Harvest
usually begins at B/F week 5 or 6
B/F
Weeks
1–12
Most recent mature leaf and petioles.
Separate petiole in the field M 20–25 Petiole
NO3-N $7
Mature
M
Weeks
1–4
Most recent mature leaf and petioles.
Separate petiole in the field M 20–25 Petiole
NO3-N $7
February 2012 NCDA&CS Plant Tissue Analysis Guide 19
Strawberry,
high tunnel All growth stages E,B,F,M Most recent mature leaf and petioles.
Separate petiole in the field M 20–25 Petiole
NO3-N $7
Strawberry Tissue Analysis
Strawberry,
greenhouse All growth stages E,B,F,M Most recent mature leaf and petioles.
Separate petiole in the field M 20–25 Petiole
NO3-N $7
Sweetpotato Midgrowth; prior to root enlargement E Most recent mature leaf (generally the 4th to
5th leaf) M 20–30 –– $5 2011 SE Vegetable Handbook
Tobacco,
burley
Seedling S Entire top of plant cut 1″ above soil W
8–12 –– $5
Production Tools for Tobacco
Growers: Solution & Plant
Analyses
Prior to bloom E
Most recent mature leaf (about 4th leaf from
growing point)
M
During bloom B, F M
Maturity M M
Tobacco,
flue-cured
Seedling (greenhouse transplants) S Entire top of plant cut 1″ above soil M 1 tray
––
$5
Production Tools for Tobacco
Growers: Solution & Plant
Analyses
Harvesting Tobacco
Based on Tissue Analysis
Before bloom E
Most recent mature leaf
(about 4th leaf from growing point)
M
8–12
During early bloom B M
During late bloom F M
Mature M M
Harvest leaf M Upper leaves (tips) (Position U)
(~21st to 30th nodes from the bottom) H $5
Harvest leaf M Middle leaves (smoking) (Position M)
(~11th to 20th nodes from the bottom) H $5
Harvest leaf M Lower leaves (lugs & cutters) (Position L)
(~1st to 10th node from the bottom) H $5
February 2012 NCDA&CS Plant Tissue Analysis Guide 20
Tomato,
field
Early growth (5-leaf stage through first
flower) S, E Most recent mature leaf
(4rd to 5th compound leaf back from the
growing point)
M
8–10 –– $5
2011 SE Vegetable Handbook
Tomato Production
Fertilization Guide
Early flower through first fruit set
(golf-ball-sized fruit) B M
First fruit set through harvest F, M M
Tomato,
greenhouse
Early growth through first fruit set S, E, B Most recent mature leaf (4rd to 5th
compound leaf back from the growing
point)
M 8–10 –– $5 Tissue Sampling & Analysis for
Greenhouse Tomatoes
First fruit set through harvest F, M
Triticale Small grains
Turnip greens Early or during bloom E, B Most recent mature leaf M 25–30 Mo $7 ––
Walnut 6 to 8 weeks after bloom M Middle pairs of leaflets from a compound
leaf on a mature shoot M 30–35 –– $5 ––
Watermelon Melons
Wheat Small grains
Zucchini Squash
1Growth-stage codes: S = Seedling, E = Early, B = Bloom (prior to first fruit), F = Fruiting, M = Mature. To receive meaningful recommendations on a plant analysis report, you must collect and submit
tissue samples from the growth stage indicated in this table and write the associated code on the form. Analysis of tissue collected at other growth stages may still provide useful
information even though there are insufficient data for the lab to issue recommendations.
2Plant -part codes: W = Whole plant, T = Top, E = Ear leaf, M = Most recent mature leaf (MRML), O = Outermost undamaged leaf, P = Petiole, H = Harvest leaf. To receive meaningful recommendations
on a plant analysis report, you must collect and submit the plant tissue part indicated in this table for the crop you are sampling and write the associated code on the form.
Samples of other tissue may still provide useful information even though there are insufficient data for the lab to issue recommendations based on it.
February 2012 NCDA&CS Plant Tissue Analysis Guide 21
Prior to analysis, samples are dried overnight (12–24 hr) at 80 oC, then processed through a
stainless steel grinder (Wiley Mini-Mill; Thomas Scientific; Swedesboro, NJ) with a 20-mesh
(1-mm) screen (Campbell and Plank 1992).
Total nitrogen concentration is determined by oxygen combustion gas chromatography with an
elemental analyzer (NA1500; CE Elantech Instruments; Lakewood, NJ) (AOAC 1990b;
Campbell 1992) on a 10-mg aliquot of the dried and ground sample. Results are expressed in
percent (%) on a dry-weight basis.
Total concentrations of P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, B, Na, Ni, Cd and Pb are determined
with an inductively-coupled-plasma (ICP) spectrophotometer (Optima 3300 DV ICP emission
spectrophotometer; Perkin Elmer Corporation; Shelton, CT) (Donohue and Aho 1992; adapted
USEPA 2001), after open-vessel HNO3 digestion in a microwave digestion system (MARS &
MDS2100 microwaves; CEM Corp.; Matthews, NC) (Campbell and Plank 1992). A 0.5- or 1.0-g
dried and ground aliquot is digested in 10 mL 15.6N HNO3 for 5–30 minutes in a microwave,
and the prepared sample volume is brought to 50 mL with deionized water prior to measurement.
Elements are measured at wavelengths listed in Table B-1. Results are expressed either as a
percentage (%) or in parts per million (ppm) [as milligrams per kilogram (mg/kg)] on a dry-weight
basis.
Boron (B) 249.772 Manganese (Mn) 257.610
Cadmium (Cd) 214.440 Nickel (Ni) 231.604
Calcium (Ca) 317.933 Phosphorus (P) 178.221
Copper (Cu) 324.752 Potassium (K) 766.490
Iron (Fe) 259.939 Sodium (Na) 589.592
Lead (Pb) 220.353 Sulfur (S) 181.975
Magnesium (Mg) 285.213 Zinc (Zn) 213.857
February 2012 NCDA&CS Plant Tissue Analysis Guide 22
Nitrate-nitrogen concentration is determined with an ion-sensitive electrode (ISE) (Orion Model
93-07; Thermo Fisher Scientific Inc., Waltham, MA) following a 0.25-M Al2(SO4)3 extraction
(25 mL) (Baker and Smith 1969) on a 0.25-g, dried and ground aliquot of sample. Results are
expressed in parts per million (ppm) [as milligrams per kilogram (mg/kg)] on a dry-weight basis.
Nitrate nitrogen will be analyzed on all strawberry and cotton samples for an addition cost of $2
(total cost of $7 per sample). Nitrate nitrogen can also be analyzed on any sample per request for
an additional cost of $2 (total cost of $7 per sample).
Molybdenum is measured colorimetrically at 600 nm with a fiber-optic, colorimetric probe
(Brinkmann PC 900; Brinkmann Instruments, Westbury, NY), following a muffle-furnace ashing
(Barnstead Thermolyne 6000, Dubuque, IA) and Rhodamine-B (5 mL) digestion (Haddad and
others 1974) on a 1.0-g aliquot of dried and ground sample. Results are expressed in parts per
million (ppm) [as milligrams per kilogram (mg/kg)] on a dry-weight basis. Molybdenum will be
analyzed on all crop, poinsettia and spinach samples for an additional cost of $2 (total
cost of $7 per sample). Molybdenum can also be analyzed on any sample per request for an
additional cost of $2 (total cost of $7 per sample).
Chloride is measured colorimetrically at 510 nm with a fiber-optic, colorimetric probe
(Brinkmann PC 900; Brinkmann Instruments, Westbury, NY), following a muffle-furnace ashing
(Barnstead Thermolyne 6000, Dubuque, IA) and silver-nitrate (2 mL) digestion (AOAC 1990a)
on a 0.25-g aliquot of dried and ground sample. Chloride analysis can be performed, by request,
on any sample for an additional cost of $2 (total cost of $7 per sample).
[AOAC] Association of Official Analytical Chemists. 1990a. AOAC modified method 963.05:
chlorides in tobacco. In: Official methods of analysis. 15th ed. Arlington (VA): AOAC
International. p 64.
[AOAC] Association of Official Analytical Chemists. 1990b. AOAC official method 972.43:
microchemical determination of carbon, hydrogen, and nitrogen. In: Official methods of
analysis. 15th ed. Arlington (VA): AOAC International. p 341.
Baker AS, Smith R. 1969. Extracting solution for potentiometric determination of nitrate in plant
tissue. J Agric Food Chem 17:1284–7.
Campbell CR. 1992. Determination of total nitrogen in plant tissue by combustion. In: Plank CO,
editor. Plant analysis reference procedures for the southern region of the United States.
Athens (GA): Georgia Cooperative Extension Service. p 20–2. Southern Cooperative
Series Bulletin 368. Available at www.ncagr.gov/agronomi/pdffiles/sera368.pdf (verified
2011 Aug 24).
February 2012 NCDA&CS Plant Tissue Analysis Guide 23
Campbell CR, Plank CO. 1992. Sample preparation. In: Plank CO, editor. Plant analysis
reference procedures for the southern region of the United States. Athens (GA): Georgia
Cooperative Extension Service. p 1–12. Southern Cooperative Series Bulletin 368.
Available at www.ncagr.gov/agronomi/pdffiles/sera368.pdf (verified 2011 Aug 24).
Donohue SJ, Aho DW. 1992. Determination of P, K, Ca, Mg, Mn, Fe, Al, B, Cu, and Zn in plant
tissue by inductively coupled plasma (ICP) emission spectroscopy. In: Plank CO, editor.
Plant analysis reference procedures for the southern region of the United States. Athens
(GA): Georgia Cooperative Extension Service. p 34–7. Southern Cooperative Series
Bulletin 368. Available at www.ncagr.gov/agronomi/pdffiles/sera368.pdf (verified 2011
Aug 24).
Haddad PR, Alexander PW, Smythe LE. 1975. Spectrophotometric and fluorometric
determination of traces of molybdenum in soils and plants. Talanta 22:60–9.
[USEPA] US Environmental Protection Agency. 2001. Method 200.7. Trace elements in water,
solids, and biosolids by inductively coupled plasma–atomic spectrometry, revision 4.4.
Cincinnati (OH): USEPA Office of Research and Development. EPA-821-R-01-010.
Available at nepis.epa.gov/EPA/ (verified 2011 Sep 12).