Leaf Sampling Procedure


Sampling Procedures for Plant Analysis

Introduction

Plant analysis is the second tool,after soil testing,that is critical to improving crop nutrition and yield. Only plant analysis can identify the actual nutrient status of a plant or crop.While soil testing identifies the nutrients offered to the crop or plants,plant analysis identifies how well the plants utilized the soil and applied nutrients. Plant analysis allows the crop or plant to tell us what nutrients it needs.

It is critical that the correct plant part and stage of growth be sampled, and that the label clearly informed of this.

The normal nutrient concentration differs between the various plant parts.Also, the normal nutrient concentration of each plant part changes as the plant matures. Plant analysis is calibrated to these norms,so correct identification of which nutrients are low or high depends on accurate information. Call our Laboratory if you have a plant not listed.


How to Take Plant Samples

1. Where to Take Samples

A. In Uniform Fields

Where plant grow this uniform over the entire area, one composite sample, taken from at least 10 widely scattered areas in the field. One plant sample is necessary. One soil sample is recommended.

B. In Problem fields

These are where the growth or appearance of one area differs from the rest of the field. Plant analysis can often determine the cause of these differences and indicate the best method to correct the problem. Sample when abnormalities are discovered. Two plant and two soil samples are required. This includes collecting soil and plant samples from the normal area.

All plant samples taken from abnormal areas should be taken from just inside of the abnormal area. Soil  samples should be taken through out the abnormal area.

A separate Plant Analysis History must be completed for each sample taken.


2. When to Take Samples

Crops can be sampled during most of the season. The following tables list the preferred plant parts and growth stages to sample for many crops.


3. Amount of Plant Material

All plant analysis requires at least a rounded double handful(soft ball size) of plant tissue. We find it difficult to analyze a sample that is too small. See the tables on the following pages for the proper number of plant parts to sample.


4. Preparing Samples for Shipping

Use a large, clean paper bag or clean plastic bucket to collect the sample. Remove any dust or residue from the leaf surface with a clean dry soft bristle brush. Do not wash the sample. Improper washing can affect the nutrient content of some elements. Samples should be dry to the touch, and strongly wilted before shipping. Wilting is not as critical if overnight shipping is used.


5. Sample Submission Form

Perhaps the most important part of a plant sample is its accompanying Plant Submission Form.This form can be downloaded from submission form. Be sure to indicate if more than one sample is being sent at the same time. 


6. Sending the Sample

Place the dry, wilted plant tissue sample in a sample bag .

Do not send fresh samples or put them into plastic bags. They will decompose during shipment, making them useless for analysis purposes.

IMPORTANT:  Accurate Analysis and meaningful interpretation require properly taken samples.

Follow these and all directions carefully and correctly.

CROP GROWTH STAGE PLANT PART TO SAMPLE QUANTITY
AGRONOMIC AND FORAGE CROPS
Alfalfa At or prior to 5% bloom Entire above ground portion of plant or top 6”,which ever is smaller. 15 to 20 plants
Barley,Oats, Rye,Wheat (othersmall grainsexcept rice) a)  Feekes Stages 3 through 9

b)  Feekes Stage 10

Entire above ground portion of plant.

Upper most mature,or Flag leaves.

30 to 40 plants, depending on size

30 to 40 leaves

Canola Seedling to Vegetative At or prior to full bloom Whole plant Fully developed leaves on upper portion of plant 20 to 30 leaves 20 to 30 leaves
Corn(Field,Pop,and Silage) (a)Seedling(6”to 12”)tall(<V 6) (b) Prior to tasseling, (V 7-VT) (c)Silk initiation to brown silk stage (R 1-R 5) Entire above ground portion of plant. First fully developed leaf below whorl. Ear Leaves. 15 to 20 plants 10 to 15 leaves 10 to 15 leaves
Cotton (a)Seedling,6”to 12”tall(b) Prior to or at first bloom(c) When first squares appear Entire above ground portion of plant Youngest fully mature leaves from the main stem of plant. Discard the petioles. 15 to 20 plants 15 to 20 leaves
Cotton (Petioles) When first squares appear to full maturity Petioles from the youngest fully mature leaves on the main stem of plant. 30 to 50 petioles
Grasses(Hay,Forage or Pasture) Prior to heading Entire above ground portion of plant or top 6”,which ever is smaller. 25 to 30 plants
Peanuts (a)Seedling stage (b) Vegetative to pegging stage Entire above ground portion of plant. Youngest fully mature leaf. No petioles. 15 to 20 plants 20 to 30 leaves

Rice

(a)Seedling stage (b) Tillering

(c)1st Joint-Panicle Initiation

(d) Panicle differentiation

(e)Flowering-Heading

Entire above ground portion of plant. Entire above ground portion of plant. Y Leaf/ Flag Leaf Y Leaf /Flag Leaf

Y Leaf/ Flag Leaf

15 to 20 plants 15 to 20 plants

20 to 30 leaves

15 to 20 leaves

20to30leaves

Soybeans (a)Seedling stage(V 2-V 5) (b) Vegetative to early pod fill(>V 5) Entire above ground portion of plant. Youngest fully mature leaf.  No petioles. 15 to 20 plants 20 to 30 leaves
Sugar Cane 2 Months to Mature Second fully mature leaf without sheath. 15 to 25 leaves
Sunflowers (a)Seedling stage (b) Vegetative to full bloom Entire above ground portion of plant. Youngest fully mature leaf.  Nopetioles. 15 to 20 plants 15 to 20 leaves
   Tea During period of active growth First mature leaf 30-50 leaves
Tobacco (a)Seedling (transplants,2 wks.+) (b) Vegetative stages Entire above ground portion of plant. Youngest fully developed leaf from top. 15 to 20 plants 10 to 20 leaves



CROP GROWTHSTAGE PLANTPARTTOSAMPLE QUANTITY
VEGETABLE CROPS
Asparagus (a) Spears (b) Ferns Entire above ground portion of plant. Youngest mature frond(top 24 inches). 10 to 20 spears 10 to 20 fronds
Beans (Field/Dry, Snap, Lima,etc.) (a) Seedling stage (b) Vegetative to early pod fill Entire above ground portion of plant. Youngest fully mature leaf.  No petioles. 20 to 30 plants 20 to 30 leaves
Beets,Table Vegetative stages. Innermost mature leaf in the whorl. 25 to 50 leaves
Broccoli,Cabbage, Cauliflower (a) Seedling stages (b) Vegetative to heading stages Entire above ground portion of plant. Mature fully expanded wrapper leaf. 20 to 30 plants 15 to 20 leaves
Carrots (a) Seedling stages (b) Vegetative stages. Entire above ground portion of plant Innermost mature leaf in the whorl. 20 to 25 plants 25 to 50 leaves
Celery Vegetative stages Petiole of youngest mature leaf. 20 to 25 petioles
Collard,Kale, Mustard, Turnip Vegetative stages Youngest mature leaf. 15 to 20 leaves
Eggplant Vegetative to full bloom stage. Youngest mature leaf on main stem. 25 to 35 leaves
Lettuce, Spinach, Endive Vegetative stages Youngest mature leaf. 20 to 30 leaves
Melons (cantalope/ muskmelon, watermelon) Vegetative to fruiting Youngest fully mature leaf.  No petioles. 15 to 20 leaves
Onion,Garlic, Leek,Shallot (a) Seedling stages (b) Vegetative stages Entire above ground portion of plant. Entire above ground portion of plant. 30 to 50 plants 25 to 30 plants
Peas (Field/sweet etc.) (a) Seedling stage(4-17 nodes) (b) Vegetative to early bloom Entire above ground portion of plant. Youngest mature leaf.  No petioles. 20 to 30 plants 25 to 35 leaves
Peppers (Chili,Sweet) Early Vegetative to Fruiting Stage. Youngest mature leaf on main stem. 25 to 35 leaves
Potato,sweet (a) Seedling stages (b) Vegetative to full bloom stage. Entire above ground portion of plant. Youngest mature leaf on main stem. 20 to 25 plants 25 to 30 leaves
Potato,white (a) Seedling stages (b) Vegetative to full bloom stage. Entire above ground portion of plant. Youngest mature leaf on main stem. 20 to 25 plants 25 to 30 leaves
Radish (a) Seedling stages (b) Vegetative stages. Entire above ground portion of plant. Innermost mature leaf in the whorl. 20 to 25 plants 40 to 50 leaves
SweetCorn (a) Seedling(6”to 12”)tall(<V 6) (b) Prior to tasseling(V 7-VT) (c) Silk initiation to brown silk stage (R 1-R 5) Entire above ground portion of plant. Youngest mature leaf below whorl. Ear Leaf. 15 to 20 plants 10 to 15 leaves 10 to 15 leaves
Squash, Pumpkins Vegetative,bloom,fruiting Youngest mature leaf.  No petioles. 15 to 20 leaves
Tomato (Field-See Pic) (a) Seedling stages (b) Vegetative,bloom,fruiting Entire above ground portion of plant. Youngest mature leaf on main stem. 20 to 25 plants 20 to 30 leaves
Tomato (Greenhouse) See Pictorial (a) Early Flowering (b) 1st to 6th Cluster Leaf Tip Terminal leaf or leaflet next to most recent fruiting cluster (identify cluster) 20 to 25 plants 50 to 70 leaves
CROP GROWTHSTAGE PLANTPARTTOSAMPLE QUANTITY
FRUIT,BERR YandNUTCROPS
Almond Mid-season(6-8 weeks after bloom) Terminal leaflets from mature leaves on terminal shoots. 25 to 40 leaflets
Apples Mid-season(4-8 weeks after bloom) Youngest fully mature leaves from mid- terminal(non-bearing spur,if spur type). 20 to 30 leaves
Apricots Mid-season(4-8 weeks after bloom) Youngest fully mature leaves of current years growth. 20 to 30 leaves
Blackberry Raspberry (other brambles) Mid-Season(2-6 weeks after bloom) Mature leaves from mid-section on non- fruiting“primo”canes. 20 to 30 leaves
Blueberry Mid-season(4-6 weeks after bloom) Post-harvest(July 15-August 15) Median leaves,non-fruiting branches. Youngest fully mature leaves. 40 to 60 leaves 40 to 60 leaves
Cherry (sweet,tart) Mid-season(4-8 weeks after bloom) Youngest fully mature leaves from mid- terminal on a non-bearing spur. 20 to 30 leaves
Citrus (a)Vegetative stages
 (b) Fruiting stages
Fully mature leaf-spring cycle growth.
Fully mature leaves adjacent to fruit.
20 to 30 leaves 20 to 30 leaves
Cranberry Late August early September, ONLY Upper 2 inches of“uprights”from the current season’s growth. Include stem. 50 to 100 uprights
GrapeLeaves (a)Vegetative stages
 (b) Fruiting stages
Youngest fully mature leaf.(Remove Petioles)
 Leaf opposite basal fruit cluster.
15 to 25 leaves 15 to 25 leaves
GrapePetioles (a)Vegetative stages
 (b) Fruiting stages
Youngest fully mature leaf Leaf opposite basal fruit cluster. 50 to 75 petioles 50 to 75 petioles
Macadamia During major flush First young full developed, hardened off leaf behind new flush 40-60 leaves
Peaches Mid-season(4-8 weeks after bloom) Youngest fully mature leaves near base of current years growth. 20 to 30 leaves
Pecans Mid-season(6-8weeksafterbloom) Middleleafletpairsfrommatureleaves onterminalshoots. 25to40leaflets
Plums Mid-season(4-8 weeks after bloom) Youngest fully mature leaves near base of current years growth. 20 to 30 leaves
Strawberry Vegetative to fruiting stages Youngest fully mature tri-foliate leaf. 50 to 60 leaves
Walnut, English Mid-season(6-8 weeks after bloom) Terminal leaflets from mature leaves on terminal shoots. 25 to 40 leaflets
ORNAMENTALS, TREES and TURF
Ferns Vegetative growth Youngest fully expanded mature frond 15 to 30 fronds
FloweringAnnuals Vegetative to full bloom Uppermost mature leaves on main stem. 20 to 40 leaves
HerbaceousPerennials New season vegetative growth Youngest fully developed leaves of the current year’s growth. 20 to 40 leaves
Roses All stages Upper three leaflets from youngest fully mature leaves. 30 to 40 leaflets
Trees,Shrubs (Conifers) Vegetative growth,mid season Current season’s“lateral”,fully hardened. 15 to 20“laterals”
Trees,Shrubs (Deciduous) Vegetative growth stages Youngest fully developed leaves of the current year’s growth. 20 to 50 leaves
Turf Vegetative growth Leaves,preferably clipped by hand. 1 pint clippings



Most Vegetables

Sample uppermost mature leaf.

Tomatoes

Field                                                                       Greenhouse 
Sample uppermost mature leaf or main stem         Sample terminal leaflet or leaf next to most recent fruiting cluster 

Grapes 

(Leaves or Petioles)
Vegetative: Sample youngest fully mature leaf.
Fruiting: Sample leaf opposite basal fruit cluster.
Leaf: for complete nutrient analysis 
Petioles: for nitrate monitoring only


Effective Uses for  Plant Analysis 

1. Confirm visual deficiency symptoms.
2. Reveal hidden nutrient stresses.
3. Check up on the effectiveness of a fertility program.
4. Improve yield goals and fertilizer needs for future crops.
5. Improve quality of plants 
A Complete Plant Analysis from Crop Nutrition Laboratory Ltd includes the total amounts found of the
nutritional elements, N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, Na and Zn. 
The status (Deficient, Low, Normal, High, Very HIgh.) for each nutrient tested is indicated numerically on
the report and a colored bar graph. A complete agronomic interpretation of the analytic results is also
available. 

Some Plant Analysis Do’s and  Don’ts 

DO'S

1. Collect a representative sample. Sample the field as you would if you were sampling the soil (10-20
sampling points.) 
2. Always collect sufficient plant material (see “Quantity” tables).
3. Fill out the plant history questionnaire as completely and accurately as possible. The more complete the 
information the more reliable the interpretation.
4. Always identify the age and growth stage (seedling, bloom, Feekes, V/R, etc.) as accurately as possible.
5. Indicate if foliar fertilizers or fungicides have been recently applied. Identify them and record their 
application rates in the questionnaire. Again, it will make for a more reliable interpretation.
6. Always collect a soil sample from problem areas.
7. When in doubt, Read the Instructions or call or email the lab.
8. Make PLANT ANALYSIS a central part of your agronomic services program. 


DON’TS

1. Sample dead plants.
2. Wash leaf tissue
3. Collect or ship samples in plastic bags or containers.
4. Use galvanized equipment in any way.
5. Sample severely insect damaged plants.
6. Sample severely mechanically injured plants.
7. Sample plants that are too old (see “Growth Stage” tables).
8. Sample during severe drought.
9. Samples covered with dirt/soil particles.

For more information please contact us through:

Office Mobiles: +254 (0)720 639933 / +254 (0)736 839933

Location: Mashiara Park, Kaptagat Rd, Loresho, Nairobi, Kenya


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