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Agronomy
Topic

Leaf and tissue testing

Your BioAg Area Manager may recommend a leaf or tissue test in addition to a soil test. In some cases, your BioAg Area Manager will do the leaf or tissue testing with you or for you. Use this procedure if you are doing the sampling without a BioAg expert present.

Why leaf or tissue testing?

Your BioAg Area Manager may recommend a leaf or tissue test in addition to a soil test. The purposes of tissue testing are:

  • To identify or diagnose a nutrient deficiency to identify a ‘hidden hunger’ in your crop or pasture
  • As part of monitoring and managing nutritional value and quality
  • As a cross reference tool with soil test data to provide more confidence in data interpretation
  • As a verification tool to check if a foliar application or system is working

Sampling Guide

The below table is a guide to when and how to sample for a range of crops.  There will be differences in timing across regions based on climate and growing season. Contact your BioAg Representative to discuss what is right for you.

Sampling time
Plant part
Plants to sample
Plant parts needed
Almonds
1-2 months after flowering. Boron status is better correlated with hulls of mature almonds at harvest.
Leaves from non-fruiting, well-exposed spurs 1.5-1.7 m above the ground
Randomly 20-30 healthy trees, avoid boundaries or damaged trees
Leaves from 5-8 spurs per tree
Apples
Jan-Feb
Sample current seasons mature leaves from non-fruiting laterals (extension growth), taken at shoulder height
30-40 trees
80-100 leaves
Avocados
Apr-May
When the summer leaf flush has hardened off from branches without fruit
Randomly 10 healthy trees per block
4 leaves per tree (one from each side)
Cherries
Jan-Feb
Collect the youngest mature leaf from the mid-section of current season’s extension growth
20-25 trees
4 leaves per tree (one from each side)
Citrus
Feb-Mar
Sample 4 to 7 month old fully expanded leaves from non-fruiting terminals
Randomly 10 healthy trees per block
4 leaves per tree (one from each side)
Vines
Full Flowering (petioles)
Petioles of leaves opposite flower clusters
approx 50 vines
1-2 petioles from a vine In total 100 petioles
Vines
Verasion (leaf blades)
Leaf blades
approx 50 vines
1-2 leaf blades from a vine In total 100 leaf blades
Olives
Nov-Dec
Mature mid-shoot leaves from non-fruiting, current-season shoots
30-40 trees
80-100 leaves
Peaches
Nov-Dec
Sample current season mature leaves from non-fruiting laterals (extension growth), taken at shoulder height
30-40 trees
80-100 leaves
Pistachios
1-1.5 months after flowering
Leaves from non-fruiting, exposed branches 1.7-2m from the ground
20-25 trees
5-10 leaves per tree
Pistachios
Jan-Feb (Summer)
In summer - collect fully expanded sub-terminal leaflets from non-fruiting branches
20-25 trees
5-10 leaves per tree

Sampling Procedure

Follow the instructions below carefully to ensure an accurate analysis.

  1. To avoid contamination of the samples, wash your hands carefully before you begin sampling. 
  2. Label a paper bag “BioAg Leaf Sample” and your name, the date, the paddock name (sample name), and the crop or pasture type.
  3. Collect 25-30 samples at intervals of 1-2 metres evenly across the block or paddock. The final result should be representative of the plants in the sampled area. We recommend collecting samples diagonally across the paddock or crop avoiding headlands, trees, stock camps etc.
  4. Sample the youngest fully mature leaf of the same species of plant. Do not mix species in the sample. 
  5. From the collected samples, select a 200 gram sample (5 gram dry weight) that is free of soil and sand. This is about one large handful of green material. See the photo for an example of the amount required. Place the sample in the labeled paper bag.
  6. Keep the sample cool by placing it in the cooler immediately it has been collected. As soon as possible, place the samples in the refrigerator. 
  7. Complete the Lab Analysis Request form as instructed by your BioAg Area Manager, including your name and address details. 
  8. “Express Post” the samples without delay to the laboratory recommended by your BioAg Area Manager. 
  9. Mark the package “Samples Under Quarantine”. 

Note: Do not post the samples over the weekend. If you need to keep the samples over the weekend, place them in the fridge and post on Monday

Results

Your BioAg Area Manager will receive the results and provide you with an interpretation of them. They will also give you recommendations for how to address the nutrient issues raised during analysis at the lab.

Need more information or assistance?

If you have any queries contact your BioAg Area Manager or the BioAg Office on 02 6958 9911 or sales@bioag.com.au.

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Download procedure

Download a copy of our leaf and tissue testing procedure.