Collecting Plant Tissue Samples

The collection of plant tissue samples is done for one of two reasons:

• Diagnosis of plant nutrition problems the sample is made up of material showing the particular symptoms to the greatest extent.

• Monitoring of crop health, the sample should comprise material from a representative part of the block or plantation - normally covering about 0.5 -1.0 hectare.

For monitoring, it is usual to make up the sample with fully expanded leaves (including the petiole) taken as close as possible to shoot tips. Having said this, there are a few special cases to remember:

Spur-bearing deciduous fruit trees should be sampled using the "Mid-shoot" leaves from non-fruiting laterals of the current seasons growth. Lateral bearing fruit trees are sampled using the standard first fully expanded leaf behind the tip".

Cereals are also sampled using the first fully expanded leaf, unless they are very young seedlings, in which case the whole plant is taken from just above the ground (high enough to avoid soil contamination).

For plants with very large leaves (eg. Banana) collect only a narrow strip of tissue from across the mid portion of each leaf. In other cases, such as Walnuts, only a single leaflet from each leaf is required.

Other special cases include Lettuce, which should be sampled by taking the outermost 'wrapper' leaf of the actual head, with 5 leaves per sample.

For Diagnosis, choose material that is exhibiting symptoms of the problem. If possible, a second sample of healthy leaves may also be useful for comparison.

For tree and vine crops, collect a selection of leaves so that the sample includes equal representation from each quarter of the plant (ie. North, South, East and West).

Usually, a sample is comprised of 20-50 leaves (depending mainly on the leaf size).

For Pasture or Lucerne, the best approach is to sample from a representative area of 0.5 to 1.0 hectares within the paddock. See Figure 1 below.

Where possible, it is best to follow an 'X' or zig-zag path through the block (Figures 2 & 3), placing leaves or other sample material directly into a plain brown paper bag.

Take special care of the following points:

• Do not sample from plants under temperature or water stress. Sampling before 10am is preferred.
• Where possible, avoid including leaves that are contaminated with soil in the sample.
• Avoid sampling leaves after flowering or after shoot growth has stopped, unless the particular crop has a specific time requirement (eg. Vines at 75% flowering).
• Before taking the sample, wash hands thoroughly or wear disposable plastic gloves.
• Do not send wet material as it may begin to rot in transit.
• Preferably send the material straight away. If this is not possible, refrigerate (but do not freeze) the sample in its paper bag until it can be sent.

If you are in Australia, we can send you a sampling kit, but if you already have your sample, or you are outside Australia you should enclose a sample information form and payment with it. Please download and print either the Australian Plant Details Form or the International Plant Details Form to send with your samples. We accept either Cheque, Credit Card or Online Payment - Do Not send Cash in the Mail! Your local Post Office is probably the best to advise on how to pack and label the sample. Having done this, mail with your cheque or credit card details and contact information to:

SWEP Analytical Laboratories
PO Box 583, Noble Park, VIC 3174
Australia.

Please Note: Additional details need to be included on the package if you are sending samples from Outside Australia.