How to Collect a Sample for Pathological Analysis

Plant Pathology


We carry out plant disease diagnostics for commercial growers and small holder farmers. Rapid and accurate diagnosis of disease is always necessary before proper control measures can be suggested. Practical and experienced recommendations are given with each report.

These services include investigations of plants, leaves, roots, soils, water and substrates for routine crop disease diagnosis, including common fungi and bacteria, such as leaf spots, root rot diseases, cankers and wilt diseases.

Our services give you the information you need to make the right decisions, ensuring you apply the correct product, quickly and effectively. Our services save you money.

We also provide virus detection using rapid field test diagnostic kits from Bioreba - for more information email

How to collect a sample for pathological analysis


Plant and soil sampling can either be done for diagnostic (problem/diseased) or predictive (routine) purposes. Proper sampling is critical as it will affect the results and therefore the decisions made.


  • 1.                 Sample bags(we can supply at no charge)
  • 2.                 Auger or shovel
  • 3.                 Bucket
  • 4.                 Sample submission forms (please request these from us)
  • 5.                 Field logbook
  • 6.                 Labels and marker pens

Diagnostic Plant samples

These are taken when the plants have obvious symptoms.  Carefully dig up the whole plant, including the roots and soil surrounding the roots.  Place the root ball and the soil in a large water proof bag.  Tie the top of the bag around the stem of the plant, to keep the root and soil intact and deliver as soon as possible to the laboratory.

Diagnostic(Problem)Soil Samples

These are taken when plant growth is not satisfactory,and the farmer suspects a pathological problem.

Where to sample

.Sample in locations in which plants are not growing properly (considering:weather, soil fertility,and other conditions).  Such areas are often circular to oval in outline and in row crops poor growth may follow the rows.

How to sample

.Whenever possible,collect soil from the root zone (10-15 cm depth) of growing plants,where disease spores will be concentrated, and include some root matter. The general sampling patterns are as shown below. At each sampling point,scrape off the top 3 cm of soil.

  •         Left: Star pattern for sampling from a damaged area.
  •         Center:circle pattern for sampling a shrub in an orchard.

Diagnostic samples are given 1st priority and must be clearly marked and separated so they do not get mixed up with predictive samples.

Predictive (Routine)Soil Samples

These are taken if the grower is interested in knowing the status of the soil prior to planting so as to take necessary precautionary measures. 

Collecting Samples

Whenever possible, collect soil from the root zone(10-15 cm depth) of growing plants,where disease spores will be concentrated, and include root fragments. The general sampling patterns is shown below. At each sampling point,scrape off the top 3 cm of soil where temperature and moisture extremes limit biological populations.

Please Note

Samples for pathological  analysis must be handled delicately, kept moist, stored in a cool dry place out of direct sunlight and reach the laboratory as soon as possible, preferably at the beginning of the working week.

Properly labeled samples cause less confusion in the laboratory and are processed faster.  Provide the same names used in previous sampling area to be able to have historical data.

The quality of any analysis is directly related to how well the sample is collected.

Plant Pathology Packages

In addition to the below we also to a rapid qualitative test for Maize Chlorotic Mottle Virus – the causal agent of MLND.

Code Analysis Name Description Days
CNPATH-PL-1/5/9/12/15 Complete Pathogen Screen Bacteria & Fungi (excl. Bacterial Wilt) in soil, plant, compost, media & water 10
CNPATH-PL-1/5/9/12/17 Bacterial Wilt Test Bacterial Wilt (Ralstonia) in soil, compost, media & water 10

For more information please contact us through:

Crop Nutrition Laboratory Services Ltd.

Off Limuru Road, Limuru, Kenya

Telephone +254 (0) 711094444, + 254 (0) 720 839 933


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