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Koch's Postulates of Brown Rot disease

This practical resource complements the new ‘A level’ specification unit 'Biology & Disease'. Koch's postulates are fundamentally important in plant pathology. The practical sets out to determine if the fungus plant pathogen, Monilinia fructigena, is responsible for brown rot disease symptoms on apple. This practical is designed to draw technical skills and learning from a wide number of curriculum topics including; Cell Structure, Biology & Disease, Classification & Implementation. There are two files that accompany this resource.

 Monilinia fructigena is deemed a low hazard fungus (category 1). It can be purchased from CABI (Centre for Agriculture and Biosciences International) or alternatively; if the practical runs during the autumn months (October), students may be encouraged to source infected material from the environment (gardens, parks, orchards). The practical is designed to cover four lessons of 60 minutes duration (or more if needed and time permits); however, the practical can be shortened to two 60 minute lessons.

Teachers notes and technical information

Teachers and technical notes and a list giving details of current suppliers of materials.

(A level Biology Specification: Biology & Disease)

Koch's Postulates Teacher's Notes (654.33 KB)


Student practical Koch’s postulates

A detailed student practical guide to studying Koch's postulates using apples displaying symptoms of brown rot disease. 

(A level Biology specification: Biology & Disease)

Koch's Postulates Practicals (1,105.99 KB)


Specification areas covered:


Practical activity groups (PAG’s):

1: Microscopy; 7: Microbial techniques, 11: Investigation into the measurement of plant and animal responses, 12: Research skills.

Specification references:

2.1.1 (a), (b), (c), (d), (e), (f); 4.2.2 (a), (b); 5.15 (a); 6.2.1 (g (i))

Mathematical requirement references:

M0.1, M0.2, M0.3, M1.1, M1.8, M2.2, M2.3, M2.4

How Science works (HSW):



3.1 Unit 1: Biology & Disease

3.2 Unit 2: 3.2.8 Classification

3.3 Unit 3: 3.3.2 Implementation

3.7 How Science works B, D, G