Illustrations of Plant Diseases

• Links marked 'APS' are to pictures that are copyright by the American Phytopathological Society and are only licensed for viewing with a computer at Newcastle University.
• Other links are to pictures or pages on this site or to other world wide web sites. Except where otherwise noted, pictures on this site are by Ethan Hack. These are unprocessed digital camera JPG files and so both the files and the pictures are quite large. Internet Explorer should scale them automatically to fit in a browser window.

Pictures taken by Ethan Hack are licensed under a Creative Commons Attribution-Noncommercial 2.0 UK: England & Wales License.

Powdery mildew diseases

Powdery mildew of barley: diseased plants (APS)

Powdery mildew of barley: close-up showing cleistothecia (APS)

Rust diseases

Barley leaf rust (APS)

Crown rust on barley (APS). This disease is more common on oats.

Crown rust on barley: telial stage (APS). Telial stages of all cereal leaf rusts look similar.

Stem rust uredia and telia

Blackberry rust: telial stage

Blackberry rust: telial stage close-up

Broad bean rust

Two different rusts on coltsfoot, Puccinia poarum (aecia) and Coleosporium tussilaginis (uredia)

Two different rusts on coltsfoot: close-up

Aecia of Puccinia poarum on coltsfoot

Groundnut (peanut) rust page at North Carolina State University

Illustrations of different degrees of resistance to rusts in wheat (APS)

Smut diseases

Loose smut of barley (APS)

Hemibiotrophic and necrotrophic diseases of leaves and stems of cereals

Eyespot of wheat (APS)

Net blotch of barley (APS)

Scald of barley (APS)

Septoria blotch of barley (APS) showing pycnidia of the fungus; Septoria blotch of wheat looks almost identical.

Late blight of potato and tomato

Blighted potato plants

Blighted potato leaf, upper (adaxial) side

Blighted potato leaf, lower (abaxial) side

Blighted tomato fruit

Fruit diseases

Apple scab

Brown rot of plums

Root diseases

Rhizoctonia root rot of barley: root symptoms (APS)

Rhizoctonia root rot of barley: field with areas of diseased plants (APS)

Take-all of wheat: root symptoms (APS)

Take-all of wheat: white heads (APS)

Take-all of wheat: runner hyphae of Gaeumannomyces graminis growing on wheat root (APS)

Vascular wilts

Fusarium wilt of alfalfa: vascular system discoloration (APS)

Verticillium wilt of alfalfa: wilting symptoms (APS)

Fungal spores

Life cycle of Phytophthora infestans, the potato late blight pathogen at North Carolina State University, with photographs of sporangia, zoospores, and oospores.

Typical single-celled, roughly spherical ascospores in an ascus (APS)

Leptosphaerulina (APS), illustrating multicellular ascospores in asci that protrude from the dark-coloured fruiting body, which is called a pseudothecium (the asci would normally be inside the pseudothecium, but the pseudothecium has been broken open).

Diseases caused by viruses and mycoplasma-like organisms

Aster yellows phytoplasma (APS)

Barley yellow dwarf virus: infected wheat plants (APS)

Barley yellow dwarf virus: infected wheat leaves (APS)

Soybean mosaic virus: classic mosaic symptoms (APS)

Papaya ringspot virus: illustrated article on transgenic disease-resistant plants