Illustrated Encyclopedia of Forage Crop Diseases


National Institute of Agro-Environmental Sciences
*Hokkaido National Agricultural Experiment Station


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Illustrated Encyclopedia of Forage Crop Diseases
As forage crops consist of more than 90 species in 40 genera belonging mainly to Gramineae and Leguminosae, the diseases associated with these plants are also very varied. When an unknown disease occurs, an appropriate diagnosis is necessary in order to control it. Moreover, as the climate of our country differs from the Americas and the Oceanic nations, disease symptoms can be quite different from those shown in publications from these countries. The internet is a good way to provide information assisting with diagnosis, so we have established "Illustrated Encyclopedia of Forage Crop Diseases".  This resource is based on research undertaken by the plant disease laboratory of National Grassland Research Institute (NGRI), Japan in 1996.
Southern corn leaf blight

Causal organism: Cochliobolus heterostrophus (Drechsler) Drechsler, Ascomycotina
The most important fungal disease. The disease begins to occur at the end of the rainy season and the lesions that are orange to yellow brown, oval, 0.5-2 x 2-5mm in size are produced in leaves and sheaths. The entire plant is often killed when the disease occurs severely. The occurrence of the disease increases at the later period of growth. Three races are known corresponding to the types of male sterile cytoplasm of corn and race O is mainly occurring in Japan.

This database is established at the website of NGRI (URL: Diseases of 82 grass and legume species of 58 genera (including corn, sorghum, orchardgrass, ryegrass, alfalfa, clover, bentgrass, zoysia grass, millet, weeds and etc.) are covered.  Descriptions include photographs of the symptoms and pathogens. In total there are 385 photographs of disease symptoms and 144 of pathogens in the database. 

Retrieval of the diseases from the database can be performed by 3 ways as described below.

1. Retrieval by plant names followed by disease names
When you select the plant which you want to retrieve, you can select the disease name associated with each plant. Because the disease names are shown with thumbnail pictures (JPEG, 2-3kb), you can judge whether or not they seem to match the disease being diagnosed.  Then you can see the full size (JPEG, 20-30kb) of the pictures of symptoms and pathogens. Literature related to the disease and published in Japan since 1980, is also listed.

2. Retrieval by pathogen names
Retrieval by pathogen names is also possible. When you select the "genus" name, virus bacteria, phytoplasma, Mastigomycotina, Ascomycotina, Basidiomycotina or unknown fungi in the left frame, you are shown a list of the species names in the right frame.  The disease's) caused by these species can then be accessed.

3. Retrieval by symptoms
The symptom retrieval function can be used to diagnosis diseases you are unsure of. You firstly decide the symptom is a systemic one such as distortion and dwarfing,  a symptom on flowers or ears such as smut and ergot or local lesions on leaves and sheaths. If you go into the local lesion page, you can decide then whether the main symptom is abundant pustules (rust), a white powdery appearance (powdery mildew) or lesions of various shapes with or without small structures (pycnidia or acervuli).

In addition, the image list of the pathogens of the graminicolous Bipolaris, Drechslera and Exserohilum (conidia) and rust fungi (uredospores and teleutospores) are available. Data on other fungi will also be added in future.


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