Late blight
Late blight
Brown leaf spot
Brown leaf spot
Black Dot
Black Dot
White Mold
White Mold
Common Scab
Common Scab
Fusarium dry rot
Fusarium dry rot
Pink Rot
Pink Rot
Aerial Stem Rot
Aerial Stem Rot
Pythium
Pythium
Early blight
Early blight
Grey mold
Grey mold

Welcome

Welcome to the Idaho Potato Diseases website. The goal of this website is to provide Idaho potato growers with reliable and up-to-date information on the identity, biology and disease-cycles, and current control methods for diseases of potatoes.

Due to the ever present threat from fungal pathogens, proper and timely diagnosis of potato diseases is paramount to effective disease management, and growers need up-to-date information to help make important decisions on optimal use and timing of pesticides and other control options. Most Idaho potato growers use some disease management practices and are seeking alternative control strategies that will help them develop practical, economically viable, and environmentally sound integrated crop management practices.

This website has been setup by the University of Idaho Potato Pathology program and is part of the University of Idaho’s continuing commitment to helping growers improve the way they manage their businesses, with an emphasis on integrated crop management, education, and safety.

Foliar Diseases
In Idaho two diseases are most common on potato foliage. These are early blight and white mold. Late blight can occur in Idaho but it is appearance has been extremely sporadic in recent years. Click the leaf for a...
Volunteer Survival
Click on the map marker closest to your location to get details on the risk level of volunteer potatoes surviving over the winter in your area. The marker color indicates the risk of volunteer survival...
Sample Page
This is an example page. It’s different from a blog post because it will stay in one place and will show up in your site navigation (in most themes). Most people start with an About...

Volunteer Survival

Click on the map marker closest to your location to get details on the risk level of volunteer potatoes surviving over the winter in your area. The marker color indicates the risk of volunteer survival (orange = high risk; yellow = moderate; green = low). For more information on volunteer potato survival in Idaho, download this article by P.S. Wharton et al. 2015.

Hello world!
This is a Bitnami WP Multisite installation. Please check the multisite configuration guide before adding content to your sites. To learn more about Bitnami stacks...
Read More "Hello world!"

Foliar Diseases

In Idaho two diseases are most common on potato foliage. These are early blight and white moldLate blight can occur in Idaho but it is appearance has been extremely sporadic in recent years. Click the leaf for a list of some common foliar diseases found in Idaho. Many of these organisms also can infect tubers. For information on tuber diseases please visit the tuber diseases page.

Late Blight of Potato

Late blight is caused by the fungus-like oomycete Phytophthora infestans. This organism is generally treated as a fungus and can cause both foliar and tuber infections. The pathogen is dispersed via wind-borne sporangia which produce flagellated zoospores. These zoospores can infect leaf tissue through either direct penetration of the epidermis or through stomata. Once inside the plant the pathogen begins to kill the tissue, causing the distinct foliar lesions. Control is accomplished by using a protectant fungicide program.

Early Blight of Potato

foliar early blight
early blight lesions

Early blight is caused by the fungus Alternaria solani. Conidia are approximately 200 µm long and have several transverse septa. The conidia possess a tail or beak. The fungus overwinters in debris and is hardy in Michigan. The lesions produced are often confused with late blight. Early blight lesions show a general dry “bulls-eye” pattern and do not usually spread very far and rarely affect petiole tissue. In contrast, late blight lesions are appear watery and spread down the petiole and the stem. A. solani can cause tuber rot but unlike late blight, infected tubers are not generally susceptible to colonization of secondary pathogens. Protectant fungicide programs used to control late blight are generally effective at controlling early blight. A related fungus Alternaria alternata produces similar lesions.

White Mold of Potato

White mold, also called Sclerotinia stem rot, is caused by the fungus Sclerotinia sclerotiorum (Lib.) de Bary. It is prevalent in the Pacific Northwest but in Michigan it is of secondary importance except in wet seasons or under excessive irrigation. The disease favors very moist conditions and is especially common in fields with overhead-irrigation such as by means of a center pivot. Agricultural practices that promote extensive canopy growth and keep relative humidity and free moisture in the crop canopy for extended periods of time and reduce wind movement, favor disease development.

Botrytis Grey Mold

Grey Mold is caused by the fungus Botrytis cinerea . This pathogen also causes gray mold. The disease is usually the result of excessive humidity and other stress and does not usually pose a large threat to the crop. The fungus overwinters on plant debris. Tuber infection can occur if the inoculum levels are high and the storage facility is very humidity. Standard fungicide protection programs offer control when conditions are not too wet.

Black leg and aerial stem rot

Both of these diseases are caused by pathovars of the bacterium Pectobacterium carotovora. Other bacteria have also be found to be involved in soft rot. The introduction of bacteria is always through a wound in the plant tissue. Black leg (a) is a rot of the lower stem region. This is encouraged by cool, damp conditions. The bacteria may migrate through the soil in water and can reside in plant residue for short periods. The primary inoculum is infected potato seed tubers. Under optimal conditions the bacteria multiply rapidly in the tuber and then spread up the xylem of the shoot killing it. The bacteria will also dissolve the cell walls and liquefy the tuber innards causing soft rot of the tuber. No distinct smell is present in true soft rot. Control is achieved by planting clean seed and rotating the crop. Aerial stem rot (b) is caused by infection through wounds in the stem. Aerial stem rot is often found after plants have been damaged by hail. Aerial stem rot can be differentiated from black leg because aerial stem rot occurs higher up the stem and spreads down towards the ground, whereas black leg occurs from the ground up.

Hello world!
This is a Bitnami WP Multisite installation. Please check the multisite configuration guide before adding content to your sites. To learn more about Bitnami stacks...
Read More "Hello world!"

Welcome

Welcome to the Idaho Potato Diseases website. The goal of this website is to provide Idaho potato growers with reliable and up-to-date information on the identity, biology and disease-cycles, and current control methods for diseases of potatoes.

Due to the ever present threat from fungal pathogens, proper and timely diagnosis of potato diseases is paramount to effective disease management, and growers need up-to-date information to help make important decisions on optimal use and timing of pesticides and other control options. Most Idaho potato growers use some disease management practices and are seeking alternative control strategies that will help them develop practical, economically viable, and environmentally sound integrated crop management practices.

This website has been setup by the University of Idaho Potato Pathology program and is part of the University of Idaho’s continuing commitment to helping growers improve the way they manage their businesses, with an emphasis on integrated crop management, education, and safety.

Hello world!
This is a Bitnami WP Multisite installation. Please check the multisite configuration guide before adding content to your sites. To learn more about Bitnami stacks...
Read More "Hello world!"

Sample Page

This is an example page. It’s different from a blog post because it will stay in one place and will show up in your site navigation (in most themes). Most people start with an About page that introduces them to potential site visitors. It might say something like this:

Hi there! I’m a bike messenger by day, aspiring actor by night, and this is my website. I live in Los Angeles, have a great dog named Jack, and I like piña coladas. (And gettin’ caught in the rain.)

…or something like this:

The XYZ Doohickey Company was founded in 1971, and has been providing quality doohickeys to the public ever since. Located in Gotham City, XYZ employs over 2,000 people and does all kinds of awesome things for the Gotham community.

As a new WordPress user, you should go to your dashboard to delete this page and create new pages for your content. Have fun!

Volunteer Survival
Click on the map marker closest to your location to get details on the risk level of volunteer potatoes surviving over the winter in your area. The marker color indicates the risk of volunteer survival...
Foliar Diseases
In Idaho two diseases are most common on potato foliage. These are early blight and white mold. Late blight can occur in Idaho but it is appearance has been extremely sporadic in recent years. Click the leaf for a...
Welcome
Welcome to the Idaho Potato Diseases website. The goal of this website is to provide Idaho potato growers with reliable and up-to-date information on the identity, biology and disease-cycles, and current control methods for diseases...

Hello world!

This is a Bitnami WP Multisite installation. Please check the multisite configuration guide before adding content to your sites. To learn more about Bitnami stacks visit our website and to get support visit our forums. Enjoy!