Internal Heat Necrosis, or IHN, has many aliases. They include internal brown spot, physiological internal necrosis, internal browning, internal brown fleck, and chocolate spot.
Whatever you choose to call this physiological disorder, it is an economically significant problem, particularly in the mid-Atlantic and southern United States. It is also the latest topic addressed in Focus on Potato, the Plant Management Network's nonprofit webcast resource for potato growers and consultants.
In this talk, Dr. Craig Yencho, Professor in the Department of Horticulture at North Carolina State University, covers various aspects of IHN including symptoms and control, when a crop is at risk of developing IHN, models to predict the occurrence of IHN, varietal resistance to IHN, and current research efforts to develop IHN resistant potato varieties.
This presentation is open access through June 30, 2012, and can be viewed at the link listed below. Users can view other recent webcasts in the Focus on Potato resource with a paid subscription.
Focus on Potato is a publication of the Plant Management Network (PMN), a nonprofit online publisher whose mission is to enhance the health, management, and production of agricultural and horticultural crops. It achieves this mission through applied, science-based resources. PMN is jointly managed by the American Society of Agronomy, American Phytopathological Society and Crop Science Society of America.
http://www.plantmanagementnetwork.org/edcenter/seminars/potato/HeatNecrosis