​​Internal Heat Necrosis of Potato

April 2012 | 39 min., 36 sec.
by Craig Yencho
North Carolina State University


​Internal heat necrosis (IHN) is a nonpathogenic physiological disorder of potato tubers. It was originally described in the early 1900s and has also been called internal brown spot, physiological internal necrosis, internal browning, internal brown fleck, and chocolate spot. Potatoes with IHN have light-brown to reddish-brown necrotic patches in the parenchyma (flesh) of the tuber. There are no aboveground symptoms and no external symptoms on the tubers. IHN is generally a significant problem in the mid-Atlantic and southeastern United States, but it can also a problem in other regions of the country when high temperatures and drought prevail. This talk will cover various aspects of IHN, including symptoms and control, risk factors for developing IHN, models to predict the occurrence of IHN, varietal resistance to IHN, and current research efforts to develop IHN-resistant potato varieties.

About the Presenter

Craig YenchoCraig Yencho is a Professor in the Department of Horticultural Science and leader of the Sweetpotato and Potato Breeding and Genetics projects at North Carolina State University. He has active research projects involving the biochemical char​acterization and genetic mapping of important traits in potato and sweetpotato; plant resistance to insects and pathogens; the development of value-added and bio-based products, including fries, chips, natural colorants, and renewable fuels from potato and sweetpotato; the development of ornamental sweetpotatoes for the ornamental and floricultural industries; and farmer participatory breeding and international agriculture, primarily in eastern and southern Africa.

Contact Information:
Email: Craig_Yencho@NCSU.edu


In 2020, Grow webcasts had more than 110,000 views. Help support our mission to provide comprehensive high-quality, science-based resources to and for plant health researchers and practitioners at no cost.

PDMR submission guidelines and schedule information are available online.


Plant Health Progress is a peer-reviewed multidiciplinary, online journal of applied plant health.