Issue link: http://read.uberflip.com/i/802944
34 POTATO GROWER | APRIL 2017 Diggin' In Diggin' In Diggin' In Diggin' In Diggin' In Diggin' In SEED | By Jeff Miller, Miller Research & Nora Olsen, University of Idaho Variety susceptibility to Fusarium dry rot and how to manage seed decay Open Wounds Great care is taken to minimize wounding, bruising, and abrasions at harvest, in order to limit entry of the pathogens that cause Fusarium dry rot and other diseases. When seed is cut prior to planting, the greatest wounding just occurred to the potato tuber: a cut with a large surface area. Fortunately, potatoes have the ability to heal these wounds by creating their own Band-Aid: wound periderm. The wound periderm is the outermost layer of tissue on a potato tuber that forms after a wound is inflicted on the surface of the tuber. The process of wound healing will depend upon several factors, including the type of wound, variety and wound healing conditions. After seed is cut, the objective is to protect the wound to stop any invasion by Fusarium dry rot or bacterial soft rot pathogens. This can be accomplished by winning the race between the wound healing process and the pathogen, and/or protecting the surface with a seed treatment. The rate of wound healing from the cut surface is a function of variety and environmental conditions. Warmer temperatures will accelerate the wound healing process. General recommendations are to increase seed temperatures to at least 45 degrees Fahrenheit prior to handling to avoid bruising and shattering upon cutting. Wounds will heal much slower at temperatures of 45 degrees or lower than at 50 or 55 degrees. Therefore, it is best to plant into soil with favorable wound healing temperatures and conditions. Planting cold seed into warm, wet soil can produce conditions on the surface of the cut seed favorable for condensation and increase the risk of seed decay. Varieties can respond differently to the wound healing process; some are faster and some are slower than the oft-grown Russet Burbank. There is also a wide range in susceptibility to Fusarium sambucinum dry LOW Alturas Russet Norkotah Teton Russet MODERATE Classic Russet Russet Burbank Sage Russet Bannock Russet Blazer Russet Owyhee Russet Mountain Gem Russet Ranger Russet Umatilla Russet HIGH Clearwater Russet Alpine Russet Payette Russet Russet variety susceptibility to Fusarium dry rot (F. sambucinum) development in storage.