Potato XXII – 19

Treating Potatoes Entering Storage

Gary D. Franc

Fusarium dry rot is a common storage disease and can be very destructive. This disease is caused by several species of the fungus Fusarium. This fungus survives in soil, crop refuse, and on contaminated equipment, walls, and floors of potato storages. Since they are soil borne, tubers have the potential to carry the fungus on their surface. A wound or a bruise, is necessary for the pathogen to become established and most tuber infections occur through wounds inflicted during harvest or storage. Any conditions that reduce the rate of wound healing increase the potential for losses from Fusarium. Control of Fusarium tuber rot can be aided by harvesting only mature tubers with well-set skins and handling the tubers in such a manner as to minimize bruising. Harvest when tuber temperatures are above 45° F to reduce bruising. Pad equipment surfaces to reduce tuber injury during handling and always run equipment at capacity. Sanitation of equipment and storage areas will reduce potential losses by killing and removing spores. Fungicides applied to tuber surfaces may reduce decay, if the fungus has not developed resistance. Application equipment should provide complete coverage of each tuber with the protectant spray. To insure maximum benefits from the treatment, situate nozzles on the bin piler. Separate soil, diseased tubers and other debris prior to treatment. Avoid getting the tuber too wet, as this will predispose tubers to additional storage problems.

Product list for treating potatoes entering storage:

Product	Disease	Product	Remarks
(grouped by active ingredient)
Sodium Hypochlorite
Agclor 310	Decay causing organisms	10-15 fl oz per 100 gal water	For treating potatoes in a pit system use a concentration of 100 to 15 ppm C12.
Thiabendazole
Decco Salt No. 19	Fusarium Tuber rot	5.67 per 2000 lb of potatoes	Seed potatoes should be treated before cutting.
Mertect 340-F	Fusarium Tuber rot	Conveyer line: 0.42 fl oz per 2000 lb of potatoes; Dipping: 0.42 fl oz per 1 gal water, dip tubers for 20 sec.	Seed potatoes should be treated before cutting.
The information herein is supplied with the understanding that no discrimination is intended and that listing of commercial products, necessary to this guide, implies no endorsement by the authors or the Extension Services of Nebraska, Colorado, Wyoming or Montana. Criticism of products or equipment not listed is neither implied nor intended. Due to constantly changing labels, laws and regulations, the Extension Services can assume no liability for the suggested use of chemicals contained herein. Pesticides must be applied legally complying with all label directions and precautions on the pesticide container and any supplemental labeling and rules of state and federal pesticide regulatory agencies. State rules and regulations and special pesticide use allowances may vary from state to state: contact your State Department of Agriculture for the rules, regulations and allowances applicable in your state and locality.

Categories: Potato, Potato storage

Date: February 24, 2002