U of I, ARS Work On 'Bacteria' Products

University of Idaho and Agricultural Research Service scientists are working on a collaborative project to see if spraying potatoes with a harmless bacteria will delay sprouting, suppress dry rot and possibly shield tubers from late blight disease.

Patricia Slininger and David Schisler at the ARS National Center for Agricultural Utilization Research in Peoria, IL, and colleagues patented methods for using 18 strains of Pseudomonas and Enterobacter bacteria to stymie postharvest sprouting and dry rot.

Caused by the fungus Fusarium sambuciunum, dry rot costs $100 million in losses in stored potatoes, which comprise 70 percent of the nation's $2.7 billion tuber crop.

The scientists have reported that their discovery of the spray-on bacteria also stymies infection of stored potatoes by Phytophthora infestans, the fungus-like organism responsible for late blight.

This disease causes losses of over $400 million in the U.S. crop alone and many more throughout the world. The emergence of fungicide-resistant strains of late blight has exacerbated the problem, according to Schisler.

In warehouse simulation studies at the University of Idaho in Kimberly, ID, scientists sprayed boxes of potatoes with mixtures of late blight and bacteria. In those studies, the bacteria curbed late blight by 35-91 percent.

A Florida company, Jet Harvest Solutions, already has a product, Bio-Save, available for growers. Several growers in Idaho are using  micro-misting applications on potatoes going into storage this fall.

Bio-Save contains Pseudomonas syringae, a naturally occurring biological control agent which was isolated over 10 years ago from produce materials.It is labeled to control dry rot and silver scurf.

Jet Harvest recently purchased the product from Village Farms LP. The EPA has approved the use of the freeze-dried formulation of Bio-Save 10 LP as a naturally occurring postharvest biocontrol agent.