Potential of Managing Iron and Zinc Deficiency in Dry Beans with Interplantings of Annual Ryegrass.
Emmanuel C. Omondi1, Mike Ridenour2, Cindy Ridenour2, and Rik Smith1. (1) Department of Plant Sciences, University of Wyoming, 1000 E University Avenue, Department 3354, Laramie, WY 82071, (2) Meadow Maid Foods, 133 Rd. 50, Yoder, WY 82244
Beans (Phaseolus sp) are extensively grown throughout the western Great Plains. However, high pH soils prevalent in this region limit the availability of many micronutrients, especially zinc and iron. Iron deficiency in high pH soils results in interveinal chlorosis in beans, and a higher susceptibility to insect and disease damage thereby reducing yield and quality. A Wyoming farmer observed that dry beans grown with an intercrop of annual ryegrass (Lolium multiflorum) did not exhibit any iron-deficiency chlorosis and produced better than beans grown without the ryegrass intercrop. Field studies were conducted in Goshen County, Wyoming in 2006 to test the hypothesis that an annual rye intercrop may result in increased iron availability in a pinto bean field. Treatments included: beans planted in annual rye residue incorporated in the soil; bean-annual rye intercrop; and beans planted alone as a control. There was significantly higher soil iron and zinc availability in the bean-annual rye intercrop compared to beans alone. Iron concentration in bean leaves declined in all treatments but at a lower rate in the bean-annual rye intercrop and beans with annual rye residue treatments compared to the control, though this difference was not significant.