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ARS Home » Plains Area » Brookings, South Dakota » Integrated Cropping Systems Research » Research » Publications at this Location » Publication #306938
Title: Organic foliar Milstop shows efficacy against soybean aphid (Aphis glycines) on soybean (Glycine max)

Author
item ROZEBOOM, PHIL - South Dakota State University
item TILMON, KELLEY - South Dakota State University
item Hesler, Louis

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/30/2014
Publication Date: 5/30/2014
Citation: Rozeboom, P., Tilmon, K., Hesler, L.S. 2014. Organic foliar Milstop shows efficacy against soybean aphid (Aphis glycines) on soybean (Glycine max). Abstract, Entomology 2014, ESA’s 62nd Annual Meeting, November 16-19, 2014, Portland OR.

Interpretive Summary: Soybean has been produced in the U.S. since 1765, but the crop was free of major pests in the upper Midwest of the U.S. until soybean aphids were first detected there in 2000. The aphids cause an estimated yield loss of up to US$4.9 billion annually. Organic soybean producers have few insecticide products available for soybean aphid control. One potential product is Milstop® (85 percent potassium bicarbonate), a broad spectrum foliar fungicide that has recently shown insecticidal activity against soybean aphid. The purpose of this study was to characterize Milstop’s efficacy against soybean aphid in both growth-chamber and field-cage tests. In growth-chamber tests, Milstop’s active ingredients had no significant effect on soybean aphid populations, but the product as a whole directly reduced aphid populations by 94 percent after 48 hours. In field-cage tests, Milstop non-significantly reduced aphid populations from 24 to 46 percent compared to the water control and non-significantly preserved soybean yield by 48 percent. Although Milstop’s efficacy against soybean aphid was demonstrated, further study is needed to determine application schemes in which it can maintain soybean aphid populations below economically injurious levels in organic soybean and to isolate ingredient(s) that are responsible for soybean aphid control.

Technical Abstract: Soybean (Glycine max (L.) Merr.) has been produced in the United States since 1765. Soybean aphids (Aphis glycines Matsumura) were first detected on soybean in the United States in 2000 and now cause an estimated yield loss of up to US$4.9 billion annually. Organic soybean producers have few insecticide products available for soybean aphid control. One product may be Milstop® (85 percent potassium bicarbonate), a broad spectrum foliar fungicide that is registered organic and has recently shown insecticidal properties, including efficacy against soybean aphid. The purpose of this study was to determine Milstop’s efficacy against soybean aphid in both growth-chamber and field-cage tests. In growth-chamber tests, Milstop’s active ingredient had no significant effect on soybean aphid populations but the product as a whole directly reduced soybean aphid populations by 94 percent after 48 hrs. In field-cage tests, Milstop non-significantly reduced soybean aphid populations from 24 to 46 percent compared to the water control and non-significantly preserved soybean yield by 48 percent. Although Milstop’s efficacy against soybean aphid was demonstrated, further study is needed to determine application schemes in which it can maintain soybean aphid populations below the economically injurious levels in organic soybean and to isolate the ingredient(s) within Milstop that are responsible for efficacy against soybean aphid.