Skip to main content
ARS Home » Pacific West Area » Logan, Utah » Forage and Range Research » Research » Publications at this Location » Publication #288714
Title: Natural glyphosate tolerance in sainfoin (onybrychis viciifolia)

Author
item Peel, Michael
item RANSOM, COREY - UTAH STATE UNIVERSITY
item MOTT, IVAN

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/12/2013
Publication Date: 2/12/2014
Citation: Peel, M., Ransom, C.V., Mott, I.W. 2014. Natural glyphosate tolerance in sainfoin (onybrychis viciifolia). Crop Science. 53:2275-2282.

Interpretive Summary: Sainfoin, a non-bloating forage legume used on rangelands of the Western US, is purported to have tolerance to the herbicide glyphosate. The effect on forage yield and survival of eight rates of glyphosate on seedlings and mature plants were determined. Treatment rates were 0.0, 0.25X, 0.50X, 1X, 2X, 4X, 8X, and 16X times a rate of 841 g ae ha-1 (1 quart per acre). Alfalfa was included as susceptible check. The dose required to produce a 50% reduction in sainfoin seedling forage yield was 868 and 2,984 g ae ha-1 (1 and 3.5 quarts per acre) at the first and second harvests, respectively. The dose required to produce a 50% reduction in alfalfa seedling forage yield were 331 and 463 g ae ha-1 at the first and second harvests, respectively. The dose estimated to cause 50% mortality (LD50) in sainfoin seedlings was 14,029 g ae ha-1 (16.7 quarts per acre). The glyphosate dose required to produce a 50% reduction in mature plant forage yield of Sainfoin and alfalfa GR50 was 2,622 and 208 g ae ha-1 28 d after a spring treatment, respectively. The average LD50 value for sainfoin treatments was 11,978 g ae ha-1. The average LD50 value for alfalfa was 583 g ae ha-1. Based on the LD50 values, sainfoin seedlings are over six times more tolerant, and mature plants over 20 times more tolerant to glyphosate than alfalfa. Based on the forage yields, glyphosate has a 10-fold greater negative impact on alfalfa than it does on sainfoin.

Technical Abstract: Sainfoin (Onybrychis viciifolia Scop.), a non-bloating forage legume, is purported to have tolerance to glyphosate [N-(phosphonomethyl) glycine]. The effect on biomass yield (BMY) and survival of eight rates of glyphosate on seedlings and mature plants were determined. Treatment rates were 0.0, 0.25X, 0.50X, 1X, 2X, 4X, 8X, and 16X times a rate of 841 g ae ha-1. Alfalfa (Medicago sativa L.) was included as susceptible check. The dose required to produce a 50% reduction (GR50) in sainfoin seedling BMY was 868 and 2,984 g ae ha-1 at the first and second harvests, respectively. Alfalfa seedling BMY GR50 values were 331 and 463 g ae ha-1 at the first and second harvests, respectively. The dose estimated to cause 50% mortality (LD50) in sainfoin seedlings was 14,029 g ae ha-1. Sainfoin and alfalfa GR50 values were 2,622 and 208 g ae ha-1 28 d after the spring treatment, respectively. The spring following treatments Sainfoin and alfalfa GR50 values averaged 11,007 and 1,093 g ae ha-1, respectively. The average LD50 value for sainfoin spring and fall treatments was 11,978 g ae ha-1. The average LD50 value for alfalfa was 583 g ae ha-1. Based on the LD50 values, sainfoin seedlings are over six times more tolerant, and mature plants over 20 times more tolerant to glyphosate than alfalfa. Based on the GR50 values, glyphosate has a 10-fold greater negative impact on alfalfa BMY than it does on sainfoin.