Natural Glyphosate Tolerance in Sweetvetch Hedysarum boreale. Issue 5 (1st September 2015)

• Record Type: Journal Article
• Authors: Peel, Michael D.; Ransom, Corey V.; Mott, Ivan W.; Waldron, Blair L.
• Is Part Of: Crop science. Volume 55:Issue 5(2015)
• Page Start: 2368
• Page End: 2376
• Publication Date: 2015-09-01
• Subjects: Crop science -- Periodicals; Cultures -- Périodiques; Cultures de plein champ -- Périodiques; Crop science; Nutzpflanzen; Zeitschrift; Pflanzenbau; Periodicals; 633
• DOI: 10.2135/cropsci2014.08.0571
• Languages: English
• ISSNs: 0011-183X

Abstract

ABSTRACT: Sweetvetch ( Hedysarum boreale Nutt.) is purported to tolerate glyphosate [ N ‐(phosphonomethyl) glycine]. Eight rates of glyphosate were tested for their effect on biomass (BM) and survival of seedlings and mature plants. Rates were 0, 210, 420, 841, 1681, 3363, 6725, and 13, 450 g a.e. ha –1 . Tall fescue ( Festuca arundinaceae Schreb.) was included as a susceptible check. Doses required to cause 50% reduction (GR50 ) in sweetvetch seedling BM was 5025 and 1636 g a.e. ha –1 at first and second harvests, respectively. Tall fescue seedling BM GR50 values were 373 and 512 g a.e. ha –1 at first and second harvests, respectively. Seedling mortality in sweetvetch was not sufficient to estimate an LD50 ; however, in tall fescue the seedling LD50 was 987 g a.e. ha –1 . Four weeks after spring field treatments, sweetvetch and tall fescue BM GR50 values were 3467 and 549 g a.e. ha –1, respectively. Thirteen months later BM GR50 estimates were 11, 595 and 886 g a.e. ha –1 for sweetvetch and tall fescue, respectively. Fall‐applied glyphosate did not reduce BM in the sweetvetch sufficient to estimate a GR50 . Tall fescue estimated BM GR50 was 413 g a.e. ha –1 . At the three lowest treatments BM of sweetvetch mature plants was unaffected. Survival of mature sweetvetch plants was ≥70% precluding estimates of LD50 values. The LD50 's for tall fescue spring and fall treatments was 751 and 541 g a.e. ha –1, respectively. Based BM GR15 values sweetvetch will withstand a glyphosate rate of 670 g a.e. ha –1 with no mortality or negative effect on subsequent harvests.