About Us | Help Videos | Contact Us | Subscriptions

Agronomy Journal Abstract -

Forage Legume Response to Dicamba and 2,4-D Applications1


This article in AJ

  1. Vol. 76 No. 3, p. 487-490
    Received: Apr 25, 1983

Request Permissions

  1. J. L. Griffin,
  2. V. H. Watson,
  3. W. E. Knight and
  4. A. W. Cole2



Weed control options in pastures containing legumes are limited due to herbicide selectivity. A field study was conducted for 2 years in northeast Mississippi on a Leeper fine sandy loam (fine, montmorillonitic, nonacid, thermic Vertic Haplaquept) soil to evaluate tolerance of subterranean (Trifolium subterraneum L.), white (T. repens L.), crimson (T. incarnatum L.), red (T. pratense L.), and arrowleaf (T. vesiculosum Savi) clovers and vetch (Vicia sativa L.) to dicamba (3,6-dichloro-o-anisic acid), 2,4-D [(2,4-dichlorophenoxy) acetic acid], and a 3:l (W:W) mixture of 2,4-D + dicamba. Stands of all clover species were generally reduced where dicamba at 0.56 kg ha−1 and where 2,4-D + dicamba at 0.42 + 0.14 or 0.84 + 0.28 kg ha−1 were applied. Forty-five days after herbicide application legume yields, with the exception of crimson clover, were reduced at least 24% when treated with dicamba. Yields of all clover species were severely reduced where 2,4-D + dicamba was applied ranging from 50% for subterranean to 84% for red clover. Subterranean clover yield was not affected and white clover yield was only slightly reduced (28%) where 2,4-D at 1.12 kg ha−1 was applied; yields of other clover species were markedly reduced. Vetch was killed with all herbicides applied. To determine residual activity, bermudagrass [Cynodon dactylon (L.) Pers.] sod was treated with dicamba and 2,4-D + dicamba 120, 90, 60, 30, and 15 days prior to overseeding crimson and white clover on 1 October. The study was conducted for 2 years on a Leeper fine sandy loam soil. Application time of dicamba at 0.28 kg ha-' and 2,4-D + dicamba at 0.42 + 0.14 kg ha−1 did not affect crimson or white clover yields measured in mid-May. However, crimson and white clover yields were reduced an average of 39 and 55% where dicamba was applied at 0.56 and 1.12 kg ha−1, respectively, and 37% when 2,4-D + dicamba was applied at 1.68 + 0.56 kg ha−1 15 days prior to overseeding compared to 30 days. Selective broadleaf control can be obtained by using 2,4-D at 1.12 kg ha−1 in pastures containing subterranean and white clover. Dicamba at 0.56 kg ha−1 or 2,4-D + dicamba at 1.68 + 0.56 kg ha−1 should be applied to warm-season grass pasture at least 30 days prior to overseeding in order to avoid residual activity on overseeded legumes.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © .