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|Title:||An Investigation Into the Resistance of Goosegrass (Eleusine Indica) to Dinitroaniline Herbicides (Biotypes, Trifluralin, Oryzalin)|
|Author(s):||Chernicky, Jon Paul|
|Department / Program:||Agronomy|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Abstract:||Research was conducted in the growth chamber and laboratory to determine if continuous dinitroaniline use in the Coastal Plain region of South Carolina has selected for a dinitroaniline-resistant goosegrass (Eleusine indica (L.) Gaertner). Seed was collected from two locations where dinitroniline herbicides were used exclusively for the past 10-12 years and from a third location which had no previous dinitroaniline history. A petridish assay was conducted with pendimethalin (N-(1-ethylpropyl)3,4 dimethyl-2,6 dinitrobenzeneamine), trifluralin ((alpha),(alpha),(alpha)-trifluoro 2,6 dinitro-N,N-dipropyl-p-toluidine) and oryzalin (3,5 dinitro-N('4)N('4)-dipropyl-sulfanilamide) indicated that resistance was associated with goosegrass that had a previous dinitroaniline history. The degree of resistance was greatest with trifluralin and pendimethalin and least with oryzalin. Sensitivity among resistant biotypes ranged from resistant to intermediately-resistant. Goosegrass, without previous dinitronaline exposure, was over 50 times more sensitive to the three dinitroanilines thus was termed susceptible.
Mitotic indicies were conducted on root tips of dinitroaniline-resistant and susceptible goosegrass to quantify their effect of mitosis. Mitosis was arrested at metaphase in the susceptible goosegrass. Polyploidy and abnormal cell shapes were evident at dinitroaniline concentrations of 1 (mu)M. Treated cells of the resistant goosegrass appeared normal, and without incidence of polyploidy or interrupted mitosis at trifluralin and pendimethalin concentrations of 16 (mu)M.
Lipid content and fatty acid distribution in dry seed and root meristems were measured in dinitroaniline-susceptible and resistant goosegrass. Seed of the resistant goosegrass contained the highest lipid level and oryzalin exposure had little influence on total lipid and fatty acid composition in root meristems. However, significant reductions in total lipid and changes in fatty acid composition were noted when the susceptible goosegrass was treated with 8 (mu)M oryzalin.
Radioautographs showed substantial acropetal movement of oryzalin and trifluralin in the dinitroaniline-susceptible goosegrass. Trifluralin plant mobility appeared restricted in the resistant goosegrass at 1 (mu)M. Oryzalin was more mobile in the resistant goosegrass at low concentrations compared to trifluralin. The greater mobility of oryzalin in the resistant biotype may be the reason that this herbicide was more active. Differences in acropetal movement of herbicides between goosegrass biotypes were overcome by increases in herbicide concentration.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1985.
|Date Available in IDEALS:||2014-12-16|