Date of this Version
Thesis (M.S.)–University of Nebraska–Lincoln, 1948. Department of Agronomy.
Spraying of winter wheat was done October 30 by use of a PT 17 biplane. Dosages as low as 0.15 pound of butyl ester type of 2, 4-D in 2.5 gallons of Diesel fuel diluent resulted in 100 per cent kill of pennycress (Thlaspi arvense) and treacle mustard (Erysimum repandum).None of the three types of 2, 4-D resulted in satisfactory kill when water was used as the diluent.Goosenecking of the top internode and in some cases the rachis was the greatest effect caused by 2, 4-D on the wheat.Approximately fifty per cent of the tillers on the treated plants showed goosenecking.Sterility as well as light shriveled berries resulted from the goosenecking of the rachis.There was no consistent correlation between the rates of 2, 4-D used and the yields obtained.However, yields varied, a few being higher than those of the check plots, but most yields were somewhat reduced in these experiments.No reduction in germination resulted in these experiments.No reduction in germination resulted from 2, 4-D.
Spraying of soybeans was done August 7 using a hand sprayer. When observed 24 hours after spraying, all sprayed plants were showing characteristic wilting of the leaves as well as a lax condition of the stems which resulted in lodging.Within a few days recovery from wilting as well as from the lax condition was apparent.However, definite 2, 4-D injury was evident. Leaf-burning and chlorosis occurred with the two higher dosages of the ester formulations.All type formulations expressed epinastic curvature of the stems.Dosage levels below ½ pound for the salts and ¼ pound for the esters continually recovered more from early 2, 4-D effects, whereas dosages above ½ pound and ¼ pound for the salts and esters respectively continued to show more injury. No killing of the plants resulted from any type formulation at the 1/8-pound level nor for dosages of ¼ pound and ½ pound of the amine and sodium salts.
Advisor: F.D. Keim