Plant Sciences Commons^™

Herbicide Effects On Cultivars Of Soybeans [Glycine Max (L.) Merr.], Mark Martin

Masters Theses & Specialist Projects

Breeding herbicide-tolerant cultivars is a means of extending herbicide utilization. In 1983 and 1984, 20 soybean [Glycine max (L. Merr] cultivars were screened for their reactions to the following herbicides: metribuzin 4-amino-6-(tert)-butyl-3-(methylthio)-astriazin-5-(4H)-one]; vernolate (S-propyl dipropylthiocarbamate); and fluchloralin [N-(2-chloroethyl)-2,6-dinitro-N-propyl-4-(trifluoromethyl) aniline]. Each herbicide was applied at the recommended rate X, 2X, and 4X in 1983. An 8X rate was added in 1984. The recommended rates (X) for the herbicides were as follows: metribuzin 0.42, vernolate 2.80, and fluchloralin 1.12 kg/ha. The cultivars were Pella, Pixie, Cumberland, Williams, Essex, Union, Semmes, Tracy, Tracy M; North American Plant Breeders 350, 68225, 420, and …

Ultrastructural Effects Of Sethoxydim On The Intercalary Meristem Of Johnsongrass (Sorghum Halpense), Bobbie Dowden

Masters Theses & Specialist Projects

This investigation represents one of the first electron microscopic studies on determining the mode of action of the chemical herbicide sethoxydim, 2-[-1-(ethoxydimino)butyl] -5-.2-(ethiothio)propyl]-3- hydroxy-2-cyclohexen-1-one. Samples were excised from the intercalary meristem of johnsongrass (Sorghum halpense) at time intervals of 1,3, 6,12,24,36,48,60, and 72 hours and examined using electron microscopy. Transmission electron micrographs revealed that cellular activity shows alterations or abnormalities as early as six hours. Membranes show deterioration at this time and chloroplasts contain densely staining starch granules. As time intervals increase, cellular degradation becomes more evident. Nuclear membranes extend outward into the cytoplasm in various types of …

The Effect Of Tillage Methods & Row-Widths On Selected Growth Characteristics & Yield Of Soybeans, G. Tom Sandifer Jr.

Masters Theses & Specialist Projects

The effect of three tillage methods confounded with three row widths on root length and depth, seed density, seeds per pod, pods per plant and yield of Glycine max was studied during the 1984 growing season. The study was conducted on class 1, Pembroke soil located in south Warren County, Kentucky. A barley crop was removed from the area just prior to the experimental plantings. A John Deere conservation tillage, plateless planter was used in all experimental treatments except the drilled plots. Plant populations were adjusted to conform to standard recommendations for drill (7 inch row widths), 15-inch row widths, …

The Performance Of Gazania Splendens Cultivars Under Kentucky Conditions, Ellen Sue Justiss

Masters Theses & Specialist Projects

Gazania splendens is a tender, herbaceous perennial that belongs to the Compositae family. The leaves are green and glabrous above, white tomentose beneath, toothed, simple and/or pinnatifid, 4”-6” long tapering to a winged petiole, lanceolate to obovate-lanceolate, and arranged in a basal clump. The flower heads are large, showy, 2”-3” in diameter, and range in color from white to yellow, orange, pink, purple, ruby, and bronze with a dark ring or spot at the base of most.

Twelve cultivars of Gazania splendens were to be evaluated to determine which would perform the best under Kentucky conditions. A seed germination test …