Life Sciences Commons^™

Evaluation Of Herbicides For Suppression Of Rhizome Growth From Johnsongrass (Sorghum Halepense L.) In Corn And Soybeans, John Oakes

Masters Theses & Specialist Projects

Johnsongrass (Sorghum halepense L.) presents a serious problem in the production of corn and soybeans in Kentucky.

Various rates of the thiocarbamates, dinitroanilines, carbamates, amides, ureas, and triazines were used in association with the crops corn (Zea mays L.) and soybeans (Glycine max L.) to determine the degree of suppression on rhizomatous johnsongrass infesting the previously named crops.

Suppression was determined by selecting areas within each treated plot, counting the number of culms, then harvesting johnsongrass rhizomes. Dry weights of rhizomes were then determined as a measure of rhizome suppression.

Results show that of …

Movement Of Soil Nitrate Through A Pembroke Soil As Affected By Tillage Method And Time Of Nitrogen Application, Noel T. Johnston

Masters Theses & Specialist Projects

Of all the plant nutrients, nitrogen has been subjected to the most extensive study. The amount of inorganic nitrogen in the soil is small while the quantity needed annually by crops is comparatively large. Of the macronutrients usually applied in commercial fertilizers, nitrogen seems to have the quickest and most pronounced effect on plant growth.

In applying the nitrogen fertilizer for crop use, one must be concerned with placement, form, and availability, and with keeping the fertilizer where it is placed throughout the critical part of the growing season. The nitrogen supply molded by non-leguminous plants is of extreme importance …