Life Sciences Commons^™

Pb1544 Comparing The Cost Of Broadcasting Versus Injecting Nitrogen In No-Tillage Corn, The University Of Tennessee Agricultural Extension Service

Field & Commercial Crops

No-tillage has become a popular production option with many Tennessee farmers in the past 20 years. In 1993, no-tillage production systems were used on 290,000 acres of corn in Tennessee, or 44 percent of the total corn acreage planted in the state (TDA). Many farmers see no-tillage as a way to reduce the cost of growing corn. Others have chosen no-tillage as a way to comply with governmental regulations covering the farming of highly-erodible soils.

Input levels and prices are important to consider in any production system. A major expense in corn production is nitrogen (N) fertilizer. No-tillage budgets published …

Use Of Microprojectile Bombardment In Transient Expression Assays To Analyze Protochlorophyllide Reductase Gene Expression In Greening Maize Seedling Leaf Cells, Jennifer J. Marden

Senior Scholar Papers

In young cells of leaf meristems the progenitors of chloroplasts are small organelles known as proplastids, which divide and differentiate into chloroplasts. However, in the absence of light, proplastids undergo a different sequence of development and become etioplasts. When light is supplied to etiolated plants during the "greening" process, etioplasts differentiate into chloroplasts containing chlorophyll. An important light dependent step in chlorophyll biosynthesis is the photoreduction of protochlorophyllide to chlorophyllide by the NADPH:protochlorophyllide reductase (PCR) enzyme. This enzyme is present at high activity only in etiolated tissue and during early stages of light-induced chlorophyll synthesis. The enzyme and its corresponding …

Effects Of Wheat Middlings On Utilization Of Mature Prairie Hay By Steers, J. S. Heldt, R. J. Pruitt

South Dakota Beef Report, 1995

A digestibility trial measuring intake, digestibility, ruminal nutrient disappearance, and ruminal pH was conducted to determine the effects of wheat middlings on utilization of mature prairie hay. Treatments included supplements used in a previous winter grazing trial at the SDSU Cottonwood Research Station that were balanced to provide the following amounts of crude protein (Ib) and metabolizable energy (Mcal) per cow daily: 1) soybean meal .75 and 2.40, 2) low wheat middlings .75 and 4.76, 3) corn-soybean meal 1.50 and 9.40, and 4) high wheat middlings 1.50 and 9.40. These supplements were fed to the steers in proportional amounts based …

Lime Source And Rate Effects On Corn Production On An Acid Soil, Kenneth L. Wells, James E. Dollarhide, V. W. Case

Agronomy Notes

Quality of lime available for use in neutralizing soil acidity can be quite variable in Kentucky. This sometimes raises questions of which locally available source is most effective. Information about the quality of individual lime sources is necessary to make such determinations.

Ec96-144 Fertilizer Management For Conservation Tillage, Charles A. Shapiro, Richard B. Ferguson

University of Nebraska-Lincoln Extension: Historical Materials

Conservation tillage as a means of reducing soil erosion has increased in popularity due to government conservation compliance and economic factors. Management of crops under reduced tillage has necessitated changes in the use of several inputs. The goal of this publication is to focus on the use of fertilizers under reduced tillage with special emphasis on corn production practices.

Ec95-1560 Use Of Cultural Practices In Crop Insect Pest Management, Robert J. Wright

University of Nebraska-Lincoln Extension: Historical Materials

This Extension Circular reviews what is known about the effects of rotations, tillage practices, and planting and harvest dates on crop insect management, focusing on major crops in Nebraska.

Before the development of synthetic organic insecticides (pre-DDT era), rotations, tillage practices, planting and harvest dates, and other nonchemical cultural controls were commonly recommended for insect management. Research focused on crop rotation and other cultural practices for insect management. With the development of DDT and later insecticides however, research on nonchemical controls decreased markedly.

With the emergence of the concept of sustainable agriculture in the 1980s, there has been increased emphasis …

Inheritance And Number Of Genes Affecting Quantitative Traits Within F2 Maize Populations, D. H. Schmidt, A. R. Hallauer

Journal of the Iowa Academy of Science: JIAS

Populations derived from crosses of elite genotypes are commonly used in plant breeding programs. Knowledge of the genetic variation among individuals and their progenies within F2 populations is essential for effective selection of important traits. The genetic variation and number of effective factors affecting the expression of quantitative traits within 30 F2 maize (Zea mays L.) populations were determined by different methods suggested for study of F2 populations. Estimates of heritability and number of effective factors varied among F2 populations for each trait, primarily because of the differences in trait expression between parents of crosses and the environmental effects upon …