Life Sciences Commons^™

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 …

Determining A Crop Production Function For Corn As Influenced By Irrigation And Salinity Levels, Timothy E. Sullivan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Production functions were generated for dry matter and grain yields of corn, A continuous variable plot design replicated four times was established in the spring of 1974 in Vernal, Utah. Each replication included ten salt treatments and twenty irrigation levels. The salt treatments resulted in an average root zone salinity ranging from 2 . 7 to 14.9 mmhos/cm. Irrigation levels ranged from 4.2 to 45.0cm of water applied. Dry matter (Kg/ha) yield showed an 83 percent reduction over the range of salt applied and a 52 percent reduction over the range of water applied. Grain yield declined 96 and 64 …

Hereford And Holstein Steer Performance On High Grain Diets With And Without Corn Silage, Cyril Bruce Russell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A factorially designed experiment had 18 Hereford and 18 Holstein steers on individually fed, high-grain diets. One diet included 59% rolled barley, 30% CSF beet pulp, 5% protein, vitamin, mineral, and stilbestrol supplement, and 6% chopped hay and straw. The other diet had corn silage (11% air dry matter equivalent) substituted for the chopped roughage and 5% of the beet pulp. The Holsteins were heavier at the start, 752 lb. as compared to the Herefords 686 lb. average. The weight differential was maintained throughout the approximately 180-day trial. The Holstein's feed consumption and rate of gain, 23.4 and 2.71 lb. …

The Effect Of Limited Moisture Supply At Various Stages Of Growth On The Development And Production Of Hybrid Corn, Ralph E. Campbell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Corn occupies from 25 to 30 percent of the crop land harvested in the United States. In recent years the acreage devoted to corn in this country has been decidedly greater than that devoted to any other cultivated crop. In 1944 its dollar value exceeded the combined values of wheat, barley, rye, grain sorghums, and cotton.

Although South Dakota lies on the northwestern fringe of the corn belt, the corn crop is one of the most important in that state. Corn production in that area is somewhat unstable because of drought. Corn often fails to reach full maturity before the …

The Effects Of Fertilizer And Moisture On The Yield Of Sweet Corn, Rex F. Nielson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sweet corn is rapidly becoming an important cash crop in many of the irrigated regions of the intermountain West. The lacome from this crop is relatively small in comparison to that from other major agricultural products; however, sweet corn production has a definite place in the economy of the region.

One of the factors limiting increasing acreage of sweet corn in many areas is low yields. Yields have been increased naterially in recent years with the development of hybrid varieties, superior to the standard varieties previously used. Better cultural practices are improving yields, but much remains to be done in …