Masters Theses

Date of Award

3-1962

Degree Type

Thesis

Degree Name

Master of Science

Major

Agronomy

Major Professor

Henry A. Fribourg

Committee Members

Robert S. Dotson, O. G. Hall

Abstract

Corn (Zea mays L.) is one of the most important livestock feeds in the United States. This crop is of great interest since it produces more dry matter per acre than most other crops grown in temperate climates. It is one of the crops best suited for mechanised agriculture and thereby becomes a potentially promising choice to allocate to agricultural land of high productive potential. "All corn roughage" programs and "high moisture corn feeding" programs are becoming increasingly popular. Consequently, any research finding which can increase knowledge about corn production should be of considerable importance to the livestock industry. The hybridization of corn has produced hundreds of hybrids of different growth, production and plant characteristics. A choice has to be made from among these many varieties to suit the individual farming conditions for producing optimum yields from an economic point of view. The full-season varieties may produce higher yields than the mid-season ones; but those maturing in a shorter season may allow the planting of winter crops in the fall. Such considerations make it necessary to know the actual dry matter yields of different hybrids grown for harvest at the silage stage of growth. On these points, adequate information applicable to Tennessee conditions is lacking. Much work has been done on the suitability of different plant populations for corn grain production. When corn is grown for silage, however, both the total dry matter production and the grain production must receive due consideration. Plant population becomes a factor of particular importance when considered in conjunction with other factors such as varying levels of soil fertility and moisture supply. The same rate of plant population may not be applicable to every location, and may have to vary from year to year in order that maximum economic benefit may accrue the grower. Much of the information available on this subject is extrapolated from conclusions drawn from corn grain production experiments. While some workers (15, 73, 75) have concluded that a population of about 24, 000 to 35,000 plants per acre was suitable for silage production, some others (53, 65) have felt that high populations of up to 200, 000 or 300,000 plants per acre were more suitable or promising ones for forage production. Thus, at the time of the study research verified informations are not available to serve as a basis for making management recommendations to farmers producing corn for silage. When corn is to be used for silage, the content of grain, which is an important source of carbohydrates, and that of leaves, which is the major source of protein in the total yield, are of primary importance. Furthermore, the plant population can possibly influence the proportion of grain, leaves and stems in the plant. If any of these were appreciably affected, the quality of corn silage also could be affected. Thus, the choice of the variety and of the plant population, as affecting the quality and quantity of corn plant yields, are additional questions that need to be answered. The three experiments reported here were designed to determine the effects of population on the growth and productivity of two corn hybrids harvested at the silage stage of growth. One of the varieties was a full-season hybrid (Dixie 33) and the other a mid-season hybrid (Tennessee 501). The components of production of the whole above-ground parts of the plants were determined separately in an effort to investigate the effects of population, genotype and environment on the potential quality for silage of these hybrids.

Download
Files over 3MB may be slow to open. For best results, right-click and select "save as..."

Share

COinS