Date of Award
Master of Science
Henry A. Fribourg
Gordon E. Hunt, Horace C. Smith
The permanent and semi-permanent pastures composed of perennial grasses and legumes seldom produce adequate amounts of forage during the hot, dry summer months. If these pastures are to be utilized to the fullest extent, some form of summer supplementary forage must be available during these periods of low production of the legume-grass pastures. The use of summer annual supplementary forage species is becoming more popular, especially with the dairy farmer, to partially solve this feed shortage problem.
Pearlmillet (Pennisetum glaucum (L.) R. Br.) is one species that appears to be particularly well-suited for use as a summer supplemental forage grass in Tennessee and other southeastern states. It is a summer annual which grows better than most forage crops during the hot, dry, summer weather. It does not contain any prussic acid-forming glucosides or other known poisonous constituents. At the present time, it is more resistant to the pathogens that affect other plants such as Sudangrass (Sorghum sudanense (Piper) Stapf.). It produces more high quality forage during the summer than does most of the other grasses, and maintains a high level of production under unfavorable climatic conditions that often reduces the quality and production of perennial grasses.
There is, however, a lack of knowledge of the basic management factors necessary to realize the greatest potential from this crop as a pasture, hay, silage, or soilage species. Information is lacking particularly in the area of carbohydrate reserves in relation to regrowth and production of high quality forage, as influenced by various management factors.
Some research has been conducted on the cutting, grazing, and fertilization management of the crop in relation to the influences of management on regrowth, production, morphological development, and nitrogen content of the plants. However, just what Influences the carbohydrate reserves have on these factors, or what influences cutting height and nitrogen fertilization have on the reserve carbohydrates, are not known.
With these problems in mind, an investigation was conducted in an attempt to answer the following questions:
1. How close to the soil surface can pearlmillet be cut and still produce good yields of high quality forage?
2. How does different cutting intensities affect total forage yield?
5. How does nitrogen fertilization and cutting intensities affect the rate and amount of regrowth?
4. How does nitrogen fertilization and cutting Intensities affect the amount of reserve carbohydrates available for utilization in initial regrowth?
5. Does the carbohydrate content of the basal stubble vary with different heights of stubble and different amounts of nitrogen fertilization?
6. How does cutting frequency affect the carbohydrate reserves?
7. Does carbohydrate reserves affect the rate of regrowth?
8. How accurate and useful is the refractometer in determining the carbohydrate content of plants?
9. How accurate and useful is the enthrone method of carbohydrate analysis for analyzing plant material?
Couch, Richard W., "A study of management effects on carbohydrate reserves in Gahi-1 pearlmillet. " Master's Thesis, University of Tennessee, 1961.