Degree Name

Master of Science (MS)

Semester of Degree Completion

1982

Thesis Director

Charles B. Arzeni

Abstract

The American persimmon (Diospyros virginiana L.) is a deciduous tree native to the Southeastern United States, and is the only genus of the Ebenaceae that is indigenous. This study is a complete reveiw of what is known about this species concerning taxonomy, ecology, morphology, history, distribution, anatomy, cytology, propagation, diseases, and pests, toxicity, chemical composition, and economic values.

The sexuality and fruit production of the persimmon is variable and not well understood. The small bell shaped flowers are usually dioecious, but they may also be monoecious, or monoecious in one year and dioecious in another. In rarer instances they are perfect. Apomitic mechanism may also be present.

The fruit is a true berry. They exceed all other fruits of the temperate zone in food value. It contains 19 of the 20 amino acids and is high in vitamin C. Proline is the most abundant amino acid followed by glutamine, serine, arginine, and traces of the others. Asparagine is absent. The fruits are astringent before ripening and become soft when ripened. A suitable method for ripening fruits has not been developed.

Persimmon is one of our heaviest and strongest native woods. It has the outstanding properties of stiffness, strength in bending and end wise compression, plus the ability to withstand severe shockloads. It is the prefered wood for shuttles employed in weaving.

The persimmon is an environmentaly important tree. In Southern Illinois it was found to be a dominant tree in the succession of old fields characterized by high radiation loads and temperature. The leaves light saturate at approximately 5,500 foot candles with a rate of photosynthesis of 17 mg CO2 dm-2h-1. The American persimmon is well adapted to high isolation and low water supply. It will form thickets on dry eroding slopes, roadsides and grows on coal stripped lands. It is also a grainery for many wild animals in late fall and winter.

There are two chromosome races of D. virginiana consisting of a 60 chromosome tetraploid race and a 90 chromosome hexaploid race. The tetraploid race is found in the Southeastern portion of its range, while the hexaploid race occurs West and North.

Economically, the American persimmon is not of much importance. The fruits are usually too soft to market after ripening. The tree produces an excellent timber and has been in great demand for a number of high grade uses. As a result, forest drain has greatly exceeded the rate of replacement. Therefore, persimmon timber of high quality is in short supply. The tree has a few medicinal properties, and the leaves can be brewed to make a tea high in vitamin C. It is an extremely hardy tree virtually disease free. The wood is resistant to termites, and the main termicidal component has been identified as 7-methyljuglone. This native tree is so prolific that it is considered a weed in some areas.

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