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Thesis (M.S.)—University of Nebraska—Lincoln, 1970. Department of Agricultural Engineering.


Copyright 1970, the author. Used by permission.


This study involves the determination of the base temperature for grain sorghum, so that heat units can be used to predict the stage of plant growth at any time.The number of heat units required for emergence is determined.

Seed viability is also an important factor in producing good stands.This study determines the relationship of seed density and weight to germination and emergence for grain sorghum.

The effect of seed weight and density on grain sorghum germination and emergence was studied in a growth chamber.It was concluded from this study that the seed weight does not affect seed germination and plant growth, but that the seed density is related to grain sorghum seed germination and seedling growth.

Time for emergence was the same for the four varieties at any given temperature.It was concluded from this that the number of heat units required for emergence is a constant for the four varieties of grain sorghum used in this study.

The emergence dropped from 91 percent at 82⁰F to 66 percent at 65⁰F.It was concluded that for good stands the seeds should be planted when the smallest amount of time elapses between planting and emergence.Heat unit theory used in conjunction with climatological data and weather forecasts can predict when to plant for optimum stands.

Advisor: Howard D. Wittmuss