Document Type

Thesis - Open Access

Award Date


Degree Name

Doctor of Philosophy (PhD)

Department / School



Excessive amounts of time and space required for water requirement measurements on individual genotypes indicate the need for a more practical method than that of direct selection for efficient water use by crop plants. The feasibility of using an indirect method of selection for this trait was examined in this study. Relative water requirements of eight oat verities, representing a wide range of adaptation, were determined. The relationship between water requirement and several commonly selected plant characters was also studied, to determine if changes in these characters could be expected to produce changes in water-use efficiency. Selections for the related characters were then made to find out whether genetic gains could be obtained in crosses among the genotypes. Highly significant differences were found among the eight verities tested for water requirement, indicating that sufficient variation existed for this character to warrant selectin for increased water-use efficiency. The strongest and most consistent relationships were found between water requirement and the two selected characters, yield (r = -.30 and -.64) and heading date (r = +.29 and +.64). In five crosses, using five of the eight verities as parents, mean contributions of yield components to yield of parents and crosses were 49.7%, 37.3%, and 13.0% for tillers per plant, seeds per tiller, and weight per seed respectively.

Library of Congress Subject Headings

Plants -- Water requirements


Includes bibliographical references




South Dakota State University