The growth habits and chemical composition of bromegrass, Bromus inermis Leyss, as affected by different environmental conditions

Bromegrass, Bromus inermis Leyss, was studied with respect to (a) the effects of nitrogen fertilizer, shade, shade combined with nitrogen fertilizer, and mixture with alfalfa upon the growth habits and chemical composition: and (b) the effects of length of day upon such qualities and characteristics. The results may be summarized as follows: Fertilization with nitrogen increased the rate of leaf production, height and total number of shoots, number of fertile shoots, and dry weight of tops, but decreased the number of rhizomes and weight of the underground parts. Shade decreased the number of shoots, number of rhizomes, number of fertile shoots, and dry weight of all plant parts. It increased the number of elongated internodes and the height of the plant. The internodes were more uniform in length than those on shoots from other plots. The associated growth of alfalfa with bromegrass decreased the number of shoots, number of rhizomes, and dry weight of the plants of bromegrass. The nitrogen-fertilized plants and check plants at bloom stage were low in percentage of nitrogen and high in percentage of carbohydrates; however, the absolute amounts of both were highest in the nitrogen-fertilized plants. The shaded plants were high in percentage of nitrogen and low in percentage of carbohydrates as compared to the check plants. Plants grown under short days (8.5 hours) produced a rosette type of growth and the shoots developed in a decumbent position. The plants grown under normal days (15 hours) and long days (18 hours) developed in an upright position, the long-day plants attaining a greater height than the normal-day plants. The total number of shoots per plant was greatest under short days and least under long days. More fertile shoots were produced on the normal-day plants than under either the short or long day treatments. The maximum number of rhizomes was produced under the normal day length in late spring or summer. The rhizomes attained the greatest size and length under the long days. The dry weight of plant parts increased as the number of light hours per day was lengthened. Both the percentage and absolute amounts of carbohydrates were highest in the long-day plants. The short-day plants contained the highest percentage of nitrogen; however, the absolute amounts were about the same under each length of day.