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The Effect of Cutting Treatments on the Carotene Content of Alfalfa in the Yakima Valley 1
Author(s) -
McGuire W. S.,
Jackobs J. A.
Publication year - 1951
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1951.00021962004300080006x
Subject(s) - citation , state (computer science) , library science , wish , political science , horticulture , mathematics , computer science , art , algorithm , biology , literature
OEVERAL factors have been shown to influence the O carotene content of grasses and legumes. Those factors of greatest importance are the stage of growth of the herbage and the seasonal effect characterized by a minimum concentration in summer. The study reported here afforded an opportunity to separate the two factors and show the effect of each. Several workers (10, 5, 7, 4) have reported that the carotene content of pasture grasses is dependent largely upon the growing season and the stage of maturity. Thompson (8) showed that for three strains of alfalfa found in California common, the carotene content decreased at successive stages of growth as the plants approached maturity. In four species of grasses studied by Bird (2), the carotene decreased to approximately one-half that of the short-grass stage by the time the plants began to bloom. In general, reports show that an increase in yield of dry matter in the advanced stages of maturity is obtained at a sacrifice of the concentration of carotene. There is a seasonal decrease in carotene content that is independent of the stage of growth. Atkeson, et al. (1) reported that, in spring and early summer, plants were relatively high in carotene, with a decrease occurring during the later summer months. The decrease was attributed to drought and high midsummer temperatures in combination with drought. In the four species of grasses studied by Bird (2), when the grasses were cut at the short-grass stage at six intervals throughout the season, the carotene content reached the lowest level in July. After that time, there was an increase in carotene concentration until fall, when values approached those of spring. In a study of weekly variation in carotene content of various herbages during the season, Snyder and Moore (7) found that first cutting alfalfa in Michigan declined from 432 ppm at an immature stage (April 25) to 171 ppm at hay stage on June 20. The second crop declined from 318 ppm at 17 days recovery (July 7) to 132 ppm at hay stage on August 16. The immature third crop decreased from 367 ppm on August 23 to 284 ppm at the three-fourths