The Carotene Content of Several Varieties and Strains of Alfalfa

INCE alfalfa is used as a principal source of vitamin S A €or mixed feed for animals, the carotene content of the plant as grown in the field is of major interest to both the grower and feed manufacturer who are concerned with obtaining a product which is rich in this valuable constituent. A considerable amount of work has been done on increasing the total yield of forage from alfalfa by fertilization, cultural practice, and selection of varieties. Tysdal and Kiesselbach (3)2 hybridized alfalfa and determined forage yields, but few workers have considered the carotene content ( I). This was caused earlier by a lack of appreciation of the nutritional value of the carotene in the plant and a lack of a rapid, reliable method for carotene determination. Nutritional work (I) showed the value of alfalfa as a vitamin A supplement and rapid chromatographic methods (4,5) for carotene were devised. Data obtained by Ham and Tysdal (2) showed some hybrid crosses to be consistently higher in carotene than others. They suggested that further breeding work would result in an alfalfa of substantially higher carotene content. These workers found also that the leaves contained an average of 77y6 of the total carotene in the plant. The purpose of the present studies was to investigate means of selecting alfalfa which was a rich starting material for use in either dehydration or field curing operations. This was done by determining the carotene content of several commercially available varieties and strains of alfalfa grown under different field conditions, In some cases the carotene content was determined at successive stages of growth so that the time of cutting could be judged more accurately. Also, the variation in carotene encountered at successive times during the day was investigated. .