The relationships of soil moisture content or soil moisture stress to growth in Ladino clover have been investigated in containers under controlled environmental conditions and in field plots. Relationships involving the following aspects of growth or plant functioning are reported: (1) transpiration rate, (2) green weight production, (3) dry weight production, (4) dry matter percentage, (5) shoot elongation, (6) photosynthesis rate, (7) respiration rate, (8) chemical composition, (9) flower formation (number and size), and (10) seed production. Dry weight production of vegetative material, photosynthesis, and respiration rates were not affected appreciably until the moisture content in the entire root zone approached the permanent wilting percentage. Green weight production and shoot elongation were reduced significantly when the soil moisture content fell into the lower half of the available range. Chemical composition, flower formation, and seed production were also influenced by moisture conditions within the available range. The different relationships obtained illustrate that the increasing soil moisture stress experienced by Ladino clover as the readily available moisture is depleted does not have a uniform effect upon various aspects of its functioning and growth. Thus there is no one simple and general relation between soil moisture conditions and all aspects of plant functioning. Some plant processes are relatively insensitive to increasing moisture stress over the available range while others are distinctly affected. Such soil moisture‐growth relationships are also dependent upon plant characteristics, soil conditions, and climatic factors. Information on these relationships should suggest opportunities for more effective irrigation by considering both the soil moisture stress and the physiological stage of plant development in the timing of water applications.

ALFALFA has long been of prime importance as a hay and forage crop because of its high protein and carotene contents. Protein is generally stable during storage, but may be lost in leaf shatter through poor management in handling the crop. Carotene, on the other hand, is very unstable and losses may be severe during harvest operations and storage. In spite of customary large losses of carotene, alfalfa products are of great importance in the feeding of livestock and poultry because of their content of beta-carotene (provitamin A). This is largely due to the initial high content of this nutrient rather than to superior methods of preventing loss. Ham and Tysdal (1946) stated that .certain crosses may be consistently different in carotene content from others. Thompson (1949) has recently discussed the desirability of obtaining alfalfa varieties with higher carotene content and indicated that differences exist among common varieties. This study was undertaken to fill a need for further and more comprehensive survey work on contents of both carotene' and protein. While extensive comparisons were being made of the carotene contents of different varieties, hybrids, and selections from the alfalfa-breeding project at this station, several factors influencing the results of carotene determinations were evaluated. A rapid and satisfactory method of sampling and comparing the carotene contents of alfalfa varieties was developed. Consideration of these factors may be applicable to studies of other constituents in alfalfa and related crops. MATERIALS AND METHODS The alfalfa was grown on the University Experiment Station Farm at Davis, California, in a field of uniform Yolo fine sandy loam. The alfalfa was planted in close-drilled rows (6 inches apart), in plots 3% x 16 feet in