Early growth of the corn seedling was studied in relation to its dependence on energy from endosperm and early photosynthetic tissue. Measurements were made of (1) endosperm utilization rate of seedlings grown in light and dark; (2) growth and leaf area of seedlings as affected by partial endosperm removal; and (3) photosynthesis (P), respiration (R), and 14CO2 uptake of seedlings as affected by endosperm excision at different ages. Endosperm utilization and growth rates were similar in light and dark until the two‐leaf stage l0 days after germination. Regression of root and shoot growth on age was 15.4 mg/day and of root and shoot growth on endosperm weight loss was .65 mg/mg. Partial removal of the endosperm at seeding resulted in decreased growth of roots and shoots and indecreased leaf area per seedling. Apparent P was negative at 9 days of age and was greatest for seedlings with endosperm excised. Apparent P was positive and similar at days 11, 12, and 13 for seedlings with endosperm excised and was positive, and increased from day 11 to day 13 for seedlings with endosperm. Energy obtained from CO2 fixation was not equivalent to that supplied by the endosperm until the 10th day. At this time seedlings had two fully emerged leaves. Absorption of 14CO2 was similar for seedlings with and without endosperm, and increased with age as a result of increased leaf area and increased absorption per unit of leaf area. Endosperm removal resulted in greater translocation of 14CO2 to seedling roots.

The increase in the ratio of leaf area to leaf weight which occurs with shading of legumes was associated with changes in leaf morphology and chlorophyll content. Alfalfa and birdsfoot trefoil had more stomata per cm2 of leaf when grown in the sun than in the shade. Sun leaves of both species were thicker than shade leaves. Number of palisade and mesophyll cells and cell volume appeared greatest in sun leaves, and the palisade layer was more clearly differentiated. Shaded leaves contained more chlorophyll per unit of leaf weight but less per unit of leaf area than sun leaves.

Seed size‐seedling vigor relationships were studied with birdsfoot trefoil (Lotus corniculatus L.), alfalfa (Medicago sativa L.), and sainfoin (Onobrychis viciaefolia Scop.). Differences in seed size were separated into those among plants and within plants. Seed weight distribution patterns were measured for each plant. An additional study measured the effect of varying number of seeds per raceme upon seed size of sainfoin.Correlations among clones of seed size with seedling vigor were significant in birdsfoot trefoil, were not significant in alfalfa, and approached a significant level in sainfoin. Differences in seed size within plants were highly correlated with seedling vigor in all legume species. The degree to which seed size can be affected by regulating seed number per raceme was shown for five sainfoin plants.Seed weight distribution patterns varied widely among plants within a species. The importance of these patterns in selecting for seedling vigor and in obtaining genetic equality in the contribution of plants to a composite variety is discussed.

Growth of ‘Vernal’ alfalfa and ‘Tana’ birdsfoot trefoil seedlings at three ages was measured under four light intensities, 2153 to 8611 lux, in growth chambers. With decreasing light: intensity or seedling age, less of the dry matter accumulated during the growth period was partitioned into roots and more into stems. Relative growth rate of both species decreased similarly with decreasing light intensity due to decreased net assimilation rate. Leaf area ratio of both species increased with decreasing light intensity. With but one exception, RGR of birdsfoot trefoil seedlings of all ages was greater than that of alfalfa.

Synopsis Spring yields of crested wheatgrass were more than doubled by application of 30 pounds per acre of N and were directly related to April and May temperatures but inversely related to the amount of fall and winter precipitation over a 4‐year period. Annual yields were directly related to fertility rate, and to the amount of precipitation received in the preceding November 1 to June 1 period. Counting residual response, the 20 pounds per acre fertility rate returned 25 pounds of herbage per pound of N applied.