1. The percentages of winterkilling of winter wheat plants determined on date of seeding test trials during three consecutive years, 1923 to 1925, inclusive, were found to vary, depending upon the date on which the seed was sown. For a series of seedings made on or close to August 15, August 31, September 21, October 6, and October 19, the percentage of winterhardiness followed in decreasing order the seedings of September 21, September 4, October 3, October 17, and August 5, respectively. 2. The root development of plants for the various dates of seeding is strikingly different. The plants from the first seeding, August 18, show the greatest development of fall root system, followed in order by plants of the second, third, fourth, and fifth seedings. New root development in the spring usually proceded from the crowns of the plant. The old fall roots as a rule do not continue active growth in the spring, but subsequent spring root development continues from the crown of the plant. 3. Winterkilling did not occur, as a rule, from the fracturing of the roots, but because of the fact that the plants were raised out of the soil. As a result of this raising of the plant, death resulted through desiccation. This is an important factor in the late dates of seeding. If the spring season is humid, the dislodged plants may form new roots and become reestablished in the soil and continue growth. 4. Plants grown in soil, with 10% moisture content lived through the winter better and recovered better in the spring than did plants grown in soil having 25 to 30% moisture content. 5. Grain yields for the three years, 1922 to 1924 inclusive, are directly correlated with the amount of winterkilling. A low percentage stand of plants in the spring and also grain yield are not always indicative of high percentage of winterkilling. Especially is this true for the late seedings, namely, October 5 and October 19. It is on these late seeding dates that the greatest "heaving" of plants results which leads to plant desiccation. Therefore, death of plants in many of these instances is due to spring desiccation and not to actual winterkilling.

In studies on the reaction of varieties of wheat to leaf rust, P. triticina, p. f. 9, in the greenhouse at Manhattan, Kan., 28 out of about 200 varieties were found to contain resistant strains. With but few exceptions the resistant strains resembled the varieties from which they came in their general morphological characters. Some of them varied slightly from the parent varieties in one or more characters, such as kernel texture. Most of the varieties in which resistant strains were found are soft red winter wheats. These studies have shown that selection within varieties of wheat is a useful method of quickly securing strains which are resistant to a single physiologic form of leaf rust.

1. Changes in the composition of the crown of the wheat seedling were studied during two consecutive winter seasons, 1923-24 and 1924-25. Plants were taken from three dates of seeding test plats. Seedings were made on or close to the following dates: August 15, August 31, September 21, October 6, and October 19. The order of mortality due to winterkilling, from high to low, for three years, 1922 to 1925, was as follows: October 19, October 6, August 12, August 31, and September 21. 2. In general there seemed to be a positive correlation between the total soluble carbohydrate compounds and better dates of seeding or winterhardiness for the year 1923. The September 21 seeding, the best date of seeding, showed in 1923, particularly, the greatest percentage of total sugars as well as total carbohydrate compounds. However, for the two years' results, winterhardiness could not be attributed to the hexose carbohydrate compounds alone. 3. The total nitrogen compounds remained about the same throughout the winter months, being somewhat higher in the young plants than in the older plants. 4. The water-soluble nitrogen and soluble nitrogen which is coagulable by heat increased during the fall months as the temperature decreased. The soluble nitrogen which is coagulable was found to increase with the lowering of the temperature to the freezing point after which it greatly decreased. 5. The percentage of water-soluble nitrogen which is coagulable was greatest for the favorable dates of seeding, before the plants were frozen, but after freezing occurred the coagulable nitrogen was much less for plants from the favorable than from the unfavorable seedings. 6. The plants from the most favorable dates of seeding have a greater capacity of changing the protein nitrogen from a precipitable to a nonprecipitable form.

The difficulties encountered in the selection of perennial forage plants in the southern Great Plains area are pointed out. The distribution of groups of forage crops in relation to the types of native vegetation of Oklahoma is given, together with a discussion of the factors favoring and limiting the distribution of the several groups. The yields, ranges of adaptation, factors favoring, and factors limiting the growth and employment of 18 species of cultivated grasses and 14 species of legumes are discussed. Many of the northern grasses, such as timothy, creeping bent, Kentucky and Canada bluegrasses, smooth brome, and slender wheat, showed themselves to be poorly adapted to the high temperatures and the at times dry periods of the summers of central Oklahoma. Such typical sod-forming grasses as creeping bent, Kentucky bluegrass, and smooth brome developed typical bunch habits of growth under prevailing conditions. This was taken as an index of lack of vigor and aggressiveness. Meadow fescue, while more drought resistant and better able to endure high temperatures than the above-mentioned northern grasses, was not sufficiently vigorous to be of great value. The fine-leaved fescues, such as sheep, hard, and red fescue, while low yielders, have shown themselves to be very drought resistant or rather drought escaping due to their ability to grow early in the season. The rye grasses, while producing high yields during the first vegetative season, especially following fall seedings, were short lived, behaving in practically all instances as annuals due to their inability to endure high summer temperatures. Tall oat, orchard grass, and redtop showed themselves to be constant yielders with a high degree of drought and high temperature endurance and sufficiently aggressive to be of value on the better soils of east-central and eastern Oklahoma. They are not sufficiently drought resistant, however, for employment on thin, dry upland soils in the central part of the state. On the better, fairly well watered soils these grasses may well be grown in combination with sweet clover in the central and with alsike and red clover in the eastern part of the state. Of the true southern grasses, bermuda alone proved sufficiently hardy to endure winter conditions in north-central Oklahoma. Carpet grass was not as drought resistant as bermuda. Dallis grass showed a most remarkable degree of drought resistance but was not winterhardy. Alfalfa and sweet clover have shown themselves to be the most dependable legumes for central Oklahoma. None of the true clovers are in position to compete with these two crops in the central part of the state. As the more humid eastern part, especially the northeastern portion of the state, is approached a definite place is found for the true clovers. The true clovers can be grown in north-central Oklahoma only with special care and on well-watered soils. Black medic and subterranean clover did not prove sufficiently drought resistant for Oklahoma conditions. Bur clover was not sufficiently winterhardy for north-central Oklahoma, but it has a place in the eastern and southeastern portions of the state. Crimson clover survived the winter of 1926-27 but did not yield enough to be of practical value. The lespedezas lack in drought resistance to be of practical value in the central part of Oklahoma, except in special locations and for special purposes. They have a definite place in the more humid portions of the state. Both Korean and Kobe have shown themselves to be superior to Japanese lespedeza.