Responses of Various Spring Wheats to Vernalization.

There is little information in the literature regarding North American varieties of spring wheat which are responsive to vernalization treatment. The same variety has been reported by different investigators to react positively or negatively to treatmenit. For example, VAN HOEK (3) obtained acceleration of maturity when springof wheat was vernalized, but treatmelnt of the same variety by GMELIN (1) gave no acceleration of flowering. WORT (4), using the same treatmenit with two different samples of Marquis wheat, found that the acceleration of flowerilig was 21 days in one case, and 2.6 days in the other, although growing conditions were similar. KOSTJUCENKO and ZARUBAILO (2) anid others suggest from experimiienits with cereals grown in northerni latitudes that at least part of the stage of vernalization (thermostage) may be completed during ripening and that this partial completion may reduce subsequent reactioni to treatment. The environment, acting on a developing seed, affects the behavior of the plant produced by the seed. Samples of various spring wheats (table I) obtained from the Departments of Agronomy at the State Universities of Illinois, North Dakota, and South Dakota,1 were vernalized in anl attempt to determnine which varieties respond to vernalization and if varieties grown in differenit areas respond differently. Methods