442 EXPERIMENT STATION RECOED. 



plants in tlie open. With data secured from these investigations as well as 

 from more recent work, he has worked out a set of tables and curves showing 

 the relation between seeds with various germiuative powers and the number 

 of yearling plants produced; the plant percentage (the number of yearling 

 plants produced from 100 seeds) being used as a function of the germination 

 percentage and the relations traced out for seed grown in the open under 

 favorable, unfavorable, partially favorable, and average conditions affecting 

 growth. 



The author finds from his investigations that the higher values of the 

 germination percentages show strikingly higher plant percentages than the 

 lower values for the germination percentages. On this account he is of the 

 opinion that a mixture of seed of various germination percentages is of equal 

 value with an unmixed seed possessing the same germination percentage as 

 the mixture, and that the tendency is even toward a higher plant percentage 

 in the mixture than in the unmixed seed. Although germination percentage 

 is not a good measure for determining plant percentage, germination energy 

 and plant percentage appear to make similar variations. Since seed of first- 

 class germiuative power is often too high priced for the grower, it would 

 appear that the seedsmen are justified in mixing these seed with cheaper seed 

 of lower germiuative power, provided the mixture shows a fair plant per- 

 centage. The adaptation of the described tables and curves in making such 

 mixtures and in determining their market value is discussed and the author's 

 methods of carrying on germination tests are described. 



In continuation of previous investigations (E. S. R., 17, p. 370) studies were 

 made relative to the best methods of storing seed in order to prevent a decrease 

 of germiuative power. The work, which is described in detail, includes studies 

 of temperature and moisture conditions, and of seed placed in air-tight re- 

 ceptacles as compared with seeds exposed to the air. Seed which were stored 

 in air-tight receptacles gave after 2 to 3 years' storage from 2 to 3 times the 

 plant percentage of similar seed exposed to the air during storage, with a cor- 

 responding increase in money value. Thus it appears that by storing seed 

 under air-tight conditions seedsmen will be enabled to lay in large supplies of 

 seed in years when the quantity and quality are high. Nothing is to be gained 

 by storing the seed longer than 3 years. 



Before storing the seed in air-tight receptacles, the author recommends that 

 it should be dried out in a temperature of from 30 to 40° C. until it has lost 

 from 1 to 2 per cent of its weight. The seed should then be placed in thoroughly 

 dry air-tight receptacles, which, when large quantities of seed are to be stored, 

 can be made of tin and soldered at the joints. As experimentally determined, 

 the development of carbonic acid from seed respiration in the receptacles does 

 not appear to be sufficient to injure the seed. It is recommended, however, that 

 a small qiiantity of quicklime be inclosed, about 1 gm. being sufficient to 

 assimilate 400 cc. of CO2. Although the seed stored in air-tight receptacles at 

 various temperatures gave in every case far better results than seed stored at 

 similar temperatures but exposed to air, storing tlie seed in an ice house gave 

 the most favorable results. For practical purposes, however, the use of a 

 deep cool cellar is recommended. 



Further fertilizer experiments w;itli forest seedlings on sandstone soils 

 and observations on the carrying' out of forest seed experiments, H. Vater 

 (Tharand. Forstl. Jahrh., 59 {1909), No. 1, pp. 93-121).— In continuation of 

 previous work (E. S. R., 17, p. 772) fertilizer experiments with forest seedlings 

 on sandstone soil are reported in detail. 



Seedlings of the common pine were used in the work. The highest growth 

 yield was obtained by the use of a complete fertilizer in which kainit was the 



