334 EXPERIMENT STATION RECORD. 



The same relative relation exists between the leading varieties of the different 

 groups for the four years 1909, 1911-1913, when both the actual and computed 

 yields can be compared." 



The leading varieties in each group of oats are described. 



In the experiments with barley, three groups were recognized, 2-rowed hulled, 

 6-rowed hulled, and G-rowed naked. A summary of the test shows that " the 

 2-rowed barleys have outyielded the G-rowed in all the years they have been 

 tested. In a 5-j'ear period (1908-1911 and 1913) the 2 leading 2-rowed varieties 

 have an actual average yield 34 per cent greater than that of the 2 leading 

 G-rowed hulled varieties and 75 per cent greater than that of the G-rowed 

 naked vareity. In the 4 years 1909-1911 and 1913, the average actual yield of 

 the leading 2-rowed variety is 32 per cent greater than that of the leading 

 G-rowed hulled variety, and 7G per cent greater than that of the G-rowed naked 

 variety. The average computed yield of the leading 2-rowed variety for the 

 same period is 25 per cent greater than that of the leading G-rowed hulled 

 variety and 58 per cent greater than that of the naked variety." 



Of all the varieties tested, the 2-rowed varieties Hannchen and Svanhals 

 have proved best adapted to the conditions at Dickinson. The leading variety 

 under each of the three groups is described. Brief notes on the tests of 

 other cereals, emmer, rye, flax, proso, and some grain sorghums, are also given. 



A brief account of nursery trials and pure-line selections showing the pos- 

 sibilities of improvement of cereals for the Dickinson territory is given. 



In summarizing the experiments the author points out that spring varieties 

 of all cereals, except rye, are better adapted to this region than winter varieties; 

 that Kubanka is the leading variety of durum and Ghirka of fife wheats; and 

 that the Early Mountain variety of oats has given the highest actual yield 

 for the 7 years, 54.1 bu. per acre, but on 4-year and 5-year averages, the Golden 

 Rain has given the highest average yield. 



Growth of maize seedlings in relation to temperature, P. A. Lehenbaueb 

 (Abs. in Physiol. Researches, 1 (19U), :So. 5, pp. 2^7-288, figs. 3).— "In the 

 experiments here discussed an attempt has been made to keep all the conditions 

 for growth considerably more uniform than has usually been the case with 

 earlier investigations of this sort. Maize seedlings were used, grown practi- 

 cally in darkness and with approximately constant temperature. The relative 

 humidity of the air was always very close to 95 per cent. Due attention was 

 also given to the time factor in its relation to the rates of growth at the differ- 

 ent temperatures. Measurements of the growth increments of the shoots were 

 hourly in most cases, and observation was continued for periods ranging in 

 length from 12 to 39 hours. The main results and conclusions brought out by 

 a study of the detailed data presented in the tables, are summarized below. 



" The somewhat widely accepted idea that the curve of growth in relation to 

 temperature shows two optima is not at all substantiated . . . The optimum 

 temperature for growth of shoots of maize seedlings in water culture, for a 

 12-hour period, is shown to be 32° C. [89.G° F.]. 



" The optimum temperature for growth, under these conditions, is found to 

 change as the length of the period of exposure is altered. 



"At high temperatures (31° and above), for shoots of maize seedlings under 

 these experimental conditions the initial growth-rate is not maintained, there 

 being a marked falling off in this rate during prolonged periods of exposure. 

 This decrease in the growth rate with prolonged periods at high temperatures 

 makes it necessary to consider the length of the periods for which average 

 growth rates are obtained, in defining the optimum for growth of these shoots. 

 Indeed, it appears that the term optimum temperature for growth, in this case 

 at least, is quite without meaning unless the length of the period of exposure 



