1"19] FIELD CROPS. 233 



way n sort is tested for at least six years before it is finally put Into general 

 use." 



Data are presented which show the average probable error as percentage 

 of the mean of some varieties of wheat and oats tested by the rod-row method 

 to have been 2.68 and 3.12, respectively, indicating a marked superiority over the 

 field-plat method. The average yield of wheat varieties grown on 2/100-acre 

 plats repeated three times in 191G was 40 bu. per acre, while for the same 

 varieties grown in rod rows repeated ten times it was 31.4 bu. With oats 

 about 242 sorts repeated ten times can be handled per acre by the rod-row 

 system, as compared with only 37 sorts by 2/100-acre plats repeated three times. 



The methods used in making and studying hybrids of the small grains are 

 also described. It is stated that the best results have been obtained by grow- 

 ing the plants in pots in the greenhouse. The Fi plants are also grown in the 

 greenhouse, while the F 2 and succeeding generations are grown in the field in 

 5-ft. rows. Clipping the glumes in emasculating wheat has not produced any 

 better results than removing the anthers without clipping. 



Small grain investigations, H. IT. Love and W. T. Ckaig {Jour. Heredity, 9 

 (1918), No. 2, pp. 61-16, figs. 7).— The authors present a brief outline of their 

 work with small grains at Cornell University, together with some of the more 

 pertinent results obtained. The principal lines of work under way embrace 

 comparisons of varieties, pure-line selections, and selections from hybrids of 

 wheat, oats, barley, and rye; pure-line breeding work with selections of wheat 

 and oats; variation and correlation studies with the different cereals; and 

 hybridization work with wheat, oats, rye, and barley. Cooperative work with 

 the Montana Experiment Station and the agronomy department of the Uni- 

 versity of Missouri in a study of the effect of widely differing environments 

 upon imported seed is also noted. 



Growth of wheat (Triticum) and corn (Zea), D. T. MacDougal [Carnegie 

 Inst. Washington Year Book, 16 (1917), pp. 85-87). — Data obtained from daily 

 observations of the rate of growth of single leaves of wheat and corn measured 

 at one-half hour intervals through a horizontal microscope led to the following 

 conclusions: 



Retardation of growth occurred at more than one place in the temperature 

 scale and at different times of the day. Cessation of growth, especially in 

 corn, might be attributed to a direct temperature effect, especially with ex- 

 tended periods of temperatures of from 30 to 35° C. (87 to 95° F.). The highest 

 rate maintained by corn for some time was found to lie between 27 and 30° C. 

 It was not possible to fix upon any definite temperature limits within which 

 growth might be continuous in this plant. No retardations occurred in either 

 corn or wheat except after 11 a. m. Corn showed an acceleration late in the 

 day after retardation at high temperatures, but wheat did not. The allowable 

 causes to which might be attributed the slackening or inhibition of growth or 

 actual shrinkage of growing joints after midday and continuing until the 

 following morning are said to be the destruction of enzyms concerned in renew- 

 ing building material, excessive transpiration, and the accumulation of acids 

 or other respiration products which might clog "metabolism and reduce the 

 water-holding capacity of the protoplasm. 



Red Rock wheat and Rosen rye, F. A. Spragg (Jour. Amer. Soc. Apron., 10 

 (1918), No. It, pp. 167-171).— This paper, a contribution from the Michigan Ex- 

 periment Station, briefly describes the development of Red Rot k winter wheat. 

 Rosen rye, and Michigan Winter barley, together with an account of the 

 method of inspecting and distributing pedigreed seed in connection with the 

 Michigan Crop Improvement Association. 



