56 



Journal of Agricultural Research 



Vol. XXn.No. a. 



started about heading time, and some plants were rusted badly 

 Measurements of height were taken on those plants which were not 

 attacked previous to heading, and yield data were taken only on plants 

 uninjured by rust. 



Both incrossed and normally pollinated seeds of the parental varieties 

 were planted. Amy and Garber (2) have shown that in some cases there 

 is a positive correlation between weight of seed planted and the vigor of 

 resultant plants. In order to determine whether the size of seed planted 

 was of importance in an analysis of individual plant yields in the present 

 experiment, correlation coefficients were calculated for the weight of seed 

 planted as subject and length of culm and yield of grain per plant as 

 relative. (Table II.) 



Table II.— Correlation coefficients for weight of seed planted and the vigor of resultant 



plants 



Variety. 



Marquis 



Velvet Chaff. ... 



Barletta 



Penny 



H. B. S. 1-16-12 



Bobs 



Little Club 



Emmer 



Mindum 



CoefBcient of correlation with weight of seed planted as subject. 



Length of tallest 

 culm (relative). 



— O. 084 ±0. 100 



+ .o69± .065 



- . I44± • 085 



- . i97± .075 



— . 242± . 071 



— . ii6± . 079 



- . ii8± .082 

 + • 024± . 086 



— . 121 ± . 076 



Total culm length 

 (relative). 



+0. i36±o. 098 



+ • 078± . 065 



.205± .083 



— . I29± .077 

 + . I2i± . 071 

 + .i69± .078 

 + . i85± .080 



— .oo7± .085 

 + .38i± .066 



Yield of grain in 



grams per plant 



(relative). 



+0. 047±0. 173 

 + .o87± . 108 



+ . OIO± . 112 



- .I94± .095 

 + . 205± . 084 

 + .032± . 099 



— . 425 ± . 080 

 + .i36± .095 



The only significant correlation was obtained with the Mindum variety. 

 A correlation coefficient of +0.381 ±0.066 was obtained for weight of 

 seed planted and total culm length. In the light of these facts it was 

 considered legitimate to use the plants from normal and incrossed seed 

 as a single parent population. 



The Fi crosses and their parents were compared for height of tallest 

 culm and for total culm length. (Table III.) 



Six of the 1 1 Fi varietal crosses showed an increase in length of tallest 

 culm as compared with the parental average, and 5 showed a decrease. 

 The two Fi crosses between Mindum and vulgare varieties were con- 

 siderably taller than either parent. Similar results were obtained from 

 crosses between Emmer and the same vulgare varieties. On the othef 

 hand, the Fi crosses of Little Club with either Emmer or Mindum did 

 not show a significant difference in average height of tallest culm when 

 compared with the average of the parents. 



In Table IV the crosses and their parents are compared for total culm 

 length. 



